Fix shim test fails

packages/npm/date/Date.parse/shim.js

@@ -6,7 +6,7 @@ const { defineProperty: ObjectDefineProperty } = Object
 
 module.exports = function shimDateParse() {
   const polyfill = getPolyfill()
-  if (polyfill && Date.parse !== polyfill) {
+  if (Date.parse !== polyfill) {
     ObjectDefineProperty(Date, 'parse', {
       __proto__: null,
       configurable: true,

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

@@ -1,6 +1,7 @@
 'use strict'
 
-const impl = require('./implementation')
+const getPolyfill = require('./polyfill')
+const polyfill = getPolyfill()
 
 const desc = value => ({
   __proto__: null,
@@ -11,11 +12,11 @@ const desc = value => ({
 
 module.exports = Object.defineProperties(
   function drop(thisArg, limit = 0) {
-    return new.target ? impl() : Reflect.apply(impl, thisArg, [limit])
+    return new.target ? polyfill() : Reflect.apply(polyfill, thisArg, [limit])
   },
   {
-    getPolyfill: desc(require('./polyfill')),
-    implementation: desc(impl),
+    getPolyfill: desc(getPolyfill),
+    implementation: desc(require('./implementation')),
     shim: desc(require('./shim'))
   }
 )

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

@@ -1,6 +1,7 @@
 'use strict'
 
-const impl = require('./implementation')
+const getPolyfill = require('./polyfill')
+const polyfill = getPolyfill()
 
 const desc = value => ({
   __proto__: null,
@@ -11,11 +12,13 @@ const desc = value => ({
 
 module.exports = Object.defineProperties(
   function filter(thisArg, predicate) {
-    return new.target ? new impl() : Reflect.apply(impl, thisArg, [predicate])
+    return new.target
+      ? new polyfill()
+      : Reflect.apply(polyfill, thisArg, [predicate])
   },
   {
-    getPolyfill: desc(require('./polyfill')),
-    implementation: desc(impl),
+    getPolyfill: desc(getPolyfill),
+    implementation: desc(require('./implementation')),
     shim: desc(require('./shim'))
   }
 )

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

@@ -1,6 +1,7 @@
 'use strict'
 
-const impl = require('./implementation')
+const getPolyfill = require('./polyfill')
+const polyfill = getPolyfill()
 
 const desc = value => ({
   __proto__: null,
@@ -11,11 +12,13 @@ const desc = value => ({
 
 module.exports = Object.defineProperties(
   function flatMap(thisArg, mapper) {
-    return new.target ? new impl() : Reflect.apply(impl, thisArg, [mapper])
+    return new.target
+      ? new polyfill()
+      : Reflect.apply(polyfill, thisArg, [mapper])
   },
   {
-    getPolyfill: desc(require('./polyfill')),
-    implementation: desc(impl),
+    getPolyfill: desc(getPolyfill),
+    implementation: desc(require('./implementation')),
     shim: desc(require('./shim'))
   }
 )

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

@@ -1,6 +1,7 @@
 'use strict'
 
-const impl = require('./implementation')
+const getPolyfill = require('./polyfill')
+const polyfill = getPolyfill()
 
 const desc = value => ({
   __proto__: null,
@@ -11,11 +12,13 @@ const desc = value => ({
 
 module.exports = Object.defineProperties(
   function map(thisArg, mapper) {
-    return new.target ? new impl() : Reflect.apply(impl, thisArg, [mapper])
+    return new.target
+      ? new polyfill()
+      : Reflect.apply(polyfill, thisArg, [mapper])
   },
   {
-    getPolyfill: desc(require('./polyfill')),
-    implementation: desc(impl),
+    getPolyfill: desc(getPolyfill),
+    implementation: desc(require('./implementation')),
     shim: desc(require('./shim'))
   }
 )

packages/npm/regexp.prototype.flags/auto.js

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

packages/npm/regexp.prototype.flags/implementation.js

@@ -1,3 +1,41 @@
 'use strict'
 
