Add tests and small syntactic improvements

.editorconfig

@@ -0,0 +1,4 @@
+[*]
+indent_size = 2
+indent_style = space
+end_of_line = lf

.gitignore

@@ -1,3 +1,5 @@
+node_modules/
+.vscode/
 *~
 .#*
 coverage

README.md

@@ -25,10 +25,10 @@ req('foo').then(…)
 req('foo').then(…)
 ```
 
-## SEE ALSO
+## Tests
 
-* [inflight](https://npmjs.com/package/inflight) - For the callback based function on which this is based.
+Run `npm test`
 
-## STILL NEEDS
+## SEE ALSO
 
-Tests!
+* [inflight](https://npmjs.com/package/inflight) - For the callback based function on which this is based.

inflight.js

@@ -1,36 +1,34 @@
 'use strict'
 module.exports = inflight
 
-let Bluebird
-try {
-  Bluebird = require('bluebird')
-} catch (_) {
-  Bluebird = Promise
+const active = {}
+
+function cleanup() {
+  delete active[unique]
+}
+
+function _inflight (unique, doFly) {
+  if (!active[unique]) {
+    active[unique] = (new Promise(function (resolve) {
+      return resolve(doFly())
+    }))
+    active[unique].then(cleanup, cleanup)
+    function cleanup() { delete active[unique] }
+  }
+  return active[unique]
 }
 
-const active = {}
 inflight.active = active
 function inflight (unique, doFly) {
-  return Bluebird.all([unique, doFly]).then(function (args) {
+  return Promise.all([unique, doFly]).then(function (args) {
     const unique = args[0]
     const doFly = args[1]
     if (Array.isArray(unique)) {
-      return Bluebird.all(unique).then(function (uniqueArr) {
+      return Promise.all(unique).then(function (uniqueArr) {
         return _inflight(uniqueArr.join(''), doFly)
       })
     } else {
       return _inflight(unique, doFly)
     }
   })
-
-  function _inflight (unique, doFly) {
-    if (!active[unique]) {
-      active[unique] = (new Bluebird(function (resolve) {
-        return resolve(doFly())
-      }))
-      active[unique].then(cleanup, cleanup)
-      function cleanup() { delete active[unique] }
-    }
-    return active[unique]
-  }
 }

inflight.spec.js

@@ -0,0 +1,79 @@
+const inflight = require('./inflight')
+
+describe('inflight()', () => {
+  it('calls a single doFly()', async () => {
+    const doFly = jest.fn()
+    await inflight('unique-key', doFly)
+    expect(doFly).toHaveBeenCalled()
+  })
+
+  it('calls multiple doFly()', async () => {
+    const req = jest.fn((key) => {
+      return inflight(key, () => {
+        return new Promise(resolve => {
+          setTimeout(resolve(key), 50)
+        })
+      })
+    })
+
+    const result = await Promise.all([
+      req('hello'),
+      req('hello'),
+    ])
+    expect(result).toEqual(['hello', 'hello'])
+  })
+
+  it('calls doFly() only once if it is in progress', async () => {
+    let calls = 0
+    const req = jest.fn((key) => {
+      return inflight(key, () => {
+        return new Promise(resolve => {
+          calls++
+          setTimeout(resolve(42), 10000)
+        })
+      })
+    })
+
+    const result = await Promise.all([
+      req('hello'),
+      req('hello'),
+    ])
+    expect(result).toEqual([42, 42])
+    expect(calls).toEqual(1)
+  })
+
+  it('calls doFly() again after it is settled', async () => {
+    let calls = 0
+    const req = jest.fn((key) => {
+      return inflight(key, () => {
+        return new Promise(resolve => {
+          calls++
+          setTimeout(resolve(calls + 100), 10000)
+        })
+      })
+    })
+
+    const firstResult = await req('hello')
+    expect(firstResult).toEqual(101)
+    const secondResult = await req('hello')
+    expect(secondResult).toEqual(102)
+  })
+
+  it('can handle `unique` that is a promise', async () => {
+    const doFly = jest.fn()
+    await inflight(Promise.resolve('unique-key'), doFly)
+    expect(doFly).toHaveBeenCalled()
+  })
+
+  it('can handle `unique` that is an array', async () => {
+    const doFly = jest.fn()
+    await inflight(Promise.resolve(['unique', 'key']), doFly)
+    expect(doFly).toHaveBeenCalled()
+  })
+
+  it('can handle `unique` that is an array of promises', async () => {
+    const doFly = jest.fn()
+    await inflight([Promise.resolve('unique'), Promise.resolve('key')], doFly)
+    expect(doFly).toHaveBeenCalled()
+  })
+})