Upgrade to PowerShell 7

.ado/jobs/e2e-test.yml

@@ -320,7 +320,7 @@ jobs:
               condition: and(failed(), eq(variables.StartedFabricTests, 'true'))
               continueOnError: true
 
-            - powershell: |
+            - pwsh: |
                 if (Test-Path "packages/e2e-test-app-fabric/test/__image_snapshots__/__diff_output__") {
                   Write-Host "##vso[task.setvariable variable=DiffOutputExists]true"
                 }

.ado/scripts/build.js

@@ -101,7 +101,7 @@ function ensureNuGet(toolsPath) {
   ensureDir(toolsPath);
   console.log(`Downloading nuget.exe to: ${localNuGet}`);
   execSync(
-    `powershell.exe -NoLogo -NoProfile -Command ` +
+    `pwsh.exe -NoLogo -NoProfile -Command ` +
       `"[Net.ServicePointManager]::SecurityProtocol = ` +
       `[Net.SecurityProtocolType]::Tls12; ` +
       `Invoke-WebRequest -Uri 'https://dist.nuget.org/win-x86-commandline/latest/nuget.exe' ` +

.ado/templates/install-SDK.yml

@@ -7,5 +7,6 @@ steps:
       targetType: filePath
       filePath: vnext\Scripts\Install-WindowsSdkISO.ps1
       arguments: ${{ parameters.sdkVersion }}
+      pwsh: true
     displayName: 'Install Insider SDK (${{ parameters.sdkVersion }})'
     condition: ne('', '${{ parameters.sdkVersion }}')

change/@react-native-windows-automation-10c8b2ce-ed81-450b-b846-4695f1ed4c4f.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Migrate to PowerShell 7",
+  "packageName": "@react-native-windows/automation",
+  "email": "julio.rocha@microsoft.com",
+  "dependentChangeType": "patch"
+}

change/@react-native-windows-cli-d0909d53-2984-4eff-bcf6-fe1702c03277.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Upgrade to PowerShell 7",
+  "packageName": "@react-native-windows/cli",
+  "email": "julio.rocha@microsoft.com",
+  "dependentChangeType": "patch"
+}

change/@react-native-windows-find-dotnet-tools-7018a5fe-0791-4fb7-ae1d-c95620216ddc.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Migrate to PowerShell 7",
+  "packageName": "@react-native-windows/find-dotnet-tools",
+  "email": "julio.rocha@microsoft.com",
+  "dependentChangeType": "patch"
+}

change/react-native-windows-f8669931-74f3-4c8e-a1d1-ecb19860ee42.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Upgrade to PowerShell 7",
+  "packageName": "react-native-windows",
+  "email": "julio.rocha@microsoft.com",
+  "dependentChangeType": "patch"
+}

packages/@react-native-windows/automation/package.json

@@ -18,6 +18,7 @@
   },
   "dependencies": {
     "@react-native-windows/automation-channel": "0.0.0-canary.1052",
+    "@react-native-windows/find-dotnet-tools": "0.0.0-canary.1",
     "@react-native-windows/fs": "^0.0.0-canary.72",
     "@typescript-eslint/eslint-plugin": "^8.36.0",
     "@typescript-eslint/parser": "^8.36.0",

packages/@react-native-windows/automation/src/AutomationEnvironment.ts

@@ -8,6 +8,7 @@
 import chalk from 'chalk';
 import {spawnSync, spawn, ChildProcess} from 'child_process';
 import fs from '@react-native-windows/fs';
+import {findPowerShell} from '@react-native-windows/find-dotnet-tools';
 import path from 'path';
 import readlineSync from 'readline-sync';
 
@@ -250,7 +251,7 @@ export default class AutomationEnvironment extends NodeEnvironment {
     if (this.breakOnStart) {
       readlineSync.question(
         chalk.bold.yellow('Breaking before tests start\n') +
-          'Press Enter to resume...',
+        'Press Enter to resume...',
       );
     }
 
