utils.ts•6.06 kB
/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
import * as path from 'path';
import chalk from 'chalk';
import * as fs from 'graceful-fs';
import naturalCompare from 'natural-compare';
import type {Config} from '@jest/types';
import type {SnapshotData} from './types';
export const SNAPSHOT_VERSION = '1';
const SNAPSHOT_HEADER_REGEXP = /^\/\/ Jest Snapshot v(.+), (.+)$/m;
export const SNAPSHOT_GUIDE_LINK = 'https://jestjs.io/docs/snapshot-testing';
export const SNAPSHOT_VERSION_WARNING = chalk.yellow(
`${chalk.bold('Warning')}: Before you upgrade snapshots, ` +
'we recommend that you revert any local changes to tests or other code, ' +
'to ensure that you do not store invalid state.',
);
const writeSnapshotVersion = () =>
`// Jest Snapshot v${SNAPSHOT_VERSION}, ${SNAPSHOT_GUIDE_LINK}`;
const validateSnapshotHeader = (snapshotContents: string) => {
const headerTest = SNAPSHOT_HEADER_REGEXP.exec(snapshotContents);
const version = headerTest && headerTest[1];
const guideLink = headerTest && headerTest[2];
if (!version) {
return new Error(
chalk.red(
`${chalk.bold('Outdated snapshot')}: No snapshot header found. ` +
'Jest 19 introduced versioned snapshots to ensure all developers ' +
'on a project are using the same version of Jest. ' +
'Please update all snapshots during this upgrade of Jest.\n\n',
) + SNAPSHOT_VERSION_WARNING,
);
}
if (version < SNAPSHOT_VERSION) {
return new Error(
// eslint-disable-next-line prefer-template
chalk.red(
`${chalk.red.bold('Outdated snapshot')}: The version of the snapshot ` +
'file associated with this test is outdated. The snapshot file ' +
'version ensures that all developers on a project are using ' +
'the same version of Jest. ' +
'Please update all snapshots during this upgrade of Jest.',
) +
'\n\n' +
`Expected: v${SNAPSHOT_VERSION}\n` +
`Received: v${version}\n\n` +
SNAPSHOT_VERSION_WARNING,
);
}
if (version > SNAPSHOT_VERSION) {
return new Error(
// eslint-disable-next-line prefer-template
chalk.red(
`${chalk.red.bold('Outdated Jest version')}: The version of this ` +
'snapshot file indicates that this project is meant to be used ' +
'with a newer version of Jest. The snapshot file version ensures ' +
'that all developers on a project are using the same version of ' +
'Jest. Please update your version of Jest and re-run the tests.',
) +
'\n\n' +
`Expected: v${SNAPSHOT_VERSION}\n` +
`Received: v${version}`,
);
}
if (guideLink !== SNAPSHOT_GUIDE_LINK) {
return new Error(
// eslint-disable-next-line prefer-template
chalk.red(
`${chalk.red.bold(
'Outdated guide link',
)}: The snapshot guide link at the top of this snapshot is outdated. ` +
'Please update all snapshots during this upgrade of Jest.',
) +
'\n\n' +
`Expected: ${SNAPSHOT_GUIDE_LINK}\n` +
`Received: ${guideLink}`,
);
}
return null;
};
const normalizeTestNameForKey = (testName: string): string =>
testName.replaceAll(/\r\n|\r|\n/g, match => {
switch (match) {
case '\r\n':
return '\\r\\n';
case '\r':
return '\\r';
case '\n':
return '\\n';
default:
return match;
}
});
const denormalizeTestNameFromKey = (key: string): string =>
key.replaceAll(/\\r\\n|\\r|\\n/g, match => {
switch (match) {
case '\\r\\n':
return '\r\n';
case '\\r':
return '\r';
case '\\n':
return '\n';
default:
return match;
}
});
export const testNameToKey = (testName: string, count: number): string =>
`${normalizeTestNameForKey(testName)} ${count}`;
export const keyToTestName = (key: string): string => {
if (!/ \d+$/.test(key)) {
throw new Error('Snapshot keys must end with a number.');
}
const testNameWithoutCount = key.replace(/ \d+$/, '');
return denormalizeTestNameFromKey(testNameWithoutCount);
};
export const getSnapshotData = (
snapshotPath: string,
update: Config.SnapshotUpdateState,
): {
data: SnapshotData;
dirty: boolean;
} => {
const data = Object.create(null);
let snapshotContents = '';
let dirty = false;
if (fs.existsSync(snapshotPath)) {
try {
snapshotContents = fs.readFileSync(snapshotPath, 'utf8');
// eslint-disable-next-line no-new-func
const populate = new Function('exports', snapshotContents);
populate(data);
} catch {}
}
const validationResult = validateSnapshotHeader(snapshotContents);
const isInvalid = snapshotContents && validationResult;
if (update === 'none' && isInvalid) {
throw validationResult;
}
if ((update === 'all' || update === 'new') && isInvalid) {
dirty = true;
}
return {data, dirty};
};
export const escapeBacktickString = (str: string): string =>
str.replaceAll(/`|\\|\${/g, '\\$&');
const printBacktickString = (str: string): string =>
`\`${escapeBacktickString(str)}\``;
export const ensureDirectoryExists = (filePath: string): void => {
try {
fs.mkdirSync(path.dirname(filePath), {recursive: true});
} catch {}
};
export const normalizeNewlines = (string: string): string =>
string.replaceAll(/\r\n|\r/g, '\n');
export const saveSnapshotFile = (
snapshotData: SnapshotData,
snapshotPath: string,
): void => {
const snapshots = Object.keys(snapshotData)
.sort(naturalCompare)
.map(
key =>
`exports[${printBacktickString(key)}] = ${printBacktickString(
normalizeNewlines(snapshotData[key]),
)};`,
);
ensureDirectoryExists(snapshotPath);
fs.writeFileSync(
snapshotPath,
`${writeSnapshotVersion()}\n\n${snapshots.join('\n\n')}\n`,
);
};