playwright/packages/playwright-test/src/matchers/toMatchSnapshot.ts

367 lines
14 KiB
TypeScript

/**
* Copyright Microsoft Corporation. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import { Locator, Page } from 'playwright-core';
import type { Page as PageEx } from 'playwright-core/lib/client/page';
import type { Locator as LocatorEx } from 'playwright-core/lib/client/locator';
import type { Expect } from '../types';
import { currentTestInfo } from '../globals';
import { mimeTypeToComparator, ImageComparatorOptions, Comparator } from 'playwright-core/lib/utils/comparators';
import type { PageScreenshotOptions } from 'playwright-core/types/types';
import { addSuffixToFilePath, serializeError, sanitizeForFilePath, trimLongString, callLogText, currentExpectTimeout } from '../util';
import { UpdateSnapshots } from '../types';
import colors from 'colors/safe';
import fs from 'fs';
import path from 'path';
import * as mime from 'mime';
import { TestInfoImpl } from '../testInfo';
// from expect/build/types
type SyncExpectationResult = {
pass: boolean;
message: () => string;
};
type NameOrSegments = string | string[];
const SNAPSHOT_COUNTER = Symbol('noname-snapshot-counter');
class SnapshotHelper<T extends ImageComparatorOptions> {
readonly testInfo: TestInfoImpl;
readonly expectedPath: string;
readonly snapshotPath: string;
readonly actualPath: string;
readonly diffPath: string;
readonly mimeType: string;
readonly kind: 'Screenshot'|'Snapshot';
readonly updateSnapshots: UpdateSnapshots;
readonly comparatorOptions: ImageComparatorOptions;
readonly allOptions: T;
constructor(
testInfo: TestInfoImpl,
anonymousSnapshotExtension: string,
nameOrOptions: NameOrSegments | { name?: NameOrSegments } & T,
optOptions: T,
) {
let options: T;
let name: NameOrSegments | undefined;
if (Array.isArray(nameOrOptions) || typeof nameOrOptions === 'string') {
name = nameOrOptions;
options = optOptions;
} else {
name = nameOrOptions.name;
options = { ...nameOrOptions };
delete (options as any).name;
}
if (!name) {
(testInfo as any)[SNAPSHOT_COUNTER] = ((testInfo as any)[SNAPSHOT_COUNTER] || 0) + 1;
const fullTitleWithoutSpec = [
...testInfo.titlePath.slice(1),
(testInfo as any)[SNAPSHOT_COUNTER],
].join(' ');
name = sanitizeForFilePath(trimLongString(fullTitleWithoutSpec)) + '.' + anonymousSnapshotExtension;
}
options = {
...(testInfo.project.expect?.toMatchSnapshot || {}),
...options,
};
if (options.pixelCount !== undefined && options.pixelCount < 0)
throw new Error('`pixelCount` option value must be non-negative integer');
if (options.pixelRatio !== undefined && (options.pixelRatio < 0 || options.pixelRatio > 1))
throw new Error('`pixelRatio` option value must be between 0 and 1');
// sanitizes path if string
const pathSegments = Array.isArray(name) ? name : [addSuffixToFilePath(name, '', undefined, true)];
const snapshotPath = testInfo.snapshotPath(...pathSegments);
const outputFile = testInfo.outputPath(...pathSegments);
const expectedPath = addSuffixToFilePath(outputFile, '-expected');
const actualPath = addSuffixToFilePath(outputFile, '-actual');
const diffPath = addSuffixToFilePath(outputFile, '-diff');
let updateSnapshots = testInfo.config.updateSnapshots;
if (updateSnapshots === 'missing' && testInfo.retry < testInfo.project.retries)
updateSnapshots = 'none';
const mimeType = mime.getType(path.basename(snapshotPath)) ?? 'application/octet-string';
const comparator: Comparator = mimeTypeToComparator[mimeType];
if (!comparator)
throw new Error('Failed to find comparator with type ' + mimeType + ': ' + snapshotPath);
this.testInfo = testInfo;
this.mimeType = mimeType;
this.actualPath = actualPath;
this.expectedPath = expectedPath;
this.diffPath = diffPath;
this.snapshotPath = snapshotPath;
this.updateSnapshots = updateSnapshots;
this.allOptions = options;
this.comparatorOptions = {
pixelCount: options.pixelCount,
pixelRatio: options.pixelRatio,
threshold: options.threshold,
};
this.kind = this.mimeType.startsWith('image/') ? 'Screenshot' : 'Snapshot';
}
handleMissingNegated() {
const isWriteMissingMode = this.updateSnapshots === 'all' || this.updateSnapshots === 'missing';
const message = `${this.snapshotPath} is missing in snapshots${isWriteMissingMode ? ', matchers using ".not" won\'t write them automatically.' : '.'}`;
return {
// NOTE: 'isNot' matcher implies inversed value.
