create-index


create-index program creates (and maintains) ES6 ./index.js file in target directories that imports and exports sibling files and directories.

Example

``sh
> tree ./
./
├── bar.js
└── foo.js

0 directories, 2 files

> create-index ./
[13:17:34] Target directories [ './' ]
[13:17:34] Update index: false
[13:17:34] ./index.js [created index]
[13:17:34] Done

> tree
.
├── bar.js
├── foo.js
└── index.js

0 directories, 3 files
`

This created index.js with:

`js
// @create-index

export { default as bar } from './bar.js';
export { default as foo } from './foo.js';

`

Lets create a new file and re-run create-index:

`js
> touch baz.js
> tree ./
./
├── bar.js
├── baz.js
├── foo.js
└── index.js

0 directories, 4 files

> create-index ./
[13:21:55] Target directories [ './' ]
[13:21:55] Update index: false
[13:21:55] ./index.js [updated index]
[13:21:55] Done
`

This have updated index.js file:

`js
// @create-index

export { default as bar } from './bar.js';
export { default as baz } from './baz.js';
export { default as foo } from './foo.js';

`

Usage

$3

`sh
npm install create-index

create-index --help

Options:
--recursive, -r Create/update index files recursively. Halts on any
unsafe "index.js" files. [boolean] [default: false]
--ignoreUnsafe, -i Ignores unsafe "index.js" files instead of halting.
[boolean] [default: false]
--ignoreDirectories, -d Ignores importing directories into the index file,
even if they have a safe "index.js".
[boolean] [default: false]
--update, -u Updates only previously created index files
(recursively). [boolean] [default: false]
--banner Add a custom banner at the top of the index file
[string]
--extensions, -x Allows some extensions to be parsed as valid source.
First extension will always be preferred to homonyms
with another allowed extension.
[array] [default: ["js"]]
--outputFile, -o Output file [string] [default: "index.js"] [array] [default: ["js"]]

Examples:
create-index ./src ./src/utilities Creates or updates an existing
create-index index file in the target
(./src, ./src/utilities) directories.
create-index --update ./src ./tests Finds all create-index index files in
the target directories and descending
directories. Updates found index
files.
create-index ./src --extensions js jsx Creates or updates an existing
create-index index file in the target
(./src) directory for both .js and
.jsx extensions.
`

$3

`js
import {
writeIndex
} from 'create-index';

/**
* @type {Function}
* @param {Array} directoryPaths
* @throws {Error} Directory "..." does not exist.
* @throws {Error} "..." is not a directory.
* @throws {Error} "..." unsafe index.
* @returns {boolean}
*/
writeIndex;
`

Note that the writeIndex function is synchronous.

`js
import {
findIndexFiles
} from 'create-index';

/**
* @type {Function}
* @param {string} directoryPath
* @returns {Array} List of directory paths that have create-index index file.
*/
findIndexFiles;
`

$3

Since Gulp can ran arbitrary JavaScript code, there is no need for a separate plugin. See Using create-index Programmatically.

`js
import {
writeIndex
} from 'create-index';

gulp.task('create-index', () => {
writeIndex(['./target_directory']);
});
`

Note that the writeIndex function is synchronous.

Implementation

create-index program will look into the target directory.

If there is no ./index.js, it will create a new file, e.g.

`js
// @create-index
`

Created index file must start with // @create-index\n\n. This is used to make sure that create-index does not accidentally overwrite your local files.

If there are sibling files, index file will import them and export, e.g.

`sh
children-directories-and-files git:(master) ✗ ls -lah
total 0
drwxr-xr-x 5 gajus staff 170B 6 Jan 15:39 .
drwxr-xr-x 10 gajus staff 340B 6 Jan 15:53 ..
drwxr-xr-x 2 gajus staff 68B 6 Jan 15:29 bar
drwxr-xr-x 2 gajus staff 68B 6 Jan 15:29 foo
-rw-r--r-- 1 gajus staff 0B 6 Jan 15:29 foo.js
`

Given the above directory contents, ./index.js will be:

`js
// @create-index

import { default as bar } from './bar';
import { default as foo } from './foo.js';

export {
bar,
foo
};
`

When file has the same name as a sibling directory, file import takes precedence.

Directories that do not have ./index.js in themselves will be excluded.

When run again, create-index will update existing ./index.js if it starts with // @create-index\n\n.

If create-index is executed against a directory that contains ./index.js, which does not start with // @create-index\n\n, an error will be thrown.

Ignore files on --update

create-index can ignore files in a directory if ./index.js contains special object with defined ignore property which takes an array of regular expressions defined as strings, e.g.

`js
> cat index.js
// @create-index {"ignore": ["/baz.js$/"]}
`

`js
> tree ./
./
├── bar.js
├── baz.js
├── foo.js
└── index.js

0 directories, 4 files
`

Given the above directory contents, after running create-index with --update flag, ./index.js will be:

`js
// @create-index {"ignore": ["/baz.js$/"]}

import { default as bar } from './bar.js';
import { default as foo } from './foo.js';

export {
bar,
foo
};
``