eslint-plugin-directory-mirror

An ESLint rule for mirroring directory structures.

Use cases:

• Ensure that every unit test file has a corresponding source file
• Ensure that every source file has a corresponding unit test file
• etc.

Installation

Execute the following command within your project's root directory:

npm i --save-dev eslint-plugin-directory-mirror

ESLint Configuration

Add directory-mirror to the plugins section of your .eslintrc file:

{
  plugins: ["directory-mirror"],
}

Plugin Configuration

There is only one rule within this plugin also named directory-mirror.

This rule has one configuration option which you can use to specify the directories that should be mirrored. Let's use an example to understand the option:

{
  rules: {
    "directory-mirror/directory-mirror": [
      "error",
      {
        "mirrors": [
          { forEach: { dir: "test", ext: ".test.ts", recursive: true }, require: { dir: "src", ext: ".ts" } },
          { forEach: { dir: "src", ext: ".ts", recursive: true }, require: { dir: "test", ext: ".test.ts" } },
        ],
      },
    ],
  },
}

The option has a mirrors array with objects describing the mirrored directories.

Read the object like this: forEach of these files require in the directory dir a file with the extension ext and the same name (without extension and including sub directory).

For the example above this means:

• For every test file with the extension .test.ts in the test folder there has to be a corresponding source file with the extension .ts in the src folder.
• And for every source file with the extension .ts in the src folder there has to be a corresponding test file with the extension .test.ts in the test folder.