diff --git a/.prettierignore b/.prettierignore
new file mode 100644
index 0000000..3c14291
--- /dev/null
+++ b/.prettierignore
@@ -0,0 +1,3 @@
+coverage/
+example.js
+test/fixtures/fail-could-not-parse-package/index.js
diff --git a/.remarkignore b/.remarkignore
new file mode 100644
index 0000000..ffa2e1f
--- /dev/null
+++ b/.remarkignore
@@ -0,0 +1,2 @@
+example/
+test/
diff --git a/example.js b/example.js
index 0c14e33..da796e3 100644
--- a/example.js
+++ b/example.js
@@ -1,26 +1,36 @@
-// This section is rendered by this module from [example.js][example-js].
+// > This section is rendered by this module from [`example.js`][example-js].
+// > Turtles all the way down.  🐢🐢🐢
 
-// Dependencies:
-var fs = require('fs')
-var remark = require('remark')
-var usage = require('./index.js') // This is changed from `./index.js` to `remark-usage`
+// remark-usage-ignore-next 4 - Get the files to show them in our usage example.
+var readFile = require('fs').readFileSync
+var join = require('path').join
+var exampleJs = readFile(join('example', 'example.js'), 'utf8')
+var exampleMd = readFile(join('example', 'readme.md'), 'utf8')
 
-// Read and parse `readme.md`:
-var readme = fs.readFileSync('readme.md', 'utf-8')
-var ast = remark()
-  .use(usage)
-  .parse(readme)
+// remark-usage-ignore-next - Use async/await so it looks nicer.
+;(async function (){
 
-// Log something with a language flag:
-console.log('markdown', remark().stringify(ast.children[2]))
+// Say we are making a module that exports just enough Pi (3.14159).
+// We’re documenting it with a readme file, [`example/readme.md`][example-md]:
+console.log('markdown', exampleMd)
 
-// Or without language:
-console.log(remark().stringify(ast.children[3]))
+// …and an example script to document it [`example/example.js`][example-js-2]:
+console.log('js', exampleJs)
+
+// …If we use `remark-usage`, we can generate the `Usage` section
+var path = require('path')
+var vfile = require('to-vfile')
+var remark = require('remark')
+var usage = require('.')
+
+var file = vfile.readSync({path: 'readme.md', cwd: 'example'})
+
+var file = await remark()
+  .use(usage)
+  .process(file)
 
-// Log something which is never captured:
-function neverCalled() {
-  console.log('javascript', 'alert("test")')
-}
+// Now, printing `file` (the newly generated readme) yields:
+console.log('markdown', String(file))
 
-// Log something which isn’t captured because it’s not a string.
-console.log(this)
+// remark-usage-ignore-next
+}())
diff --git a/example/example.js b/example/example.js
new file mode 100644
index 0000000..93d28b6
--- /dev/null
+++ b/example/example.js
@@ -0,0 +1,5 @@
+// Load dependencies:
+var pi = require('.')
+
+// Logging `pi` yields:
+console.log('txt', pi)
diff --git a/example/index.js b/example/index.js
new file mode 100644
index 0000000..561d1ff
--- /dev/null
+++ b/example/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.floor(Math.PI * 1e5) / 1e5
diff --git a/example/package.json b/example/package.json
new file mode 100644
index 0000000..1e579ed
--- /dev/null
+++ b/example/package.json
@@ -0,0 +1,5 @@
+{
+  "private": true,
+  "name": "pi",
+  "main": "./index.js"
+}
diff --git a/example/readme.md b/example/readme.md
new file mode 100644
index 0000000..cb1a64b
--- /dev/null
+++ b/example/readme.md
@@ -0,0 +1,9 @@
+# PI
+
+More than enough 🍰
+
+## Usage
+
+## License
+
+MIT
diff --git a/index.js b/index.js
index 2356077..3541ac5 100644
--- a/index.js
+++ b/index.js
@@ -1,339 +1,3 @@
 'use strict'
 
