lodash-es#matches TypeScript Examples
The following examples show how to use
lodash-es#matches.
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Example #1
| Source File: find.spec.ts From s-libs with MIT License | 4 votes |
|
describe('find()', () => {
it('has fancy typing for arrays', () => {
expect().nothing();
type A = Array<number | string>;
const a = [1, 'b'] as A;
const aOrU = a as A | undefined;
const aOrN = a as A | null;
expectTypeOf(find(a, () => true)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(a, () => true, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(aOrU, () => true)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(aOrU, () => true, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(aOrN, () => true)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(aOrN, () => true, 1)).toEqualTypeOf<
number | string | undefined
>();
// Narrowing
expectTypeOf(find(a, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(a, isString, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(aOrU, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(aOrU, isString, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(aOrN, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(aOrN, isString, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(a, isDateOrString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(a, isDateOrString, 1)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(aOrU, isDateOrString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(aOrU, isDateOrString, 1)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(aOrN, isDateOrString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(aOrN, isDateOrString, 1)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(a, isA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(aOrU, isA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(aOrN, isA)).toEqualTypeOf<'a' | undefined>();
type AB = Array<'a' | 'b'>;
const ab = ['a'] as AB;
const abOrU = ['a'] as AB | undefined;
const abOrN = ['a'] as AB | null;
expectTypeOf(find(ab, isA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(abOrU, isA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(abOrN, isA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(ab, isString)).toEqualTypeOf<'a' | 'b' | undefined>();
expectTypeOf(find(abOrU, isString)).toEqualTypeOf<'a' | 'b' | undefined>();
expectTypeOf(find(abOrN, isString)).toEqualTypeOf<'a' | 'b' | undefined>();
type AN = Array<number | 'a'>;
const an = ['a'] as AN;
const anOrN = ['a'] as AN | null;
const anOrU = ['a'] as AN | undefined;
expectTypeOf(find(an, isStringOr2)).toEqualTypeOf<'a' | 2 | undefined>();
expectTypeOf(find(anOrU, isStringOr2)).toEqualTypeOf<'a' | 2 | undefined>();
expectTypeOf(find(anOrN, isStringOr2)).toEqualTypeOf<'a' | 2 | undefined>();
});
it('has fancy typing for objects', () => {
expect().nothing();
interface O {
a: number;
2: string;
c: Date | Document;
}
const o = { a: 1, 2: 'b', c: document } as O;
const oOrU = o as O | undefined;
const oOrN = o as O | null;
expectTypeOf(find(o, () => true)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(o, () => true, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrU, () => true)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrU, () => true, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrN, () => true)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrN, () => true, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
// Value narrowing
expectTypeOf(find(o, isString)).toEqualTypeOf<string>();
expectTypeOf(find(o, isString, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(o, isString, 1 as number | undefined)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(oOrU, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrU, isString, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrN, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrN, isString, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(o, isDate)).toEqualTypeOf<Date | undefined>();
