deno.land / std@0.166.0 / testing / snapshot.ts

نووسراو ببینە
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
/** A snapshotting library. * * @module */
import { fromFileUrl, parse, resolve, toFileUrl } from "../path/mod.ts";import { ensureFile, ensureFileSync } from "../fs/mod.ts";import { bold, green, red } from "../fmt/colors.ts";import { assert, AssertionError, equal } from "./asserts.ts";import { buildMessage, diff, diffstr } from "./_diff.ts";
const CAN_NOT_DISPLAY = "[Cannot display]";const SNAPSHOT_DIR = "__snapshots__";const SNAPSHOT_EXT = "snap";
export type SnapshotMode = "assert" | "update";
export type SnapshotOptions<T = unknown> = { /** * Snapshot output directory. Snapshot files will be written to this directory. * This can be relative to the test directory or an absolute path. * * If both `dir` and `path` are specified, the `dir` option will be ignored and * the `path` option will be handled as normal. */ dir?: string; /** * Snapshot mode. Defaults to `assert`, unless the `-u` or `--update` flag is * passed, in which case this will be set to `update`. This option takes higher * priority than the update flag. If the `--update` flag is passed, it will be * ignored if the `mode` option is set. */ mode?: SnapshotMode; /** * Failure message to log when the assertion fails. Specifying this option will * cause the diff not to be logged. */ msg?: string; /** * Name of the snapshot to use in the snapshot file. */ name?: string; /** * Snapshot output path. The shapshot will be written to this file. This can be * a path relative to the test directory or an absolute path. * * If both `dir` and `path` are specified, the `dir` option will be ignored and * the `path` option will be handled as normal. */ path?: string; /** * Function to use when serializing the snapshot. */ serializer?: (actual: T) => string;};
function getErrorMessage(message: string, options: SnapshotOptions) { return typeof options.msg === "string" ? options.msg : message;}
/** * Default serializer for `assertSnapshot`. */export function serialize(actual: unknown): string;export function serialize<T>(actual: T): string;export function serialize(actual: unknown): string { return Deno.inspect(actual, { depth: Infinity, sorted: true, trailingComma: true, compact: false, iterableLimit: Infinity, strAbbreviateSize: Infinity, }).replace(/\\n/g, "\n");}
/** * Converts a string to a valid JavaScript string which can be wrapped in backticks. * * @example * * "special characters (\ ` $) will be escaped" -> "special characters (\\ \` \$) will be escaped" */function escapeStringForJs(str: string) { return str .replace(/\\/g, "\\\\") .replace(/`/g, "\\`") .replace(/\$/g, "\\$");}
let _mode: SnapshotMode;/** * Get the snapshot mode. */function getMode(options: SnapshotOptions) { if (options.mode) { return options.mode; } else if (_mode) { return _mode; } else { _mode = Deno.args.some((arg) => arg === "--update" || arg === "-u") ? "update" : "assert"; return _mode; }}
/** * Return `true` when snapshot mode is `update`. */function getIsUpdate(options: SnapshotOptions) { return getMode(options) === "update";}
class AssertSnapshotContext { static contexts = new Map<string, AssertSnapshotContext>();
/** * Returns an instance of `AssertSnapshotContext`. This will be retrieved from * a cache if an instance was already created for a given snapshot file path. */ static fromOptions( testContext: Deno.TestContext, options: SnapshotOptions, ): AssertSnapshotContext { let path: string; const testFilePath = fromFileUrl(testContext.origin); const { dir, base } = parse(testFilePath); if (options.path) { path = resolve(dir, options.path); } else if (options.dir) { path = resolve(dir, options.dir, `${base}.${SNAPSHOT_EXT}`); } else { path = resolve(dir, SNAPSHOT_DIR, `${base}.${SNAPSHOT_EXT}`); }
let context = this.contexts.get(path); if (context) { return context; }
context = new this(toFileUrl(path)); this.contexts.set(path, context); return context; }
#teardownRegistered = false; #currentSnapshots: Map<string, string | undefined> | undefined; #updatedSnapshots = new Map<string, string>(); #snapshotCounts = new Map<string, number>(); #snapshotsUpdated = new Array<string>(); #snapshotFileUrl: URL; snapshotUpdateQueue = new Array<string>();
