add types for set methods proposal

src/lib/esnext.collection.d.ts

@@ -9,3 +9,49 @@ interface MapConstructor {
         keySelector: (item: T, index: number) => K,
     ): Map<K, T[]>;
 }
+
+interface SetLike<T> {
+    /**
+     * Despite its name, returns an iterable of the values in the set-like.
+     */
+    keys(): Iterable<T>;
+    /**
+     * @returns a boolean indicating whether an element with the specified value exists in the set-like or not.
+     */
+    has(value: T): boolean;
+    /**
+     * @returns the number of (unique) elements in the set-like.
+     */
+    readonly size: number;
+}
+
+interface Set<T> {
+    /**
+     * @returns a new Set containing all the elements in this Set and also all the elements in the argument.
+     */
+    union(other: SetLike<T>): Set<T>;
+    /**
+     * @returns a new Set containing all the elements which are both in this Set and in the argument.
+     */
+    intersection(other: SetLike<T>): Set<T>;
+    /**
+     * @returns a new Set containing all the elements in this Set which are not also in the argument.
+     */
+    difference(other: SetLike<T>): Set<T>;
+    /**
+     * @returns a new Set containing all the elements in this Set which are in this or in the argument, but not in both.
+     */
+    symmetricDifference(other: SetLike<T>): Set<T>;
+    /**
+     * @returns a boolean indicating whether all the elements in this Set are also in the argument.
+     */
+    isSubsetOf(other: SetLike<T>): Set<T>;
+    /**
+     * @returns a boolean indicating whether all the elements in the argument are also in this Set.
+     */
+    isSupersetOf(other: SetLike<T>): Set<T>;
+    /**
+     * @returns a boolean indicating whether this Set has no elements in common with the argument.
+     */
+    isDisjointFrom(other: SetLike<T>): Set<T>;
+}