expectTypeOf(find(o, isDate, 1)).toEqualTypeOf<Date | undefined>();
expectTypeOf(find(oOrU, isDate)).toEqualTypeOf<Date | undefined>();
expectTypeOf(find(oOrU, isDate, 1)).toEqualTypeOf<Date | undefined>();
expectTypeOf(find(oOrN, isDate)).toEqualTypeOf<Date | undefined>();
expectTypeOf(find(oOrN, isDate, 1)).toEqualTypeOf<Date | undefined>();
expectTypeOf(find(o, isNumberOrString)).toEqualTypeOf<number | string>();
expectTypeOf(find(o, isNumberOrString, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrU, isNumberOrString)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrU, isNumberOrString, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrN, isNumberOrString)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrN, isNumberOrString, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(o, isDateOrString)).toEqualTypeOf<Date | string>();
expectTypeOf(find(o, isDateOrString, 1)).toEqualTypeOf<
Date | string | undefined
>();
expectTypeOf(find(oOrU, isDateOrString)).toEqualTypeOf<
Date | string | undefined
>();
expectTypeOf(find(oOrU, isDateOrString, 1)).toEqualTypeOf<
Date | string | undefined
>();
expectTypeOf(find(oOrN, isDateOrString)).toEqualTypeOf<
Date | string | undefined
>();
expectTypeOf(find(oOrN, isDateOrString, 1)).toEqualTypeOf<
Date | string | undefined
>();
expectTypeOf(find(o, isMap)).toEqualTypeOf<undefined>();
expectTypeOf(find(o, isMap, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(oOrU, isMap)).toEqualTypeOf<undefined>();
expectTypeOf(find(oOrU, isMap, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(oOrN, isMap)).toEqualTypeOf<undefined>();
expectTypeOf(find(oOrN, isMap, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(o, isMapOrString)).toEqualTypeOf<string>();
expectTypeOf(find(o, isMapOrString, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(o, isMapOrString, 1 as number | undefined)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(oOrU, isMapOrString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrU, isMapOrString, 1)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(oOrN, isMapOrString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrN, isMapOrString, 1)).toEqualTypeOf<
string | undefined
>();
interface S2 {
a: number | 'a';
}
const s2 = { a: 2 } as S2;
const s2OrU = { a: 2 } as S2 | undefined;
const s2OrN = { a: 2 } as S2 | null;
expectTypeOf(find(s2, isA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(s2, isA, 1)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(s2OrU, isA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(s2OrU, isA, 1)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(s2OrN, isA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(s2OrN, isA, 1)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(find(s2, isStringOr2)).toEqualTypeOf<'a' | 2 | undefined>();
expectTypeOf(find(s2, isStringOr2, 1)).toEqualTypeOf<'a' | 2 | undefined>();
expectTypeOf(find(s2OrU, isStringOr2)).toEqualTypeOf<'a' | 2 | undefined>();
expectTypeOf(find(s2OrU, isStringOr2, 1)).toEqualTypeOf<
'a' | 2 | undefined
>();
expectTypeOf(find(s2OrN, isStringOr2)).toEqualTypeOf<'a' | 2 | undefined>();
expectTypeOf(find(s2OrN, isStringOr2, 1)).toEqualTypeOf<
'a' | 2 | undefined
>();
// Key narrowing
interface S {
a: number;
b: string;
c: Date | Document;
}
const s = { a: 1, b: '2', c: document } as S;
const sOrU = s as S | undefined;
const sOrN = s as S | null;
expectTypeOf(find(s, keyIsString)).toEqualTypeOf<
Date | Document | number | string
>();
expectTypeOf(find(s, keyIsString, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(sOrU, keyIsString)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(sOrU, keyIsString, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(sOrN, keyIsString)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(sOrN, keyIsString, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(o, keyIsString)).toEqualTypeOf<
Date | Document | number | string
>();