-var fs = require('fs')
-var path = require('path')
-var uncached = require('require-uncached')
-var heading = require('mdast-util-heading-range')
-var trimTrailingLines = require('trim-trailing-lines')
-var unquote = require('unquote')
-var cept = require('cept')
-var unified = require('unified')
-var markdown = require('remark-parse')
-var resolveFrom = require('resolve-from')
-
-module.exports = usage
-
-var exists = fs.existsSync
-var read = fs.readFileSync
-var write = fs.writeFileSync
-var remove = fs.unlinkSync
-var resolve = path.resolve
-
-var processor = unified().use(markdown)
-
-// List of locations to look for an example.
-var examples = [
-  'docs/example.js',
-  'doc/example.js',
-  'examples',
-  'example',
-  'example.js'
-]
-
-// Expressions.
-var expressionLog = /(console\.log\()(.+)(\);?)/g
-var expressionRequire = /(require\()(.+)(\);?)/g
-var expressionComment = /^(?:\s*)(?:\/\/)(?:\s*)(.+)/
-var expressionIgnore = /^remark-usage-ignore-next(?:(?:\s+)(\d+))?/
-
-// Constants.
-var defaultHeading = 'usage'
-
-// Post-process the example document.
-function postprocess(value, logs, options) {
-  var tokens = []
-  var start = 0
-  var match
-  var content
-  var info
-  var parameters
-  var end
-  var markdown
-
-  expressionLog.lastIndex = 0
-  match = expressionLog.exec(value)
-
-  while (match) {
-    end = expressionLog.lastIndex
-
-    content = value.slice(start, end - match[0].length)
-
-    parameters = match[2].split(/\s*,\s*/)
-
-    info = parameters[0]
-    info = unquote(info.trim())
-    info = logs[info]
-
-    if (info && info.value) {
-      tokens = tokens.concat(script(content, options), log(info))
-    } else {
-      parameters = parameters.slice(1).join(', ')
-
-      tokens = tokens.concat(
-        script(content + match[1] + parameters + match[3], options)
-      )
-    }
-
-    start = end
-    match = expressionLog.exec(value)
-  }
-
-  if (start < value.length) {
-    tokens = tokens.concat(script(value.slice(start), options))
-  }
-
-  markdown = []
-
-  tokens.forEach(each)
-
-  markdown = markdown.filter(filter)
-
-  return markdown
-
-  function each(token) {
-    var prev
-    var lang
-
-    if (token.type === 'markdown') {
-      markdown = markdown.concat(parse(token.value))
-    } else {
-      prev = markdown[markdown.length - 1]
-      lang = 'lang' in token ? token.lang : token.type
-
-      if (prev && prev.type === 'code' && prev.lang === lang) {
-        prev.value += token.value ? '\n' + token.value : ''
-      } else {
-        markdown.push({
-          type: 'code',
-          lang: lang,
-          value: token.value
-        })
-      }
-    }
-  }
-
-  function filter(token) {
-    if ('value' in token) {
-      token.value = trimTrailingLines(token.value)
-
-      return token.value !== ''
-    }
-
-    return true
-  }
-}
-
-// Update the example section.
-function usage(options) {
-  var settings = {}
-  var pack
-  var main
-  var example
-  var name
-  var cwd
-  var header
-
-  if (!options) {
-    options = {}
-  }
-
-  cwd = options.cwd || process.cwd()
-
-  try {
-    pack = require(resolve(cwd, 'package.json'))
-  } catch (error) {
-    pack = {}
-  }
-
-  name = options.name || pack.name || null
-
-  main = resolve(cwd, options.main || pack.main || 'index.js')
-
-  example = options.example
-
-  if (example) {
-    example = require.resolve(resolve(cwd, example))
-  } else {
-    examples.some(some)
-  }
-
-  settings.cwd = cwd
-  settings.name = name
-  settings.main = main
-  settings.example = example
-
-  header = toExpression(options.heading || defaultHeading)
-
-  return transform
-
-  function transform(tree) {
-    heading(tree, header, runFactory(settings))
-  }
-
-  function some(filepath) {
-    filepath = resolve(cwd, filepath)
-
-    if (exists(filepath)) {
-      example = require.resolve(filepath)
-      return true
-    }
-
-    return false
-  }
-}
-
-// Construct a transformer based on `options`.
-function runFactory(options) {
-  return run
-
-  // Add an example section based on a valid example JavaScript document to a
-  // `Usage` section.
-  function run(start, nodes, end) {
-    var logs = {}
-    var example = options.example
-    var source
-    var tmp
-    var stop
-
-    if (!exists(example)) {
-      throw new Error(
-        'Missing example: `' +
-          example +
-          '`. Pass an `example` or use a file at: ' +
-          examples.join(', ')
-      )
-    }
-
-    tmp = example + '-tmp'
-
-    source = preprocess(read(example, 'utf-8'))
-
-    write(tmp, source, 'utf-8')
-
-    // To Do: better tmp file management.
-    stop = cept(console, 'log', intercept)
-
-    try {
-      uncached(tmp)
-    } catch (error) {
-      error.message =
-        'Invalid example `' +
-        example +
-        '`. ' +
-        'Ensure example is a valid JavaScript file:\n\n' +
-        error.message
-
-      throw error
-    } finally {
-      stop()
-
-      /* istanbul ignore next */
-      if (exists(tmp)) {
-        remove(tmp)
-      }
-    }
-
-    // Add Markdown.
-    return [start].concat(postprocess(source, logs, options), end)
-
-    function intercept(id, lang, value) {
-      if (!value) {
-        value = lang
-        lang = null
-      }
-
-      if (typeof value === 'string' && typeof id === 'string') {
-        logs[id] = {id: id, lang: lang, value: value}
-      }
-    }
-  }
-}
-
-// Transform a script into an intermediate nodes, removes the IDs from
-// `console.log` calls, and resolves the main `require` call.
-function script(source, options) {
-  var tokens
-  var lines
-  var index
-  var length
-  var line
-  var match
-
-  // Make sure the require to the main module is shown as if it was a require
-  // from `./node_modules`.
-  // For example, when the example file (`test/example.js`) requires the main
-  // file (as listed in `test/package.json`, `main: "module.js"`) as `./module`,
-  // it is replaced with `test`.
-  source = source.replace(expressionRequire, replace)
-
-  // Transform comments into markdown:
-  tokens = []
-
-  lines = source.split('\n')
-  index = -1
-  length = lines.length
-
-  while (++index < length) {
-    line = lines[index]
-    match = line.match(expressionComment)
-
-    if (match) {
-      line = match[1]
-      match = line.match(expressionIgnore)
-
-      if (match) {
-        index += (match[1] !== undefined && parseInt(match[1], 10)) || 1
-      } else {
-        tokens.push({type: 'markdown', value: line})
-      }
-    } else {
-      tokens.push({type: 'javascript', value: line})
-    }
-  }
-
-  return tokens
-
-  function replace($0, $1, $2, $3) {
-    var filepath = resolveFrom.silent(
-      path.dirname(options.example),
-      unquote($2)
-    )
-    var quote
-
-    if (options.main === filepath && options.name) {
-      // Honour quote style.
-      quote = $2.charAt(0)
-
-      return $1 + quote + options.name + quote + $3
-    }
-
-    return $0
-  }
-}
-
-// Preprocess `value` to add IDs to `console.log` invocations.
-function preprocess(value) {
-  var index = 0
-
-  return value.replace(expressionLog, replace)
-
-  function replace($0, $1, $2, $3) {
-    index++
-    return $1 + '"remark-usage-' + index + '",' + $2 + $3
-  }
-}
-
-// Parse Markdown into nodes, without positional information.
-function parse(value) {
-  return processor.parse(value, {position: false}).children
-}
-
-// Transform a log into an mdast `code` node.
-function log(info) {
-  return {type: 'code', lang: info.lang, value: info.value}
-}
-
-// Transform a string into an applicable expression.
-function toExpression(value) {
-  return new RegExp('^(' + value + ')$', 'i')
-}
+module.exports = require('./lib')
diff --git a/lib/generate/config.js b/lib/generate/config.js
new file mode 100644
index 0000000..db0c2b1
--- /dev/null
+++ b/lib/generate/config.js
@@ -0,0 +1,25 @@
+'use strict'
+
+var nanoid = require('nanoid')
+var resolveFrom = require('resolve-from')
+var relativeModule = require('../util/relative-module')
+
+module.exports = config
+
+function config(ctx) {
+  var settings = ctx.settings
+  var pkg = ctx.pkg || {}
+  var cwd = ctx.file.cwd
+  var mainRoot = settings.main ? cwd : ctx.pkgRoot || cwd
+  var mainId = relativeModule(settings.main || pkg.main || '')
+  var main
+
+  try {
+    main = resolveFrom(mainRoot, mainId)
+  } catch (error) {}
+
+  ctx.cwd = cwd
+  ctx.main = main
+  ctx.name = settings.name || pkg.name || null
+  ctx.id = 'remark-usage-example-' + nanoid().toLowerCase()
+}
diff --git a/lib/generate/find-example.js b/lib/generate/find-example.js
new file mode 100644
