@fluidframework/eslint-config-fluid/library/rules/strict.mts

Shareable ESLint config for the Fluid Framework

/*!
 * Copyright (c) Microsoft Corporation and contributors. All rights reserved.
 * Licensed under the MIT License.
 */

/**
 * Strict ESLint rules.
 *
 * This module contains the strictest rules, extending the recommended configuration.
 * The strict config adds mandatory JSDoc requirements, explicit member accessibility,
 * and enables additional TypeScript rules that are disabled in lower-level configs.
 * Use this config for packages requiring comprehensive documentation and strict type safety.
 */

import type { Linter } from "eslint";

/**
 * Rules from strict.js.
 */
export const strictRules = {
	/**
	 * Require jsdoc/tsdoc comments on public/exported API items.
	 */
	"jsdoc/require-jsdoc": [
		"error",
		{
			// Indicates that only module exports should be flagged for lacking jsdoc comments
			publicOnly: true,
			// Prevents eslint from adding empty comment blocks when run with `--fix`
			enableFixer: false,
			require: {
				ArrowFunctionExpression: true,
				ClassDeclaration: true,
				ClassExpression: true,
				FunctionDeclaration: true,
				FunctionExpression: true,

				// Will report for *any* methods on exported classes, regardless of whether or not they are public
				MethodDefinition: false,
			},
			contexts: [
				"TSEnumDeclaration",
				"TSInterfaceDeclaration",
				"TSTypeAliasDeclaration",

				// Require JSDoc/TSDoc comments on variable declarations, but only those that are named exports.
				// Specifying just "VariableDeclaration" results in eslint flagging all variable declarations scoped within something that is exported, including in the body of functions, which is not desired.
				"ExportNamedDeclaration > VariableDeclaration",
			],
			// Require docs on overload signatures.
			skipInterveningOverloadedDeclarations: false,

			// Do not require docs on overload implementations - only the overload signatures need them.
			exemptOverloadedImplementations: true,
		},
	],
} as const satisfies Linter.RulesRecord;

/**
 * TypeScript-specific strict rules from strict.js.
 */
export const strictTsRules = {
	"@typescript-eslint/explicit-member-accessibility": [
		"error",
		{
			accessibility: "explicit",
			overrides: {
				accessors: "explicit",
				constructors: "explicit",
				methods: "explicit",
				properties: "explicit",
				parameterProperties: "explicit",
			},
		},
	],

	/**
	 * Prefer Record to index-signature object style. That is, prefer:
	 *
	 * ```ts
	 * type Foo = Record<string, unknown>;
	 * ```
	 *
	 * to
	 *
	 * ```ts
	 * type Foo = {
	 *   [key: string]: unknown;
	 * }
	 * ```
	 */
	"@typescript-eslint/consistent-indexed-object-style": "error",

	/**
	 * Flags when an enum-typed value is compared to a non-enum number.
	 */
	"@typescript-eslint/no-unsafe-enum-comparison": "error",

	/**
	 * Prefer generic type annotations on the constructor.
	 *
	 * @example
	 *
	 * This:
	 *
	 * ```ts
	 * const map = new Map<string, number>();
	 * ```
	 *
	 * instead of:
	 *
	 * ```ts
	 * const map: Map<string, number> = new Map();
	 * ```
	 */
	"@typescript-eslint/consistent-generic-constructors": "error",

	"@typescript-eslint/no-redundant-type-constituents": "error",
} as const satisfies Linter.RulesRecord;