Update es-iterator-helpers with Iterator.concat shim and fix typos

packages/npm/es-iterator-helpers/Iterator.concat/auto.d.ts

@@ -0,0 +1 @@
+/* empty */

packages/npm/es-iterator-helpers/Iterator.concat/auto.js

@@ -0,0 +1,3 @@
+'use strict'
+
+require('./shim')()

packages/npm/es-iterator-helpers/Iterator.concat/implementation.d.ts

@@ -0,0 +1,4 @@
+declare function concat<T>(
+  ...items: Iterable<T>[]
+): Iterator<T> & { return(): IteratorResult<T> }
+export = concat

packages/npm/es-iterator-helpers/Iterator.concat/implementation.js

@@ -0,0 +1,89 @@
+'use strict'
+
+const sentinel = Symbol('sentinel')
+
+// Implementation based on the following spec:
+// https://tc39.es/proposal-iterator-sequencing/#sec-iterator.concat
+module.exports = function concat(...items) {
+  // Step 1: If called with `new`, throw an error.
+  if (new.target) {
+    throw new TypeError('`Iterator.concat` is not a constructor')
+  }
+  // Step 1: Initialize empty list for iterables.
+  const iterables = []
+  // Step 2: Validate each item and add to iterables list.
+  for (const item of items) {
+    // Step 2a: Ensure each item is an object.
+    if (item === null || typeof item !== 'object') {
+      throw new TypeError(
+        '`Iterator.concat` requires all arguments to be objects'
+      )
+    }
+    const method = item[Symbol.iterator]
+    // Step 2c: Ensure each item is iterable.
+    if (typeof method !== 'function') {
+      throw new TypeError(
+        '`Iterator.concat` requires all arguments to be iterable'
+      )
+    }
+    // Step 2d: Add to iterables list.
+    iterables.push({ OpenMethod: method, Iterable: item })
+  }
+  // Step 3: Initialize the inner iterator.
+  let innerIterator = sentinel
+  const closeIfAbrupt = (iterator, abruptCompletion) => {
+    if (iterator && typeof iterator.return === 'function') {
+      try {
+        // Step 3a.v.3.b: Close iterator on abrupt completion.
+        iterator.return()
+      } catch {
+        // If `return` throws, rethrow the original error.
+        throw abruptCompletion
+      }
+    }
+    throw abruptCompletion
+  }
+  // Step 3: Create a closure function to handle iteration.
+  let index = 0
+  const closure = () => {
+    // Step 3a: Iterate through each iterable.
+    while (index < iterables.length) {
+      const { Iterable, OpenMethod } = iterables[index]
+      if (innerIterator === sentinel) {
+        // Step 3a.i: Call the iterator method.
+        innerIterator = OpenMethod.call(Iterable)
+        // Step 3a.ii: Ensure iterator is an object.
+        if (typeof innerIterator !== 'object' || innerIterator === null) {
+          closeIfAbrupt(
+            innerIterator,
+            new TypeError('Iterator result is not an object')
+          )
+        }
+      }
+      // Step 3a.v.1: Get the next value.
+      const { done, value } = innerIterator.next()
+      // Step 3a.v.2: Check if done, move to next iterable if true.
+      if (done) {
+        innerIterator = sentinel
+        index += 1
+      } else {
+        // Step 3a.v.3.a: Yield the current value.
+        return { value, done: false }
+      }
+    }
+    // Step 3b: If all iterables are done, return completed.
+    return { value: undefined, done: true }
+  }
+  // Step 4: Return the iterator.
+  return {
+    [Symbol.iterator]: function () {
+      return this
+    },
+    next: closure,
+    return() {
+      // Step 3a.v.3.b: Handle abrupt generator close.
+      closeIfAbrupt(innerIterator, new Error('Generator closed abruptly'))
+      return { value: undefined, done: true }
+    }
+  }
+}

packages/npm/es-iterator-helpers/Iterator.concat/index.d.ts

@@ -0,0 +1,10 @@
+import Impl from './implementation'
+declare const {
+  x: EsIteratorConcat
+}: {
+  x: typeof Impl & {
+    getPolyfill(): typeof Impl
+    shim(): typeof Impl
+  }
+}
+export = EsIteratorConcat

packages/npm/es-iterator-helpers/Iterator.concat/index.js

@@ -0,0 +1,25 @@
+'use strict'
+
+const getPolyfill = require('./polyfill')
+const polyfill = getPolyfill()
+
+const desc = value => ({
+  __proto__: null,
+  configurable: true,
+  value,
+  writable: true
+})
+
+module.exports = Object.defineProperties(
+  function concat(...args) {
+    return new.target ? new polyfill() : polyfill(...args)
+  },
+  {
+    getPolyfill: desc(getPolyfill),
+    implementation: desc(require('./implementation')),
+    shim: desc(require('./shim'))
+  }
+)
+module.exports.getPolyfill = module.exports.getPolyfill
+module.exports.implementation = module.exports.implementation
+module.exports.shim = module.exports.shim

packages/npm/es-iterator-helpers/Iterator.concat/polyfill.d.ts

@@ -0,0 +1,3 @@
+import Impl from './implementation'
+declare function getPolyfill(): () => typeof Impl
+export = getPolyfill