@@ -335,8 +336,14 @@ function resolveAppName(appName: string): string {
   }
 
   try {
-    const packageFamilyName = spawnSync('powershell', [
-      `(Get-AppxPackage -Name ${appName}).PackageFamilyName`,
+    const useAppxCompatibility = !!process.env.TF_BUILD;
+    const packageFamilyNameCommand = useAppxCompatibility
+      ? `& { Import-Module Appx -UseWindowsPowerShell -WarningAction SilentlyContinue; (Get-AppxPackage -Name '${appName}').PackageFamilyName }`
+      : `(Get-AppxPackage -Name '${appName}').PackageFamilyName`;
+    const packageFamilyName = spawnSync(findPowerShell(), [
+      '-NoProfile',
+      '-Command',
+      packageFamilyNameCommand,
     ])
       .stdout.toString()
       .trim();

packages/@react-native-windows/cli/package.json

@@ -18,6 +18,7 @@
   },
   "dependencies": {
     "@react-native-windows/codegen": "0.0.0-canary.133",
+    "@react-native-windows/find-dotnet-tools": "0.0.0-canary.1",
     "@react-native-windows/fs": "^0.0.0-canary.72",
     "@react-native-windows/package-utils": "^0.0.0-canary.98",
     "@react-native-windows/telemetry": "^0.0.0-canary.133",

packages/@react-native-windows/cli/src/commands/healthCheck/healthChecks.ts

@@ -14,9 +14,11 @@ import type {
   HealthCheckCategory,
   HealthCheckInterface,
 } from '@react-native-community/cli-doctor/build/types';
-import {powershell} from '../../utils/commandWithProgress';
+import {findPowerShell} from '@react-native-windows/find-dotnet-tools';
 import {HealthCheckList} from './healthCheckList';
 
+const powershell = findPowerShell();
+
 export function getHealthChecks(): HealthCheckCategory[] | undefined {
   // #8471: There are known cases where the dependencies script will error out.
   // Fail gracefully if that happens in the meantime.
@@ -76,7 +78,7 @@ function getHealthChecksUnsafe(): HealthCheckCategory[] | undefined {
             };
           },
           runAutomaticFix: async ({loader, logManualInstallation}) => {
-            const command = `${powershell} -ExecutionPolicy Unrestricted -NoProfile "${rnwDepScriptPath}" -Check ${id}`;
+            const command = `"${powershell}" -ExecutionPolicy Unrestricted -NoProfile "${rnwDepScriptPath}" -Check ${id}`;
             try {
               const {exitCode} = await execa(command, {stdio: 'inherit'});
               if (exitCode) {

packages/@react-native-windows/cli/src/e2etest/healthChecks.test.ts

@@ -6,9 +6,11 @@
 
 import {execSync} from 'child_process';
 import path from 'path';
-import {powershell} from '../utils/commandWithProgress';
+import {findPowerShell} from '@react-native-windows/find-dotnet-tools';
 import {HealthCheckList} from '../commands/healthCheck/healthCheckList';
 
+const powershell = findPowerShell();
+
 test('Verify list of health checks aligns with rnw-dependencies', async () => {
   const rnwDepScriptPath = path.join(
     path.dirname(
@@ -20,7 +22,7 @@ test('Verify list of health checks aligns with rnw-dependencies', async () => {
   );
 
   const rnwDeps = execSync(
-    `${powershell} -ExecutionPolicy Unrestricted -NoProfile "${rnwDepScriptPath}" -NoPrompt -ListChecks`,
+    `"${powershell}" -ExecutionPolicy Unrestricted -NoProfile "${rnwDepScriptPath}" -NoPrompt -ListChecks`,
     {stdio: 'pipe'},
   );
   const deps = rnwDeps.toString().trim().split('\n');

packages/@react-native-windows/cli/src/utils/commandWithProgress.ts

@@ -14,6 +14,7 @@ import {
   CodedErrors,
   CodedErrorType,
 } from '@react-native-windows/telemetry';
+import {findPowerShell} from '@react-native-windows/find-dotnet-tools';
 
 function setSpinnerText(spinner: ora.Ora, prefix: string, text: string) {
   text = prefix + spinnerString(text);
@@ -47,18 +48,23 @@ export function newSpinner(text: string) {
   return ora(options).start();
 }
 
