feat(linter/plugins): support default options (#16170)

A step towards #15630. Where a rule provides default options, pass them to `create` function as `context.options`.

We don't yet have full options support (#14825), so this is incomplete. Once user can provide options for rules in config, those options need to be merged with default options.

Initially, we should probably do that merging on JS side (borrowing ESLint's code), and then later on port it to Rust.

Author: overlookmotel

apps/oxlint/src-js/plugins/lint.ts

@@ -156,7 +156,8 @@ function lintFileImpl(
     // Set `options` for rule
     const optionsId = optionsIds[i];
     debugAssert(optionsId < allOptions.length, "Options ID out of bounds");
-    ruleDetails.options = allOptions[optionsId];
+    ruleDetails.options =
+      optionsId === DEFAULT_OPTIONS_ID ? ruleDetails.defaultOptions : allOptions[optionsId];
 
     let { visitor } = ruleDetails;
     if (visitor === null) {

apps/oxlint/src-js/plugins/load.ts

@@ -1,4 +1,5 @@
 import { createContext } from "./context.js";
+import { DEFAULT_OPTIONS } from "./options.js";
 import { getErrorMessage } from "../utils/utils.js";
 
 import type { Writable } from "type-fest";
@@ -8,7 +9,8 @@ import type { RuleMeta } from "./rule_meta.ts";
 import type { AfterHook, BeforeHook, Visitor, VisitorWithHooks } from "./types.ts";
 import type { SetNullable } from "../utils/types.ts";
 
-const ObjectKeys = Object.keys;
+const ObjectKeys = Object.keys,
+  { isArray } = Array;
 
 /**
  * Linter plugin, comprising multiple rules
@@ -55,6 +57,7 @@ interface RuleDetailsBase {
   readonly context: Readonly<Context>;
   readonly isFixable: boolean;
   readonly messages: Readonly<Record<string, string>> | null;
+  readonly defaultOptions: Readonly<Options>;
   // Updated for each file
   ruleIndex: number;
   options: Readonly<Options> | null; // Initially `null`, set to options object before linting a file
@@ -147,7 +150,8 @@ async function loadPluginImpl(url: string, packageName: string | null): Promise<
 
     // Validate `rule.meta` and convert to vars with standardized shape
     let isFixable = false,
-      messages: Record<string, string> | null = null;
+      messages: Record<string, string> | null = null,
+      defaultOptions: Readonly<Options> = DEFAULT_OPTIONS;
     const ruleMeta = rule.meta;
     if (ruleMeta != null) {
       if (typeof ruleMeta !== "object") throw new TypeError("Invalid `rule.meta`");
@@ -159,6 +163,15 @@ async function loadPluginImpl(url: string, packageName: string | null): Promise<
         isFixable = true;
       }
 
+      const inputDefaultOptions = ruleMeta.defaultOptions;
+      if (inputDefaultOptions != null) {
+        // TODO: Validate is JSON-serializable, and validate against provided options schema
+        if (!isArray(inputDefaultOptions)) {
+          throw new TypeError("`rule.meta.defaultOptions` must be an array if provided");
+        }
+        defaultOptions = inputDefaultOptions;
+      }
+
       // Extract messages for messageId support
       const inputMessages = ruleMeta.messages;
       if (inputMessages != null) {
@@ -175,6 +188,7 @@ async function loadPluginImpl(url: string, packageName: string | null): Promise<
       context: null!, // Filled in below
       isFixable,
       messages,
+      defaultOptions,
       ruleIndex: 0,
       options: null,
       visitor: null,

apps/oxlint/src-js/plugins/options.ts

@@ -10,7 +10,7 @@ import type { JsonValue } from "./json.ts";
 export type Options = JsonValue[];
 
 // Default rule options
-const DEFAULT_OPTIONS: Readonly<Options> = Object.freeze([]);
+export const DEFAULT_OPTIONS: Readonly<Options> = Object.freeze([]);
 
 // All rule options
 export const allOptions: Readonly<Options>[] = [DEFAULT_OPTIONS];

apps/oxlint/test/fixtures/options/.oxlintrc.json

@@ -0,0 +1,10 @@
+{
+  "jsPlugins": ["./plugin.ts"],
+  "categories": {
+    "correctness": "off"
+  },
+  "rules": {
+    "options-plugin/options": "error",
+    "options-plugin/default-options": "error"
+  }
+}

apps/oxlint/test/fixtures/options/files/index.js

@@ -0,0 +1 @@
+debugger;

apps/oxlint/test/fixtures/options/output.snap.md

@@ -0,0 +1,26 @@
+# Exit code
+1
+
+# stdout
+```
+  x options-plugin(default-options): options: ["string",123,true,{"toBe":false,"notToBe":true}]
+   ,-[files/index.js:1:1]
+ 1 | debugger;
+   : ^
+   `----
+
+  x options-plugin(options): options: []
+   ,-[files/index.js:1:1]
+ 1 | debugger;
+   : ^
+   `----
+
+Found 0 warnings and 2 errors.
+Finished in Xms on 1 file using X threads.
+```
+
+# stderr
+```
+WARNING: JS plugins are experimental and not subject to semver.
+Breaking changes are possible while JS plugins support is under development.
+```

apps/oxlint/test/fixtures/options/plugin.ts

@@ -0,0 +1,42 @@
+import type { Node, Plugin } from "#oxlint";
+
+const SPAN: Node = {
+  start: 0,
+  end: 0,
+  range: [0, 0],
+  loc: {
+    start: { line: 0, column: 0 },
+    end: { line: 0, column: 0 },
+  },
+};
+
+const plugin: Plugin = {
+  meta: {
+    name: "options-plugin",
+  },
+  rules: {
+    options: {
+      create(context) {
+        context.report({
+          message: `options: ${JSON.stringify(context.options)}`,
+          node: SPAN,
+        });
+        return {};
+      },
+    },
+    "default-options": {
+      meta: {
+        defaultOptions: ["string", 123, true, { toBe: false, notToBe: true }],
+      },
+      create(context) {
+        context.report({
+          message: `options: ${JSON.stringify(context.options)}`,
+          node: SPAN,
+        });
+        return {};
+      },
+    },
+  },
+};
+
+export default plugin;