feat: Add extendable config types (#210)

Co-authored-by: Francesco Trotta <github@fasttime.org>

Author: nzakas

eslint.config.js

@@ -59,6 +59,7 @@ export default defineConfig([
 	// TypeScript
 	...tseslint.config({
 		files: ["**/*.ts"],
+		ignores: ["**/tests/**/*.ts"],
 		extends: [...tseslint.configs.strict, ...tseslint.configs.stylistic],
 		rules: {
 			"no-use-before-define": "off",

packages/core/src/types.ts

@@ -666,22 +666,36 @@ export interface LinterOptionsConfig {
 	 * Indicates what to do when an unused disable directive is found.
 	 */
 	reportUnusedDisableDirectives?: boolean | Severity;
+
+	/**
+	 * A severity value indicating if and how unused inline configs should be
+	 * tracked and reported.
+	 */
+	reportUnusedInlineConfigs?: Severity;
 }
 
 /**
- * Shared settings that are accessible from within plugins.
+ * The configuration for a rule.
  */
-export type SettingsConfig = Record<string, unknown>;
+export type RuleConfig<RuleOptions extends unknown[] = unknown[]> =
+	| Severity
+	| [Severity, ...RuleOptions];
 
+/* eslint-disable @typescript-eslint/consistent-indexed-object-style -- needed to allow extension */
 /**
- * The configuration for a rule.
+ * A collection of rules and their configurations.
  */
-export type RuleConfig = Severity | [Severity, ...unknown[]];
+export interface RulesConfig {
+	[key: string]: RuleConfig;
+}
 
 /**
- * A collection of rules and their configurations.
+ * A collection of settings.
  */
-export type RulesConfig = Record<string, RuleConfig>;
+export interface SettingsConfig {
+	[key: string]: unknown;
+}
+/* eslint-enable @typescript-eslint/consistent-indexed-object-style -- needed to allow extension */
 
 //------------------------------------------------------------------------------
 // Languages

packages/core/tests/types/types.test.ts

@@ -15,15 +15,18 @@ import type {
 	Language,
 	LanguageContext,
 	LanguageOptions,
+	LinterOptionsConfig,
 	OkParseResult,
 	ParseResult,
+	RuleConfig,
 	RuleContext,
 	RuleDefinition,
 	RulesConfig,
 	RulesMeta,
 	RuleTextEdit,
 	RuleTextEditor,
 	RuleVisitor,
+	SettingsConfig,
 	SourceLocation,
 	SourceRange,
 	TextSourceCode,
@@ -46,6 +49,41 @@ interface TestRootNode {
 	length: number;
 }
 
+//-----------------------------------------------------------------------------
+// Tests for config types
+//-----------------------------------------------------------------------------
+
+const emptyRules: RulesConfig = {};
+
+const rules: RulesConfig = {
+	"no-console": "error",
+	"no-unused-vars": 0,
+	"json/no-duplicate-keys": ["warn"],
+	"css/use-baseline": [1, { available: "widely" }],
+};
+
+const emptySettings: SettingsConfig = {};
+
+const settings: SettingsConfig = {
+	foo: true,
+	bar: "baz",
+};
+
+const ruleConfig1: RuleConfig = "error";
+const ruleConfig2: RuleConfig = 1;
+const ruleConfig3: RuleConfig = ["error", { foo: "bar" }];
+const ruleConfig4: RuleConfig<string[]> = ["error", "foo", "bar"];
+const ruleConfig5: RuleConfig<[{ available: "widely" | "newly" }]> = [
+	"error",
+	{ available: "widely" },
+];
+
+const linterConfig: LinterOptionsConfig = {
+	noInlineConfig: true,
+	reportUnusedDisableDirectives: "error",
+	reportUnusedInlineConfigs: "warn",
+};
+
 //-----------------------------------------------------------------------------
 // Tests for shared types
 //-----------------------------------------------------------------------------