expectTypeOf(find(o, keyIsString, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrU, keyIsString)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrU, keyIsString, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrN, keyIsString)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrN, keyIsString, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(s, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(find(s, keyIsNumber, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrU, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrU, keyIsNumber, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrN, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrN, keyIsNumber, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(o, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(find(o, keyIsNumber, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(oOrU, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(find(oOrU, keyIsNumber, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(oOrN, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(find(oOrN, keyIsNumber, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(s, keyIsA)).toEqualTypeOf<number>();
expectTypeOf(find(s, keyIsA, 1)).toEqualTypeOf<number | undefined>();
expectTypeOf(find(sOrU, keyIsA)).toEqualTypeOf<number | undefined>();
expectTypeOf(find(sOrU, keyIsA, 1)).toEqualTypeOf<number | undefined>();
expectTypeOf(find(sOrN, keyIsA)).toEqualTypeOf<number | undefined>();
expectTypeOf(find(sOrN, keyIsA, 1)).toEqualTypeOf<number | undefined>();
expectTypeOf(find(o, keyIsA)).toEqualTypeOf<number | string>();
expectTypeOf(find(o, keyIsA, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrU, keyIsA)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrU, keyIsA, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrN, keyIsA)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrN, keyIsA, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(s, keyIsString2)).toEqualTypeOf<undefined>();
expectTypeOf(find(s, keyIsString2, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrU, keyIsString2)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrU, keyIsString2, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrN, keyIsString2)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrN, keyIsString2, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(o, keyIsString2)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(o, keyIsString2, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrU, keyIsString2)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrU, keyIsString2, 1)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(oOrN, keyIsString2)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrN, keyIsString2, 1)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(s, keyIsString3)).toEqualTypeOf<undefined>();
expectTypeOf(find(s, keyIsString3, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrU, keyIsString3)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrU, keyIsString3, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrN, keyIsString3)).toEqualTypeOf<undefined>();
expectTypeOf(find(sOrN, keyIsString3, 1)).toEqualTypeOf<undefined>();
expectTypeOf(find(o, keyIsString3)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(o, keyIsString3, 1)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrU, keyIsString3)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrU, keyIsString3, 1)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(oOrN, keyIsString3)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(oOrN, keyIsString3, 1)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(find(s, keyIsC)).toEqualTypeOf<Date | Document>();
expectTypeOf(find(s, keyIsC, 1)).toEqualTypeOf<
Date | Document | undefined
>();
expectTypeOf(find(sOrU, keyIsC)).toEqualTypeOf<
Date | Document | undefined
>();
expectTypeOf(find(sOrU, keyIsC, 1)).toEqualTypeOf<
Date | Document | undefined
>();
expectTypeOf(find(sOrN, keyIsC)).toEqualTypeOf<
Date | Document | undefined
>();
expectTypeOf(find(sOrN, keyIsC, 1)).toEqualTypeOf<
Date | Document | undefined
>();
