|
1 | 1 | import { Observable } from 'rxjs' |
2 | 2 | import { describe, expect, test } from 'vitest' |
3 | | -import { observableToAsyncGenerator } from './util.js' |
| 3 | +import { asyncGeneratorToObservable, isAsyncGenerator, observableToAsyncGenerator } from './util.js' |
4 | 4 |
|
5 | 5 | describe('observableToAsyncGenerator', () => { |
6 | 6 | test('observable that emits and completes', async () => { |
@@ -69,3 +69,124 @@ describe('observableToAsyncGenerator', () => { |
69 | 69 | expect(results).toEqual([1, 2, 3, 4, 5]) |
70 | 70 | }) |
71 | 71 | }) |
| 72 | +describe('asyncGeneratorToObservable', () => { |
| 73 | + function readObservable(observable: Observable<number>): Promise<number[]> { |
| 74 | + return new Promise<number[]>(resolve => { |
| 75 | + const results: number[] = [] |
| 76 | + observable.subscribe({ |
| 77 | + next: value => results.push(value), |
| 78 | + complete: () => resolve(results), |
| 79 | + }) |
| 80 | + }) |
| 81 | + } |
| 82 | + |
| 83 | + test('async generator that yields and completes', async () => { |
| 84 | + const observable = asyncGeneratorToObservable( |
| 85 | + (async function* () { |
| 86 | + yield 1 |
| 87 | + yield 2 |
| 88 | + yield 3 |
| 89 | + })(), |
| 90 | + ) |
| 91 | + expect(await readObservable(observable)).toEqual([1, 2, 3]) |
| 92 | + }) |
| 93 | + |
| 94 | + test('async generator that throws an error', async () => { |
| 95 | + const ERROR = new Error('Test error') |
| 96 | + async function* generator() { |
| 97 | + yield 1 |
| 98 | + throw ERROR |
| 99 | + } |
| 100 | + |
| 101 | + const observable = asyncGeneratorToObservable(generator()) |
| 102 | + const results: number[] = [] |
| 103 | + let error: Error | null = null |
| 104 | + |
| 105 | + await new Promise<void>(resolve => { |
| 106 | + observable.subscribe({ |
| 107 | + next: value => results.push(value), |
| 108 | + error: err => { |
| 109 | + error = err |
| 110 | + resolve() |
| 111 | + }, |
| 112 | + complete: () => resolve(), |
| 113 | + }) |
| 114 | + }) |
| 115 | + |
| 116 | + expect(results).toEqual([1]) |
| 117 | + expect(error).toBe(ERROR) |
| 118 | + }) |
| 119 | + |
| 120 | + test('async generator with no yields', async () => { |
| 121 | + async function* generator() { |
| 122 | + // Empty generator |
| 123 | + } |
| 124 | + |
| 125 | + const observable = asyncGeneratorToObservable(generator()) |
| 126 | + let completed = false |
| 127 | + |
| 128 | + await new Promise<void>(resolve => { |
| 129 | + observable.subscribe({ |
| 130 | + next: () => expect.fail('should not yield any values'), |
| 131 | + complete: () => { |
| 132 | + completed = true |
| 133 | + resolve() |
| 134 | + }, |
| 135 | + }) |
| 136 | + }) |
| 137 | + |
| 138 | + expect(completed).toBe(true) |
| 139 | + }) |
| 140 | +}) |
| 141 | + |
| 142 | +describe('isAsyncGenerator', () => { |
| 143 | + test('true for valid async generator', () => { |
| 144 | + async function* validAsyncGenerator() { |
| 145 | + yield 1 |
| 146 | + } |
| 147 | + expect(isAsyncGenerator(validAsyncGenerator())).toBe(true) |
| 148 | + }) |
| 149 | + |
| 150 | + test('false for other values', () => { |
| 151 | + expect(isAsyncGenerator(42)).toBe(false) |
| 152 | + expect(isAsyncGenerator('string')).toBe(false) |
| 153 | + expect(isAsyncGenerator(true)).toBe(false) |
| 154 | + expect(isAsyncGenerator(undefined)).toBe(false) |
| 155 | + expect(isAsyncGenerator(null)).toBe(false) |
| 156 | + expect(isAsyncGenerator({})).toBe(false) |
| 157 | + expect(isAsyncGenerator(function regularFunction() {})).toBe(false) |
| 158 | + }) |
| 159 | + |
| 160 | + test('false for async functions', () => { |
| 161 | + async function asyncFunction() {} |
| 162 | + expect(isAsyncGenerator(asyncFunction)).toBe(false) |
| 163 | + }) |
| 164 | + |
| 165 | + test('false for non-async generator functions', () => { |
| 166 | + function* generatorFunction() { |
| 167 | + yield 1 |
| 168 | + } |
| 169 | + expect(isAsyncGenerator(generatorFunction())).toBe(false) |
| 170 | + }) |
| 171 | + |
| 172 | + test('false for objects with some but not all required methods', () => { |
| 173 | + const incompleteObject = { |
| 174 | + next: () => {}, |
| 175 | + throw: () => {}, |
| 176 | + [Symbol.asyncIterator]: function () { |
| 177 | + return this |
| 178 | + }, |
| 179 | + } |
| 180 | + expect(isAsyncGenerator(incompleteObject)).toBe(false) |
| 181 | + }) |
| 182 | + |
| 183 | + test('false for objects with all methods but incorrect Symbol.asyncIterator implementation', () => { |
| 184 | + const incorrectObject = { |
| 185 | + next: () => {}, |
| 186 | + throw: () => {}, |
| 187 | + return: () => {}, |
| 188 | + [Symbol.asyncIterator]: () => ({}), |
| 189 | + } |
| 190 | + expect(isAsyncGenerator(incorrectObject)).toBe(false) |
| 191 | + }) |
| 192 | +}) |
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