aboutsummaryrefslogtreecommitdiff
path: root/node_modules/jest-validate/README.md
blob: 2406bd568ec227f38f2d7b53428caeba0fd5b67d (plain)
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
# jest-validate

Generic configuration validation tool that helps you with warnings, errors and deprecation messages as well as showing users examples of correct configuration.

```bash
npm install --save jest-validate
```

## Usage

```js
import {validate} from 'jest-validate';

validate(config, validationOptions); // => {hasDeprecationWarnings: boolean, isValid: boolean}
```

Where `ValidationOptions` are:

```ts
type ValidationOptions = {
  comment?: string;
  condition?: (option: unknown, validOption: unknown) => boolean;
  deprecate?: (
    config: Record<string, unknown>,
    option: string,
    deprecatedOptions: DeprecatedOptions,
    options: ValidationOptions,
  ) => boolean;
  deprecatedConfig?: DeprecatedOptions;
  error?: (
    option: string,
    received: unknown,
    defaultValue: unknown,
    options: ValidationOptions,
    path?: Array<string>,
  ) => void;
  exampleConfig: Record<string, unknown>;
  recursive?: boolean;
  recursiveBlacklist?: Array<string>;
  recursiveDenylist?: Array<string>;
  title?: Title;
  unknown?: (
    config: Record<string, unknown>,
    exampleConfig: Record<string, unknown>,
    option: string,
    options: ValidationOptions,
    path?: Array<string>,
  ) => void;
};

type Title = {
  deprecation?: string;
  error?: string;
  warning?: string;
};
```

`exampleConfig` is the only option required.

## API

By default `jest-validate` will print generic warning and error messages. You can however customize this behavior by providing `options: ValidationOptions` object as a second argument:

Almost anything can be overwritten to suite your needs.

### Options

- `recursiveDenylist` – optional array of string keyPaths that should be excluded from deep (recursive) validation.
- `comment` – optional string to be rendered below error/warning message.
- `condition` – an optional function with validation condition.
- `deprecate`, `error`, `unknown` – optional functions responsible for displaying warning and error messages.
- `deprecatedConfig` – optional object with deprecated config keys.
- `exampleConfig` – the only **required** option with configuration against which you'd like to test.
- `recursive` - optional boolean determining whether recursively compare `exampleConfig` to `config` (default: `true`).
- `title` – optional object of titles for errors and messages.

You will find examples of `condition`, `deprecate`, `error`, `unknown`, and `deprecatedConfig` inside source of this repository, named respectively.

## exampleConfig syntax

`exampleConfig` should be an object with key/value pairs that contain an example of a valid value for each key. A configuration value is considered valid when:

- it matches the JavaScript type of the example value, e.g. `string`, `number`, `array`, `boolean`, `function`, or `object`
- it is `null` or `undefined`
- it matches the Javascript type of any of arguments passed to `MultipleValidOptions(...)`

The last condition is a special syntax that allows validating where more than one type is permissible; see example below. It's acceptable to have multiple values of the same type in the example, so you can also use this syntax to provide more than one example. When a validation failure occurs, the error message will show all other values in the array as examples.

## Examples

Minimal example:

```js
validate(config, {exampleConfig});
```

Example with slight modifications:

```js
validate(config, {
  comment: '  Documentation: http://custom-docs.com',
  deprecatedConfig,
  exampleConfig,
  title: {
    deprecation: 'Custom Deprecation',
    // leaving 'error' and 'warning' as default
  },
});
```

This will output:

#### Warning:

```bash
● Validation Warning:

  Unknown option transformx with value "<rootDir>/node_modules/babel-jest" was found.
  This is either a typing error or a user mistake. Fixing it will remove this message.

  Documentation: http://custom-docs.com
```

#### Error:

```bash
● Validation Error:

  Option transform must be of type:
    object
  but instead received:
    string

  Example:
  {
    "transform": {
      "\\.js$": "<rootDir>/preprocessor.js"
    }
  }

  Documentation: http://custom-docs.com
```

## Example validating multiple types

```js
import {multipleValidOptions} from 'jest-validate';

validate(config, {
  // `bar` will accept either a string or a number
  bar: multipleValidOptions('string is ok', 2),
});
```

#### Error:

```bash
● Validation Error:

  Option foo must be of type:
    string or number
  but instead received:
    array

  Example:
  {
    "bar": "string is ok"
  }

  or

  {
    "bar": 2
  }

  Documentation: http://custom-docs.com
```

#### Deprecation

Based on `deprecatedConfig` object with proper deprecation messages. Note custom title:

```bash
Custom Deprecation:

  Option scriptPreprocessor was replaced by transform, which support multiple preprocessors.

  Jest now treats your current configuration as:
  {
    "transform": {".*": "xxx"}
  }

  Please update your configuration.

  Documentation: http://custom-docs.com
```