-module.exports = RegExp.prototype.__lookupGetter__('flags')
+const { flagsGetter } = require('./shared')
+
+module.exports = {
+  get flags() {
+    if (new.target || this === null || typeof this !== 'object') {
+      // Defer to builtin flags getter for the error case.
+      return flagsGetter.call(this)
+    }
+    // Flag check order defined as hasIndices, global, ignoreCase, multiline,
+    // dotAll, unicode, unicodeSets, and sticky.
+    // https://tc39.es/ecma262/#sec-get-regexp.prototype.flags
+    let result = ''
+    if (this.hasIndices) {
+      result += 'd'
+    }
+    if (this.global) {
+      result += 'g'
+    }
+    if (this.ignoreCase) {
+      result += 'i'
+    }
+    if (this.multiline) {
+      result += 'm'
+    }
+    if (this.dotAll) {
+      result += 's'
+    }
+    if (this.unicode) {
+      result += 'u'
+    }
+    if (this.unicodeSets) {
+      result += 'v'
+    }
+    if (this.sticky) {
+      result += 'y'
+    }
+    return result
+  }
+}.__lookupGetter__('flags')

packages/npm/regexp.prototype.flags/index.js

@@ -1,6 +1,7 @@
 'use strict'
 
-const impl = require('./implementation')
+const getPolyfill = require('./polyfill')
+const polyfill = getPolyfill()
 
 const desc = value => ({
   __proto__: null,
@@ -11,11 +12,11 @@ const desc = value => ({
 
 module.exports = Object.defineProperties(
   function flags(thisArg) {
-    return new.target ? new impl() : Reflect.apply(impl, thisArg, [])
+    return new.target ? new polyfill() : Reflect.apply(polyfill, thisArg, [])
   },
   {
-    getPolyfill: desc(require('./polyfill')),
-    implementation: desc(impl),
+    getPolyfill: desc(getPolyfill),
+    implementation: desc(require('./implementation')),
     shim: desc(require('./shim'))
   }
 )

packages/npm/regexp.prototype.flags/polyfill.js

@@ -1,7 +1,19 @@
 'use strict'
 
 const impl = require('./implementation')
+const { flagsGetter } = require('./shared')
 
 module.exports = function getPolyfill() {
-  return impl
+  let calls = ''
+  flagsGetter.call({
+    // eslint-disable-next-line getter-return
+    get hasIndices() {
+      calls += 'd'
+    },
+    // eslint-disable-next-line getter-return
+    get sticky() {
+      calls += 'y'
+    }
+  })
+  return calls === 'dy' ? flagsGetter : impl
 }

packages/npm/regexp.prototype.flags/shared.d.ts

@@ -0,0 +1,5 @@
+declare interface InternalShared {
+  flagsGetter(): string
+}
+declare const shared: InternalShared
+export = shared

packages/npm/regexp.prototype.flags/shared.js

@@ -0,0 +1,7 @@
+'use strict'
+
+const flagsGetter = RegExp.prototype.__lookupGetter__('flags')
+
+module.exports = {
+  flagsGetter
+}

packages/npm/regexp.prototype.flags/shim.js

@@ -1,7 +1,20 @@
 'use strict'
 
-const impl = require('./implementation')
+const getPolyfill = require('./polyfill')
+
+const { defineProperty: ObjectDefineProperty } = Object
+const { __lookupGetter__: ObjectProtoLookupGetter } = Object.prototype
+const { prototype: RegExpPrototype } = RegExp
 
 module.exports = function shimRegExpProtoFlags() {
-  return impl
+  const polyfill = getPolyfill()
+  if (ObjectProtoLookupGetter.call(RegExpPrototype, 'flags') !== polyfill) {
+    ObjectDefineProperty(RegExpPrototype, 'flags', {
+      __proto__: null,
+      configurable: true,
+      enumerable: false,
+      get: polyfill
+    })
+  }
+  return polyfill
 }