fix: generating projects with yarn

Author: dannyhw

.changeset/cold-rivers-tell.md

@@ -0,0 +1,6 @@
+---
+'create-expo-stack': patch
+'rn-new': patch
+---
+
+fixes for yarn project generations

bun.lockb

@@ -186,5 +186,8 @@
   <% if (props.navigationPackage?.name !== "expo-router") { %>
     "main": "node_modules/expo/AppEntry.js",
   <% } %>
-  "private": true
+  "private": true,
+  <% if  (props.packageManager === "yarn"){ %>
+    "packageManager": "[email protected]"
+  <% } %>
 }

cli/src/templates/base/package.json.ejs

@@ -83,7 +83,13 @@ export function getDefaultPackageManagerVersion() {
 }
 
 export function getVersionForPackageManager(packageManager: PackageManager): string {
-  const version = require('child_process').execSync(`${packageManager} --version`);
+  try {
+    const version = require('child_process').execSync(`${packageManager} --version`);
 
-  return version.toString().replace('\n', '');
+    return version.toString().replace('\n', '');
+  } catch (_error) {
+    // this happens with yarn because its dumb
+    console.log(`Error getting version for package manager ${packageManager}`);
+    return 'unknown';
+  }
 }

cli/src/utilities/getPackageManager.ts

@@ -1,12 +1,18 @@
 import { outro, spinner } from '@clack/prompts';
 import { Toolbox } from 'gluegun/build/types/domain/toolbox';
+import os from 'os';
 import { AvailablePackages, CliResults } from '../types';
 import { copyBaseAssets } from './copyBaseAssets';
+import { generateNWUI } from './generateNWUI';
 import { getPackageManager, getPackageManagerRunnerX } from './getPackageManager';
 import { easConfigure } from './runEasConfigure';
 import { ONLY_ERRORS, runSystemCommand } from './systemCommand';
-import { generateNWUI } from './generateNWUI';
-import os from 'os';
+import { appendFile, writeFile } from 'fs/promises';
+
+const yarnRcFixes = `
+enableGlobalCache: false
+
+nodeLinker: node-modules`;
 
 export async function printOutput(
   cliResults: CliResults,
@@ -47,6 +53,21 @@ export async function printOutput(
 
     const additionalFlags = isNpm ? '--silent --no-audit --progress=false --legacy-peer-deps' : '--silent';
 
+    if (packageManager === 'yarn') {
+      // create empty yarn.lock to stop yarn from complaining
+      await writeFile(`${projectName}/yarn.lock`, '');
+
+      // apply fixes to .yarnrc.yml to stop issues with PnP and caching
+      await appendFile(`${projectName}/.yarnrc.yml`, yarnRcFixes);
+
+      await runSystemCommand({
+        toolbox,
+        command: `cd ${projectName} && yarn set version stable`,
+        stdio: ONLY_ERRORS,
+        errorMessage: 'Error setting yarn version'
+      });
+    }
+
     await runSystemCommand({
       toolbox,
       command: `cd ${projectName} && ${packageManager} install ${additionalFlags}`,