Add support for Twitter, custom handles

Closes GH-6.
retextjs · Apr 24, 2020 · 641f66f · 641f66f
1 parent 543c411
commit 641f66f
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Showing 3 changed files with 120 additions and 32 deletions.
diff --git a/index.js b/index.js
@@ -6,45 +6,69 @@ var toString = require('nlcst-to-string')
 
 module.exports = mentions
 
-var name = /^(?:[a-z\d]{1,2}|[a-z\d][a-z\d-]{1,37}[a-z\d])(['’]s)?$/i
+var genitive = /['’]s?$/i
 
-function mentions() {
-  return transform
-}
+var gh = /^@(?:[a-z\d]{1,2}|[a-z\d][a-z\d-]{1,37}[a-z\d])(\/(?:[a-z\d]{1,2}|[a-z\d][a-z\d-]{1,37}[a-z\d]))?$/i
+var tw = /^@\w{1,15}$/i
 
-function transform(tree) {
-  visit(tree, 'SymbolNode', visitor)
-}
+function mentions(options) {
+  var style = (options || {}).style || 'github'
 
-function visitor(node, index, parent) {
-  var siblings = parent.children
-  var offset = index
-
-  if (toString(node) !== '@') {
-    return
+  if (style === 'github') {
+    style = gh
+  } else if (style === 'twitter') {
+    style = tw
   }
 
-  if (!name.test(valueOf(siblings[++offset]))) {
-    return
-  }
+  return transform
 
-  if (
-    valueOf(siblings[offset + 1]) === '/' &&
-    name.test(valueOf(siblings[offset + 2]))
-  ) {
-    offset += 2
+  function transform(tree) {
+    visit(tree, 'SymbolNode', visitor)
   }
 
-  siblings.splice(index, offset - index + 1, {
-    type: 'SourceNode',
-    value: toString(siblings.slice(index, offset + 1)),
-    position: {
-      start: position.start(node),
-      end: position.end(siblings[offset])
+  function visitor(node, index, parent) {
+    var siblings = parent.children
+    var length = siblings.length
+    var offset = index
+    var slice
+
+    if (toString(node) !== '@') {
+      return
     }
-  })
-}
 
-function valueOf(node) {
-  return node ? toString(node) : ''
+    offset++
+
+    while (offset <= length) {
+      if (offset === length) break
+      if (siblings[offset].type === 'WhiteSpaceNode') break
+
+      if (
+        toString(siblings[offset]) !== '/' &&
+        !check(siblings.slice(index, offset + 1))
+      ) {
+        break
+      }
+
+      offset++
+    }
+
+    slice = siblings.slice(index, offset)
+
+    if (!check(slice)) {
+      return
+    }
+
+    siblings.splice(index, offset - index, {
+      type: 'SourceNode',
+      value: toString(slice),
+      position: {
+        start: position.start(node),
+        end: position.end(slice[slice.length - 1])
+      }
+    })
+  }
+
+  function check(nodes) {
+    return style.test(toString(nodes).replace(genitive, ''))
+  }
 }
diff --git a/readme.md b/readme.md
@@ -66,13 +66,19 @@ no issues found
 
 ## API
 
-### `retext().use(mentions)`
+### `retext().use(mentions[, options])`
 
 Classify [**@mentions**](https://github.com/blog/821) as [**source**][source],
 which represent “external (ungrammatical) values” instead of natural language.
 This hides mentions from [`retext-spell`][spell],
 [`retext-readability`][readability], [`retext-equality`][equality], and more.
 
+###### `options.style`
+
+Style can be either `'github'` (for GitHub user and team mentions), `'twitter'`
+(for Twitter handles), or a regular expression (such as `/^@\w{1,15}$/i`, which
+is the Twitter regex).
+
 ## Related
 
 *   [`retext-syntax-urls`][syntax-urls]

diff --git a/test.js b/test.js
@@ -208,6 +208,64 @@ test('mentions()', function (t) {
     'should work as only item in sentence'
   )
 
+  t.deepEqual(
+    retext()
+      .use(mentions, {style: 'twitter'})
+      .use(strip)
+      .runSync(
+        noPosition.parse(
+          '@_philippkuehn (my twitter handle) is not recognized.'
+        )
+      ),
+    u('RootNode', [
+      u('ParagraphNode', [
+        u('SentenceNode', [
+          u('SourceNode', '@_philippkuehn'),
+          u('WhiteSpaceNode', ' '),
+          u('PunctuationNode', '('),
+          u('WordNode', [u('TextNode', 'my')]),
+          u('WhiteSpaceNode', ' '),
+          u('WordNode', [u('TextNode', 'twitter')]),
+          u('WhiteSpaceNode', ' '),
+          u('WordNode', [u('TextNode', 'handle')]),
+          u('PunctuationNode', ')'),
+          u('WhiteSpaceNode', ' '),
+          u('WordNode', [u('TextNode', 'is')]),
+          u('WhiteSpaceNode', ' '),
+          u('WordNode', [u('TextNode', 'not')]),
+          u('WhiteSpaceNode', ' '),
+          u('WordNode', [u('TextNode', 'recognized')]),
+          u('PunctuationNode', '.')
+        ])
+      ])
+    ]),
+    'should support twitter handles'
+  )
+
+  t.deepEqual(
+    retext()
+      .use(mentions, {style: /^@[a-z]{1,15}$/i})
+      .use(strip)
+      .runSync(noPosition.parse('@lettersOnly, no @123123 digits.')),
+    u('RootNode', [
+      u('ParagraphNode', [
+        u('SentenceNode', [
+          u('SourceNode', '@lettersOnly'),
+          u('PunctuationNode', ','),
+          u('WhiteSpaceNode', ' '),
+          u('WordNode', [u('TextNode', 'no')]),
+          u('WhiteSpaceNode', ' '),
+          u('SymbolNode', '@'),
+          u('WordNode', [u('TextNode', '123123')]),
+          u('WhiteSpaceNode', ' '),
+          u('WordNode', [u('TextNode', 'digits')]),
+          u('PunctuationNode', '.')
+        ])
+      ])
+    ]),
+    'should support custom handles'
+  )
+
   t.end()
 })