Add ES2019 Object.fromEntries function (#30934)

* add ES2019 Object.fromEntries function

* add some comments

* apply suggested changes

* add readonly and general any

src/compiler/commandLineParser.ts

@@ -45,6 +45,7 @@ namespace ts {
         ["es2018.promise", "lib.es2018.promise.d.ts"],
         ["es2018.regexp", "lib.es2018.regexp.d.ts"],
         ["es2019.array", "lib.es2019.array.d.ts"],
+        ["es2019.object", "lib.es2019.object.d.ts"],
         ["es2019.string", "lib.es2019.string.d.ts"],
         ["es2019.symbol", "lib.es2019.symbol.d.ts"],
         ["es2020.string", "lib.es2020.string.d.ts"],

src/lib/es2019.d.ts

@@ -1,4 +1,5 @@
 /// <reference lib="es2018" />
 /// <reference lib="es2019.array" />
+/// <reference lib="es2019.object" />
 /// <reference lib="es2019.string" />
 /// <reference lib="es2019.symbol" />

src/lib/es2019.object.d.ts

@@ -0,0 +1,15 @@
+/// <reference lib="es2015.iterable" />
+
+interface ObjectConstructor {
+    /**
+     * Returns an object created by key-value entries for properties and methods
+     * @param entries An iterable object that contains key-value entries for properties and methods.
+     */
+    fromEntries<T = any>(entries: Iterable<readonly [PropertyKey, T]>): { [k in PropertyKey]: T };
+
+    /**
+     * Returns an object created by key-value entries for properties and methods
+     * @param entries An iterable object that contains key-value entries for properties and methods.
+     */
+    fromEntries(entries: Iterable<readonly any[]>): any;
+}

src/lib/libs.json

@@ -36,6 +36,7 @@
         "es2018.promise",
         "es2018.intl",
         "es2019.array",
+        "es2019.object",
         "es2019.string",
         "es2019.symbol",
         "es2020.string",

src/testRunner/unittests/config/commandLineParsing.ts

@@ -57,7 +57,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,invalidOption", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'es2018', 'es2019', 'es2020', 'esnext', 'dom', 'dom.iterable', 'webworker', 'webworker.importscripts', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'es2017.typedarrays', 'es2018.asynciterable', 'es2018.intl', 'es2018.promise', 'es2018.regexp', 'es2019.array', 'es2019.string', 'es2019.symbol', 'es2020.string', 'es2020.symbol.wellknown', 'esnext.array', 'esnext.symbol', 'esnext.asynciterable', 'esnext.intl', 'esnext.bigint'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'es2018', 'es2019', 'es2020', 'esnext', 'dom', 'dom.iterable', 'webworker', 'webworker.importscripts', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'es2017.typedarrays', 'es2018.asynciterable', 'es2018.intl', 'es2018.promise', 'es2018.regexp', 'es2019.array', 'es2019.object', 'es2019.string', 'es2019.symbol', 'es2020.string', 'es2020.symbol.wellknown', 'esnext.array', 'esnext.symbol', 'esnext.asynciterable', 'esnext.intl', 'esnext.bigint'.",
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         file: undefined,
@@ -259,7 +259,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'es2018', 'es2019', 'es2020', 'esnext', 'dom', 'dom.iterable', 'webworker', 'webworker.importscripts', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'es2017.typedarrays', 'es2018.asynciterable', 'es2018.intl', 'es2018.promise', 'es2018.regexp', 'es2019.array', 'es2019.string', 'es2019.symbol', 'es2020.string', 'es2020.symbol.wellknown', 'esnext.array', 'esnext.symbol', 'esnext.asynciterable', 'esnext.intl', 'esnext.bigint'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'es2018', 'es2019', 'es2020', 'esnext', 'dom', 'dom.iterable', 'webworker', 'webworker.importscripts', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'es2017.typedarrays', 'es2018.asynciterable', 'es2018.intl', 'es2018.promise', 'es2018.regexp', 'es2019.array', 'es2019.object', 'es2019.string', 'es2019.symbol', 'es2020.string', 'es2020.symbol.wellknown', 'esnext.array', 'esnext.symbol', 'esnext.asynciterable', 'esnext.intl', 'esnext.bigint'.",
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         file: undefined,
@@ -278,7 +278,7 @@ namespace ts {
             assertParseResult(["--lib", "es5, ", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'es2018', 'es2019', 'es2020', 'esnext', 'dom', 'dom.iterable', 'webworker', 'webworker.importscripts', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'es2017.typedarrays', 'es2018.asynciterable', 'es2018.intl', 'es2018.promise', 'es2018.regexp', 'es2019.array', 'es2019.string', 'es2019.symbol', 'es2020.string', 'es2020.symbol.wellknown', 'esnext.array', 'esnext.symbol', 'esnext.asynciterable', 'esnext.intl', 'esnext.bigint'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'es2018', 'es2019', 'es2020', 'esnext', 'dom', 'dom.iterable', 'webworker', 'webworker.importscripts', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'es2017.typedarrays', 'es2018.asynciterable', 'es2018.intl', 'es2018.promise', 'es2018.regexp', 'es2019.array', 'es2019.object', 'es2019.string', 'es2019.symbol', 'es2020.string', 'es2020.symbol.wellknown', 'esnext.array', 'esnext.symbol', 'esnext.asynciterable', 'esnext.intl', 'esnext.bigint'.",
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         file: undefined,