pass: true,
message: () => message,
};
}
handleDifferentNegated() {
// NOTE: 'isNot' matcher implies inversed value.
return { pass: false, message: () => '' };
}
handleMatchingNegated() {
const message = [
colors.red(`${this.kind} comparison failed:`),
'',
indent('Expected result should be different from the actual one.', ' '),
].join('\n');
// NOTE: 'isNot' matcher implies inversed value.
return { pass: true, message: () => message };
}
handleMissing(actual: Buffer | string) {
const isWriteMissingMode = this.updateSnapshots === 'all' || this.updateSnapshots === 'missing';
if (isWriteMissingMode) {
writeFileSync(this.snapshotPath, actual);
writeFileSync(this.actualPath, actual);
}
const message = `${this.snapshotPath} is missing in snapshots${isWriteMissingMode ? ', writing actual.' : '.'}`;
if (this.updateSnapshots === 'all') {
/* eslint-disable no-console */
console.log(message);
return { pass: true, message: () => message };
}
if (this.updateSnapshots === 'missing') {
this.testInfo._failWithError(serializeError(new Error(message)), false /* isHardError */);
return { pass: true, message: () => '' };
}
return { pass: false, message: () => message };
}
handleDifferent(
actual: Buffer | string | undefined,
expected: Buffer | string | undefined,
diff: Buffer | string | undefined,
diffError: string | undefined,
log: string[] | undefined,
title = `${this.kind} comparison failed:`) {
const output = [
colors.red(title),
'',
];
if (diffError) {
output.push(...[
indent(diffError, ' '),
'',
]);
}
if (log)
output.push(callLogText(log));
if (expected !== undefined) {
writeFileSync(this.expectedPath, expected);
this.testInfo.attachments.push({ name: 'expected', contentType: this.mimeType, path: this.expectedPath });
output.push(`Expected: ${colors.yellow(this.expectedPath)}`);
}
if (actual !== undefined) {
writeFileSync(this.actualPath, actual);
this.testInfo.attachments.push({ name: 'actual', contentType: this.mimeType, path: this.actualPath });
output.push(`Received: ${colors.yellow(this.actualPath)}`);
}
if (diff !== undefined) {
writeFileSync(this.diffPath, diff);
this.testInfo.attachments.push({ name: 'diff', contentType: this.mimeType, path: this.diffPath });
output.push(` Diff: ${colors.yellow(this.diffPath)}`);
}
return { pass: false, message: () => output.join('\n'), };
}
handleMatching() {
return { pass: true, message: () => '' };
}
}
export function toMatchSnapshot(
this: ReturnType<Expect['getState']>,
received: Buffer | string,
nameOrOptions: NameOrSegments | { name?: NameOrSegments } & ImageComparatorOptions = {},
optOptions: ImageComparatorOptions = {}
): SyncExpectationResult {
const testInfo = currentTestInfo();
if (!testInfo)
throw new Error(`toMatchSnapshot() must be called during the test`);
const helper = new SnapshotHelper(testInfo, determineFileExtension(received), nameOrOptions, optOptions);
const comparator: Comparator = mimeTypeToComparator[helper.mimeType];
if (!comparator)
throw new Error('Failed to find comparator with type ' + helper.mimeType + ': ' + helper.snapshotPath);
if (this.isNot) {
if (!fs.existsSync(helper.snapshotPath))
return helper.handleMissingNegated();
const isDifferent = !!comparator(received, fs.readFileSync(helper.snapshotPath), helper.comparatorOptions);
return isDifferent ? helper.handleDifferentNegated() : helper.handleMatchingNegated();
}
if (!fs.existsSync(helper.snapshotPath))
return helper.handleMissing(received);
const expected = fs.readFileSync(helper.snapshotPath);
const result = comparator(received, expected, helper.comparatorOptions);
if (!result)
return helper.handleMatching();
if (helper.updateSnapshots === 'all') {
writeFileSync(helper.snapshotPath, received);
/* eslint-disable no-console */
console.log(helper.snapshotPath + ' does not match, writing actual.');
return { pass: true, message: () => helper.snapshotPath + ' running with --update-snapshots, writing actual.' };
}
return helper.handleDifferent(received, expected, result.diff, result.errorMessage, undefined);
}
type HaveScreenshotOptions = ImageComparatorOptions & Omit<PageScreenshotOptions, 'type' | 'quality' | 'path'>;
export async function toHaveScreenshot(
this: ReturnType<Expect['getState']>,
pageOrLocator: Page | Locator,
nameOrOptions: NameOrSegments | { name?: NameOrSegments } & HaveScreenshotOptions = {},
optOptions: HaveScreenshotOptions = {}
): Promise<SyncExpectationResult> {
const testInfo = currentTestInfo();
if (!testInfo)
throw new Error(`toHaveScreenshot() must be called during the test`);
const helper = new SnapshotHelper(testInfo, 'png', nameOrOptions, optOptions);
const [page, locator] = pageOrLocator.constructor.name === 'Page' ? [(pageOrLocator as PageEx), undefined] : [(pageOrLocator as Locator).page() as PageEx, pageOrLocator as LocatorEx];
const screenshotOptions = {
...helper.allOptions,
mask: (helper.allOptions.mask || []) as LocatorEx[],
name: undefined,
threshold: undefined,
pixelCount: undefined,
pixelRatio: undefined,
};
const hasSnapshot = fs.existsSync(helper.snapshotPath);
if (this.isNot) {
if (!hasSnapshot)
return helper.handleMissingNegated();
// Having `errorMessage` means we timed out while waiting
// for screenshots not to match, so screenshots
// are actually the same in the end.