index 0000000..586f0ea
--- /dev/null
+++ b/lib/generate/find-example.js
@@ -0,0 +1,73 @@
+'use strict'
+
+var fs = require('fs')
+var resolveFrom = require('resolve-from')
+var relativeModule = require('../util/relative-module')
+
+module.exports = findExample
+
+function findExample(ctx, next) {
+  var fn = ctx.settings.example ? findExplicitExample : findImplicitExample
+
+  fn(ctx, onexample)
+
+  function onexample(filePath) {
+    if (filePath) {
+      fs.readFile(filePath, onfile)
+    } else {
+      next(new Error('Could not find example'))
+    }
+
+    function onfile(err, buf) {
+      var example
+
+      /* istanbul ignore if - ENOENT is already caught above, so this rarely happens */
+      if (err) {
+        return next(new Error('Could not read example: ' + err))
+      }
+
+      example = String(buf)
+
+      // Make sure there is a final line feed.
+      if (example.charAt(example.length - 1) !== '\n') {
+        example += '\n'
+      }
+
+      ctx.examplePath = filePath
+      ctx.example = example
+      next()
+    }
+  }
+}
+
+function findExplicitExample(ctx, next) {
+  var cwd = ctx.cwd
+  var moduleId = relativeModule(ctx.settings.example)
+  var filePath
+
+  try {
+    filePath = resolveFrom(cwd, moduleId)
+  } catch (error) {}
+
+  next(filePath)
+}
+
+function findImplicitExample(ctx, next) {
+  var cwd = ctx.cwd
+  var examples = ['./example', './examples', './doc/example', './docs/example']
+  var length = examples.length
+  var index = -1
+  var filePath
+
+  while (++index < length) {
+    try {
+      filePath = resolveFrom(cwd, examples[index])
+    } catch (error) {
+      continue
+    }
+
+    return next(filePath)
+  }
+
+  next()
+}
diff --git a/lib/generate/find-package.js b/lib/generate/find-package.js
new file mode 100644
index 0000000..e3ae9ae
--- /dev/null
+++ b/lib/generate/find-package.js
@@ -0,0 +1,56 @@
+'use strict'
+
+var fs = require('fs')
+var path = require('path')
+
+var packageName = 'package.json'
+
+module.exports = findPackage
+
+function findPackage(ctx, next) {
+  var file = ctx.file
+  var base = file.cwd
+
+  if (file.path) {
+    base = path.dirname(path.resolve(base, file.path))
+  }
+
+  read()
+
+  function read() {
+    fs.readFile(path.join(base, packageName), onread)
+  }
+
+  function onread(err, buf) {
+    var parent
+    var pkg
+
+    if (err) {
+      /* istanbul ignore if - Doesn’t consistently happen. */
+      if (err.code !== 'ENOENT') {
+        return next(new Error('Could not read package: ' + err))
+      }
+
+      parent = path.dirname(base)
+
+      // No `package.json`.
+      if (parent === base) {
+        return next()
+      }
+
+      base = parent
+      return read()
+    }
+
+    try {
+      pkg = JSON.parse(buf)
+    } catch (error) {
+      // Invalid JSON.
+      return next(new Error('Could not parse package: ' + error))
+    }
+
+    ctx.pkg = pkg
+    ctx.pkgRoot = base
+    return next()
+  }
+}
diff --git a/lib/generate/generate.js b/lib/generate/generate.js
new file mode 100644
index 0000000..afe26f9
--- /dev/null
+++ b/lib/generate/generate.js
@@ -0,0 +1,120 @@
+'use strict'
+
+var unified = require('unified')
+var markdown = require('remark-parse')
+
+module.exports = generate
+
+var processor = unified().use(markdown, {position: false})
+
+function generate(ctx) {
+  var nodes = []
+  var tokens = ctx.tokens
+  var length = tokens.length
+  var index = -1
+  var node
+  var fn
+
+  while (++index < length) {
+    node = tokens[index]
+    fn = node.type === 'comment' ? comment : node.type === 'code' ? code : noop
+    nodes = nodes.concat(fn(node, ctx) || [])
+  }
+
+  ctx.nodes = nodes
+}
+
+function noop() {}
+
+function comment(node) {
+  return processor.parse(node.values.join('')).children
+}
+
+function code(node, ctx) {
+  var example = ctx.example
+  var start = node.start
+  var end = node.end
+  var tokens = []
+  var token
+  var consoleCall
+  var mainReference
+  var nodes
+  var length
+  var index
+  var lineEnd
+  var line
+
+  while (start < end) {
+    lineEnd = example.indexOf('\n', start)
+    lineEnd = lineEnd === -1 || lineEnd >= end ? end : lineEnd
+
+    consoleCall = findInLine(ctx.logs, start, lineEnd)
+
+    if (consoleCall && consoleCall.values.length !== 0) {
+      line = example.slice(start, lineEnd)
+
+      if (token && token === consoleCall) {
+        // Ignore: it’s the same multiline console call.
+      } else {
+        token = consoleCall
+        tokens.push(token)
+      }
+    } else {
+      mainReference = ctx.name && findInLine(ctx.mainReferences, start, lineEnd)
+
+      if (mainReference) {
+        line =
+          example.slice(start, mainReference.start) +
+          mainReference.quote +
+          ctx.name +
+          mainReference.quote +
+          example.slice(mainReference.end, lineEnd)
+      } else {
+        line = example.slice(start, lineEnd)
+      }
+
+      if (!token || token.type !== 'code') {
+        token = {type: 'code', values: []}
+        tokens.push(token)
+      }
+
+      token.values.push(line)
+    }
+
+    start = lineEnd + 1
+  }
+
+  nodes = []
+  length = tokens.length
+  index = -1
+
+  while (++index < length) {
+    token = tokens[index]
+    nodes.push({
+      type: 'code',
+      lang: token.type === 'code' ? 'javascript' : token.language,
+      value: token.values.join('\n').replace(/^\n+|\n+$/g, '')
+    })
+  }
+
+  return nodes
+}
+
+function findInLine(values, start, end) {
+  var length = values.length
+  var index = -1
+  var reference
+
+  while (++index < length) {
+    reference = values[index]
+
+    if (
+      // Reference in:
+      (reference.start >= start && reference.end <= end) ||
+      // Line in reference:
+      (start >= reference.start && end <= reference.end)
+    ) {
+      return reference
+    }
+  }
+}
diff --git a/lib/generate/index.js b/lib/generate/index.js
new file mode 100644
index 0000000..64dc535
--- /dev/null
+++ b/lib/generate/index.js
@@ -0,0 +1,21 @@
+'use strict'
+
+var trough = require('trough')
+var config = require('./config')
+var findPackage = require('./find-package')
+var findExample = require('./find-example')
+var generate = require('./generate')
+var instrument = require('./instrument')
+var run = require('./run')
+var tokenize = require('./tokenize')
+var write = require('./write')
+
+module.exports = trough()
+  .use(findPackage)
+  .use(config)
+  .use(findExample)
+  .use(instrument)
+  .use(write)
+  .use(run)
+  .use(tokenize)
+  .use(generate)
diff --git a/lib/generate/instrument.js b/lib/generate/instrument.js
new file mode 100644
index 0000000..319e46b
--- /dev/null
+++ b/lib/generate/instrument.js
@@ -0,0 +1,107 @@
+'use strict'
+
+var path = require('path')
+var babel = require('@babel/core')
+var resolveFrom = require('resolve-from')
+
+module.exports = instrument
+
+function instrument(ctx, next) {
+  var logs = []
+  var mainReferences = []
+
+  babel.transform(
+    ctx.example,
+    {
+      plugins: [addIdToConsoleLog],
+      cwd: ctx.cwd,
+      filename: ctx.examplePath,
+      caller: {name: 'remark-usage'},
+      sourceType: 'unambiguous'
+    },
+    ontransform
+  )
+
+  function ontransform(err, result) {
+    if (err) {
+      next(new Error('Could not parse example: ' + err))
+    } else {
+      ctx.exampleInstrumented = result.code
+      ctx.logs = logs
+      ctx.mainReferences = mainReferences
+      next()
+    }
+  }
+
+  function addIdToConsoleLog() {
+    var t = babel.types
+    var index = -1
+
+    return {
+      visitor: {
+        CallExpression: function(path) {
+          var callee = path.get('callee')
+
+          if (
+            callee.isIdentifier({name: 'require'}) &&
+            path.get('arguments.0').isStringLiteral()
+          ) {
+            instrumentMainReference(path.get('arguments.0').node)
+          }
+
+          if (callee.matchesPattern('console.log')) {
+            instrumentConsoleLog(path)
+          }
+        }
+      }
+    }
+
+    function instrumentMainReference(node) {
+      var raw = node && node.extra && node.extra.raw
+      var filePath = resolveFrom.silent(
+        path.dirname(ctx.examplePath),
+        node.value
+      )
+
+      /* istanbul ignore if - Babel always adds raw, but just to be sure. */
+      if (!raw) {
+        raw = "'"
+      }
+
+      if (filePath && filePath === ctx.main) {
+        mainReferences.push({
+          start: node.start,
+          end: node.end,
+          quote: raw.charAt(0)
+        })
+      }
+    }
+
+    function instrumentConsoleLog(path) {
+      var node = path.node
