LibJS: Add %TypedArray%.prototype.map

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.map.js

@@ -0,0 +1,259 @@
+const TYPED_ARRAYS = [
+    Uint8Array,
+    Uint8ClampedArray,
+    Uint16Array,
+    Uint32Array,
+    Int8Array,
+    Int16Array,
+    Int32Array,
+    Float32Array,
+    Float64Array,
+];
+
+const BIGINT_TYPED_ARRAYS = [BigUint64Array, BigInt64Array];
+
+test("length is 1", () => {
+    TYPED_ARRAYS.forEach(T => {
+        expect(T.prototype.map).toHaveLength(1);
+    });
+
+    BIGINT_TYPED_ARRAYS.forEach(T => {
+        expect(T.prototype.map).toHaveLength(1);
+    });
+});
+
+describe("errors", () => {
+    function argumentErrorTests(T) {
+        test(`requires at least one argument (${T.name})`, () => {
+            expect(() => {
+                new T().map();
+            }).toThrowWithMessage(
+                TypeError,
+                "TypedArray.prototype.map() requires at least one argument"
+            );
+        });
+
+        test(`callback must be a function (${T.name})`, () => {
+            expect(() => {
+                new T().map(undefined);
+            }).toThrowWithMessage(TypeError, "undefined is not a function");
+        });
+    }
+
+    TYPED_ARRAYS.forEach(T => argumentErrorTests(T));
+    BIGINT_TYPED_ARRAYS.forEach(T => argumentErrorTests(T));
+
+    test("throws if mappedValue is not the same type of the typed array", () => {
+        TYPED_ARRAYS.forEach(T => {
+            let callbackCalled = 0;
+            let result;
+
+            expect(() => {
+                result = new T([1, 2, 3]).map((value, index) => {
+                    callbackCalled++;
+                    return index % 2 === 0 ? 1n : 1;
+                });
+            }).toThrowWithMessage(TypeError, "Cannot convert BigInt to number");
+
+            expect(callbackCalled).toBe(1);
+            expect(result).toBeUndefined();
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            let callbackCalled = 0;
+            let result;
+
+            expect(() => {
+                result = new T([1n, 2n, 3n]).map((value, index) => {
+                    callbackCalled++;
+                    return index % 2 === 0 ? 1 : 1n;
+                });
+            }).toThrowWithMessage(TypeError, "Cannot convert number to BigInt");
+
+            expect(callbackCalled).toBe(1);
+            expect(result).toBeUndefined();
+        });
+    });
+
+    test("Symbol.species returns a typed array with a different content type", () => {
+        TYPED_ARRAYS.forEach(T => {
+            class TypedArray extends T {
+                static get [Symbol.species]() {
+                    return BigUint64Array;
+                }
+            }
+
+            let result;
+
+            expect(() => {
+                result = new TypedArray().map(() => {});
+            }).toThrowWithMessage(TypeError, `Can't create BigUint64Array from ${T.name}`);
+
+            expect(result).toBeUndefined();
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            class TypedArray extends T {
+                static get [Symbol.species]() {
+                    return Uint32Array;
+                }
+            }
+
+            let result;
+
+            expect(() => {
+                result = new TypedArray().map(() => {});
+            }).toThrowWithMessage(TypeError, `Can't create Uint32Array from ${T.name}`);
+
+            expect(result).toBeUndefined();
+        });
+    });
+
+    test("Symbol.species doesn't return a typed array", () => {
+        TYPED_ARRAYS.forEach(T => {
+            class TypedArray extends T {
+                static get [Symbol.species]() {
+                    return Array;
+                }
+            }
+
+            let result;
+
+            expect(() => {
+                result = new TypedArray().map(() => {});
+            }).toThrowWithMessage(TypeError, "Not a TypedArray object");
+
+            expect(result).toBeUndefined();
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            class TypedArray extends T {
+                static get [Symbol.species]() {
+                    return Array;
+                }
+            }
+
+            let result;
+
+            expect(() => {
+                result = new TypedArray().map(() => {});
+            }).toThrowWithMessage(TypeError, "Not a TypedArray object");
+
+            expect(result).toBeUndefined();
+        });
+    });
+});
+
+describe("normal behaviour", () => {
+    test("never calls callback with empty array", () => {
+        TYPED_ARRAYS.forEach(T => {
+            let callbackCalled = 0;
+            expect(
+                new T([]).map(() => {
+                    callbackCalled++;
+                })
+            ).toHaveLength(0);
+            expect(callbackCalled).toBe(0);
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            let callbackCalled = 0;
+            expect(
+                new T([]).map(() => {
+                    callbackCalled++;
+                })
+            ).toHaveLength(0);
+            expect(callbackCalled).toBe(0);
+        });
+    });
+
+    test("calls callback once for every item", () => {
+        TYPED_ARRAYS.forEach(T => {
+            let callbackCalled = 0;
+            expect(
+                new T([1, 2, 3]).map(value => {
+                    callbackCalled++;
+                    // NOTE: This is just to prevent a conversion exception.
