Remove lodash

package.json

@@ -50,6 +50,7 @@
     "chalk": "^4.1.2",
     "cross-spawn": "^7.0.5",
     "dedent": "^0.7.0",
+    "deepmerge-ts": "^7.1.3",
     "eslint": "^8.57.0",
     "eslint-config-airbnb-base": "^15.0.0",
     "eslint-config-airbnb-typescript": "^18.0.0",
@@ -70,7 +71,6 @@
     "lint-staged": "15.2.10",
     "listr": "^0.14.3",
     "listr-inquirer": "^0.1.0",
-    "lodash": "^4.17.21",
     "prettier": "^3.3.3",
     "read-pkg-up": "^7.0.1",
     "semver": "^7.6.3",
@@ -89,7 +89,6 @@
     "@types/inquirer": "^8.2.10",
     "@types/is-ci": "^3.0.4",
     "@types/listr": "^0.14.9",
-    "@types/lodash": "^4.17.13",
     "@types/node": "^18.19.0",
     "@types/prettier": "^3.0.0",
     "@types/semver": "^7.5.8",

src/cli/debug.ts

@@ -13,17 +13,20 @@
  * limitations under the License.
  */
 
-import { isArray, isEmpty, mapValues } from 'lodash/fp';
-
 import { getOptions } from '../lib/options';
 import * as logger from '../lib/logger';
+import { isArray } from '../lib/type-check';
+import { isEmpty } from '../lib/helpers';
 
 export function debug(): void {
   const options = getOptions();
 
-  const stringifiedOptions = mapValues(
-    (value) => (isArray(value) && !isEmpty(value) ? value.join(', ') : value),
-    options,
+  const stringifiedOptions = Object.entries(options).reduce(
+    (acc, [key, value]) => {
+      acc[key] = isArray(value) && !isEmpty(value) ? value.join(', ') : value;
+      return acc;
+    },
+    {} as Record<string, unknown>,
   );
 
   logger.empty();

src/cli/run.ts

@@ -17,11 +17,10 @@ import { dirname, resolve, join, relative } from 'node:path';
 import { access, readFile } from 'node:fs';
 import { promisify } from 'node:util';
 
-import { isString } from 'lodash/fp';
-
 import type { PackageJson } from '../types/shared';
 import { spawn } from '../lib/spawn';
 import * as logger from '../lib/logger';
+import { isString } from '../lib/type-check';
 
 const readFileAsync = promisify(readFile);
 const accessAsync = promisify(access);

src/configs/eslint/config.ts

@@ -16,7 +16,7 @@
 import { cwd } from 'node:process';
 import path from 'node:path';
 
-import { flow, mergeWith, isArray, isObject, isEmpty, uniq } from 'lodash/fp';
+import { deepmergeCustom } from 'deepmerge-ts';
 
 import {
   Language,
@@ -27,30 +27,25 @@ import {
 } from '../../types/shared';
 import * as logger from '../../lib/logger';
 import { getOptions } from '../../lib/options';
+import { isEmpty, flow, uniq } from '../../lib/helpers';
 
 // NOTE: Using the Linter.Config interface from ESLint causes errors
 //       and I couldn't figure out how to fix them. — @connor_baer
 type ESLintConfig = unknown;
 
-export const customizeConfig = mergeWith(customizer);
-
-function isArrayTypeGuard(array: unknown): array is unknown[] {
-  return isArray(array);
-}
-
-function customizer(
-  objValue: unknown,
-  srcValue: unknown,
-  key: string,
-): unknown {
-  if (isArrayTypeGuard(objValue) && isArrayTypeGuard(srcValue)) {
-    return uniq([...objValue, ...srcValue]);
-  }
-  if (isObject(objValue) && isObject(srcValue)) {
-    return key === 'rules' ? { ...objValue, ...srcValue } : undefined;
-  }
-  return undefined;
-}
+export const customizeConfig = deepmergeCustom({
+  mergeArrays: (values) => {
+    const [baseValue, sourceValue] = values;
+    return uniq([...baseValue, ...sourceValue]);
+  },
+  mergeRecords: (values, utils, meta) => {
+    const [baseValue, sourceValue] = values;
+    if (meta?.key === 'rules') {
+      return { ...baseValue, ...sourceValue };
+    }
+    return utils.actions.defaultMerge;
+  },
+});
 
 export function getFileGlobsForWorkspaces(
   workspaces: Workspaces,
@@ -452,7 +447,7 @@ function customizeLanguage(language: Language, useBiome: boolean) {
       return config;
     }
     const overrides = languageMap[language];
-    return customizeConfig(config, overrides);
+    return overrides ? customizeConfig(config, overrides) : config;
   };
 }
 
@@ -516,7 +511,7 @@ function customizeEnvironments(environments: Environment[]) {
     }
     return environments.reduce((acc, environment: Environment) => {
       const overrides = environmentMap[environment];
-      return customizeConfig(acc, overrides);
+      return overrides ? customizeConfig(acc, overrides) : acc;
     }, config);
   };
 }
@@ -614,7 +609,7 @@ function customizeFramework(frameworks: Framework[]) {
 
     return frameworks.reduce((acc, framework: Framework) => {
       const overrides = frameworkMap[framework];
-      return customizeConfig(acc, overrides);
+      return overrides ? customizeConfig(acc, overrides) : acc;
     }, config);
   };
 }
@@ -709,7 +704,7 @@ function customizePlugin(plugins: Plugin[], workspaces: Workspaces) {
 