expectTypeOf(find(o, keyIsC)).toEqualTypeOf<Date | Document | string>();
expectTypeOf(find(o, keyIsC, 1)).toEqualTypeOf<
Date | Document | string | undefined
>();
expectTypeOf(find(oOrU, keyIsC)).toEqualTypeOf<
Date | Document | string | undefined
>();
expectTypeOf(find(oOrU, keyIsC, 1)).toEqualTypeOf<
Date | Document | string | undefined
>();
expectTypeOf(find(oOrN, keyIsC)).toEqualTypeOf<
Date | Document | string | undefined
>();
expectTypeOf(find(oOrN, keyIsC, 1)).toEqualTypeOf<
Date | Document | string | undefined
>();
expectTypeOf(find(s, keyIsAorC)).toEqualTypeOf<Date | Document | number>();
expectTypeOf(find(s, keyIsAorC, 1)).toEqualTypeOf<
Date | Document | number | undefined
>();
expectTypeOf(find(sOrU, keyIsAorC)).toEqualTypeOf<
Date | Document | number | undefined
>();
expectTypeOf(find(sOrU, keyIsAorC, 1)).toEqualTypeOf<
Date | Document | number | undefined
>();
expectTypeOf(find(sOrN, keyIsAorC)).toEqualTypeOf<
Date | Document | number | undefined
>();
expectTypeOf(find(sOrN, keyIsAorC, 1)).toEqualTypeOf<
Date | Document | number | undefined
>();
expectTypeOf(find(o, keyIsAorC)).toEqualTypeOf<
Date | Document | number | string
>();
expectTypeOf(find(o, keyIsAorC, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrU, keyIsAorC)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrU, keyIsAorC, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrN, keyIsAorC)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(oOrN, keyIsAorC, 1)).toEqualTypeOf<
Date | Document | number | string | undefined
>();
expectTypeOf(find(s, keyIsAorNumber)).toEqualTypeOf<number>();
expectTypeOf(find(s, keyIsAorNumber, 1)).toEqualTypeOf<
number | undefined
>();
expectTypeOf(find(sOrU, keyIsAorNumber)).toEqualTypeOf<
number | undefined
>();
expectTypeOf(find(sOrU, keyIsAorNumber, 1)).toEqualTypeOf<
number | undefined
>();
expectTypeOf(find(sOrN, keyIsAorNumber)).toEqualTypeOf<
number | undefined
>();
expectTypeOf(find(sOrN, keyIsAorNumber, 1)).toEqualTypeOf<
number | undefined
>();
expectTypeOf(find(o, keyIsAorNumber)).toEqualTypeOf<number | string>();
expectTypeOf(find(o, keyIsAorNumber, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrU, keyIsAorNumber)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrU, keyIsAorNumber, 1)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrN, keyIsAorNumber)).toEqualTypeOf<
number | string | undefined
>();
expectTypeOf(find(oOrN, keyIsAorNumber, 1)).toEqualTypeOf<
number | string | undefined
>();
const so = {} as Record<string, number | string>;
expectTypeOf(find(so, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(so, isNumber)).toEqualTypeOf<number | undefined>();
expectTypeOf(find(so, isDate)).toEqualTypeOf<undefined>();
expectTypeOf(find(so, isDateOrString)).toEqualTypeOf<string | undefined>();
expectTypeOf(find(so, keyIsString)).toEqualTypeOf<number | string>();
expectTypeOf(find(so, keyIsA)).toEqualTypeOf<number | string | undefined>();
expectTypeOf(find(so, keyIsNumber)).toEqualTypeOf<undefined>();
});
//
// stolen from https://github.com/lodash/lodash
//
const objects = [
{ a: 0, b: 0 },
{ a: 1, b: 1 },
{ a: 2, b: 2 },
];
it('should return the found value', () => {
expect(find(objects, (object) => !!object.a)).toBe(objects[1]);
});
it('should return `undefined` if value is not found', () => {
expect(find(objects, (object) => object.a === 3)).toBe(undefined);
});
it('should return `undefined` for empty collections', () => {
expect(find({}, matches({ a: 3 }))).toBe(undefined);
expect(find([], matches({ a: 3 }))).toBe(undefined);
expect(find(false, matches({ a: 3 }))).toBe(undefined);
expect(find(0, matches({ a: 3 }))).toBe(undefined);
expect(find('', matches({ a: 3 }))).toBe(undefined);
expect(find(null, matches({ a: 3 }))).toBe(undefined);
expect(find(undefined, matches({ a: 3 }))).toBe(undefined);
expect(find(NaN, matches({ a: 3 }))).toBe(undefined);
});
it('should provide correct `predicate` arguments for arrays', () => {
const spy = jasmine.createSpy();
find(['a'], spy);
expect(spy).toHaveBeenCalledTimes(1);
