i18n-extract

> Manage localization with static analysis.



Installation

``sh
npm install --save-dev i18n-extract
`

The problem solved

This module analyses code statically for key usages, such as i18n.t('some.key'), in order to:

- Report keys that are missing
- Report keys that are unused.
- Report keys that are highly duplicated.

E.g. This module works well in conjunction with:
- polyglot.js (marker: 'polyglot.t',)
- webpack and his localisation plugin: i18n-webpack-plugin (marker: 'i18n',)

Supported keys

- static:
`js
i18n('key.static')
`
- string concatenation:
`js
i18n('key.' + 'concat')
`
- template string:
`js
i18n(key.template)
`
- dynamic:
`js
i18n(key.${dynamic})
`
- comment:
`js
/ i18n-extract key.comment /
`

API

$3

Parse the code to extract the argument of calls of i18n(key).

- code should be a string.
- Return an array containing keys used.

##### Example

`js
import {extractFromCode} from 'i18n-extract';
const keys = extractFromCode("const followMe = i18n('b2b.follow');", {
marker: 'i18n',
});
// keys = ['b2b.follow']
`

$3

Parse the files to extract the argument of calls of i18n(key).

- files can be either an array of strings or a string. You can also use a glob.
- Return an array containing keys used in the source code.

##### Example

`js
import {extractFromFiles} from 'i18n-extract';
const keys = extractFromFiles([
'*.jsx',
'*.js',
], {
marker: 'i18n',
});
`

$3

- marker: The name of the internationalized string marker function. Defaults to i18n.
- keyLoc: An integer indicating the position of the key in the arguments. Defaults to 0. Negative numbers, e.g., -1, indicate a position relative to the end of the argument list.
- parser: Enum indicate the parser to use, can be typescript or flow. Defaults to flow.
- babelOptions: A Babel configuration object to allow applying custom transformations or plugins before scanning for i18n keys. Defaults to a config with all babylon plugins enabled.

$3

Report the missing keys. Those keys should probably be translated.

- locale should be a object containing the translations.
- keysUsed should be an array. Containes the keys used in the source code.
It can be retrieve with extractFromFiles our extractFromCode.
- Return a report.

##### Example

`js
import {findMissing} from 'i18n-extract';
const missing = findMissing({
key1: 'key 1',
}, ['key1', 'key2']);

/**
* missing = [{
* type: 'MISSING',
* key: 'key2',
* }];
*/
`

Plugins

$3

Report the unused key. Those keys should probably be removed.

- locale should be a object containing the translations.
- keysUsed should be an array. Containes the keys used in the source code.
It can be retrieve with extractFromFiles our extractFromCode.
- Return a report.

##### Example

`js
import {findUnused} from 'i18n-extract';
const unused = findUnused({
key1: 'key 1',
key2: 'key 2',
}, ['key1']);

/**
* unused = [{
* type: 'UNUSED',
* key: 'key2',
* }];
*/
`

$3

Report the duplicated key. Those keys should probably be mutualized.
The default threshold is 1, it will report any duplicated translations.

- locale should be a object containing the translations.
- keysUsed should be an array. Containes the keys used in the source code.
It can be retrieve with extractFromFiles our extractFromCode.
- options should be an object. You can provide a threshold property to change the number of duplicated value before it's added to the report.
- Return a report.

##### Example

`js
import {findDuplicated} from 'i18n-extract';
const duplicated = findDuplicated({
key1: 'Key 1',
key2: 'Key 2',
key3: 'Key 2',
});

/**
* unused = [{
* type: 'DUPLICATED',
* keys: [
* 'key2',
* 'key3',
* ],
* value: 'Key 2',
* }];
*/
`

$3

Report any dynamic key. It's arguably more dangerous to use dynamic key. They may break.

- locale should be a object containing the translations.
- keysUsed should be an array. Containes the keys used in the source code.
It can be retrieve with extractFromFiles our extractFromCode.
- Return a report.

##### Example

`js
import {forbidDynamic} from 'i18n-extract';
const forbidDynamic = forbidDynamic({}, ['key.*']);

/**
* forbidDynamic = [{
* type: 'FORBID_DYNAMIC',
key: 'key.',
* }];
*/
`

$3

Flatten the object.

- object should be a object.

##### Example

`js
import {flatten} from 'i18n-extract';
const flattened = flatten({
key2: 'Key 2',
key4: {
key41: 'Key 4.1',
key42: {
key421: 'Key 4.2.1',
},
},
});

/**
* flattened = {
* key2: 'Key 2',
* 'key4.key41': 'Key 4.1',
* 'key4.key42.key421': 'Key 4.2.1',
* };
*/
`

$3

Output a new po file with only the messages present in messages.
If a message is already present in the poInput, we keep the translation.
If a message is not present, we add a new empty translation.

- messages should be an array.
- poInput should be a string.
- poOutput should be a string.

##### Example

`js
import {mergeMessagesWithPO} from 'i18n-extract';

const messages = ['Message 1', 'Message 2'];
mergeMessagesWithPO(messages, 'messages.po', 'messages.output.po');

/**
* Will output :
* > messages.output.po has 812 messages.
* > We have added 7 messages.
* > We have removed 3 messages.
*/
``

License

MIT