     return plugins.reduce((acc, plugin: Plugin) => {
       const overrides = pluginMap[plugin];
-      return customizeConfig(acc, overrides);
+      return overrides ? customizeConfig(acc, overrides) : acc;
     }, config);
   };
 }

src/configs/husky/config.ts

@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { merge } from 'lodash/fp';
+import { deepmerge } from 'deepmerge-ts';
 
 interface HuskyConfig {
   skipCI?: boolean;
@@ -27,5 +27,5 @@ export const base: HuskyConfig = {
 };
 
 export function config(overrides: HuskyConfig = {}): HuskyConfig {
-  return merge(base, overrides);
+  return deepmerge(base, overrides);
 }

src/configs/stylelint/config.ts

@@ -14,30 +14,25 @@
  */
 
 import type { Config as StylelintConfig } from 'stylelint';
-import { flow, mergeWith, isArray, isObject, uniq, isEmpty } from 'lodash/fp';
+import { deepmergeCustom } from 'deepmerge-ts';
 
 import { getOptions } from '../../lib/options';
+import { isEmpty, flow, uniq } from '../../lib/helpers';
 import { Plugin } from '../../types/shared';
 
-export const customizeConfig = mergeWith(customizer);
-
-function isArrayTypeGuard(array: unknown): array is unknown[] {
-  return isArray(array);
-}
-
-function customizer(
-  objValue: unknown,
-  srcValue: unknown,
-  key: string,
-): unknown {
-  if (isArrayTypeGuard(objValue) && isArrayTypeGuard(srcValue)) {
-    return uniq([...objValue, ...srcValue]);
-  }
-  if (isObject(objValue) && isObject(srcValue)) {
-    return key === 'rules' ? { ...objValue, ...srcValue } : undefined;
-  }
-  return undefined;
-}
+export const customizeConfig = deepmergeCustom({
+  mergeArrays: (values) => {
+    const [baseValue, sourceValue] = values;
+    return uniq([...baseValue, ...sourceValue]);
+  },
+  mergeRecords: (values, utils, meta) => {
+    const [baseValue, sourceValue] = values;
+    if (meta?.key === 'rules') {
+      return { ...baseValue, ...sourceValue };
+    }
+    return utils.actions.defaultMerge;
+  },
+});
 
 const base: StylelintConfig = {
   extends: ['stylelint-config-standard', 'stylelint-config-recess-order'],
@@ -87,7 +82,7 @@ function customizePlugin(plugins: Plugin[]) {
 
     return plugins.reduce((acc, plugin: Plugin) => {
       const overrides = pluginMap[plugin];
-      return customizeConfig(acc, overrides);
+      return overrides ? customizeConfig(acc, overrides) : config;
     }, config);
   };
 }

src/lib/choices.ts

@@ -13,28 +13,24 @@
  * limitations under the License.
  */
 
-import { isArray } from 'lodash/fp';
+import { isArray } from './type-check';
 
 type Enum = { [key: string]: string };
 type Choices = { [key: string]: Enum | Enum[] };
 type Combination = { [key: string]: string | string[] };
 
-function isArrayTypeGuard(array: unknown): array is unknown[] {
-  return isArray(array);
-}
-
 export function getAllChoiceCombinations(
   possibleChoices: Choices,
 ): Combination[] {
   return Object.entries(possibleChoices).reduce(
     (acc, [optionName, choices]) => {
-      const choiceEnum = isArrayTypeGuard(choices) ? choices[0] : choices;
+      const choiceEnum = isArray(choices) ? choices[0] : choices;
       const choicesForOption = Object.values(choiceEnum);
       const allCombinations: Combination[] = [];
 
       acc.forEach((combination: Combination) => {
         choicesForOption.forEach((value) => {
-          const choice = isArrayTypeGuard(choices) ? [value] : value;
+          const choice = isArray(choices) ? [value] : value;
           allCombinations.push({
             ...combination,
             [optionName]: choice,

src/lib/helpers.spec.ts

@@ -0,0 +1,56 @@
+/**
+ * Copyright 2024, SumUp Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { describe, expect, it, vi } from 'vitest';
+
+import { flow, uniq } from './helpers.js';
+
+describe('helpers', () => {
+  describe('flow', () => {
+    it('should call each function', () => {
+      const fn1 = vi.fn((value: string) => value);
+      const fn2 = vi.fn((value: string) => value);
+      const fn3 = vi.fn((value: string) => value);
+      const value = 'foo';
+      const actual = flow(fn1, fn2, fn3)(value);
+
+      expect(fn1).toHaveBeenCalledWith(value);
+      expect(fn2).toHaveBeenCalledWith(value);
+      expect(fn3).toHaveBeenCalledWith(value);
+      expect(actual).toBe(value);
+    });
+
+    it('should call the next function with the previous return value', () => {
+      const fn1 = vi.fn((value: number) => value + 1);
+      const fn2 = vi.fn((value: number) => value + 2);
+      const fn3 = vi.fn((value: number) => value + 3);
+      const value = 0;
+      const actual = flow(fn1, fn2, fn3)(value);
+
+      expect(fn1).toHaveBeenCalledWith(0);
+      expect(fn2).toHaveBeenCalledWith(1);
+      expect(fn3).toHaveBeenCalledWith(3);
+      expect(actual).toBe(6);
+    });
+  });
+
+  describe('uniq', () => {
+    it('should return an array of unique values', () => {
+      const values = [1, 3, 3, 4, 5, 1, 'foo', 'bar', 'foo'];
+      const actual = uniq(values);
+      expect(actual).toEqual([1, 3, 4, 5, 'foo', 'bar']);
+    });
+  });
+});