tests/baselines/reference/setMethods.errors.txt

@@ -0,0 +1,111 @@
+setMethods.ts(13,17): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+  Type 'undefined[]' is missing the following properties from type 'SetLike<number>': has, size
+setMethods.ts(15,17): error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+  The types returned by 'keys()[Symbol.iterator]().next(...)' are incompatible between these types.
+    Type 'IteratorResult<string, any>' is not assignable to type 'IteratorResult<number, any>'.
+      Type 'IteratorYieldResult<string>' is not assignable to type 'IteratorResult<number, any>'.
+        Type 'IteratorYieldResult<string>' is not assignable to type 'IteratorYieldResult<number>'.
+          Type 'string' is not assignable to type 'number'.
+setMethods.ts(19,24): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(21,24): error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(25,22): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(27,22): error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(31,31): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(33,31): error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(37,22): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(39,22): error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(43,24): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(45,24): error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(49,26): error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+setMethods.ts(51,26): error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+
+
+==== setMethods.ts (14 errors) ====
+    let numberSet = new Set([0, 1, 2]);
+
+    let stringSet = new Set(["a", "b"]);
+
+    let numberMap = new Map([[4, {}], [5, {}]]);
+
+    let numberSetLike = {
+      size: 1,
+      *keys() { yield 3 },
+      has(x) { return x === 3 },
+    };
+
+    numberSet.union([]);
+                    ~~
+!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+!!! error TS2345:   Type 'undefined[]' is missing the following properties from type 'SetLike<number>': has, size
+    numberSet.union(new Set);
+    numberSet.union(stringSet);
+                    ~~~~~~~~~
+!!! error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+!!! error TS2345:   The types returned by 'keys()[Symbol.iterator]().next(...)' are incompatible between these types.
+!!! error TS2345:     Type 'IteratorResult<string, any>' is not assignable to type 'IteratorResult<number, any>'.
+!!! error TS2345:       Type 'IteratorYieldResult<string>' is not assignable to type 'IteratorResult<number, any>'.
+!!! error TS2345:         Type 'IteratorYieldResult<string>' is not assignable to type 'IteratorYieldResult<number>'.
+!!! error TS2345:           Type 'string' is not assignable to type 'number'.
+    numberSet.union(numberMap);
+    numberSet.union(numberSetLike);
+
+    numberSet.intersection([]);
+                           ~~
+!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.intersection(new Set);
+    numberSet.intersection(stringSet);
+                           ~~~~~~~~~
+!!! error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.intersection(numberMap);
+    numberSet.intersection(numberSetLike);
+
+    numberSet.difference([]);
+                         ~~
+!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.difference(new Set);
+    numberSet.difference(stringSet);
+                         ~~~~~~~~~
+!!! error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.difference(numberMap);
+    numberSet.difference(numberSetLike);
+
+    numberSet.symmetricDifference([]);
+                                  ~~
+!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.symmetricDifference(new Set);
+    numberSet.symmetricDifference(stringSet);
+                                  ~~~~~~~~~
+!!! error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.symmetricDifference(numberMap);
+    numberSet.symmetricDifference(numberSetLike);
+
+    numberSet.isSubsetOf([]);
+                         ~~
+!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.isSubsetOf(new Set);
+    numberSet.isSubsetOf(stringSet);
+                         ~~~~~~~~~
+!!! error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.isSubsetOf(numberMap);
+    numberSet.isSubsetOf(numberSetLike);
+
+    numberSet.isSupersetOf([]);
+                           ~~
+!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.isSupersetOf(new Set);
+    numberSet.isSupersetOf(stringSet);
+                           ~~~~~~~~~
+!!! error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.isSupersetOf(numberMap);
+    numberSet.isSupersetOf(numberSetLike);
+
+    numberSet.isDisjointFrom([]);
+                             ~~
+!!! error TS2345: Argument of type 'undefined[]' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.isDisjointFrom(new Set);
+    numberSet.isDisjointFrom(stringSet);
+                             ~~~~~~~~~
+!!! error TS2345: Argument of type 'Set<string>' is not assignable to parameter of type 'SetLike<number>'.
+    numberSet.isDisjointFrom(numberMap);
+    numberSet.isDisjointFrom(numberSetLike);
+

tests/baselines/reference/setMethods.js

@@ -0,0 +1,102 @@
+//// [tests/cases/compiler/setMethods.ts] ////
+
+//// [setMethods.ts]
+let numberSet = new Set([0, 1, 2]);
+
+let stringSet = new Set(["a", "b"]);
+
+let numberMap = new Map([[4, {}], [5, {}]]);
+
+let numberSetLike = {
+  size: 1,
+  *keys() { yield 3 },
+  has(x) { return x === 3 },
+};
+
+numberSet.union([]);
+numberSet.union(new Set);
+numberSet.union(stringSet);
+numberSet.union(numberMap);
+numberSet.union(numberSetLike);
+
+numberSet.intersection([]);
+numberSet.intersection(new Set);
+numberSet.intersection(stringSet);
+numberSet.intersection(numberMap);
+numberSet.intersection(numberSetLike);
+
+numberSet.difference([]);
+numberSet.difference(new Set);
+numberSet.difference(stringSet);
+numberSet.difference(numberMap);
+numberSet.difference(numberSetLike);
+
+numberSet.symmetricDifference([]);
+numberSet.symmetricDifference(new Set);
+numberSet.symmetricDifference(stringSet);
+numberSet.symmetricDifference(numberMap);
+numberSet.symmetricDifference(numberSetLike);
+
+numberSet.isSubsetOf([]);
+numberSet.isSubsetOf(new Set);
+numberSet.isSubsetOf(stringSet);
+numberSet.isSubsetOf(numberMap);
+numberSet.isSubsetOf(numberSetLike);
+
+numberSet.isSupersetOf([]);
+numberSet.isSupersetOf(new Set);
+numberSet.isSupersetOf(stringSet);
+numberSet.isSupersetOf(numberMap);
+numberSet.isSupersetOf(numberSetLike);
+
+numberSet.isDisjointFrom([]);
+numberSet.isDisjointFrom(new Set);
+numberSet.isDisjointFrom(stringSet);
+numberSet.isDisjointFrom(numberMap);
+numberSet.isDisjointFrom(numberSetLike);
+
+
+//// [setMethods.js]
+let numberSet = new Set([0, 1, 2]);
+let stringSet = new Set(["a", "b"]);
+let numberMap = new Map([[4, {}], [5, {}]]);
+let numberSetLike = {
+    size: 1,
+    *keys() { yield 3; },
+    has(x) { return x === 3; },
+};
+numberSet.union([]);
+numberSet.union(new Set);
+numberSet.union(stringSet);
+numberSet.union(numberMap);
+numberSet.union(numberSetLike);
+numberSet.intersection([]);
+numberSet.intersection(new Set);
+numberSet.intersection(stringSet);
+numberSet.intersection(numberMap);
+numberSet.intersection(numberSetLike);
+numberSet.difference([]);
+numberSet.difference(new Set);
+numberSet.difference(stringSet);
+numberSet.difference(numberMap);
+numberSet.difference(numberSetLike);
+numberSet.symmetricDifference([]);
+numberSet.symmetricDifference(new Set);
+numberSet.symmetricDifference(stringSet);
+numberSet.symmetricDifference(numberMap);
+numberSet.symmetricDifference(numberSetLike);
+numberSet.isSubsetOf([]);
+numberSet.isSubsetOf(new Set);
+numberSet.isSubsetOf(stringSet);
+numberSet.isSubsetOf(numberMap);
+numberSet.isSubsetOf(numberSetLike);
+numberSet.isSupersetOf([]);
+numberSet.isSupersetOf(new Set);
+numberSet.isSupersetOf(stringSet);
+numberSet.isSupersetOf(numberMap);
+numberSet.isSupersetOf(numberSetLike);
+numberSet.isDisjointFrom([]);
+numberSet.isDisjointFrom(new Set);
+numberSet.isDisjointFrom(stringSet);
+numberSet.isDisjointFrom(numberMap);
+numberSet.isDisjointFrom(numberSetLike);