+      var args = node.arguments.concat()
+      var head
+      var language
+
+      index++
+
+      if (args.length > 1 && args[0].type === 'StringLiteral') {
+        head = args.shift()
+        language = head.value
+      }
+
+      logs[index] = {
+        start: node.start,
+        end: node.end,
+        language: language,
+        values: []
+      }
+
+      node.arguments = [].concat(
+        t.stringLiteral('<' + ctx.id + '-' + index + '>'),
+        args,
+        t.stringLiteral('</' + ctx.id + '>')
+      )
+    }
+  }
+}
diff --git a/lib/generate/run.js b/lib/generate/run.js
new file mode 100644
index 0000000..f565e13
--- /dev/null
+++ b/lib/generate/run.js
@@ -0,0 +1,56 @@
+'use strict'
+
+var exec = require('child_process').exec
+
+module.exports = run
+
+function run(ctx, next) {
+  exec('node ' + ctx.exampleInstrumentedPath, onexec)
+
+  function onexec(err, stdout) {
+    var logs = ctx.logs
+    var out
+    var open
+    var close
+    var startMatch
+    var endMatch
+    var start
+    var end
+    var logIndex
+    var value
+
+    if (err) {
+      return next(new Error('Could not run example: ' + err))
+    }
+
+    out = stdout
+    open = new RegExp('<' + ctx.id + '-(\\d+)>', 'g')
+    close = new RegExp('</' + ctx.id + '>', 'g')
+
+    while ((startMatch = open.exec(out))) {
+      close.lastIndex = startMatch.index
+      endMatch = close.exec(out)
+
+      /* istanbul ignore else - should never occur, console is sync, but just to
+       * be sure. */
+      if (endMatch) {
+        start = startMatch.index + startMatch[0].length
+        end = endMatch.index
+        logIndex = parseInt(startMatch[1], 10)
+        value = out.slice(start, end)
+
+        /* istanbul ignore else - console adds spaces at start and end, just to
+         * be sure we’re checking it though. */
+        if (value.charAt(0) === ' ' && value.charAt(value.length - 1) === ' ') {
+          value = value.slice(1, -1)
+        }
+
+        logs[logIndex].values.push(value)
+      }
+
+      open.lastIndex = end
+    }
+
+    next()
+  }
+}
diff --git a/lib/generate/tokenize.js b/lib/generate/tokenize.js
new file mode 100644
index 0000000..45e6ea1
--- /dev/null
+++ b/lib/generate/tokenize.js
@@ -0,0 +1,72 @@
+'use strict'
+
+module.exports = tokenize
+
+function tokenize(ctx) {
+  var lineBreak = /\r?\n/g
+  var lineComment = /^\s*\/\/\s*/
+  var ignoreComment = /^remark-usage-ignore-next(?:(?:\s+)(\d+))?/
+  var example = ctx.example
+  var start = 0
+  var end
+  var skip = 0
+  var match
+  var line
+  var comment
+  var ignore
+  var tokens = []
+  var token
+
+  while ((match = lineBreak.exec(example))) {
+    end = match.index
+    line = example.slice(start, end)
+
+    // If the line is supposed to be skipped, skip it.
+    // Skipping can only happen by starting a comment.
+    if (skip) {
+      skip--
+    }
+    // Empty:
+    else if (line.trim().length === 0) {
+      if (token) {
+        if (token.type === 'comment') {
+          token.values.push(match[0])
+        } else if (token.type === 'code') {
+          token.end = end
+        }
+      }
+    } else {
+      comment = line.match(lineComment)
+
+      if (comment) {
+        line = line.slice(comment[0].length)
+        ignore = line.match(ignoreComment)
+
+        if (ignore) {
+          // Skip next couple of lines.
+          skip = (ignore[1] !== undefined && parseInt(ignore[1], 10)) || 1
+          token = {type: 'skip', skip: skip}
+          tokens.push(token)
+        } else {
+          if (!token || token.type !== 'comment') {
+            token = {type: 'comment', values: []}
+            tokens.push(token)
+          }
+
+          token.values.push(line, match[0])
+        }
+      } else {
+        if (!token || token.type !== 'code') {
+          token = {type: 'code', start: start, end: end}
+          tokens.push(token)
+        }
+
+        token.end = end
+      }
+    }
+
+    start = end + match[0].length
+  }
+
+  ctx.tokens = tokens
+}
diff --git a/lib/generate/write.js b/lib/generate/write.js
new file mode 100644
index 0000000..c2c135f
--- /dev/null
+++ b/lib/generate/write.js
@@ -0,0 +1,23 @@
+'use strict'
+
+var fs = require('fs')
+var path = require('path')
+
+module.exports = write
+
+function write(ctx, next) {
+  var dir = path.dirname(ctx.examplePath)
+  var filePath = path.join(dir, ctx.id + '.js')
+
+  fs.writeFile(filePath, ctx.exampleInstrumented, onwrite)
+
+  function onwrite(err) {
+    /* istanbul ignore if - Doesn’t happen consistently */
+    if (err) {
+      return next(new Error('Could not write example: ' + err))
+    }
+
+    ctx.exampleInstrumentedPath = filePath
+    next()
+  }
+}
diff --git a/lib/index.js b/lib/index.js
new file mode 100644
index 0000000..3190300
--- /dev/null
+++ b/lib/index.js
@@ -0,0 +1,61 @@
+'use strict'
+
+var fs = require('fs')
+var heading = require('mdast-util-heading-range')
+var generate = require('./generate')
+
+var defaultHeading = 'usage'
+
+module.exports = usage
+
+function usage(options) {
+  var settings = options || {}
+  var header = new RegExp(
+    '^(' + (settings.heading || defaultHeading) + ')$',
+    'i'
+  )
+
+  return transform
+
+  function transform(tree, file, next) {
+    var ctx = {tree: tree, file: file, settings: settings}
+    var exists = false
+
+    // Walk the tree once to check if the heading exists.
+    // Walking the tree may be slow, but it’s much more slow to run Babel, spawn
+    // node, and generate the example.
+    heading(tree, header, ifExists)
+
+    if (exists) {
+      generate.run(ctx, done)
+    } else {
+      next()
+    }
+
+    function done(err) {
+      // If something failed and there’s an example, remove it.
+      if (ctx && ctx.exampleInstrumentedPath) {
+        try {
+          fs.unlinkSync(ctx.exampleInstrumentedPath)
+        } catch (error) {}
+      }
+
+      if (err) {
+        return next(err)
+      }
+
+      // Add example.
+      heading(tree, header, run)
+      next()
+
+      function run(start, _, end) {
+        return [start].concat(ctx.nodes, end)
+      }
+    }
+
+    function ifExists(start, nodes, end) {
+      exists = true
+      return [start].concat(nodes, end)
+    }
+  }
+}
diff --git a/lib/util/relative-module.js b/lib/util/relative-module.js
new file mode 100644
index 0000000..32f8d82
--- /dev/null
+++ b/lib/util/relative-module.js
@@ -0,0 +1,9 @@
+'use strict'
+
+var prefix = './'
+
+module.exports = relativeModule
+
+function relativeModule(moduleId) {
+  return moduleId.slice(0, 2) === prefix ? moduleId : prefix + moduleId
+}
diff --git a/package.json b/package.json
index f9d0e70..89971e0 100644
--- a/package.json
+++ b/package.json
@@ -24,14 +24,13 @@
     "index.js"
   ],
   "dependencies": {
-    "cept": "^1.0.0",
+    "@babel/core": "^7.0.0",
     "mdast-util-heading-range": "^2.0.0",
+    "nanoid": "^2.0.0",
     "remark-parse": "^6.0.0",
-    "require-uncached": "^2.0.0",
     "resolve-from": "^5.0.0",
-    "trim-trailing-lines": "^1.0.0",
-    "unified": "^7.0.0",
-    "unquote": "^1.1.0"
+    "trough": "^1.0.0",
+    "unified": "^7.0.0"
   },
   "devDependencies": {
     "is-hidden": "^1.0.0",
@@ -42,10 +41,13 @@
     "remark-cli": "^6.0.0",
     "remark-preset-wooorm": "^5.0.0",
     "tape": "^4.0.0",
+    "to-vfile": "^6.0.0",
     "xo": "^0.24.0"
   },
   "scripts": {
-    "format": "remark *.md -qfo && prettier --write *.js test/*.js && xo *.js test/*.js --fix",
+    "format:md": "remark . -qfo",
+    "format:js": "prettier --no-config --config ./package.json --write \"**/*.js\" && xo --fix",
+    "format": "npm run format:md && npm run format:js",
     "test-api": "node test",
     "test-coverage": "nyc --reporter lcov tape test/index.js",
     "test": "npm run format && npm run test-coverage"
@@ -67,17 +69,9 @@
   "xo": {
     "prettier": true,
     "esnext": false,
-    "rules": {
-      "no-unused-expressions": "off",
-      "no-unused-vars": "off",
-      "eol-last": "off",
-      "import/no-dynamic-require": "off",
-      "import/order": "off",
-      "unicorn/import-index": "off",
-      "ava/no-import-test-files": "off"
-    },
     "ignore": [
-      "example.js"
+      "example.js",
+      "test/fixtures"
     ]
   },
   "remarkConfig": {
@@ -87,7 +81,12 @@
         "remark-lint-fenced-code-flag",
         false
       ],
-      "./"
+      [
+        "./",
+        {
+          "heading": "use"
+        }
+      ]
     ]
   }
 }
diff --git a/readme.md b/readme.md
index 919fdf1..8a3d326 100644
--- a/readme.md
+++ b/readme.md
@@ -20,51 +20,75 @@ npm install remark-usage
 