+                    return value;
+                })
+            ).toHaveLength(3);
+            expect(callbackCalled).toBe(3);
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            let callbackCalled = 0;
+            expect(
+                new T([1n, 2n, 3n]).map(value => {
+                    callbackCalled++;
+                    // NOTE: This is just to prevent a conversion exception.
+                    return value;
+                })
+            ).toHaveLength(3);
+            expect(callbackCalled).toBe(3);
+        });
+    });
+
+    test("can map based on callback return value", () => {
+        TYPED_ARRAYS.forEach(T => {
+            const squaredNumbers = new T([0, 1, 2, 3, 4]).map(x => x ** 2);
+            expect(squaredNumbers).toHaveLength(5);
+            expect(squaredNumbers[0]).toBe(0);
+            expect(squaredNumbers[1]).toBe(1);
+            expect(squaredNumbers[2]).toBe(4);
+            expect(squaredNumbers[3]).toBe(9);
+            expect(squaredNumbers[4]).toBe(16);
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            const squaredNumbers = new T([0n, 1n, 2n, 3n, 4n]).map(x => x ** 2n);
+            expect(squaredNumbers).toHaveLength(5);
+            expect(squaredNumbers[0]).toBe(0n);
+            expect(squaredNumbers[1]).toBe(1n);
+            expect(squaredNumbers[2]).toBe(4n);
+            expect(squaredNumbers[3]).toBe(9n);
+            expect(squaredNumbers[4]).toBe(16n);
+        });
+    });
+
+    test("Symbol.species returns a typed array with a matching content type", () => {
+        TYPED_ARRAYS.forEach(T => {
+            class TypedArray extends T {
+                static get [Symbol.species]() {
+                    return Uint32Array;
+                }
+            }
+
+            let result;
+
+            expect(() => {
+                result = new TypedArray([1, 2, 3]).map(value => value + 2);
+            }).not.toThrowWithMessage(TypeError, `Can't create Uint32Array from ${T.name}`);
+
+            expect(result).toBeInstanceOf(Uint32Array);
+            expect(result).toHaveLength(3);
+            expect(result[0]).toBe(3);
+            expect(result[1]).toBe(4);
+            expect(result[2]).toBe(5);
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            class TypedArray extends T {
+                static get [Symbol.species]() {
+                    return BigUint64Array;
+                }
+            }
+
+            let result;
+
+            expect(() => {
+                result = new TypedArray([1n, 2n, 3n]).map(value => value + 2n);
+            }).not.toThrowWithMessage(TypeError, `Can't create BigUint64Array from ${T.name}`);
+
+            expect(result).toBeInstanceOf(BigUint64Array);
+            expect(result).toHaveLength(3);
+            expect(result[0]).toBe(3n);
+            expect(result[1]).toBe(4n);
+            expect(result[2]).toBe(5n);
+        });
+    });
+});