/
snapshot_resolver.ts
112 lines (97 loc) · 3.43 KB
/
snapshot_resolver.ts
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
/**
* Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
import path from 'path';
import {Config, Snapshot} from '@jest/types';
import chalk from 'chalk';
export const EXTENSION = 'snap';
export const DOT_EXTENSION = '.' + EXTENSION;
export const isSnapshotPath = (path: string): boolean =>
path.endsWith(DOT_EXTENSION);
const cache: Map<Config.Path, Snapshot.SnapshotResolver> = new Map();
export const buildSnapshotResolver = (
config: Config.ProjectConfig,
): Snapshot.SnapshotResolver => {
const key = config.rootDir;
if (!cache.has(key)) {
cache.set(key, createSnapshotResolver(config.snapshotResolver));
}
return cache.get(key)!;
};
function createSnapshotResolver(
snapshotResolverPath?: Config.Path | null,
): Snapshot.SnapshotResolver {
return typeof snapshotResolverPath === 'string'
? createCustomSnapshotResolver(snapshotResolverPath)
: createDefaultSnapshotResolver();
}
function createDefaultSnapshotResolver(): Snapshot.SnapshotResolver {
return {
resolveSnapshotPath: (testPath: Config.Path) =>
path.join(
path.join(path.dirname(testPath), '__snapshots__'),
path.basename(testPath) + DOT_EXTENSION,
),
resolveTestPath: (snapshotPath: Config.Path) =>
path.resolve(
path.dirname(snapshotPath),
'..',
path.basename(snapshotPath, DOT_EXTENSION),
),
testPathForConsistencyCheck: path.posix.join(
'consistency_check',
'__tests__',
'example.test.js',
),
};
}
function createCustomSnapshotResolver(
snapshotResolverPath: Config.Path,
): Snapshot.SnapshotResolver {
const custom: Snapshot.SnapshotResolver = require(snapshotResolverPath);
const keys: [keyof Snapshot.SnapshotResolver, string][] = [
['resolveSnapshotPath', 'function'],
['resolveTestPath', 'function'],
['testPathForConsistencyCheck', 'string'],
];
keys.forEach(([propName, requiredType]) => {
if (typeof custom[propName] !== requiredType) {
throw new TypeError(mustImplement(propName, requiredType));
}
});
const customResolver = {
resolveSnapshotPath: (testPath: Config.Path) =>
custom.resolveSnapshotPath(testPath, DOT_EXTENSION),
resolveTestPath: (snapshotPath: Config.Path) =>
custom.resolveTestPath(snapshotPath, DOT_EXTENSION),
testPathForConsistencyCheck: custom.testPathForConsistencyCheck,
};
verifyConsistentTransformations(customResolver);
return customResolver;
}
function mustImplement(propName: string, requiredType: string) {
return (
chalk.bold(
`Custom snapshot resolver must implement a \`${propName}\` as a ${requiredType}.`,
) +
'\nDocumentation: https://facebook.github.io/jest/docs/en/configuration.html#snapshotResolver'
);
}
function verifyConsistentTransformations(custom: Snapshot.SnapshotResolver) {
const resolvedSnapshotPath = custom.resolveSnapshotPath(
custom.testPathForConsistencyCheck,
);
const resolvedTestPath = custom.resolveTestPath(resolvedSnapshotPath);
if (resolvedTestPath !== custom.testPathForConsistencyCheck) {
throw new Error(
chalk.bold(
`Custom snapshot resolver functions must transform paths consistently, i.e. expects resolveTestPath(resolveSnapshotPath('${
custom.testPathForConsistencyCheck
}')) === ${resolvedTestPath}`,
),
);
}
}