refactor: remove lodash

With the help of [You don't need lodash](https://github.com/you-dont-need/You-Dont-Need-Lodash-Underscore). Exceptions are:

- Replaced _.isEqual with [fast-deep-equal](https://github.com/epoberezkin/fast-deep-equal)
- Reimplemented sampleSize
- Reimplemented camelCase

Done as part of my investigation into jest memory leakage. Unfortunately it's brought in via a lot of our dependencies, but it helps a bit

lib/manager/npm/update.ts

@@ -1,4 +1,4 @@
-import { isEqual } from 'lodash';
+import equal from 'fast-deep-equal';
 import { ReleaseType, inc } from 'semver';
 import { logger } from '../../logger';
 import { matchAt, replaceAt } from '../../util/string';
@@ -117,7 +117,7 @@ export function updateDependency({
           newString
         );
         // Compare the parsed JSON structure of old and new
-        if (isEqual(parsedContents, JSON.parse(testContent))) {
+        if (equal(parsedContents, JSON.parse(testContent))) {
           newFileContent = testContent;
           break;
         }
@@ -172,7 +172,7 @@ export function updateDependency({
               newResolution
             );
             // Compare the parsed JSON structure of old and new
-            if (isEqual(parsedContents, JSON.parse(testContent))) {
+            if (equal(parsedContents, JSON.parse(testContent))) {
               newFileContent = testContent;
               break;
             }

lib/manager/travis/package.ts

@@ -1,5 +1,5 @@
 import is from '@sindresorhus/is';
-import { isEqual } from 'lodash';
+import equal from 'fast-deep-equal';
 import { getPkgReleases } from '../../datasource';
 import * as datasourceGithubTags from '../../datasource/github-tags';
 import { logger } from '../../logger';
@@ -124,7 +124,7 @@ export async function getPackageUpdates(
 
   // TODO: `config.currentValue` is a string!
   (config.currentValue as any).sort((a, b) => a - b);
-  if (isEqual(config.currentValue, newValue)) {
+  if (equal(config.currentValue, newValue)) {
     return [];
   }
   return [

lib/util/index.ts

@@ -23,3 +23,21 @@ export async function resolveFile(file: string): Promise<string> {
   }
   return join(pkg, '../', file);
 }
+
+export function sampleSize(array: string[], n: number): string[] {
+  const length = array == null ? 0 : array.length;
+  if (!length || n < 1) {
+    return [];
+  }
+  // eslint-disable-next-line no-param-reassign
+  n = n > length ? length : n;
+  let index = 0;
+  const lastIndex = length - 1;
+  const result = [...array];
+  while (index < n) {
+    const rand = index + Math.floor(Math.random() * (lastIndex - index + 1));
+    [result[rand], result[index]] = [result[index], result[rand]];
+    index += 1;
+  }
+  return result.slice(0, n);
+}

lib/util/string.ts

@@ -23,3 +23,11 @@ export function replaceAt(
     content.substr(index + oldString.length)
   );
 }
+
+export function camelCase(input: string): string {
+  return input
+    .replace(/(?:^\w|[A-Z]|\b\w)/g, (char, index) => {
+      return index === 0 ? char.toLowerCase() : char.toUpperCase();
+    })
+    .replace(/-/g, '');
+}

lib/versioning/ruby/version.ts

@@ -1,6 +1,5 @@
 import { diff, major, minor, patch, prerelease } from '@snyk/ruby-semver';
 import { create } from '@snyk/ruby-semver/lib/ruby/gem-version';
-import last from 'lodash/last';
 
 interface RubyVersion {
   major: number;
@@ -25,9 +24,9 @@ const floor = (version: string): string =>
 // istanbul ignore next
 const incrementLastSegment = (version: string): string => {
   const segments = create(version).release().getSegments();
-  const nextLast = parseInt(last(segments), 10) + 1;
+  const nextLast = parseInt(segments.pop(), 10) + 1;
 
-  return [...segments.slice(0, -1), nextLast].join('.');
+  return [...segments, nextLast].join('.');
 };
 
 // istanbul ignore next

lib/workers/branch/index.ts

@@ -1,5 +1,4 @@
 import is from '@sindresorhus/is';
-import { concat } from 'lodash';
 import { DateTime } from 'luxon';
 import minimatch from 'minimatch';
 import { RenovateConfig } from '../../config';
@@ -344,8 +343,7 @@ export async function processBranch(
 
       if (is.nonEmptyArray(commands)) {
         // Persist updated files in file system so any executed commands can see them
-        for (const file of concat(
-          config.updatedPackageFiles,
+        for (const file of config.updatedPackageFiles.concat(
           config.updatedArtifacts
         )) {
           if (file.name !== '|delete|') {

lib/workers/pr/index.ts

@@ -1,5 +1,3 @@
-import sampleSize from 'lodash/sampleSize';
-import uniq from 'lodash/uniq';
 import { RenovateConfig } from '../../config/common';
 import {
   PLATFORM_FAILURE,
@@ -10,6 +8,7 @@ import {
 import { logger } from '../../logger';
 import { PlatformPrOptions, Pr, platform } from '../../platform';
 import { BranchStatus } from '../../types';
+import { sampleSize } from '../../util';
 import { BranchConfig, PrResult } from '../common';
 import { getPrBody } from './body';
 import { ChangeLogError } from './changelog';
@@ -27,7 +26,7 @@ async function addCodeOwners(
   assigneesOrReviewers: string[],
   pr: Pr
 ): Promise<string[]> {
-  return uniq(assigneesOrReviewers.concat(await codeOwnersForPr(pr)));
+  return [...new Set(assigneesOrReviewers.concat(await codeOwnersForPr(pr)))];
 }
 
 export async function addAssigneesReviewers(
@@ -69,7 +68,7 @@ export async function addAssigneesReviewers(
         const additionalReviewers = config.additionalReviewers.map(
           noLeadingAtSymbol
         );
-        reviewers = uniq(reviewers.concat(additionalReviewers));
+        reviewers = [...new Set(reviewers.concat(additionalReviewers))];
       }
       if (config.reviewersSampleSize !== null) {
         reviewers = sampleSize(reviewers, config.reviewersSampleSize);

package.json

@@ -124,6 +124,7 @@
     "delay": "4.3.0",
     "detect-indent": "6.0.0",
     "email-addresses": "3.1.0",
+    "fast-deep-equal": "3.1.3",
     "fast-safe-stringify": "2.0.7",
     "find-up": "4.1.0",
     "fs-extra": "9.0.1",
@@ -141,7 +142,6 @@
     "json5": "2.1.3",
     "later": "1.2.0",
     "linkify-markdown": "1.0.0",
-    "lodash": "4.17.15",
     "luxon": "1.24.1",
     "markdown-it": "10.0.0",
     "markdown-table": "1.1.3",

tools/generate-imports.ts

@@ -1,7 +1,8 @@
 import fs from 'fs-extra';
-import _ from 'lodash';
 import shell from 'shelljs';
 
+import { camelCase } from '../lib/util/string';
+
 shell.echo('generating imports');
 const newFiles = new Set();
 
@@ -43,7 +44,7 @@ async function generate({
   for (const ds of findModules(`lib/${path}`).filter(
     (n) => !excludes?.includes(n)
   )) {
-    const name = _.camelCase(ds);
+    const name = camelCase(ds);
     imports += `import * as ${name} from './${ds}';\n`;
     maps += `api.set('${ds}', ${name}${map});\n`;
   }