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feat!: Switch to flat config
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- Switch recommended config to flat config format
- Rename old recommended config to recommended-legacy
- Updated documentation
- Upgraded ESLint
- Updated tests

fixes #231
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nzakas committed Jan 31, 2024
1 parent 4d9f36f commit afc9c23
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3 changes: 0 additions & 3 deletions .eslintignore

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50 changes: 0 additions & 50 deletions .eslintrc.js

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195 changes: 94 additions & 101 deletions README.md
Original file line number Diff line number Diff line change
Expand Up @@ -17,15 +17,28 @@ Lint JS, JSX, TypeScript, and more inside Markdown.

### Installing

Install the plugin alongside ESLint v6 or greater:
Install the plugin alongside ESLint v8 or greater:

```sh
npm install --save-dev eslint eslint-plugin-markdown
```

### Configuring

Extending the `plugin:markdown/recommended` config will enable the Markdown processor on all `.md` files:
In your `eslint.config.js` file, import `eslint-plugin-markdown` and included the recommended config to enable the Markdown processor on all `.md` files:

```js
// / eslint.config.js
import markdown from "eslint-plugin-markdown";

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export default [
...markdown.configs.recommended

// your other configs here
];
```

If you are still using the deprecated `.eslintrc.js` file format for ESLint, you can extend the `plugin:markdown/recommended` config to enable the Markdown processor on all `.md` files:

```js
// .eslintrc.js
Expand All @@ -36,12 +49,48 @@ module.exports = {

#### Advanced Configuration

Add the plugin to your `.eslintrc` and use the `processor` option in an `overrides` entry to enable the plugin's `markdown/markdown` processor on Markdown files.
You can manually include the Markdown processor by setting the `processor` option in your configuration file for all `.md` files.

Each fenced code block inside a Markdown document has a virtual filename appended to the Markdown file's path.

The virtual filename's extension will match the fenced code block's syntax tag, so for example, <code>```js</code> code blocks in <code>README.md</code> would match <code>README.md/*.js</code>.
[`overrides` glob patterns](https://eslint.org/docs/user-guide/configuring#configuration-based-on-glob-patterns) for these virtual filenames can customize configuration for code blocks without affecting regular code.
You can use glob patterns for these virtual filenames to customize configuration for code blocks without affecting regular code.
For more information on configuring processors, refer to the [ESLint documentation](https://eslint.org/docs/user-guide/configuring#specifying-processor).

Here's an example:

```js
// / eslint.config.js
import markdown from "eslint-plugin-markdown";

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export default [
{
// 1. Add the plugin
plugins: {
markdown
}
},
{
// 2. Enable the Markdown processor for all .md files.
files: ["**/*.md"],
processor: "markdown/markdown"
},
{
// 3. Optionally, customize the configuration ESLint uses for ```js
// fenced code blocks inside .md files.
files: ["**/*.md/*.js"],
// ...
rules: {
// ...
}
}

// your other configs here
];
```

In the deprecated `.eslintrc.js` format:

```js
// .eslintrc.js
module.exports = {
Expand Down Expand Up @@ -77,13 +126,47 @@ The `plugin:markdown/recommended` config disables these rules in Markdown files:
- [`no-unused-vars`](https://eslint.org/docs/rules/no-unused-vars)
- [`padded-blocks`](https://eslint.org/docs/rules/padded-blocks)

Use [`overrides` glob patterns](https://eslint.org/docs/user-guide/configuring#configuration-based-on-glob-patterns) to disable more rules just for Markdown code blocks:
Use glob patterns to disable more rules just for Markdown code blocks:

```js
// / eslint.config.js
import markdown from "eslint-plugin-markdown";

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export default [
{
plugins: {
markdown
}
},
{
files: ["**/*.md"],
processor: "markdown/markdown"
},
{
// 1. Target ```js code blocks in .md files.
files: ["**/*.md/*.js"],
rules: {
// 2. Disable other rules.
"no-console": "off",
"import/no-unresolved": "off"
}
}

// your other configs here
];
```

And in the deprecated `.eslintrc.js` format:

```js
// .eslintrc.js
module.exports = {
// ...
plugins: ["markdown"],
overrides: [
// ...
{
files: ["**/*.md"],
processor: "markdown/markdown"
},
{
// 1. Target ```js code blocks in .md files.
files: ["**/*.md/*.js"],
Expand Down Expand Up @@ -111,99 +194,9 @@ The `plugin:markdown/recommended` config disables these rules in Markdown files:
- [`eol-last`](https://eslint.org/docs/rules/eol-last): The Markdown parser trims trailing newlines from code blocks.
- [`unicode-bom`](https://eslint.org/docs/rules/unicode-bom): Markdown code blocks do not have Unicode Byte Order Marks.

#### Migrating from `eslint-plugin-markdown` v1

`eslint-plugin-markdown` v1 used an older version of ESLint's processor API.
The Markdown processor automatically ran on `.md`, `.mkdn`, `.mdown`, and `.markdown` files, and it only extracted fenced code blocks marked with `js`, `javascript`, `jsx`, or `node` syntax.
Configuration specifically for fenced code blocks went inside an `overrides` entry with a `files` pattern matching the containing Markdown document's filename that applied to all fenced code blocks inside the file.

