chore: Upgrade to Yarn 4.x

.github/workflows/continuous-integration.yaml

@@ -6,11 +6,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+      - run: corepack enable
       - uses: actions/setup-node@v4
         with:
           node-version: '20'
           cache: 'yarn'
-      - run: yarn install --frozen-lockfile
+      - run: yarn install --immutable
       - run: yarn run test
       - run: yarn run lint
       - run: yarn run flow

.gitignore

@@ -1,4 +1,5 @@
-index-dist.js
-node_modules/
+.yarn/
 dist/
+node_modules/
+index-dist.js
 npm-debug.log

.yarnrc.yml

@@ -0,0 +1 @@
+nodeLinker: node-modules

package.json

@@ -2,7 +2,7 @@
   "name": "react-element-to-jsx-string",
   "version": "16.0.0",
   "description": "Turn a ReactElement into the corresponding JSX string.",
-  "packageManager": "yarn@1.22.22+sha1.ac34549e6aa8e7ead463a7407e1c7390f61a6610",
+  "packageManager": "yarn@4.6.0",
   "main": "dist/cjs/index.js",
   "module": "dist/esm/index.js",
   "browser": "dist/cjs/index.js",

tests/smoke/.gitignore

@@ -1,3 +1,3 @@
 node_modules
 package.json
-yarn.lock
+package-lock.json

tests/smoke/.yarnrc.yml

@@ -0,0 +1,4 @@
+nodeLinker: node-modules
+
+enableHardenedMode: false
+enableImmutableInstalls: false

tests/smoke/prepare.js

@@ -54,7 +54,7 @@ const installDependencies = () => () =>
       return;
     }
 
-    execSync('yarn install --no-lockfile', {
+    execSync('npm install', {
       cwd: __dirname,
       stdio: 'inherit',
     });

tests/smoke/smoke.js

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 
-/* eslint-disable no-console, import/no-extraneous-dependencies, no-global-assign */
+/* eslint-disable no-console, import/no-extraneous-dependencies, no-global-assign, import/extensions */
 
 require = require('esm')(module);
 

tests/smoke/yarn.lock

@@ -0,0 +1,8 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+react@19.0.0:
+  version "19.0.0"
+  resolved "https://registry.npmjs.org/react/-/react-19.0.0.tgz"
+  integrity sha512-V8AVnmPIICiWpGfm6GLzCR/W5FXLchHop40W4nXBmdlEceh16rCN8O8LNWm5bh5XUX91fh7KpA+W0TgMKmgTpQ==