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LibJS: Implement proposed TypedArray.prototype.findLast{,Index}

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Proposal: https://tc39.es/proposal-array-find-from-last/
This commit is contained in:
davidot 2021-08-06 15:39:25 +02:00 • committed by Linus Groh
parent b6523906b3
commit 871a29884d
4 changed files with 302 additions and 0 deletions
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121
Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.findLast.js Normal file
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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.findLast).toHaveLength(1);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
expect(T.prototype.findLast).toHaveLength(1);
});
});
describe("errors", () => {
function errorTests(T) {
test(`requires at least one argument (${T.name})`, () => {
expect(() => {
new T().findLast();
}).toThrowWithMessage(
TypeError,
"TypedArray.prototype.findLast() requires at least one argument"
);
});
test(`callback must be a function (${T.name})`, () => {
expect(() => {
new T().findLast(undefined);
}).toThrowWithMessage(TypeError, "undefined is not a function");
});
}
TYPED_ARRAYS.forEach(T => errorTests(T));
BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
});
describe("normal behaviour", () => {
test("basic functionality", () => {
TYPED_ARRAYS.forEach(T => {
const typedArray = new T([1, 2, 3]);
expect(typedArray.findLast(value => value === 1)).toBe(1);
expect(typedArray.findLast(value => value === 2)).toBe(2);
expect(typedArray.findLast(value => value === 3)).toBe(3);
expect(typedArray.findLast((value, index) => index === 1)).toBe(2);
expect(typedArray.findLast(value => value == "1")).toBe(1);
expect(typedArray.findLast(value => value === 10)).toBeUndefined();
const typedArrayDuplicates = new T([2, 1, 2, 3, 1]);
expect(typedArrayDuplicates.findLast(value => value < 3)).toBe(1);
expect(typedArrayDuplicates.findLast(value => value < 2)).toBe(1);
expect(typedArrayDuplicates.findLast(value => value > 1)).toBe(3);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
const typedArray = new T([1n, 2n, 3n]);
expect(typedArray.findLast(value => value === 1n)).toBe(1n);
expect(typedArray.findLast(value => value === 2n)).toBe(2n);
expect(typedArray.findLast(value => value === 3n)).toBe(3n);
expect(typedArray.findLast((value, index) => index === 1)).toBe(2n);
expect(typedArray.findLast(value => value == 1)).toBe(1n);
expect(typedArray.findLast(value => value == "1")).toBe(1n);
expect(typedArray.findLast(value => value === 1)).toBeUndefined();
const typedArrayDuplicates = new T([2n, 1n, 2n, 3n, 1n]);
expect(typedArrayDuplicates.findLast(value => value < 3)).toBe(1n);
expect(typedArrayDuplicates.findLast(value => value < 2)).toBe(1n);
expect(typedArrayDuplicates.findLast(value => value > 1)).toBe(3n);
});
});
test("never calls callback with empty array", () => {
function emptyTest(T) {
var callbackCalled = 0;
expect(
new T().findLast(() => {
callbackCalled++;
})
).toBeUndefined();
expect(callbackCalled).toBe(0);
}
TYPED_ARRAYS.forEach(T => emptyTest(T));
BIGINT_TYPED_ARRAYS.forEach(T => emptyTest(T));
});
test("calls callback once for every item", () => {
TYPED_ARRAYS.forEach(T => {
var callbackCalled = 0;
expect(
new T([1, 2, 3]).findLast(() => {
callbackCalled++;
})
).toBeUndefined();
expect(callbackCalled).toBe(3);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
var callbackCalled = 0;
expect(
new T([1n, 2n, 3n]).findLast(() => {
callbackCalled++;
})
).toBeUndefined();
expect(callbackCalled).toBe(3);
});
});
});

121
Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.findLastIndex.js Normal file
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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.findLastIndex).toHaveLength(1);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
expect(T.prototype.findLastIndex).toHaveLength(1);
});
});
describe("errors", () => {
function errorTests(T) {
test(`requires at least one argument (${T.name})`, () => {
expect(() => {
new T().findLastIndex();
}).toThrowWithMessage(
TypeError,
"TypedArray.prototype.findLastIndex() requires at least one argument"
);
});
test(`callback must be a function (${T.name})`, () => {
expect(() => {
new T().findLastIndex(undefined);
}).toThrowWithMessage(TypeError, "undefined is not a function");
});
}
TYPED_ARRAYS.forEach(T => errorTests(T));
BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
});
describe("normal behaviour", () => {
test("basic functionality", () => {
TYPED_ARRAYS.forEach(T => {
const typedArray = new T([1, 2, 3]);
expect(typedArray.findLastIndex(value => value === 1)).toBe(0);
expect(typedArray.findLastIndex(value => value === 2)).toBe(1);
expect(typedArray.findLastIndex(value => value === 3)).toBe(2);
expect(typedArray.findLastIndex((value, index) => index === 1)).toBe(1);
expect(typedArray.findLastIndex(value => value == "1")).toBe(0);
expect(typedArray.findLastIndex(value => value === 10)).toBe(-1);
const typedArrayDuplicates = new T([1, 2, 3, 1]);
expect(typedArrayDuplicates.findLastIndex(value => value === 1)).toBe(3);
expect(typedArrayDuplicates.findLastIndex(value => value === 2)).toBe(1);
expect(typedArrayDuplicates.findLastIndex(value => value === 3)).toBe(2);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
const typedArray = new T([1n, 2n, 3n]);
expect(typedArray.findLastIndex(value => value === 1n)).toBe(0);
expect(typedArray.findLastIndex(value => value === 2n)).toBe(1);
expect(typedArray.findLastIndex(value => value === 3n)).toBe(2);
expect(typedArray.findLastIndex((value, index) => index === 1)).toBe(1);
expect(typedArray.findLastIndex(value => value == 1)).toBe(0);
expect(typedArray.findLastIndex(value => value == "1")).toBe(0);
expect(typedArray.findLastIndex(value => value === 1)).toBe(-1);
const typedArrayDuplicates = new T([1n, 2n, 3n, 1n]);
expect(typedArrayDuplicates.findLastIndex(value => value === 1n)).toBe(3);
expect(typedArrayDuplicates.findLastIndex(value => value === 2n)).toBe(1);
expect(typedArrayDuplicates.findLastIndex(value => value === 3n)).toBe(2);
});
});
test("never calls callback with empty array", () => {
function emptyTest(T) {
var callbackCalled = 0;
expect(
new T().findLastIndex(() => {
callbackCalled++;
})
).toBe(-1);
expect(callbackCalled).toBe(0);
}
TYPED_ARRAYS.forEach(T => emptyTest(T));
BIGINT_TYPED_ARRAYS.forEach(T => emptyTest(T));
});
test("calls callback once for every item", () => {
TYPED_ARRAYS.forEach(T => {
var callbackCalled = 0;
expect(
new T([1, 2, 3]).findLastIndex(() => {
callbackCalled++;
})
).toBe(-1);
expect(callbackCalled).toBe(3);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
var callbackCalled = 0;
expect(
new T([1n, 2n, 3n]).findLastIndex(() => {
callbackCalled++;
})
).toBe(-1);
expect(callbackCalled).toBe(3);
});
});
});