compose-iterator - npm Package Compare versions

Comparing version 1.0.1 to 1.1.0

examples/compose.js

@@ -30,11 +30,2 @@ 'use strict'
   /**
-   * Make an iterator for middleware.
-   */
-
-  middleware[Symbol.iterator] = iterator
-
-  // Alternative iteration.
-  const iter = middleware[Symbol.iterator]()
-
-  /**
    * @param {Object} context
@@ -46,4 +37,7 @@ * @return {Promise}
   return function (context, next) {
+    // iteration object
+    const iter = iterator[Symbol.iterator](middleware, context, next)
+
     try {
-      return Promise.resolve(iter.next(context, next).value)
+      return Promise.resolve(iter.next().value)
     } catch (err) {
@@ -50,0 +44,0 @@ return Promise.reject(err)

index.js

 'use strict'
 
 /**
- * Expose iterator.
- */
-
-module.exports = iterator
-
-/**
  * Make an iterator for middleware.
@@ -16,32 +10,29 @@ *
 
-function iterator () {
-  const self = this
-  const length = this.length
-  let i = 0
-  let context
-  let nextFunc
+const iterator = {
+  [Symbol.iterator] (middleware, context, nextFunc) {
+    const length = middleware.length
+    let i = -1
 
-  return {
-    next (c, n) {
-      if (!context) context = c
-      if (!nextFunc) nextFunc = n
+    return {
 
-      let fn = self[i++] || nextFunc
-      let done = i > length
-      let value
-      let nextCalled = false
+      next () {
+        let fn = middleware[++i] || nextFunc
+        let done = i === length
+        let value
+        let nextCalled = false
 
-      if (fn) {
-        value = fn(context, () => {
-          if (nextCalled) {
-            return Promise.reject(new Error('next() called multiple times'))
-          }
-          nextCalled = true
-          return Promise.resolve().then(() => this.next().value)
-        })
-      }
+        if (fn) {
+          value = fn(context, () => {
+            if (nextCalled) {
+              throw new Error('next() called multiple times')
+            }
+            nextCalled = true
+            return Promise.resolve().then(() => this.next().value)
+          })
+        }
 
-      return {
-        value,
-        done
+        return {
+          value,
+          done
+        }
       }
@@ -51,1 +42,7 @@ }
 }
+
+/**
+ * Expose iterator.
+ */
+
+module.exports = iterator

package.json

 {
   "name": "compose-iterator",
-  "version": "1.0.1",
+  "version": "1.1.0",
   "description": "Fastest iterator for middleware composition",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

 # Compose Iterator
 
-Fastest iterator for middleware composition. The biggest performance improvements for Koa middleware.
+Use iterator for middleware composition.
 
-## Benchmarks
-
-**For [koa-compose v3](https://github.com/koajs/compose/tree/3.1.0)**, https://github.com/koajs/compose/pull/57
-
-### Before
-
-```
-                      compose
-          43,981 op/s » (fn * 1)
-          25,044 op/s » (fn * 2)
-          13,359 op/s » (fn * 4)
-           6,972 op/s » (fn * 8)
-           3,555 op/s » (fn * 16)
-           1,803 op/s » (fn * 32)
-             920 op/s » (fn * 64)
-             466 op/s » (fn * 128)
-             231 op/s » (fn * 256)
-             113 op/s » (fn * 512)
-              55 op/s » (fn * 1024)
-              27 op/s » (fn * 2048)
-              13 op/s » (fn * 4096)
-               6 op/s » (fn * 8192)
-```
-
-### After
-
-```
-                      compose
-         206,669 op/s » (fn * 1)
-         202,517 op/s » (fn * 2)
-         209,224 op/s » (fn * 4)
-         208,893 op/s » (fn * 8)
-         205,962 op/s » (fn * 16)
-         205,885 op/s » (fn * 32)
-         205,316 op/s » (fn * 64)
-         206,602 op/s » (fn * 128)
-         205,352 op/s » (fn * 256)
-         201,229 op/s » (fn * 512)
-         188,328 op/s » (fn * 1024)
-         167,314 op/s » (fn * 2048)
-         182,743 op/s » (fn * 4096)
-         174,105 op/s » (fn * 8192)
-```
-
 ## Installation
@@ -64,3 +20,3 @@
 
-const iterator = require('compose-iterator')
+const iterator = require('..')
 
@@ -90,11 +46,2 @@ /**
   /**
-   * Make an iterator for middleware.
-   */
-
-  middleware[Symbol.iterator] = iterator
-
-  // Alternative iteration.
-  const iter = middleware[Symbol.iterator]()
-
-  /**
    * @param {Object} context
@@ -106,4 +53,7 @@ * @return {Promise}
   return function (context, next) {
+    // iteration object
+    const iter = iterator[Symbol.iterator](middleware, context, next)
+
     try {
-      return Promise.resolve(iter.next(context, next).value)
+      return Promise.resolve(iter.next().value)
     } catch (err) {
@@ -110,0 +60,0 @@ return Promise.reject(err)

test/test.js

@@ -47,2 +47,43 @@ 'use strict'
 
+  it('should be able to be called twice', () => {
+    var stack = []
+
+    stack.push(function * (context, next) {
+      context.arr.push(1)
+      yield wait(1)
+      yield next()
+      yield wait(1)
+      context.arr.push(6)
+    })
+
+    stack.push(function * (context, next) {
+      context.arr.push(2)
+      yield wait(1)
+      yield next()
+      yield wait(1)
+      context.arr.push(5)
+    })
+
+    stack.push(function * (context, next) {
+      context.arr.push(3)
+      yield wait(1)
+      yield next()
+      yield wait(1)
+      context.arr.push(4)
+    })
+
+    const fn = compose(stack.map((fn) => co.wrap(fn)))
+    const ctx1 = { arr: [] }
+    const ctx2 = { arr: [] }
+    const out = [1, 2, 3, 4, 5, 6]
+
+    return fn(ctx1).then(() => {
+      assert.deepEqual(out, ctx1.arr)
+
+      return fn(ctx2)
+    }).then(() => {
+      assert.deepEqual(out, ctx2.arr)
+    })
+  })
+
   it('should only accept an array', function () {
@@ -260,2 +301,20 @@ var err
   })
+
+  it('should not affect the original middleware array', () => {
+    const middleware = []
+    const fn1 = (ctx, next) => {
+      return next()
+    }
+    middleware.push(fn1)
+
+    for (const fn of middleware) {
+      assert.equal(fn, fn1)
+    }
+
+    compose(middleware)
+
+    for (const fn of middleware) {
+      assert.equal(fn, fn1)
+    }
+  })
 })

No alert changes

Improved metrics

Lines of code

392

increased by11.68%

Worsened metrics

Total package byte prevSize

13970

decreased by-1.9%

Number of lines in readme file

116

decreased by-30.12%

No dependency changes