feat: export configuration types (#321)

* feat: export `config` typings as part of public API

* docs: typescript configuration file instructions

README.md

@@ -59,6 +59,7 @@ Add new script to your `package.json` file.
 Create new configuration file `eslint-remote-tester.config.js` in the root of your project. This is used as configuration file by default. Use `-c` or `--config` argument for custom configuration file, e.g. `--config path/custom.config.js`.
 
 ```js
+/** @type {import('eslint-remote-tester').Config} */
 module.exports = {
     repositories: ['mui-org/material-ui', 'reach/reach-ui'],
     extensions: ['js', 'jsx', 'ts', 'tsx'],
@@ -75,6 +76,23 @@ module.exports = {
 };
 ```
 
+Configuration file can also be written in TypeScript if [`ts-node`](https://www.npmjs.com/package/ts-node) is installed. Use `--config` argument for TypeScript configuration file, e.g. `--config eslint-remote-tester.config.ts`.
+
+```ts
+import type { Config } from 'eslint-remote-tester';
+
+const config: Config = {
+    repositories: ['mui-org/material-ui', 'reach/reach-ui'],
+    extensions: ['js', 'jsx', 'ts', 'tsx'],
+    eslintrc: {
+        root: true,
+        extends: ['eslint:recommended'],
+    },
+};
+
+export default config;
+```
+
 #### Configuration options
 
 | Name                        | Description                                              | Type                                                                                                | Required           | Default                                | Example                                                                                                                          |

lib/config/types.ts

@@ -14,27 +14,81 @@ export type LogLevel = typeof LogLevels[number];
 
 /** Internal config typings after defaults have been set */
 export interface Config {
+    /** Repositories to scan in format of `owner/project` */
     repositories: string[];
+
+    /** Extensions of files under scanning */
     extensions: string[];
+
+    /** Regexp pattern string used to exclude paths */
     pathIgnorePattern?: RegExp;
+
+    /** Max file size used to exclude bigger files */
     maxFileSizeBytes: number;
+
+    /**
+     * Array of rules or a filter method used to filter out results.
+     * Use `undefined` or empty array when ESLint crashes are the only interest.
+     */
     rulesUnderTesting:
         | string[]
         | ((ruleId: string, options: { repository: string }) => boolean);
+
+    /** Syntax for the result parser */
     resultParser: ResultParser;
+
+    /** Maximum amount of tasks run concurrently */
     concurrentTasks: number;
+
+    /**
+     * ESLint configuration.
+     * Supports lazy initialization based on currently tested repository when a function is passed.
+     * Function is called with current repository and its location on filesystem.
+     */
     eslintrc:
         | Linter.Config
         | ((options?: {
               repository: string;
               location: string;
           }) => Linter.Config);
+
+    /** Flag used to set CI mode. `process.env.CI` is used when not set. */
     CI: boolean;
+
+    /** Filter log messages based on their priority */
     logLevel: LogLevel;
+
+    /**
+     * Flag used to enable caching of cloned repositories.
+     * For CIs it's ideal to disable caching due to limited disk space.
+     */
     cache: boolean;
+
+    /**
+     * Time limit before scan is interrupted and **exited successfully**.
+     * Ideal for avoiding CI timeouts in regression tests.
+     */
     timeLimit: number;
+
+    /**
+     * Flag used to enable result comparison mode.
+     * Compares results of two scans and output the diff.
+     * Ideal for identifying new false positives when fixing existing rules.
+     */
     compare: boolean;
+
+    /**
+     * Flag used to enable result comparison reference updating.
+     * Indicates whether comparison base should be updated after scan has finished.
+     * Ideal to be turned off once initial comparison base has been collected.
+     */
     updateComparisonReference: boolean;
+
+    /**
+     * Callback invoked once scan is completed.
+     * Asynchronous functions are supported.
+     * Ideal for extending the process with custom features.
+     */
     onComplete?: (
         results: Result[],
         comparisonResults: ComparisonResults | null,

lib/types.ts

@@ -0,0 +1,18 @@
+/*
+ * Typings exported as part of public API
+ */
+
+import type { ConfigWithOptionals } from '@config/types';
+
+/**
+ * Configuration for `eslint-remote-tester.config.ts`
+ */
+interface Config extends Omit<ConfigWithOptionals, 'pathIgnorePattern'> {
+    /** Regexp pattern string used to exclude paths */
+    pathIgnorePattern?: Exclude<
+        ConfigWithOptionals['pathIgnorePattern'],
+        RegExp
+    >;
+}
+
+export type { Config };

package.json

@@ -7,6 +7,7 @@
     "files": [
         "dist"
     ],
+    "types": "dist/types.d.ts",
     "bin": {
         "eslint-remote-tester": "dist/index.js"
     },