constructor(snapshotFileUrl: URL) { this.#snapshotFileUrl = snapshotFileUrl; }
/** * Asserts that `this.#currentSnapshots` has been initialized and then returns it. * * Should only be called when `this.#currentSnapshots` has already been initialized. */ #getCurrentSnapshotsInitialized() { assert( this.#currentSnapshots, "Snapshot was not initialized. This is a bug in `assertSnapshot`.", ); return this.#currentSnapshots; }
/** * Write updates to the snapshot file and log statistics. */ #teardown = () => { const buf = ["export const snapshot = {};"]; const currentSnapshots = this.#getCurrentSnapshotsInitialized(); this.snapshotUpdateQueue.forEach((name) => { const updatedSnapshot = this.#updatedSnapshots.get(name); const currentSnapshot = currentSnapshots.get(name); let formattedSnapshot: string; if (typeof updatedSnapshot === "string") { formattedSnapshot = updatedSnapshot; } else if (typeof currentSnapshot === "string") { formattedSnapshot = currentSnapshot; } else { // This occurs when `assertSnapshot` is called in "assert" mode but // the snapshot doesn't exist and `assertSnapshot` is also called in // "update" mode. In this case, we have nothing to write to the // snapshot file so we can just exit early return; } formattedSnapshot = escapeStringForJs(formattedSnapshot); formattedSnapshot = formattedSnapshot.includes("\n") ? `\n${formattedSnapshot}\n` : formattedSnapshot; const formattedName = escapeStringForJs(name); buf.push(`\nsnapshot[\`${formattedName}\`] = \`${formattedSnapshot}\`;`); }); const snapshotFilePath = fromFileUrl(this.#snapshotFileUrl); ensureFileSync(snapshotFilePath); Deno.writeTextFileSync(snapshotFilePath, buf.join("\n") + "\n");
const contexts = Array.from(AssertSnapshotContext.contexts.values()); if (contexts[contexts.length - 1] === this) { let updated = 0; for (const context of contexts) { updated += context.getUpdatedCount(); } if (updated > 0) { console.log( green(bold(`\n > ${updated} snapshots updated.`)), ); } } };
/** * Returns `this.#currentSnapshots` and if necessary, tries to initialize it by reading existing * snapshots from the snapshot file. If the snapshot mode is `update` and the snapshot file does * not exist then it will be created. */ async #readSnapshotFile(options: SnapshotOptions) { if (this.#currentSnapshots) { return this.#currentSnapshots; }
if (getIsUpdate(options)) { await ensureFile(fromFileUrl(this.#snapshotFileUrl)); }
try { const snapshotFileUrl = this.#snapshotFileUrl.toString(); const { snapshot } = await import(snapshotFileUrl); this.#currentSnapshots = typeof snapshot === "undefined" ? new Map() : new Map( Object.entries(snapshot).map(([name, snapshot]) => { if (typeof snapshot !== "string") { throw new AssertionError( getErrorMessage( `Corrupt snapshot:\n\t(${name})\n\t${snapshotFileUrl}`, options, ), ); } return [ name, snapshot.includes("\n") ? snapshot.slice(1, -1) : snapshot, ]; }), ); return this.#currentSnapshots; } catch (error) { if ( error instanceof TypeError && error.message.startsWith("Module not found") ) { throw new AssertionError( getErrorMessage( "Missing snapshot file.", options, ), ); } throw error; } }
/** * Register a teardown function which writes the snapshot file to disk and logs the number * of snapshots updated after all tests have run. * * This method can safely be called more than once and will only register the teardown * function once. */ public registerTeardown() { if (!this.#teardownRegistered) { globalThis.addEventListener("unload", this.#teardown); this.#teardownRegistered = true; } }
/** * Gets the number of snapshots which have been created with the same name and increments * the count by 1. */ public getCount(snapshotName: string) { let count = this.#snapshotCounts.get(snapshotName) || 0; this.#snapshotCounts.set(snapshotName, ++count); return count; }
/** * Get an existing snapshot by name or returns `undefined` if the snapshot does not exist. */ public async getSnapshot(snapshotName: string, options: SnapshotOptions) { const snapshots = await this.#readSnapshotFile(options); return snapshots.get(snapshotName); }