 ## Usage
 
-This section is rendered by this module from [example.js][example-js].
+> This section is rendered by this module from [`example.js`][example-js].
+> Turtles all the way down.  🐢🐢🐢
 
-Dependencies:
+Say we are making a module that exports just enough Pi (3.14159).
+We’re documenting it with a readme file, [`example/readme.md`][example-md]:
 
-```javascript
-var fs = require('fs')
-var remark = require('remark')
-var usage = require('remark-usage') // This is changed from `./index.js` to `remark-usage`
+```markdown
+# PI
+
+More than enough 🍰
+
+## Use
+
+## License
+
+MIT
+```
+
+…and an example script to document it [`example/example.js`][example-js-2]:
+
+```js
+// Load dependencies:
+var pi = require('.')
+
+// Logging `pi` yields:
+console.log('txt', pi)
 ```
 
-Read and parse `readme.md`:
+…If we use `remark-usage`, we can generate the `Usage` section
 
 ```javascript
-var readme = fs.readFileSync('readme.md', 'utf-8')
-var ast = remark()
+var path = require('path')
+var vfile = require('to-vfile')
+var remark = require('remark')
+var usage = require('remark-usage')
+
+var file = vfile.readSync({path: 'readme.md', cwd: 'example'})
+
+var file = await remark()
   .use(usage)
-  .parse(readme)
+  .process(file)
 ```
 
-Log something with a language flag:
+Now, printing `file` (the newly generated readme) yields:
 
-```markdown
-[**remark**][remark] plugin to add a [usage][] example to a readme.
-```
+````markdown
+# PI
 
-Or without language:
+More than enough 🍰
 
-```
-## Install
-```
+## Usage
 
-Log something which is never captured:
+Load dependencies:
 
 ```javascript
-function neverCalled() {
-  console.log('javascript', 'alert("test")')
-}
+var pi = require('pi')
 ```
 
-Log something which isn’t captured because it’s not a string.
+Logging `pi` yields:
 
-```javascript
-console.log(this)
+```txt
+3.14159
 ```
 
+## License
+
+MIT
+````
+
 ## API
 
 <!--lint enable code-block-style-->
@@ -77,7 +101,7 @@ Removes the current content between the heading containing the text “usage”,
 the next heading of the same (or higher) depth, and replaces it with the
 example.
 
-The example is run as JavaScript.
+The example is run in Node.
 Line comments are parsed as Markdown.
 Calls to `console.log()` are exposed as code blocks, containing the logged
 values (optionally with a language flag).
@@ -85,10 +109,8 @@ values (optionally with a language flag).
 It’s easiest to check out and compare [`example.js`][example-js] with the above
 [Usage][] section.
 