tests/baselines/reference/objectFromEntries.js

@@ -0,0 +1,20 @@
+//// [objectFromEntries.ts]
+const o = Object.fromEntries([['a', 1], ['b', 2], ['c', 3]]);
+const o2 = Object.fromEntries(new URLSearchParams());
+const o3 = Object.fromEntries(new Map([[Symbol("key"), "value"]]));
+
+const frozenArray = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+const o4 = Object.fromEntries(frozenArray);
+
+const frozenArray2: readonly [string, number][] = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+const o5 = Object.fromEntries(frozenArray2);
+
+
+//// [objectFromEntries.js]
+const o = Object.fromEntries([['a', 1], ['b', 2], ['c', 3]]);
+const o2 = Object.fromEntries(new URLSearchParams());
+const o3 = Object.fromEntries(new Map([[Symbol("key"), "value"]]));
+const frozenArray = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+const o4 = Object.fromEntries(frozenArray);
+const frozenArray2 = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+const o5 = Object.fromEntries(frozenArray2);

tests/baselines/reference/objectFromEntries.symbols

@@ -0,0 +1,48 @@
+=== tests/cases/compiler/objectFromEntries.ts ===
+const o = Object.fromEntries([['a', 1], ['b', 2], ['c', 3]]);
+>o : Symbol(o, Decl(objectFromEntries.ts, 0, 5))
+>Object.fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+
+const o2 = Object.fromEntries(new URLSearchParams());
+>o2 : Symbol(o2, Decl(objectFromEntries.ts, 1, 5))
+>Object.fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>URLSearchParams : Symbol(URLSearchParams, Decl(lib.dom.d.ts, --, --), Decl(lib.dom.d.ts, --, --), Decl(lib.dom.d.ts, --, --), Decl(lib.dom.iterable.d.ts, --, --))
+
+const o3 = Object.fromEntries(new Map([[Symbol("key"), "value"]]));
+>o3 : Symbol(o3, Decl(objectFromEntries.ts, 2, 5))
+>Object.fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>Map : Symbol(Map, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+>Symbol : Symbol(Symbol, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2019.symbol.d.ts, --, --))
+
+const frozenArray = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+>frozenArray : Symbol(frozenArray, Decl(objectFromEntries.ts, 4, 5))
+>Object.freeze : Symbol(ObjectConstructor.freeze, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>freeze : Symbol(ObjectConstructor.freeze, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+
+const o4 = Object.fromEntries(frozenArray);
+>o4 : Symbol(o4, Decl(objectFromEntries.ts, 5, 5))
+>Object.fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>frozenArray : Symbol(frozenArray, Decl(objectFromEntries.ts, 4, 5))
+
+const frozenArray2: readonly [string, number][] = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+>frozenArray2 : Symbol(frozenArray2, Decl(objectFromEntries.ts, 7, 5))
+>Object.freeze : Symbol(ObjectConstructor.freeze, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>freeze : Symbol(ObjectConstructor.freeze, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+
+const o5 = Object.fromEntries(frozenArray2);
+>o5 : Symbol(o5, Decl(objectFromEntries.ts, 8, 5))
+>Object.fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>Object : Symbol(Object, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+>fromEntries : Symbol(ObjectConstructor.fromEntries, Decl(lib.es2019.object.d.ts, --, --), Decl(lib.es2019.object.d.ts, --, --))
+>frozenArray2 : Symbol(frozenArray2, Decl(objectFromEntries.ts, 7, 5))
+