const isDifferent = !(await page._expectScreenshot({
expected: await fs.promises.readFile(helper.snapshotPath),
isNot: true,
locator,
comparatorOptions: helper.comparatorOptions,
screenshotOptions,
timeout: currentExpectTimeout(helper.allOptions),
})).errorMessage;
return isDifferent ? helper.handleDifferentNegated() : helper.handleMatchingNegated();
}
// Fast path: there's no screenshot and we don't intend to update it.
if (helper.updateSnapshots === 'none' && !hasSnapshot)
return { pass: false, message: () => `${helper.snapshotPath} is missing in snapshots.` };
if (helper.updateSnapshots === 'all' || !hasSnapshot) {
// Regenerate a new screenshot by waiting until two screenshots are the same.
const timeout = currentExpectTimeout(helper.allOptions);
const { actual, previous, diff, errorMessage, log } = await page._expectScreenshot({
expected: undefined,
isNot: false,
locator,
comparatorOptions: helper.comparatorOptions,
screenshotOptions,
timeout,
});
// We tried re-generating new snapshot but failed.
// This can be due to e.g. spinning animation, so we want to show it as a diff.
if (errorMessage) {
// TODO(aslushnikov): rename attachments to "actual" and "previous". They still should be somehow shown in HTML reporter.
const title = actual && previous ?
`Timeout ${timeout}ms exceeded while generating screenshot because ${locator ? 'element' : 'page'} kept changing:` :
`Timeout ${timeout}ms exceeded while generating screenshot:`;
return helper.handleDifferent(actual, previous, diff, undefined, log, title);
}
// We successfully (re-)generated new screenshot.
if (!hasSnapshot)
return helper.handleMissing(actual!);
writeFileSync(helper.snapshotPath, actual!);
/* eslint-disable no-console */
console.log(helper.snapshotPath + ' is re-generated, writing actual.');
return {
pass: true,
message: () => helper.snapshotPath + ' running with --update-snapshots, writing actual.'
};
}
// General case:
// - snapshot exists
// - regular matcher (i.e. not a `.not`)
// - no flags to update screenshots
const expected = await fs.promises.readFile(helper.snapshotPath);
const { actual, diff, errorMessage, log } = await page._expectScreenshot({
expected,
isNot: false,
locator,
comparatorOptions: helper.comparatorOptions,
screenshotOptions,
timeout: currentExpectTimeout(helper.allOptions),
});
return errorMessage ?
helper.handleDifferent(actual, expected, diff, errorMessage, log) :
helper.handleMatching();
}
function writeFileSync(aPath: string, content: Buffer | string) {
fs.mkdirSync(path.dirname(aPath), { recursive: true });
fs.writeFileSync(aPath, content);
}
function indent(lines: string, tab: string) {
return lines.replace(/^(?=.+$)/gm, tab);
}
function determineFileExtension(file: string | Buffer): string {
if (typeof file === 'string')
return 'txt';
if (compareMagicBytes(file, [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]))
return 'png';
if (compareMagicBytes(file, [0xff, 0xd8, 0xff, 0xe0, 0x00, 0x10, 0x4a, 0x46, 0x49, 0x46, 0x00, 0x01, 0x01]))
return 'jpg';
return 'dat';
}
function compareMagicBytes(file: Buffer, magicBytes: number[]): boolean {
return Buffer.compare(Buffer.from(magicBytes), file.slice(0, magicBytes.length)) === 0;
}