feat: add jest mutator to lint-staged and refactor lint-staged mutators

Author: allohamora

src/categories/js/jest/jest.utils.ts

@@ -0,0 +1,5 @@
+import { isInstalledAndInRootCheck } from 'src/utils/installed';
+import { SCRIPT_NAME } from '../commitlint/commitlint.const';
+import { CONFIG_FILE_NAME } from './jest.const';
+
+export const isJestInstalled = isInstalledAndInRootCheck(SCRIPT_NAME, CONFIG_FILE_NAME);

src/categories/js/lint-staged/config/default.config.ts

@@ -1,7 +1,7 @@
-import { prettierMutator } from '../lint-staged.utils';
+import { eslintMutator, jestMutator, prettierMutator } from '../lint-staged.utils';
 import { Config } from './config.interface';
 
 export const defaultConfig: Config = {
   config: {},
-  mutators: [prettierMutator],
+  mutators: [prettierMutator, eslintMutator('*.js'), jestMutator('*.js')],
 };

src/categories/js/lint-staged/config/node:ts.config.ts

@@ -1,14 +1,7 @@
-import { isEslintInstalled } from '../../eslint/eslint.utils';
-import { prettierMutator } from '../lint-staged.utils';
-import { Config, LintStagedConfig } from './config.interface';
-
-const eslintNodeTsConfigMutator = async (config: LintStagedConfig) => {
-  if (await isEslintInstalled()) {
-    config['*.ts'] = 'eslint --fix';
-  }
-};
+import { eslintMutator, jestMutator, prettierMutator } from '../lint-staged.utils';
+import { Config } from './config.interface';
 
 export const nodeTsConfig: Config = {
   config: {},
-  mutators: [prettierMutator, eslintNodeTsConfigMutator],
+  mutators: [prettierMutator, eslintMutator('*.ts'), jestMutator('*.ts')],
 };

src/categories/js/lint-staged/lint-staged.utils.ts

@@ -3,15 +3,70 @@ import { isPrettierInstalled } from '../prettier/prettier.utils';
 import { addHook, isHuskyInstalled } from '../husky/husky.utils';
 import { CLI_NAME } from './lint-staged.const';
 import { CLI_NAME as PRETTIER_CLI_NAME } from '../prettier/prettier.const';
+import { isJestInstalled } from '../jest/jest.utils';
+import { isEslintInstalled } from '../eslint/eslint.utils';
+
+type ScriptFileExtension = '*.js' | '*.ts';
+
+interface OptionMutator {
+  check: (config: LintStagedConfig, key: string, value: string) => boolean;
+  mutate: (config: LintStagedConfig, key: string, value: string) => void;
+}
+
+const arrayOptionMutator: OptionMutator = {
+  check: (config, key) => Array.isArray(config[key]),
+  mutate: (config, key, value) => {
+    config[key] = Array.from(new Set([...(config[key] as unknown[]), value]));
+  },
+};
+
+const stringOptionMutator: OptionMutator = {
+  check: (config, key) => typeof config[key] === 'string',
+  mutate: (config, key, value) => {
+    const array = Array.from(new Set([config[key], value]));
+    config[key] = array.length === 0 ? array[0] : array;
+  },
+};
+
+const undefinedOptionMutator: OptionMutator = {
+  check: (config, key) => typeof config[key] === 'undefined',
+  mutate: (config, key, value) => {
+    config[key] = value;
+  },
+};
+
+const optionMutators: OptionMutator[] = [arrayOptionMutator, stringOptionMutator, undefinedOptionMutator];
+
+export const addOptionToLintStagedConfig = (config: LintStagedConfig, key: string, value: string) => {
+  const finded = optionMutators.find(({ check }) => check(config, key, value));
+
+  if (!finded) {
+    throw new Error('option mutator is not found!');
+  }
+
+  finded.mutate(config, key, value);
+};
 
 export const huskyIntegration = async () => {
   if (await isHuskyInstalled()) {
     await addHook('pre-commit', `npx --no-install ${CLI_NAME}`);
   }
 };
 
+export const jestMutator = (fileExtension: ScriptFileExtension) => async (config: LintStagedConfig) => {
+  if (await isJestInstalled()) {
+    addOptionToLintStagedConfig(config, fileExtension, 'jest --findRelatedTests');
+  }
+};
+
+export const eslintMutator = (fileExtension: ScriptFileExtension) => async (config: LintStagedConfig) => {
+  if (await isEslintInstalled()) {
+    addOptionToLintStagedConfig(config, fileExtension, 'eslint --fix');
+  }
+};
+
 export const prettierMutator = async (config: LintStagedConfig) => {
   if (await isPrettierInstalled()) {
-    config['*.{js,json,yml,md}'] = `${PRETTIER_CLI_NAME} --write`;
+    addOptionToLintStagedConfig(config, '*.{js,json,yml,md}', `${PRETTIER_CLI_NAME} --write`);
   }
 };