-*   Operate this from an npm package, or provide a `cwd`
+*   Operate this from an npm package
 *   Make sure no side effects occur when running `example.js`
-*   Don’t do weird things.
-    This is mostly regexes
 
 You can ignore lines like so:
 
@@ -106,33 +128,30 @@ function sum(a, b) {
 
 ##### `options`
 
-###### `options.cwd`
-
-Path to a directory containing a node module (`string?`).
-Used to infer `name`, `main`, and `example`.
-
-###### `options.name`
-
-Name of the module (`string?`).
-Inferred from `package.json`s `name` property.
-Used to rewrite `require('.')` to `require('some-name')`.
-
-###### `options.main`
+###### `options.heading`
 
-Path to the main script (`string?`).
-Resolved from `package.json`s `main` property (or `index.js`).
-Used to rewrite `require('./index.js')` to `require('some-name')`.
+Heading to look for (`string?`, default: `'usage'`).
+Wrapped in `new RegExp('^(' + value + ')$', 'i');`.
 
 ###### `options.example`
 
 Path to the example script (`string?`).
-`remark-usage` checks for `docs/example.js`, `doc/example.js`,
-`examples/index.js`, `example/index.js`, and `example.js`.
+If given, resolved from [`file.cwd`][file-cwd].
+If not given, the following values are attempted and resolved from `file.cwd`:
+`'./example'`, `'./examples'`, `'./doc/example'`, `'./docs/example'`.
+The first that exists, is used.
 
-###### `options.heading`
+###### `options.name`
 
-Heading to look for (`string?`, default: `'usage'`).
-Wrapped in `new RegExp('^(' + value + ')$', 'i');`.
+Name of the module (`string?`, default: `pkg.name`, optional).
+Used to rewrite `require('.')` to `require('name')`.
+
+###### `options.main`
+
+Path to the main file (`string?`, default: `pkg.main` or `'.'`, optional).
+If given, resolved from [`file.cwd`][file-cwd].
+If inferred from `package.json`, resolved relating to that package root.
+Used to rewrite `require('.')` to `require('name')`.
 
 ## Contribute
 
@@ -192,6 +211,12 @@ abide by its terms.
 
 [remark]: https://github.com/remarkjs/remark
 
+[file-cwd]: https://github.com/vfile/vfile#vfilecwd
+
 [usage]: #usage
 
 [example-js]: example.js
+
+[example-md]: ./example/readme.md
+
+[example-js-2]: ./example/example.js
diff --git a/test/fixtures/code-without-eof/example.js b/test/fixtures/code-without-eof/example.js
new file mode 100644
index 0000000..36e3e40
--- /dev/null
+++ b/test/fixtures/code-without-eof/example.js
@@ -0,0 +1,3 @@
+var pi = require('./index.js')
+
+pi + pi
\ No newline at end of file
diff --git a/test/fixtures/code-without-eof/index.js b/test/fixtures/code-without-eof/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/code-without-eof/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/code-without-eof/output.md b/test/fixtures/code-without-eof/output.md
new file mode 100644
index 0000000..eaea538
--- /dev/null
+++ b/test/fixtures/code-without-eof/output.md
@@ -0,0 +1,9 @@
+# PI
+
+## Usage
+
+```javascript
+var pi = require('pi')
+
+pi + pi
+```
diff --git a/test/fixtures/fail-invalid-example/package.json b/test/fixtures/code-without-eof/package.json
similarity index 89%
rename from test/fixtures/fail-invalid-example/package.json
rename to test/fixtures/code-without-eof/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/fail-invalid-example/package.json
+++ b/test/fixtures/code-without-eof/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/fail-invalid-example/readme.md b/test/fixtures/code-without-eof/readme.md
similarity index 100%
rename from test/fixtures/fail-invalid-example/readme.md
rename to test/fixtures/code-without-eof/readme.md
diff --git a/test/fixtures/fail-could-not-find-example/index.js b/test/fixtures/fail-could-not-find-example/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/fail-could-not-find-example/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/fail-missing-example/package.json b/test/fixtures/fail-could-not-find-example/package.json
similarity index 89%
rename from test/fixtures/fail-missing-example/package.json
rename to test/fixtures/fail-could-not-find-example/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/fail-missing-example/package.json
+++ b/test/fixtures/fail-could-not-find-example/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/fail-missing-example/readme.md b/test/fixtures/fail-could-not-find-example/readme.md
similarity index 100%
rename from test/fixtures/fail-missing-example/readme.md
rename to test/fixtures/fail-could-not-find-example/readme.md
diff --git a/test/fixtures/fail-could-not-parse-example/example.js b/test/fixtures/fail-could-not-parse-example/example.js
new file mode 100644
index 0000000..eef843b
--- /dev/null
+++ b/test/fixtures/fail-could-not-parse-example/example.js
@@ -0,0 +1 @@
+'
diff --git a/test/fixtures/fail-could-not-parse-example/index.js b/test/fixtures/fail-could-not-parse-example/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/fail-could-not-parse-example/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/fail-could-not-parse-example/package.json b/test/fixtures/fail-could-not-parse-example/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/fail-could-not-parse-example/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/fail-could-not-parse-example/readme.md b/test/fixtures/fail-could-not-parse-example/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/fail-could-not-parse-example/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/fail-could-not-parse-package/index.js b/test/fixtures/fail-could-not-parse-package/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/fail-could-not-parse-package/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/fail-could-not-parse-package/package.json b/test/fixtures/fail-could-not-parse-package/package.json
new file mode 100644
index 0000000..98232c6
--- /dev/null
+++ b/test/fixtures/fail-could-not-parse-package/package.json
@@ -0,0 +1 @@
+{
diff --git a/test/fixtures/fail-could-not-parse-package/readme.md b/test/fixtures/fail-could-not-parse-package/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/fail-could-not-parse-package/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/fail-invalid-example/example.js b/test/fixtures/fail-could-not-run-example/example.js
similarity index 100%
rename from test/fixtures/fail-invalid-example/example.js
rename to test/fixtures/fail-could-not-run-example/example.js
diff --git a/test/fixtures/fail-could-not-run-example/index.js b/test/fixtures/fail-could-not-run-example/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/fail-could-not-run-example/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/fail-could-not-run-example/package.json b/test/fixtures/fail-could-not-run-example/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/fail-could-not-run-example/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/fail-could-not-run-example/readme.md b/test/fixtures/fail-could-not-run-example/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/fail-could-not-run-example/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/fail-invalid-example/index.js b/test/fixtures/fail-invalid-example/index.js
deleted file mode 100644
index 2cc299c..0000000
--- a/test/fixtures/fail-invalid-example/index.js
+++ /dev/null
@@ -1,3 +0,0 @@
-'use strict';
-
-module.exports = Math.PI.toString().slice(0, 6);
diff --git a/test/fixtures/fail-missing-example/index.js b/test/fixtures/fail-missing-example/index.js
deleted file mode 100644
index 2cc299c..0000000
--- a/test/fixtures/fail-missing-example/index.js
+++ /dev/null
@@ -1,3 +0,0 @@
-'use strict';
-
-module.exports = Math.PI.toString().slice(0, 6);
diff --git a/test/fixtures/file-without-file-path/config.json b/test/fixtures/file-without-file-path/config.json
new file mode 100644
index 0000000..84ec767
--- /dev/null
+++ b/test/fixtures/file-without-file-path/config.json
@@ -0,0 +1,3 @@
+{
+  "withoutFilePath": true
+}
diff --git a/test/fixtures/file-without-file-path/example.js b/test/fixtures/file-without-file-path/example.js
new file mode 100644
index 0000000..ccad136
--- /dev/null
+++ b/test/fixtures/file-without-file-path/example.js
@@ -0,0 +1,4 @@
+var pi = require('./index.js')
+
+// Logs:
+console.log('text', pi)
diff --git a/test/fixtures/file-without-file-path/index.js b/test/fixtures/file-without-file-path/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/file-without-file-path/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/file-without-file-path/output.md b/test/fixtures/file-without-file-path/output.md
new file mode 100644
index 0000000..644ddb2
--- /dev/null
+++ b/test/fixtures/file-without-file-path/output.md
@@ -0,0 +1,13 @@
+# PI
+
+## Usage
+
+```javascript
+var pi = require('pi')
+```
+
+Logs:
+
+```text
+3.1415
+```
diff --git a/test/fixtures/file-without-file-path/package.json b/test/fixtures/file-without-file-path/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/file-without-file-path/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/file-without-file-path/readme.md b/test/fixtures/file-without-file-path/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/file-without-file-path/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/ignore-lines/index.js b/test/fixtures/ignore-lines/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/ignore-lines/index.js
+++ b/test/fixtures/ignore-lines/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/image-with-alt/example.js b/test/fixtures/image-with-alt/example.js
index 78a8167..ff50019 100644
--- a/test/fixtures/image-with-alt/example.js
+++ b/test/fixtures/image-with-alt/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/image-with-alt/index.js b/test/fixtures/image-with-alt/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/image-with-alt/index.js
+++ b/test/fixtures/image-with-alt/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/image-with-alt/output.md b/test/fixtures/image-with-alt/output.md
index e6f9a90..7e7fdd8 100644
--- a/test/fixtures/image-with-alt/output.md
+++ b/test/fixtures/image-with-alt/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/image-with-alt/package.json b/test/fixtures/image-with-alt/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/image-with-alt/package.json
+++ b/test/fixtures/image-with-alt/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/initial-code/example.js b/test/fixtures/initial-code/example.js
new file mode 100644
index 0000000..ccad136
--- /dev/null
+++ b/test/fixtures/initial-code/example.js
@@ -0,0 +1,4 @@
+var pi = require('./index.js')
+
+// Logs:
+console.log('text', pi)
diff --git a/test/fixtures/initial-code/index.js b/test/fixtures/initial-code/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/initial-code/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/initial-code/output.md b/test/fixtures/initial-code/output.md
new file mode 100644
index 0000000..644ddb2
--- /dev/null
+++ b/test/fixtures/initial-code/output.md
@@ -0,0 +1,13 @@
+# PI
+
+## Usage
+
+```javascript
+var pi = require('pi')
+```
+
+Logs:
+
+```text
+3.1415
+```
diff --git a/test/fixtures/initial-code/package.json b/test/fixtures/initial-code/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/initial-code/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/initial-code/readme.md b/test/fixtures/initial-code/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/initial-code/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/initial-whitespace/example.js b/test/fixtures/initial-whitespace/example.js
new file mode 100644
index 0000000..6b6f132
--- /dev/null
+++ b/test/fixtures/initial-whitespace/example.js
@@ -0,0 +1,7 @@
+
+
+// Require `pi`:
+var pi = require('./index.js')
+
+// Logs:
+console.log('text', pi)
diff --git a/test/fixtures/initial-whitespace/index.js b/test/fixtures/initial-whitespace/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/initial-whitespace/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/initial-whitespace/output.md b/test/fixtures/initial-whitespace/output.md
new file mode 100644
index 0000000..62885c5
--- /dev/null
+++ b/test/fixtures/initial-whitespace/output.md
@@ -0,0 +1,15 @@
+# PI
+
+## Usage
+
+Require `pi`:
+
+```javascript
+var pi = require('pi')
+```
+
+Logs:
+
+```text
+3.1415
+```
diff --git a/test/fixtures/initial-whitespace/package.json b/test/fixtures/initial-whitespace/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/initial-whitespace/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/initial-whitespace/readme.md b/test/fixtures/initial-whitespace/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/initial-whitespace/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/link-with-title/example.js b/test/fixtures/link-with-title/example.js
index 78a8167..ff50019 100644
--- a/test/fixtures/link-with-title/example.js
+++ b/test/fixtures/link-with-title/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/link-with-title/index.js b/test/fixtures/link-with-title/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/link-with-title/index.js
+++ b/test/fixtures/link-with-title/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/link-with-title/output.md b/test/fixtures/link-with-title/output.md
index 4fa9381..6d518bc 100644
--- a/test/fixtures/link-with-title/output.md
+++ b/test/fixtures/link-with-title/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/link-with-title/package.json b/test/fixtures/link-with-title/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/link-with-title/package.json
+++ b/test/fixtures/link-with-title/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/log-handling/example.js b/test/fixtures/log-handling/example.js
index 05e1cb0..2417fd6 100644
--- a/test/fixtures/log-handling/example.js
+++ b/test/fixtures/log-handling/example.js
@@ -1,16 +1,16 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Log an object:
-console.log(this);
+console.log(this)
 