-export const powershell = `${process.env.SystemRoot}\\System32\\WindowsPowerShell\\v1.0\\powershell.exe`;
+const powershell = findPowerShell();
 
 export async function runPowerShellScriptFunction(
   taskDescription: string,
   script: string | null,
   funcName: string,
   verbose: boolean,
   errorCategory: CodedErrorType,
+  useAppxCompatibility = false,
 ) {
   try {
     const printException = verbose ? '$_;' : '';
-    const importScript = script ? `Import-Module "${script}"; ` : '';
+    const importAppx = useAppxCompatibility
+      ? 'Import-Module Appx -UseWindowsPowerShell -WarningAction SilentlyContinue; '
+      : '';
+    const importScript = script ? `Import-Module '${script}'; ` : '';
+    const powershellCommand = `${importAppx}${importScript}try { ${funcName} -ErrorAction Stop; $lec = $LASTEXITCODE; } catch { $lec = 1; ${printException} }; exit $lec`;
     await commandWithProgress(
       newSpinner(taskDescription),
       taskDescription,
@@ -67,7 +73,8 @@ export async function runPowerShellScriptFunction(
         '-NoProfile',
         '-ExecutionPolicy',
         'RemoteSigned',
-        `${importScript}try { ${funcName} -ErrorAction Stop; $lec = $LASTEXITCODE; } catch { $lec = 1; ${printException} }; exit $lec`,
+        '-Command',
+        `&{${powershellCommand}}`,
       ],
       verbose,
       errorCategory,
@@ -88,7 +95,7 @@ export function commandWithProgress(
   errorCategory: CodedErrorType,
 ) {
   return new Promise<void>((resolve, reject) => {
-    const spawnOptions: SpawnOptions = verbose ? {stdio: 'inherit'} : {};
+    const spawnOptions: SpawnOptions = verbose ? { stdio: 'inherit' } : {};
 
     if (verbose) {
       spinner.stop();

packages/@react-native-windows/cli/src/utils/deploy.ts

@@ -4,7 +4,7 @@
  * @format
  */
 
-import {spawn, execSync, SpawnOptions} from 'child_process';
+import {spawn, execFileSync, SpawnOptions} from 'child_process';
 import fs from '@react-native-windows/fs';
 import http from 'http';
 import path from 'path';
@@ -19,8 +19,8 @@ import {
   newSpinner,
   commandWithProgress,
   runPowerShellScriptFunction,
-  powershell,
 } from './commandWithProgress';
+import {findPowerShell} from '@react-native-windows/find-dotnet-tools';
 import * as build from './build';
 import {
   BuildConfig,
@@ -183,9 +183,12 @@ function getWindowsStoreAppUtils(options: RunWindowsOptions) {
     'powershell',
     'WindowsStoreAppUtils.psm1',
   );
-  execSync(
-    `${powershell} -NoProfile Unblock-File '${windowsStoreAppUtilsPath}'`,
-  );
+  const powershell = findPowerShell();
+  execFileSync(powershell, [
+    '-NoProfile',
+    '-Command',
+    `& { Unblock-File '${windowsStoreAppUtilsPath}' }`,
+  ]);
   popd();
   return windowsStoreAppUtilsPath;
 }
@@ -359,6 +362,7 @@ export async function deployToDesktop(
   config: Config,
   buildTools: MSBuildTools,
 ) {
+  const useAppxCompatibility = !!process.env.TF_BUILD;
   const windowsConfig: Partial<WindowsProjectConfig> | undefined =
     config.project.windows;
   const slnFile =
@@ -391,6 +395,7 @@ export async function deployToDesktop(
     'EnableDevMode',
     verbose,
     'EnableDevModeFailure',
+    useAppxCompatibility,
   );
 
   const appPackageFolder = getAppPackage(options, projectName);
@@ -403,6 +408,7 @@ export async function deployToDesktop(
       `Uninstall-App ${appName}`,
       verbose,
       'RemoveOldAppVersionFailure',
+      useAppxCompatibility,
     );
 
     const script = glob.sync(
@@ -415,6 +421,7 @@ export async function deployToDesktop(
       `Install-App "${script}" -Force`,
       verbose,
       'InstallAppFailure',
+      useAppxCompatibility,
     );
   } else {
     // Deploy from layout
@@ -442,6 +449,7 @@ export async function deployToDesktop(
         `Install-AppDependencies ${appxManifestPath} ${appPackageFolder} ${options.arch}`,
         verbose,
         'InstallAppDependenciesFailure',
+        useAppxCompatibility,
       );
       await build.buildSolution(
         buildTools,
@@ -456,9 +464,14 @@ export async function deployToDesktop(
     }
   }
 