packages/npm/es-iterator-helpers/Iterator.concat/polyfill.js

@@ -0,0 +1,8 @@
+'use strict'
+
+const impl = require('./implementation')
+const Iterator = require('../Iterator/implementation')
+
+module.exports = function getPolyfill() {
+  return typeof Iterator.concat === 'function' ? Iterator.concat : impl
+}

packages/npm/es-iterator-helpers/Iterator.concat/shim.d.ts

@@ -0,0 +1,3 @@
+import Impl from './implementation'
+declare function shim(): () => typeof Impl
+export = shim

packages/npm/es-iterator-helpers/Iterator.concat/shim.js

@@ -0,0 +1,20 @@
+'use strict'
+
+const getPolyfill = require('./polyfill')
+const Iterator = require('../Iterator/implementation')
+
+const { defineProperty: ObjectDefineProperty } = Object
+
+module.exports = function shimIteratorConcat() {
+  const polyfill = getPolyfill()
+  if (Iterator.concat !== polyfill) {
+    ObjectDefineProperty(Iterator, 'concat', {
+      __proto__: null,
+      configurable: true,
+      enumerable: false,
+      value: polyfill,
+      writable: true
+    })
+  }
+  return polyfill
+}

packages/npm/es-iterator-helpers/Iterator.prototype.drop/polyfill.js

@@ -5,5 +5,7 @@ const IteratorPrototype = require('../Iterator.prototype/implementation')
 const { isIteratorNextCheckBuggy } = require('../shared')
 
 module.exports = function getPolyfill() {
-  return isIteratorNextCheckBuggy ? impl : IteratorPrototype.drop
+  return isIteratorNextCheckBuggy(IteratorPrototype, 'drop', 0)
+    ? impl
+    : IteratorPrototype.drop
 }

packages/npm/es-iterator-helpers/Iterator.prototype.filter/polyfill.js

@@ -5,5 +5,7 @@ const IteratorPrototype = require('../Iterator.prototype/implementation')
 const { isIteratorNextCheckBuggy } = require('../shared')
 
 module.exports = function getPolyfill() {
-  return isIteratorNextCheckBuggy ? impl : IteratorPrototype.filter
+  return isIteratorNextCheckBuggy(IteratorPrototype, 'filter', () => {})
+    ? impl
+    : IteratorPrototype.filter
 }

packages/npm/es-iterator-helpers/Iterator.prototype.filter/shim.js

@@ -7,7 +7,7 @@ const { defineProperty: ObjectDefineProperty } = Object
 
 module.exports = function shimIteratorProtoFilter() {
   const polyfill = getPolyfill()
-  if (polyfill && IteratorPrototype.drop !== polyfill) {
+  if (polyfill && IteratorPrototype.filter !== polyfill) {
     ObjectDefineProperty(IteratorPrototype, 'filter', {
       __proto__: null,
       configurable: true,

packages/npm/es-iterator-helpers/Iterator.prototype.flatMap/polyfill.js

@@ -5,5 +5,7 @@ const IteratorPrototype = require('../Iterator.prototype/implementation')
 const { isIteratorNextCheckBuggy } = require('../shared')
 
 module.exports = function getPolyfill() {
-  return isIteratorNextCheckBuggy ? impl : IteratorPrototype.flatMap
+  return isIteratorNextCheckBuggy(IteratorPrototype, 'flatMap', () => {})
+    ? impl
+    : IteratorPrototype.flatMap
 }

packages/npm/es-iterator-helpers/Iterator.prototype.flatMap/shim.js

@@ -7,7 +7,7 @@ const { defineProperty: ObjectDefineProperty } = Object
 
 module.exports = function shimIteratorProtoFlatMap() {
   const polyfill = getPolyfill()
-  if (polyfill && IteratorPrototype.drop !== polyfill) {
+  if (polyfill && IteratorPrototype.flatMap !== polyfill) {
     ObjectDefineProperty(IteratorPrototype, 'flatMap', {
       __proto__: null,
       configurable: true,

packages/npm/es-iterator-helpers/Iterator.prototype.map/polyfill.js

@@ -5,5 +5,7 @@ const IteratorPrototype = require('../Iterator.prototype/implementation')
 const { isIteratorNextCheckBuggy } = require('../shared')
 
 module.exports = function getPolyfill() {
-  return isIteratorNextCheckBuggy ? impl : IteratorPrototype.map
+  return isIteratorNextCheckBuggy(IteratorPrototype, 'map', () => {})
+    ? impl
+    : IteratorPrototype.map
 }

packages/npm/es-iterator-helpers/Iterator.prototype.map/shim.js

@@ -7,7 +7,7 @@ const { defineProperty: ObjectDefineProperty } = Object
 
 module.exports = function shimIteratorProtoMap() {
   const polyfill = getPolyfill()
-  if (polyfill && IteratorPrototype.drop !== polyfill) {
+  if (polyfill && IteratorPrototype.map !== polyfill) {
     ObjectDefineProperty(IteratorPrototype, 'map', {
       __proto__: null,
       configurable: true,

packages/npm/es-iterator-helpers/index.json

@@ -1,5 +1,6 @@
 [
   "Iterator",
+  "Iterator.concat",
   "Iterator.from",
   "Iterator.prototype",
   "Iterator.prototype.constructor",