 // Log nothing, _twice_:
 
 // Another comment.
-console.log();
-console.log();
+console.log()
+console.log()
 
 // A commented log: `console.log()`.
 // A final comment, missing an EOL.
 
-console.log('markdown', 'Some **thing**.');
\ No newline at end of file
+console.log('markdown', 'Some **thing**.')
\ No newline at end of file
diff --git a/test/fixtures/log-handling/index.js b/test/fixtures/log-handling/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/log-handling/index.js
+++ b/test/fixtures/log-handling/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/log-handling/output.md b/test/fixtures/log-handling/output.md
index 8d94ca8..239c29c 100644
--- a/test/fixtures/log-handling/output.md
+++ b/test/fixtures/log-handling/output.md
@@ -5,26 +5,26 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Log an object:
 
-```javascript
-console.log(this);
-```
+    {}
 
 Log nothing, _twice_:
 
 Another comment.
 
-```javascript
-console.log();
-console.log();
 ```
 
-A commented log: `console.log()`.
+```
 
+```
+
+```
+
+A commented log: `console.log()`.
 A final comment, missing an EOL.
 
 ```markdown
diff --git a/test/fixtures/log-then-code/example.js b/test/fixtures/log-then-code/example.js
new file mode 100644
index 0000000..0cd798c
--- /dev/null
+++ b/test/fixtures/log-then-code/example.js
@@ -0,0 +1,6 @@
+var pi = require('./index.js')
+
+// Logs:
+console.log('text', pi)
+
+pi + pi
diff --git a/test/fixtures/log-then-code/index.js b/test/fixtures/log-then-code/index.js
new file mode 100644
index 0000000..aadb3b0
--- /dev/null
+++ b/test/fixtures/log-then-code/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.floor(Math.PI * 1e6) / 1e6
diff --git a/test/fixtures/log-then-code/output.md b/test/fixtures/log-then-code/output.md
new file mode 100644
index 0000000..e1c0c22
--- /dev/null
+++ b/test/fixtures/log-then-code/output.md
@@ -0,0 +1,17 @@
+# PI
+
+## Usage
+
+```javascript
+var pi = require('pi')
+```
+
+Logs:
+
+```text
+3.141592
+```
+
+```javascript
+pi + pi
+```
diff --git a/test/fixtures/log-then-code/package.json b/test/fixtures/log-then-code/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/log-then-code/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/log-then-code/readme.md b/test/fixtures/log-then-code/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/log-then-code/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/multiline-console-calls/example.js b/test/fixtures/multiline-console-calls/example.js
new file mode 100644
index 0000000..447904e
--- /dev/null
+++ b/test/fixtures/multiline-console-calls/example.js
@@ -0,0 +1,7 @@
+var pi = require('./index.js')
+
+// Logs:
+console.log(
+  'text',
+  pi
+)
diff --git a/test/fixtures/multiline-console-calls/index.js b/test/fixtures/multiline-console-calls/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/multiline-console-calls/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/multiline-console-calls/output.md b/test/fixtures/multiline-console-calls/output.md
new file mode 100644
index 0000000..644ddb2
--- /dev/null
+++ b/test/fixtures/multiline-console-calls/output.md
@@ -0,0 +1,13 @@
+# PI
+
+## Usage
+
+```javascript
+var pi = require('pi')
+```
+
+Logs:
+
+```text
+3.1415
+```
diff --git a/test/fixtures/multiline-console-calls/package.json b/test/fixtures/multiline-console-calls/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/multiline-console-calls/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/multiline-console-calls/readme.md b/test/fixtures/multiline-console-calls/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/multiline-console-calls/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/multiple-calls/example.js b/test/fixtures/multiple-calls/example.js
new file mode 100644
index 0000000..4907c69
--- /dev/null
+++ b/test/fixtures/multiple-calls/example.js
@@ -0,0 +1,8 @@
+var pi = require('./index.js')
+
+var i = 0
+
+while (++i < 5) {
+  // Print `Number(pi) + i`:
+  console.log(Number(pi) + i)
+}
diff --git a/test/fixtures/multiple-calls/index.js b/test/fixtures/multiple-calls/index.js
new file mode 100644
index 0000000..45a6d8c
--- /dev/null
+++ b/test/fixtures/multiple-calls/index.js
@@ -0,0 +1,3 @@
+'use strict'
+
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/multiple-calls/output.md b/test/fixtures/multiple-calls/output.md
new file mode 100644
index 0000000..95c6f2f
--- /dev/null
+++ b/test/fixtures/multiple-calls/output.md
@@ -0,0 +1,22 @@
+# PI
+
+## Usage
+
+```javascript
+var pi = require('pi')
+
+var i = 0
+
+while (++i < 5) {
+```
+
+Print `Number(pi) + i`:
+
+    4.141500000000001
+    5.141500000000001
+    6.141500000000001
+    7.141500000000001
+
+```javascript
+}
+```
diff --git a/test/fixtures/multiple-calls/package.json b/test/fixtures/multiple-calls/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/multiple-calls/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/multiple-calls/readme.md b/test/fixtures/multiple-calls/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/multiple-calls/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/multiple-usage-headings/example.js b/test/fixtures/multiple-usage-headings/example.js
index 78a8167..53941c1 100644
--- a/test/fixtures/multiple-usage-headings/example.js
+++ b/test/fixtures/multiple-usage-headings/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Logs:
 console.log('text', pi);
diff --git a/test/fixtures/multiple-usage-headings/index.js b/test/fixtures/multiple-usage-headings/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/multiple-usage-headings/index.js
+++ b/test/fixtures/multiple-usage-headings/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/multiple-usage-headings/output.md b/test/fixtures/multiple-usage-headings/output.md
index 0094730..38f4a07 100644
--- a/test/fixtures/multiple-usage-headings/output.md
+++ b/test/fixtures/multiple-usage-headings/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/multiple-usage-headings/package.json b/test/fixtures/multiple-usage-headings/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/multiple-usage-headings/package.json
+++ b/test/fixtures/multiple-usage-headings/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/no-main/example.js b/test/fixtures/no-main/example.js
new file mode 100644
index 0000000..5ee225b
--- /dev/null
+++ b/test/fixtures/no-main/example.js
@@ -0,0 +1,7 @@
+var a = 1
+var b = 2
+
+var result = a + b
+
+// Yields:
+console.log(result)
diff --git a/test/fixtures/no-main/output.md b/test/fixtures/no-main/output.md
new file mode 100644
index 0000000..07783f6
--- /dev/null
+++ b/test/fixtures/no-main/output.md
@@ -0,0 +1,14 @@
+# PI
+
+## Usage
+
+```javascript
+var a = 1
+var b = 2
+
+var result = a + b
+```
+
+Yields:
+
+    3
diff --git a/test/fixtures/no-main/package.json b/test/fixtures/no-main/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/no-main/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/no-main/readme.md b/test/fixtures/no-main/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/no-main/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/fixtures/no-usage-heading/example.js b/test/fixtures/no-usage-heading/example.js
index 78a8167..ff50019 100644
--- a/test/fixtures/no-usage-heading/example.js
+++ b/test/fixtures/no-usage-heading/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/no-usage-heading/index.js b/test/fixtures/no-usage-heading/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/no-usage-heading/index.js
+++ b/test/fixtures/no-usage-heading/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-custom-example/config.json b/test/fixtures/normal-custom-example/config.json
index 6f9135b..f66f9c2 100644
--- a/test/fixtures/normal-custom-example/config.json
+++ b/test/fixtures/normal-custom-example/config.json
@@ -1,3 +1,3 @@
 {
-  "example": "ex"
+  "example": "./ex"
 }
diff --git a/test/fixtures/normal-custom-example/ex.js b/test/fixtures/normal-custom-example/ex.js
index 78a8167..ff50019 100644
--- a/test/fixtures/normal-custom-example/ex.js
+++ b/test/fixtures/normal-custom-example/ex.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-custom-example/index.js b/test/fixtures/normal-custom-example/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-custom-example/index.js
+++ b/test/fixtures/normal-custom-example/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-custom-example/output.md b/test/fixtures/normal-custom-example/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal-custom-example/output.md
+++ b/test/fixtures/normal-custom-example/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-custom-example/package.json b/test/fixtures/normal-custom-example/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/normal-custom-example/package.json
+++ b/test/fixtures/normal-custom-example/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/normal-custom-heading/example.js b/test/fixtures/normal-custom-heading/example.js
index 78a8167..ff50019 100644
--- a/test/fixtures/normal-custom-heading/example.js
+++ b/test/fixtures/normal-custom-heading/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-custom-heading/index.js b/test/fixtures/normal-custom-heading/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-custom-heading/index.js
+++ b/test/fixtures/normal-custom-heading/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-custom-heading/output.md b/test/fixtures/normal-custom-heading/output.md
index 9bf7d62..b48434f 100644
--- a/test/fixtures/normal-custom-heading/output.md
+++ b/test/fixtures/normal-custom-heading/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-custom-main-with-package/example.js b/test/fixtures/normal-custom-main-with-package/example.js
index 6d35f2a..7007c42 100644
--- a/test/fixtures/normal-custom-main-with-package/example.js
+++ b/test/fixtures/normal-custom-main-with-package/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./pi.js');
+var pi = require('./pi.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-custom-main-with-package/output.md b/test/fixtures/normal-custom-main-with-package/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal-custom-main-with-package/output.md
+++ b/test/fixtures/normal-custom-main-with-package/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-custom-main-with-package/pi.js b/test/fixtures/normal-custom-main-with-package/pi.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-custom-main-with-package/pi.js
+++ b/test/fixtures/normal-custom-main-with-package/pi.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-custom-main-without-package/example.js b/test/fixtures/normal-custom-main-without-package/example.js
index 6d35f2a..7007c42 100644
--- a/test/fixtures/normal-custom-main-without-package/example.js
+++ b/test/fixtures/normal-custom-main-without-package/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./pi.js');
+var pi = require('./pi.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-custom-main-without-package/output.md b/test/fixtures/normal-custom-main-without-package/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal-custom-main-without-package/output.md
+++ b/test/fixtures/normal-custom-main-without-package/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-custom-main-without-package/pi.js b/test/fixtures/normal-custom-main-without-package/pi.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-custom-main-without-package/pi.js
+++ b/test/fixtures/normal-custom-main-without-package/pi.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-custom-main/example.js b/test/fixtures/normal-custom-main/example.js
index 6d35f2a..7007c42 100644
--- a/test/fixtures/normal-custom-main/example.js
+++ b/test/fixtures/normal-custom-main/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./pi.js');
+var pi = require('./pi.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-custom-main/output.md b/test/fixtures/normal-custom-main/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal-custom-main/output.md
+++ b/test/fixtures/normal-custom-main/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-custom-main/package.json b/test/fixtures/normal-custom-main/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/normal-custom-main/package.json
+++ b/test/fixtures/normal-custom-main/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/normal-custom-main/pi.js b/test/fixtures/normal-custom-main/pi.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-custom-main/pi.js
+++ b/test/fixtures/normal-custom-main/pi.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-custom-name-without-package/example.js b/test/fixtures/normal-custom-name-without-package/example.js
index 78a8167..7579560 100644
--- a/test/fixtures/normal-custom-name-without-package/example.js
+++ b/test/fixtures/normal-custom-name-without-package/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('.')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-custom-name-without-package/index.js b/test/fixtures/normal-custom-name-without-package/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-custom-name-without-package/index.js
+++ b/test/fixtures/normal-custom-name-without-package/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-custom-name-without-package/output.md b/test/fixtures/normal-custom-name-without-package/output.md
index 20fe2ac..dbd936e 100644
--- a/test/fixtures/normal-custom-name-without-package/output.md
+++ b/test/fixtures/normal-custom-name-without-package/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('usage');
+var pi = require('usage')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-custom-name/example.js b/test/fixtures/normal-custom-name/example.js
index 78a8167..ff50019 100644
--- a/test/fixtures/normal-custom-name/example.js
+++ b/test/fixtures/normal-custom-name/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-custom-name/index.js b/test/fixtures/normal-custom-name/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-custom-name/index.js
+++ b/test/fixtures/normal-custom-name/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-custom-name/output.md b/test/fixtures/normal-custom-name/output.md
index 20fe2ac..dbd936e 100644
--- a/test/fixtures/normal-custom-name/output.md
+++ b/test/fixtures/normal-custom-name/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('usage');
+var pi = require('usage')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-custom-name/package.json b/test/fixtures/normal-custom-name/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/normal-custom-name/package.json
+++ b/test/fixtures/normal-custom-name/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/normal-doc-directory/doc/example.js b/test/fixtures/normal-doc-directory/doc/example.js
index 491babc..4439dbb 100644
--- a/test/fixtures/normal-doc-directory/doc/example.js
+++ b/test/fixtures/normal-doc-directory/doc/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('../index.js');
+var pi = require('../index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-doc-directory/index.js b/test/fixtures/normal-doc-directory/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-doc-directory/index.js
+++ b/test/fixtures/normal-doc-directory/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-doc-directory/output.md b/test/fixtures/normal-doc-directory/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal-doc-directory/output.md
+++ b/test/fixtures/normal-doc-directory/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-doc-directory/package.json b/test/fixtures/normal-doc-directory/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/normal-doc-directory/package.json
+++ b/test/fixtures/normal-doc-directory/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/normal-docs-directory/docs/example.js b/test/fixtures/normal-docs-directory/docs/example.js
index 491babc..4439dbb 100644
--- a/test/fixtures/normal-docs-directory/docs/example.js
+++ b/test/fixtures/normal-docs-directory/docs/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('../index.js');
+var pi = require('../index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-docs-directory/index.js b/test/fixtures/normal-docs-directory/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-docs-directory/index.js
+++ b/test/fixtures/normal-docs-directory/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-docs-directory/output.md b/test/fixtures/normal-docs-directory/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal-docs-directory/output.md
+++ b/test/fixtures/normal-docs-directory/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-docs-directory/package.json b/test/fixtures/normal-docs-directory/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/normal-docs-directory/package.json
+++ b/test/fixtures/normal-docs-directory/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/normal-example-directory/example/index.js b/test/fixtures/normal-example-directory/example/index.js
index 491babc..4439dbb 100644
--- a/test/fixtures/normal-example-directory/example/index.js
+++ b/test/fixtures/normal-example-directory/example/index.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('../index.js');
+var pi = require('../index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-example-directory/index.js b/test/fixtures/normal-example-directory/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-example-directory/index.js
+++ b/test/fixtures/normal-example-directory/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-example-directory/output.md b/test/fixtures/normal-example-directory/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal-example-directory/output.md
+++ b/test/fixtures/normal-example-directory/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-example-directory/package.json b/test/fixtures/normal-example-directory/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/normal-example-directory/package.json
+++ b/test/fixtures/normal-example-directory/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/normal-examples-directory/examples/index.js b/test/fixtures/normal-examples-directory/examples/index.js
index 491babc..4439dbb 100644
--- a/test/fixtures/normal-examples-directory/examples/index.js
+++ b/test/fixtures/normal-examples-directory/examples/index.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('../index.js');
+var pi = require('../index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal-examples-directory/index.js b/test/fixtures/normal-examples-directory/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-examples-directory/index.js
+++ b/test/fixtures/normal-examples-directory/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal-examples-directory/output.md b/test/fixtures/normal-examples-directory/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal-examples-directory/output.md
+++ b/test/fixtures/normal-examples-directory/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/normal-examples-directory/package.json b/test/fixtures/normal-examples-directory/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/normal-examples-directory/package.json
+++ b/test/fixtures/normal-examples-directory/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/normal-without-options-or-package/index.js b/test/fixtures/normal-without-options-or-package/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal-without-options-or-package/index.js
+++ b/test/fixtures/normal-without-options-or-package/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal/example.js b/test/fixtures/normal/example.js
index 78a8167..ff50019 100644
--- a/test/fixtures/normal/example.js
+++ b/test/fixtures/normal/example.js
@@ -1,5 +1,5 @@
 // Require `pi`:
-var pi = require('./index.js');
+var pi = require('./index.js')
 