expect(spy).toHaveBeenCalledWith('a', 0);
});
it('should work with an object for `collection`', () => {
expect(find({ a: 1, b: 2, c: 3 }, (n) => n < 3)).toBe(1);
});
it('should provide correct `predicate` arguments for objects', () => {
const spy = jasmine.createSpy();
find({ a: 1 }, spy);
expectSingleCallAndReset(spy, 1, 'a');
});
it('should work with an array and a positive `fromIndex`', () => {
const array = [1, 2, 3];
expect(find(array, (n) => n === 3, 2)).toBe(3);
expect(find(array, (n) => n === 2, 2)).toBe(undefined);
});
it('should work with an array and a `fromIndex` >= `length`', () => {
const array = [1, 2, 3];
for (const key of [1, undefined, '']) {
for (const fromIndex of [4, 6, 2 ** 32, Infinity]) {
expect(find(array, (n) => Object.is(n, key), fromIndex)).toBe(
undefined,
);
}
}
});
it('should work with an array and coerce `fromIndex` to an integer', () => {
const array = [1, 2, 3];
expect(find(array, (n) => n === 1, 0.1)).toBe(1);
expect(find(array, (n) => n === 1, NaN)).toBe(1);
});
it('should work with an array and a negative `fromIndex`', () => {
const array = [1, 2, 3];
expect(find(array, (n) => n === 3, -1)).toBe(3);
expect(find(array, (n) => n === 2, -1)).toBe(undefined);
});
it('should work with an array and a negative `fromIndex` <= `-length`', () => {
const array = [1, 2, 3];
for (const fromIndex of [-4, -6, -Infinity]) {
expect(find(array, (n) => n === 1, fromIndex)).toBe(1);
}
});
it('should provide correct iteratee arguments', () => {
const spy = jasmine.createSpy();
find([1, 2, 3], spy);
expect(spy.calls.first().args).toEqual([1, 0]);
});
it('should treat sparse arrays as dense', () => {
const array = [1];
array[2] = 3;
const spy = jasmine.createSpy();
find(array, spy);
expectCallsAndReset(spy, [1, 0], [undefined, 1], [3, 2]);
});
it('should not iterate custom properties of arrays', () => {
const array = [1];
(array as any).a = 1;
const spy = jasmine.createSpy();
find(array, spy);
expectCallsAndReset(spy, [1, 0]);
});
it('iterates over own string keyed properties of objects', () => {
const object = { a: 1 };
const spy = jasmine.createSpy();
find(object, spy);
expectCallsAndReset(spy, [1, 'a']);
});
it('should ignore changes to `length`', () => {
const array = [1];
const spy = jasmine.createSpy().and.callFake(() => {
array.push(2);
return false;
});
find(array, spy);
expect(spy).toHaveBeenCalledTimes(1);
});
it('should ignore added `object` properties', () => {
const object: any = { a: 1 };
const spy = jasmine.createSpy().and.callFake(() => {
object.b = 2;
return false;
});
find(object, spy);
expect(spy).toHaveBeenCalledTimes(1);
});
});
Example #2
| Source File: find-key.spec.ts From s-libs with MIT License | 4 votes |
|
describe('findKey()', () => {
it('has fancy typing', () => {
expect().nothing();
//
// Array
//
type A = Array<number | string>;
const a = [1, 'b'] as A;
const aOrU = a as A | undefined;
const aOrN = a as A | null;
expectTypeOf(findKey(a, () => true)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(aOrU, () => true)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(aOrN, () => true)).toEqualTypeOf<string | undefined>();
//
// Object
//
interface O {
a: number;
2: string;
c: Date | Document;
}
const o = { a: 1, 2: 'b', c: document } as O;
const oOrU = o as O | undefined;
const oOrN = o as O | null;
interface S {
a: number;
b: string;
c: Date | Document;
}
const s = { a: 1, b: '2', c: document } as S;
const sOrU = s as S | undefined;
const sOrN = s as S | null;
expectTypeOf(findKey(o, () => true)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(oOrU, () => true)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(oOrN, () => true)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(s, () => true)).toEqualTypeOf<
'a' | 'b' | 'c' | undefined
>();
expectTypeOf(findKey(sOrU, () => true)).toEqualTypeOf<
'a' | 'b' | 'c' | undefined
>();
expectTypeOf(findKey(sOrN, () => true)).toEqualTypeOf<
'a' | 'b' | 'c' | undefined
>();
// Value narrowing
expectTypeOf(findKey(o, isString)).toEqualTypeOf<string>();
