This commit adds an unstable lint plugin API.
Plugins are specified in the `deno.json` file under
`lint.plugins` option like so:
```
{
"lint": {
"plugins": [
"./plugins/my-plugin.ts",
"jsr:@deno/lint-plugin1",
"npm:@deno/lint-plugin2"
]
}
}
```
The API is considered unstable and might be subject
to changes in the future.
Plugin API was modelled after ESLint API for the
most part, but there are no guarantees for compatibility.
The AST format exposed to plugins is closely modelled
after the AST that `typescript-eslint` uses.
Lint plugins use the visitor pattern and can add
diagnostics like so:
```
export default {
name: "lint-plugin",
rules: {
"plugin-rule": {
create(context) {
return {
Identifier(node) {
if (node.name === "a") {
context.report({
node,
message: "should be b",
fix(fixer) {
return fixer.replaceText(node, "_b");
},
});
}
},
};
},
},
},
} satisfies Deno.lint.Plugin;
```
Besides reporting errors (diagnostics) plugins can provide
automatic fixes that use text replacement to apply changes.
---------
Co-authored-by: Marvin Hagemeister <marvin@deno.com>
Co-authored-by: David Sherret <dsherret@gmail.com>
From upgrading `deno_lint`.
Previously if you had a node project that used a bunch of node globals
(`process.env`, etc), you would have to fix the errors by hand. This PR
includes a new lint that detects usages of node globals (`process`,
`setImmediate`, `Buffer`, etc.) and provides an autofix to import the
correct value. For instance:
```ts
// main.ts
const _foo = process.env.FOO;
```
`deno lint` gives you
```ts
error[no-node-globals]: NodeJS globals are not available in Deno
--> /home/foo.ts:1:14
|
1 | const _foo = process.env.FOO;
| ^^^^^^^
= hint: Add `import process from "node:process";`
docs: https://lint.deno.land/rules/no-node-globals
Found 1 problem (1 fixable via --fix)
Checked 1 file
```
And `deno lint --fix` adds the import for you:
```ts
// main.ts
import process from "node:process";
const _foo = process.env.FOO;
```