feat(validator): improve configuration validation

- run validation only once, from main thread
- combine eslintrc.rules validation into same method
- rulesUnderTesting: from required to optional field
- array configs: only unique strings allowed
- numeric configs: only positive numbers allowed
- add tests for config, tested via package public API

.gitignore

@@ -1,4 +1,5 @@
 node_modules
+coverage
 log
 libraries-io.json
 

README.md

@@ -70,7 +70,7 @@ module.exports = {
     /** Optional max file size used to exclude bigger files. Defaults to 2 megabytes. */
     maxFileSizeBytes: 2000000,
 
-    /** Rules used to filter out results. Use empty array when ESLint crashes are the only interest */
+    /** Optional array of rules used to filter out results. Use undefined or empty array when ESLint crashes are the only interest */
     rulesUnderTesting: [],
 
     /** Optional syntax for the result parser. Valid values are plaintext, markdown. Defaults to markdown on CLI, plaintext on CI */

eslint-remote-tester.react.config.js

@@ -193,7 +193,7 @@ module.exports = {
         'jquery-3\\.4\\.1\\.min\\.js',
     ].join('|')})`,
 
-    /** Rules used to filter out results */
+    /** Optional array of rules used to filter out results. Use undefined or empty array when ESLint crashes are the only interest */
     rulesUnderTesting: ['react/no-unstable-nested-components'],
 
     /** Optional syntax for the result parser. Valid values are plaintext, markdown. Defaults to markdown on CLI, plaintext on CI */

lib/config/config-templates.ts

@@ -19,7 +19,7 @@ export const CONFIGURATION_FILE_TEMPLATE =
     /** Optional max file size (bytes) used to exclude bigger files. Defaults to 2 megabytes. */
     maxFileSizeBytes: 2000000,
 
-    /** Rules used to filter out results */
+    /** Optional array of rules used to filter out results. Use undefined or empty array when ESLint crashes are the only interest */
     rulesUnderTesting: ['react/no-direct-mutation-state'],
 
     /** Optional syntax for the result parser. Valid values are plaintext, markdown. Defaults to markdown on CLI, plaintext on CI */

lib/config/config.ts

@@ -3,9 +3,8 @@ import path from 'path';
 import chalk from 'chalk';
 import { workerData, isMainThread } from 'worker_threads';
 
-import constructAndValidateConfiguration from './validator';
+import { getConfigWithDefaults } from './validator';
 import { CONFIGURATION_FILE_TEMPLATE } from './config-templates';
-import { Config } from './types';
 import { WorkerData } from '@engine/types';
 
 const DEFAULT_CONFIGURATION_FILE = 'eslint-remote-tester.config.js';
@@ -57,6 +56,7 @@ if (!fs.existsSync(CONFIGURATION_FILE)) {
     process.exit();
 }
 
-const config: Config = require(path.resolve(CONFIGURATION_FILE));
+const configFileContents = require(path.resolve(CONFIGURATION_FILE));
+const config = getConfigWithDefaults(configFileContents);
 
-export default constructAndValidateConfiguration(config);
+export default config;

lib/config/index.ts

@@ -1,2 +1,2 @@
 export { default, resolveConfigurationLocation } from './config';
-export { validateEslintrcRules } from './validator';
+export { default as validateConfig } from './validator';

lib/config/types.d.ts

@@ -2,13 +2,17 @@ import { Linter } from 'eslint';
 
 import { ResultTemplateOptions } from '@file-client/result-templates';
 
+type AllKeysOptional<T extends { [K: string]: any }> = {
+    [K in keyof T]?: T[K];
+};
+
 export const ResultParsers: ['plaintext', 'markdown'];
 export type ResultParser = typeof ResultParsers[number];
 
 export const LogLevels: ['verbose', 'info', 'warn', 'error'];
 export type LogLevel = typeof LogLevels[number];
 
-/** Contents of the `eslint-remote-tester.config.js` */
+/** Internal config typings after defaults have been set */
 export interface Config {
     repositories: string[];
     extensions: string[];
@@ -25,9 +29,20 @@ export interface Config {
     onComplete?: (results: ResultTemplateOptions[]) => Promise<void> | void;
 }
 
-type AllKeysOptional<T extends { [K: string]: any }> = {
-    [K in keyof T]?: T[K];
-};
+type RequiredFields = Pick<Config, 'repositories' | 'extensions' | 'eslintrc'>;
+type OptionalFields = AllKeysOptional<
+    Pick<
+        Config,
+        Exclude<keyof Config, keyof RequiredFields | 'pathIgnorePattern'>
+    >
+> &
+    // Internally a RegExp, publicly string
+    AllKeysOptional<{
+        pathIgnorePattern: string | Config['pathIgnorePattern'];
+    }>;
+
+/** Config matching public API */
+export type ConfigWithOptionals = RequiredFields & OptionalFields;
 
 /** Config before validation */
-export type ConfigToValidate = AllKeysOptional<Config>;
+export type ConfigToValidate = AllKeysOptional<ConfigWithOptionals>;