 // Logs:
-console.log('text', pi);
+console.log('text', pi)
diff --git a/test/fixtures/normal/index.js b/test/fixtures/normal/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/normal/index.js
+++ b/test/fixtures/normal/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/normal/output.md b/test/fixtures/normal/output.md
index 0bd7b11..62885c5 100644
--- a/test/fixtures/normal/output.md
+++ b/test/fixtures/normal/output.md
@@ -5,7 +5,7 @@
 Require `pi`:
 
 ```javascript
-var pi = require('pi');
+var pi = require('pi')
 ```
 
 Logs:
diff --git a/test/fixtures/require-handling/index.js b/test/fixtures/require-handling/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/require-handling/index.js
+++ b/test/fixtures/require-handling/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/require-handling/package.json b/test/fixtures/require-handling/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/require-handling/package.json
+++ b/test/fixtures/require-handling/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/require-last/index.js b/test/fixtures/require-last/index.js
index 2cc299c..45a6d8c 100644
--- a/test/fixtures/require-last/index.js
+++ b/test/fixtures/require-last/index.js
@@ -1,3 +1,3 @@
-'use strict';
+'use strict'
 
-module.exports = Math.PI.toString().slice(0, 6);
+module.exports = Math.PI.toString().slice(0, 6)
diff --git a/test/fixtures/require-last/package.json b/test/fixtures/require-last/package.json
index 34386b7..7d35bc7 100644
--- a/test/fixtures/require-last/package.json
+++ b/test/fixtures/require-last/package.json
@@ -1,3 +1,3 @@
 {
   "name": "pi"
-}
\ No newline at end of file
+}
diff --git a/test/fixtures/stdout/example.js b/test/fixtures/stdout/example.js
new file mode 100644
index 0000000..d97c9a5
--- /dev/null
+++ b/test/fixtures/stdout/example.js
@@ -0,0 +1,3 @@
+process.stdout.write('foo')
+console.log('bar')
+process.stdout.write('baz')
diff --git a/test/fixtures/stdout/output.md b/test/fixtures/stdout/output.md
new file mode 100644
index 0000000..b1caec3
--- /dev/null
+++ b/test/fixtures/stdout/output.md
@@ -0,0 +1,13 @@
+# PI
+
+## Usage
+
+```javascript
+process.stdout.write('foo')
+```
+
+    bar
+
+```javascript
+process.stdout.write('baz')
+```
diff --git a/test/fixtures/stdout/package.json b/test/fixtures/stdout/package.json
new file mode 100644
index 0000000..7d35bc7
--- /dev/null
+++ b/test/fixtures/stdout/package.json
@@ -0,0 +1,3 @@
+{
+  "name": "pi"
+}
diff --git a/test/fixtures/stdout/readme.md b/test/fixtures/stdout/readme.md
new file mode 100644
index 0000000..f78b72b
--- /dev/null
+++ b/test/fixtures/stdout/readme.md
@@ -0,0 +1,3 @@
+# PI
+
+## Usage
diff --git a/test/index.js b/test/index.js
index ad94276..1f67962 100644
--- a/test/index.js
+++ b/test/index.js
@@ -9,7 +9,6 @@ var negate = require('negate')
 var usage = require('..')
 
 var read = fs.readFileSync
-var exists = fs.existsSync
 
 test('usage()', function(t) {
   t.equal(typeof usage, 'function', 'should be a function')
@@ -24,40 +23,62 @@ test('usage()', function(t) {
 var root = path.join(__dirname, 'fixtures')
 var fixtures = fs.readdirSync(root).filter(negate(hidden))
 
+fs.renameSync('package.json', 'package.json.bak')
+
+test.onFinish(function() {
+  fs.renameSync('package.json.bak', 'package.json')
+})
+
 test('Fixtures', function(t) {
   fixtures.forEach(function(fixture) {
-    var filepath = root + '/' + fixture
-    var config = filepath + '/config.json'
-    var output = filepath + '/output.md'
-    var input
-    var result
-    var fail
-
-    config = exists(config) ? require(config) : {}
-    output = exists(output) ? read(output, 'utf-8') : ''
+    t.test(fixture, function(st) {
+      var base = path.join(root, fixture)
+      var input = read(path.join(base, 'readme.md'))
+      var expected = ''
+      var config = {}
+      var file
 
-    input = read(filepath + '/readme.md', 'utf-8')
+      st.plan(1)
 
-    config.cwd = filepath
+      try {
+        expected = String(read(path.join(base, 'output.md')))
+      } catch (error) {}
 
-    fail = fixture.indexOf('fail-') === 0 ? fixture.slice(5) : ''
+      try {
+        config = JSON.parse(read(path.join(base, 'config.json')))
+      } catch (error) {}
 
-    try {
-      result = remark()
-        .use(usage, config)
-        .processSync(input)
-        .toString()
+      file = {contents: input, cwd: base}
 
-      t.equal(result, output, 'should work on `' + fixture + '`')
-    } catch (error) {
-      if (!fail) {
-        throw error
+      if (!config.withoutFilePath) {
+        file.path = 'readme.md'
       }
 
-      fail = new RegExp(fail.replace(/-/, ' '), 'i')
-
-      t.equal(fail.test(error), true, 'should fail on `' + fixture + '`')
-    }
+      remark()
+        .use(usage, config)
+        .process(file, onprocess)
+
+      function onprocess(err, file) {
+        var fail = fixture.indexOf('fail-') === 0 ? fixture.slice(5) : ''
+        var errMessage = fail ? new RegExp(fail.replace(/-/g, ' '), 'i') : null
+
+        if (fail) {
+          if (err) {
+            if (errMessage.test(err)) {
+              st.pass('should fail')
+            } else {
+              st.error(err, 'should fail')
+            }
+          } else {
+            st.fail('should fail instead of work')
+          }
+        } else if (err) {
+          st.error(err, 'should work instead of fail')
+        } else {
+          st.equal(String(file), expected, 'should work')
+        }
+      }
+    })
   })
 
   t.end()