expectTypeOf(findKey(oOrU, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(oOrN, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(o, isDate)).toEqualTypeOf<'c' | undefined>();
expectTypeOf(findKey(oOrU, isDate)).toEqualTypeOf<'c' | undefined>();
expectTypeOf(findKey(oOrN, isDate)).toEqualTypeOf<'c' | undefined>();
expectTypeOf(findKey(o, isNumberOrString)).toEqualTypeOf<string>();
expectTypeOf(findKey(oOrU, isNumberOrString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(findKey(oOrN, isNumberOrString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(findKey(s, isNumberOrString)).toEqualTypeOf<'a' | 'b'>();
expectTypeOf(findKey(sOrU, isNumberOrString)).toEqualTypeOf<
'a' | 'b' | undefined
>();
expectTypeOf(findKey(sOrN, isNumberOrString)).toEqualTypeOf<
'a' | 'b' | undefined
>();
expectTypeOf(findKey(s, isDateOrString)).toEqualTypeOf<'b' | 'c'>();
expectTypeOf(findKey(sOrU, isDateOrString)).toEqualTypeOf<
'b' | 'c' | undefined
>();
expectTypeOf(findKey(sOrN, isDateOrString)).toEqualTypeOf<
'b' | 'c' | undefined
>();
expectTypeOf(findKey(o, isMap)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(oOrU, isMap)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(oOrN, isMap)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(o, isMapOrString)).toEqualTypeOf<string>();
expectTypeOf(findKey(oOrU, isMapOrString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(findKey(oOrN, isMapOrString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(findKey(s, isMapOrString)).toEqualTypeOf<'b'>();
expectTypeOf(findKey(sOrU, isMapOrString)).toEqualTypeOf<'b' | undefined>();
expectTypeOf(findKey(sOrN, isMapOrString)).toEqualTypeOf<'b' | undefined>();
interface S2 {
b: number | 'a';
}
const s2 = { b: 2 } as S2;
const s2OrU = s2 as S2 | undefined;
const s2OrN = s2 as S2 | null;
expectTypeOf(findKey(s2, isA)).toEqualTypeOf<'b' | undefined>();
expectTypeOf(findKey(s2OrU, isA)).toEqualTypeOf<'b' | undefined>();
expectTypeOf(findKey(s2OrN, isA)).toEqualTypeOf<'b' | undefined>();
expectTypeOf(findKey(s2, isStringOr2)).toEqualTypeOf<'b' | undefined>();
expectTypeOf(findKey(s2OrU, isStringOr2)).toEqualTypeOf<'b' | undefined>();
expectTypeOf(findKey(s2OrN, isStringOr2)).toEqualTypeOf<'b' | undefined>();
// Key narrowing
expectTypeOf(findKey(s, keyIsString)).toEqualTypeOf<'a' | 'b' | 'c'>();
expectTypeOf(findKey(sOrU, keyIsString)).toEqualTypeOf<
'a' | 'b' | 'c' | undefined
>();
expectTypeOf(findKey(sOrN, keyIsString)).toEqualTypeOf<
'a' | 'b' | 'c' | undefined
>();
expectTypeOf(findKey(o, keyIsString)).toEqualTypeOf<string>();
expectTypeOf(findKey(oOrU, keyIsString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(findKey(oOrN, keyIsString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(findKey(s, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(sOrU, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(sOrN, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(o, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(oOrU, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(oOrN, keyIsNumber)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(s, keyIsA)).toEqualTypeOf<'a'>();
expectTypeOf(findKey(sOrU, keyIsA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(findKey(sOrN, keyIsA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(findKey(o, keyIsA)).toEqualTypeOf<'a'>();
expectTypeOf(findKey(oOrU, keyIsA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(findKey(oOrN, keyIsA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(findKey(s, keyIsString2)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(sOrU, keyIsString2)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(sOrN, keyIsString2)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(o, keyIsString2)).toEqualTypeOf<'2' | undefined>();
expectTypeOf(findKey(oOrU, keyIsString2)).toEqualTypeOf<'2' | undefined>();
expectTypeOf(findKey(oOrN, keyIsString2)).toEqualTypeOf<'2' | undefined>();
