create-index

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

Example

> 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:

// @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:

> 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:

// @create-index

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

Usage

Using CLI Program

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.

Using create-index Programmatically

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.

import {
    findIndexFiles
} from 'create-index';

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

Gulp

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

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.

// @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.

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:

// @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.

> cat index.js
// @create-index {"ignore": ["/baz.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:

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

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

export {
    bar,
    foo
};