```js
// .eslintrc.js for eslint-plugin-markdown v1
module.exports = {
plugins: ["markdown"],
overrides: [
{
files: ["**/*.md"],
// In v1, configuration for fenced code blocks went inside an
// `overrides` entry with a .md pattern, for example:
parserOptions: {
ecmaFeatures: {
impliedStrict: true
}
},
rules: {
"no-console": "off"
}
}
]
};
```

[RFC3](https://github.com/eslint/rfcs/blob/master/designs/2018-processors-improvements/README.md) designed a new processor API to remove these limitations, and the new API was [implemented](https://github.com/eslint/eslint/pull/11552) as part of ESLint v6.
`eslint-plugin-markdown` v2 uses this new API.

```bash
$ npm install --save-dev eslint@latest eslint-plugin-markdown@latest
```

All of the Markdown file extensions that were previously hard-coded are now fully configurable in `.eslintrc.js`.
Use the new `processor` option to apply the `markdown/markdown` processor on any Markdown documents matching a `files` pattern.
Each fenced code block inside a Markdown document has a virtual filename appended to the Markdown file's path.
The virtual filename's extension will match the fenced code block's syntax tag, so for example, <code>```js</code> code blocks in <code>README.md</code> would match <code>README.md/*.js</code>.

```js
// eslintrc.js for eslint-plugin-markdown v2
module.exports = {
plugins: ["markdown"],
overrides: [
{
// In v2, explicitly apply eslint-plugin-markdown's `markdown`
// processor on any Markdown files you want to lint.
files: ["**/*.md"],
processor: "markdown/markdown"
},
{
// In v2, configuration for fenced code blocks is separate from the
// containing Markdown file. Each code block has a virtual filename
// appended to the Markdown file's path.
files: ["**/*.md/*.js"],
// Configuration for fenced code blocks goes with the override for
// the code block's virtual filename, for example:
parserOptions: {
ecmaFeatures: {
impliedStrict: true
}
},
rules: {
"no-console": "off"
}
}
]
};
```

If you need to precisely mimic the behavior of v1 with the hard-coded Markdown extensions and fenced code block syntaxes, you can use those as glob patterns in `overrides[].files`:

```js
// eslintrc.js for v2 mimicking v1 behavior
module.exports = {
plugins: ["markdown"],
overrides: [
{
files: ["**/*.{md,mkdn,mdown,markdown}"],
processor: "markdown/markdown"
},
{
files: ["**/*.{md,mkdn,mdown,markdown}/*.{js,javascript,jsx,node}"]
// ...
}
]
};
```

### Running

#### ESLint v7
#### ESLint v7+

You can run ESLint as usual and do not need to use the `--ext` option.
ESLint v7 [automatically lints file extensions specified in `overrides[].files` patterns in config files](https://github.com/eslint/rfcs/blob/0253e3a95511c65d622eaa387eb73f824249b467/designs/2019-additional-lint-targets/README.md).
Expand Down Expand Up @@ -282,7 +275,7 @@ Comment bodies are passed through unmodified, so the plugin supports any [config
This example enables the `browser` environment, disables the `no-alert` rule, and configures the `quotes` rule to prefer single quotes:

````markdown
<!-- eslint-env browser -->
<!-- global alert -->
<!-- eslint-disable no-alert -->
<!-- eslint quotes: ["error", "single"] -->

Expand All @@ -296,7 +289,7 @@ Each code block in a file is linted separately, so configuration comments apply
````markdown
Assuming `no-alert` is enabled in `.eslintrc`, the first code block will have no error from `no-alert`:

<!-- eslint-env browser -->
<!-- global alert -->
<!-- eslint-disable no-alert -->

```js
Expand All @@ -305,7 +298,7 @@ alert("Hello, world!");

But the next code block will have an error from `no-alert`:

<!-- eslint-env browser -->
<!-- global alert -->

```js
alert("Hello, world!");
Expand Down
52 changes: 52 additions & 0 deletions eslint.config.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,52 @@
"use strict";

module.exports = [
...require("eslint-config-eslint").map(config => ({
...config,
files: ["**/*.js"]
})),
{
plugins: {
markdown: require(".")
}
},
{
ignores: [
"**/examples",
"**/coverage",
"**/tests/fixtures"
]
},
{
files: ["**/*.js"],
languageOptions: {
sourceType: "commonjs"
}
},
{
files: ["tests/**/*.js"],
languageOptions: {
globals: {
...require("globals").mocha
}
}
},
{
files: ["**/*.md"],
processor: "markdown/markdown"
},
{
files: ["**/*.md/*.js"],
languageOptions: {
sourceType: "module",
parserOptions: {
ecmaFeatures: {
impliedStrict: true
}
}
},
rules: {
"lines-around-comment": "off"
}
}
];

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