expectTypeOf(findKey(s, keyIsString3)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(sOrU, keyIsString3)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(sOrN, keyIsString3)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(o, keyIsString3)).toEqualTypeOf<'3' | undefined>();
expectTypeOf(findKey(oOrU, keyIsString3)).toEqualTypeOf<'3' | undefined>();
expectTypeOf(findKey(oOrN, keyIsString3)).toEqualTypeOf<'3' | undefined>();
expectTypeOf(findKey(s, keyIsC)).toEqualTypeOf<'c'>();
expectTypeOf(findKey(sOrU, keyIsC)).toEqualTypeOf<'c' | undefined>();
expectTypeOf(findKey(sOrN, keyIsC)).toEqualTypeOf<'c' | undefined>();
expectTypeOf(findKey(o, keyIsC)).toEqualTypeOf<'c'>();
expectTypeOf(findKey(oOrU, keyIsC)).toEqualTypeOf<'c' | undefined>();
expectTypeOf(findKey(oOrN, keyIsC)).toEqualTypeOf<'c' | undefined>();
expectTypeOf(findKey(s, keyIsAorC)).toEqualTypeOf<'a' | 'c'>();
expectTypeOf(findKey(sOrU, keyIsAorC)).toEqualTypeOf<
'a' | 'c' | undefined
>();
expectTypeOf(findKey(sOrN, keyIsAorC)).toEqualTypeOf<
'a' | 'c' | undefined
>();
expectTypeOf(findKey(o, keyIsAorC)).toEqualTypeOf<'a' | 'c'>();
expectTypeOf(findKey(oOrU, keyIsAorC)).toEqualTypeOf<
'a' | 'c' | undefined
>();
expectTypeOf(findKey(oOrN, keyIsAorC)).toEqualTypeOf<
'a' | 'c' | undefined
>();
expectTypeOf(findKey(s, keyIsAorNumber)).toEqualTypeOf<'a'>();
expectTypeOf(findKey(sOrU, keyIsAorNumber)).toEqualTypeOf<
'a' | undefined
>();
expectTypeOf(findKey(sOrN, keyIsAorNumber)).toEqualTypeOf<
'a' | undefined
>();
expectTypeOf(findKey(o, keyIsAorNumber)).toEqualTypeOf<'a'>();
expectTypeOf(findKey(oOrU, keyIsAorNumber)).toEqualTypeOf<
'a' | undefined
>();
expectTypeOf(findKey(oOrN, keyIsAorNumber)).toEqualTypeOf<
'a' | undefined
>();
const so = {} as Record<string, number | string>;
expectTypeOf(findKey(so, isString)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(so, isNumber)).toEqualTypeOf<string | undefined>();
expectTypeOf(findKey(so, isDate)).toEqualTypeOf<undefined>();
expectTypeOf(findKey(so, isDateOrString)).toEqualTypeOf<
string | undefined
>();
expectTypeOf(findKey(so, keyIsString)).toEqualTypeOf<string>();
expectTypeOf(findKey(so, keyIsA)).toEqualTypeOf<'a' | undefined>();
expectTypeOf(findKey(so, keyIsNumber)).toEqualTypeOf<undefined>();
});
//
// stolen from https://github.com/lodash/lodash
//
const objects = [
{ a: 0, b: 0 },
{ a: 1, b: 1 },
{ a: 2, b: 2 },
];
it('should return the found value', () => {
expect(findKey(objects, (object) => !!object.a)).toBe('1');
});
it('should return `undefined` if value is not found', () => {
expect(findKey(objects, (object) => object.a === 3)).toBe(undefined);
});
it('should return `undefined` for empty collections', () => {
expect(findKey({}, matches({ a: 3 }))).toBe(undefined);
expect(findKey([], matches({ a: 3 }))).toBe(undefined);
expect(findKey(false, matches({ a: 3 }))).toBe(undefined);
expect(findKey(0, matches({ a: 3 }))).toBe(undefined);
expect(findKey('', matches({ a: 3 }))).toBe(undefined);
expect(findKey(null, matches({ a: 3 }))).toBe(undefined);
expect(findKey(undefined, matches({ a: 3 }))).toBe(undefined);
expect(findKey(NaN, matches({ a: 3 }))).toBe(undefined);
});
it('should work with an object for `collection`', () => {
expect(findKey({ a: 1, b: 2, c: 3 }, (n) => n < 3)).toBe('a');
});
it('should provide correct `predicate` arguments for objects', () => {
const spy = jasmine.createSpy();
findKey({ a: 1 }, spy);
expectSingleCallAndReset(spy, 1, 'a');
});
it('should provide correct iteratee arguments', () => {
const spy = jasmine.createSpy();
findKey([1, 2, 3], spy);
expect(spy.calls.first().args).toEqual([1, '0']);
});
it('should ignore changes to `length`', () => {
const array = [1];
const spy = jasmine.createSpy().and.callFake(() => {
array.push(2);
return false;
});
findKey(array, spy);
expect(spy).toHaveBeenCalledTimes(1);
});
it('should ignore added `object` properties', () => {
const object: any = { a: 1 };
const spy = jasmine.createSpy().and.callFake(() => {
object.b = 2;
return false;
});
findKey(object, spy);
expect(spy).toHaveBeenCalledTimes(1);
});
});