-  const appFamilyName = execSync(
-    `${powershell} -NoProfile -c $(Get-AppxPackage -Name ${appName}).PackageFamilyName`,
-  )
+  const appFamilyNameCommand = useAppxCompatibility
+    ? `& { Import-Module Appx -UseWindowsPowerShell -WarningAction SilentlyContinue; (Get-AppxPackage -Name '${appName}').PackageFamilyName }`
+    : `(Get-AppxPackage -Name '${appName}').PackageFamilyName`;
+  const appFamilyName = execFileSync(findPowerShell(), [
+    '-NoProfile',
+    '-Command',
+    appFamilyNameCommand,
+  ])
     .toString()
     .trim();
 
@@ -488,6 +501,7 @@ export async function deployToDesktop(
       `Start-Locally ${appName} ${args}`,
       verbose,
       'AppStartupFailure',
+      useAppxCompatibility,
     );
   } else {
     newInfo('Skip the step to start the app');

packages/@react-native-windows/cli/src/utils/msbuildtools.ts

@@ -18,8 +18,8 @@ import {
   newSpinner,
   newSuccess,
   newError,
-  powershell,
 } from './commandWithProgress';
+import {findPowerShell} from '@react-native-windows/find-dotnet-tools';
 import {execSync} from 'child_process';
 import {BuildArch, BuildConfig} from '../commands/runWindows/runWindowsOptions';
 import {findLatestVsInstall} from './vsInstalls';
@@ -317,7 +317,7 @@ export default class MSBuildTools {
         'Eval-MsBuildProperties.ps1',
       );
 
-      let command = `${powershell} -ExecutionPolicy Unrestricted -NoProfile "${msbuildEvalScriptPath}" -SolutionFile '${solutionFile}' -ProjectFile '${projectFile}' -MSBuildPath '${this.msbuildPath()}'`;
+      let command = `"${findPowerShell()}" -ExecutionPolicy Unrestricted -NoProfile "${msbuildEvalScriptPath}" -SolutionFile '${solutionFile}' -ProjectFile '${projectFile}' -MSBuildPath '${this.msbuildPath()}'`;
 
       if (propertyNames && propertyNames.length > 0) {
         command += ` -PropertyNames '${propertyNames.join(',')}'`;

packages/@react-native-windows/find-dotnet-tools/.eslintrc.js

@@ -0,0 +1,4 @@
+module.exports = {
+  extends: ['@rnw-scripts'],
+  parserOptions: {tsconfigRootDir : __dirname},
+};

packages/@react-native-windows/find-dotnet-tools/.gitignore

@@ -0,0 +1,2 @@
+lib/
+lib-commonjs/

packages/@react-native-windows/find-dotnet-tools/README.md

@@ -0,0 +1,50 @@
+# @react-native-windows/find-dotnet-tools
+
+Helpers to locate .NET-based tools (e.g. PowerShell) restored via `dotnet tool restore` or
+available on PATH.
+
+Used to resolve tool paths consistently across local development and CI
+environments.
+
+## Usage
+
+Add the package as a dependency:
+
+```json
+{
+  "dependencies": {
+    "@react-native-windows/find-dotnet-tools": "<version>"
+  }
+}
+```
+
+### findPowerShell
+
+Locates a PowerShell executable by checking, in order:
+
+1. A `dotnet-tool`-restored copy of `pwsh.exe` (skipped in CI builds)
+2. `pwsh.exe` on the system PATH
+
+Throws an error if `pwsh.exe` cannot be found.
+
+```js
+import {findPowerShell} from '@react-native-windows/find-dotnet-tools';
+
+const pwsh = findPowerShell();
+// e.g. "C:\\Users\\user\\.nuget\\packages\\PowerShell\\7.6.1\\tools\\net10.0\\any\\win\\pwsh.exe"
+```
+
+### getNugetGlobalPackagesFolder
+
+Returns the path to the global NuGet packages folder by checking, in order:
+
+1. The `NUGET_PACKAGES` environment variable
+2. The output of `dotnet nuget locals global-packages --list`
+3. The default `~/.nuget/packages` location
+
+```js
+import {getNugetGlobalPackagesFolder} from '@react-native-windows/find-dotnet-tools';
+
+const packagesDir = getNugetGlobalPackagesFolder();
+// e.g. "C:\\Users\\user\\.nuget\\packages"
+```