chore: migrate from yarn to pnpm

.github/workflows/CI.yml

@@ -23,16 +23,19 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.head.ref || github.ref_name }}
 
-      - name: Set Node.js 18.x
+      - name: Set up pnpm
+        uses: pnpm/action-setup@v6
+
+      - name: Set Node.js 24.x
         uses: actions/setup-node@v4
         with:
-          node-version: 18.x
-          cache: "yarn"
+          node-version: 24.x
+          cache: "pnpm"
 
-      - run: yarn install
+      - run: pnpm install
 
       - run: |
-          yarn all
+          pnpm all
 
       - name: Compare the expected and actual dist/ directories
         id: diff

__tests__/readConfig.test.ts

@@ -2,6 +2,7 @@ import * as fs from 'fs';
 import { readConfig, readJSONSync } from '../src/readConfig';
 
 jest.mock('fs', () => ({
+    ...jest.requireActual('fs'),
     existsSync: jest.fn(),
     readFileSync: jest.fn(),
     promises: {

action.yml

@@ -116,5 +116,5 @@ outputs:
   hasDuplicates:
     description: "A value indicating if any files were duplicated when `jscpdCheck` is `true`."
 runs:
-  using: "node16"
+  using: "node20"
   main: "dist/index.js"