tests/baselines/reference/objectFromEntries.types

@@ -0,0 +1,92 @@
+=== tests/cases/compiler/objectFromEntries.ts ===
+const o = Object.fromEntries([['a', 1], ['b', 2], ['c', 3]]);
+>o : { [x: string]: number; [x: number]: number; }
+>Object.fromEntries([['a', 1], ['b', 2], ['c', 3]]) : { [x: string]: number; [x: number]: number; }
+>Object.fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>Object : ObjectConstructor
+>fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>[['a', 1], ['b', 2], ['c', 3]] : [string, number][]
+>['a', 1] : [string, number]
+>'a' : "a"
+>1 : 1
+>['b', 2] : [string, number]
+>'b' : "b"
+>2 : 2
+>['c', 3] : [string, number]
+>'c' : "c"
+>3 : 3
+
+const o2 = Object.fromEntries(new URLSearchParams());
+>o2 : { [x: string]: string; [x: number]: string; }
+>Object.fromEntries(new URLSearchParams()) : { [x: string]: string; [x: number]: string; }
+>Object.fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>Object : ObjectConstructor
+>fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>new URLSearchParams() : URLSearchParams
+>URLSearchParams : { new (init?: string | URLSearchParams | string[][] | Record<string, string>): URLSearchParams; prototype: URLSearchParams; }
+
+const o3 = Object.fromEntries(new Map([[Symbol("key"), "value"]]));
+>o3 : { [x: string]: string; [x: number]: string; }
+>Object.fromEntries(new Map([[Symbol("key"), "value"]])) : { [x: string]: string; [x: number]: string; }
+>Object.fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>Object : ObjectConstructor
+>fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>new Map([[Symbol("key"), "value"]]) : Map<symbol, string>
+>Map : MapConstructor
+>[[Symbol("key"), "value"]] : [symbol, string][]
+>[Symbol("key"), "value"] : [symbol, string]
+>Symbol("key") : symbol
+>Symbol : SymbolConstructor
+>"key" : "key"
+>"value" : "value"
+
+const frozenArray = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+>frozenArray : readonly (string | number)[][]
+>Object.freeze([['a', 1], ['b', 2], ['c', 3]]) : readonly (string | number)[][]
+>Object.freeze : { <T>(a: T[]): readonly T[]; <T extends Function>(f: T): T; <T>(o: T): Readonly<T>; }
+>Object : ObjectConstructor
+>freeze : { <T>(a: T[]): readonly T[]; <T extends Function>(f: T): T; <T>(o: T): Readonly<T>; }
+>[['a', 1], ['b', 2], ['c', 3]] : (string | number)[][]
+>['a', 1] : (string | number)[]
+>'a' : "a"
+>1 : 1
+>['b', 2] : (string | number)[]
+>'b' : "b"
+>2 : 2
+>['c', 3] : (string | number)[]
+>'c' : "c"
+>3 : 3
+
+const o4 = Object.fromEntries(frozenArray);
+>o4 : any
+>Object.fromEntries(frozenArray) : any
+>Object.fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>Object : ObjectConstructor
+>fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>frozenArray : readonly (string | number)[][]
+
+const frozenArray2: readonly [string, number][] = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+>frozenArray2 : readonly [string, number][]
+>Object.freeze([['a', 1], ['b', 2], ['c', 3]]) : readonly [string, number][]
+>Object.freeze : { <T>(a: T[]): readonly T[]; <T extends Function>(f: T): T; <T>(o: T): Readonly<T>; }
+>Object : ObjectConstructor
+>freeze : { <T>(a: T[]): readonly T[]; <T extends Function>(f: T): T; <T>(o: T): Readonly<T>; }
+>[['a', 1], ['b', 2], ['c', 3]] : [string, number][]
+>['a', 1] : [string, number]
+>'a' : "a"
+>1 : 1
+>['b', 2] : [string, number]
+>'b' : "b"
+>2 : 2
+>['c', 3] : [string, number]
+>'c' : "c"
+>3 : 3
+
+const o5 = Object.fromEntries(frozenArray2);
+>o5 : { [x: string]: number; [x: number]: number; }
+>Object.fromEntries(frozenArray2) : { [x: string]: number; [x: number]: number; }
+>Object.fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>Object : ObjectConstructor
+>fromEntries : { <T = any>(entries: Iterable<readonly [string | number | symbol, T]>): { [x: string]: T; [x: number]: T; }; (entries: Iterable<readonly any[]>): any; }
+>frozenArray2 : readonly [string, number][]
+

tests/cases/compiler/objectFromEntries.ts

@@ -0,0 +1,11 @@
+// @target: es2019
+
+const o = Object.fromEntries([['a', 1], ['b', 2], ['c', 3]]);
+const o2 = Object.fromEntries(new URLSearchParams());
+const o3 = Object.fromEntries(new Map([[Symbol("key"), "value"]]));
+
+const frozenArray = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+const o4 = Object.fromEntries(frozenArray);
+
+const frozenArray2: readonly [string, number][] = Object.freeze([['a', 1], ['b', 2], ['c', 3]]);
+const o5 = Object.fromEntries(frozenArray2);