/** * Update a snapshot by name. Updates will be written to the snapshot file when all tests * have run. If the snapshot does not exist, it will be created. * * Should only be called when mode is `update`. */ public updateSnapshot(snapshotName: string, snapshot: string) { if (!this.#snapshotsUpdated.includes(snapshotName)) { this.#snapshotsUpdated.push(snapshotName); } const currentSnapshots = this.#getCurrentSnapshotsInitialized(); if (!currentSnapshots.has(snapshotName)) { currentSnapshots.set(snapshotName, undefined); } this.#updatedSnapshots.set(snapshotName, snapshot); }
/** * Get the number of updated snapshots. */ public getUpdatedCount() { return this.#snapshotsUpdated.length; }
/** * Add a snapshot to the update queue. * * Tracks the order in which snapshots were created so that they can be written to * the snapshot file in the correct order. * * Should be called with each snapshot, regardless of the mode, as a future call to * `assertSnapshot` could cause updates to be written to the snapshot file if the * `update` mode is passed in the options. */ public pushSnapshotToUpdateQueue(snapshotName: string) { this.snapshotUpdateQueue.push(snapshotName); }
/** * Check if exist snapshot */ public hasSnapshot(snapshotName: string): boolean { return this.#currentSnapshots ? this.#currentSnapshots.has(snapshotName) : false; }}
/** * Make an assertion that `actual` matches a snapshot. If the snapshot and `actual` do * not a match, then throw. * * Type parameter can be specified to ensure values under comparison have the same type. * For example: * ```ts * import { assertSnapshot } from "https://deno.land/std@$STD_VERSION/testing/snapshot.ts"; * * Deno.test("snapshot", async (test) => { * await assertSnapshot<number>(test, 2); * }); * ``` */export async function assertSnapshot<T>( context: Deno.TestContext, actual: T, options: SnapshotOptions<T>,): Promise<void>;export async function assertSnapshot<T>( context: Deno.TestContext, actual: T, message?: string,): Promise<void>;export async function assertSnapshot( context: Deno.TestContext, actual: unknown, msgOrOpts?: string | SnapshotOptions<unknown>,) { const options = getOptions(); const assertSnapshotContext = AssertSnapshotContext.fromOptions( context, options, ); const testName = getTestName(context, options); const count = assertSnapshotContext.getCount(testName); const name = `${testName} ${count}`; const snapshot = await assertSnapshotContext.getSnapshot( name, options, );
assertSnapshotContext.pushSnapshotToUpdateQueue(name); const _serialize = options.serializer || serialize; const _actual = _serialize(actual); if (getIsUpdate(options)) { assertSnapshotContext.registerTeardown(); if (!equal(_actual, snapshot)) { assertSnapshotContext.updateSnapshot(name, _actual); } } else { if ( !assertSnapshotContext.hasSnapshot(name) || typeof snapshot === "undefined" ) { throw new AssertionError( getErrorMessage(`Missing snapshot: ${name}`, options), ); } if (equal(_actual, snapshot)) { return; } let message = ""; try { const stringDiff = !_actual.includes("\n"); const diffResult = stringDiff ? diffstr(_actual, snapshot) : diff(_actual.split("\n"), snapshot.split("\n")); const diffMsg = buildMessage(diffResult, { stringDiff }).join("\n"); message = `Snapshot does not match:\n${diffMsg}`; } catch { message = `Snapshot does not match:\n${red(CAN_NOT_DISPLAY)} \n\n`; } throw new AssertionError( getErrorMessage(message, options), ); }
function getOptions(): SnapshotOptions { if (typeof msgOrOpts === "object" && msgOrOpts !== null) { return msgOrOpts; }
return { msg: msgOrOpts, }; } function getTestName( context: Deno.TestContext, options?: SnapshotOptions, ): string { if (options && options.name) { return options.name; } else if (context.parent) { return `${getTestName(context.parent)} > ${context.name}`; } return context.name; }}
export function createAssertSnapshot<T>( options: SnapshotOptions<T>, baseAssertSnapshot: typeof assertSnapshot = assertSnapshot,): typeof assertSnapshot { return async function _assertSnapshot( context: Deno.TestContext, actual: T, messageOrOptions?: string | SnapshotOptions<T>, ) { const mergedOptions: SnapshotOptions<T> = { ...options, ...(typeof messageOrOptions === "string" ? { msg: messageOrOptions, } : messageOrOptions), };
await baseAssertSnapshot(context, actual, mergedOptions); };}
std
Deno standard library
GitHub Repositorydenoland/deno_std
GitHub Stars
2457

Version Info

Tagged at
2 months ago