fix: fix code review comments

Author: y-schwab

lib/commands/powershell.ts

@@ -44,7 +44,7 @@ export async function startPowerShellSession(this: NovaWindowsDriver): Promise<v
         }
         const envVars = Array.from(envVarsSet);
         for (const envVar of envVars) {
-            this.caps.appWorkingDir = this.caps.appWorkingDir.replaceAll(`%${envVar}%`, process.env[envVar.toUpperCase()] ?? '');
+            this.caps.appWorkingDir = this.caps.appWorkingDir.replaceAll(`%${envVar}%`, spawnEnv[envVar.toUpperCase()] ?? '');
         }
         this.sendPowerShellCommand(`Set-Location -Path '${this.caps.appWorkingDir}'`);
     }
@@ -82,7 +82,7 @@ export async function startPowerShellSession(this: NovaWindowsDriver): Promise<v
         this.log.info(`Detected the following environment variables in app path: ${envVars.map((envVar) => `%${envVar}%`).join(', ')}`);
 
         for (const envVar of envVars) {
-            this.caps.app = this.caps.app.replaceAll(`%${envVar}%`, process.env[envVar.toUpperCase()] ?? '');
+            this.caps.app = this.caps.app.replaceAll(`%${envVar}%`, spawnEnv[envVar.toUpperCase()] ?? '');
         }
 
         await this.changeRootElement(this.caps.app);
@@ -108,7 +108,6 @@ export async function sendIsolatedPowerShellCommand(this: NovaWindowsDriver, com
     const powerShell = spawn('powershell.exe', ['-NoExit', '-Command', '-'], { env: spawnEnv });
     try {
         powerShell.stdout.setEncoding('utf8');
-        powerShell.stdout.setEncoding('utf8');
 
         let localStdOut = '';
         let localStdErr = '';
@@ -135,7 +134,7 @@ export async function sendIsolatedPowerShellCommand(this: NovaWindowsDriver, com
                 }
                 const envVars = Array.from(envVarsSet);
                 for (const envVar of envVars) {
-                    this.caps.appWorkingDir = this.caps.appWorkingDir.replaceAll(`%${envVar}%`, process.env[envVar.toUpperCase()] ?? '');
+                    this.caps.appWorkingDir = this.caps.appWorkingDir.replaceAll(`%${envVar}%`, spawnEnv[envVar.toUpperCase()] ?? '');
                 }
                 powerShell.stdin.write(`Set-Location -Path '${this.caps.appWorkingDir}'\n`);
             }

lib/driver.ts

@@ -176,6 +176,16 @@ export class NovaWindowsDriver extends BaseDriver<NovaWindowsDriverConstraints,
             if (caps.app && caps.appTopLevelWindow) {
                 throw new errors.InvalidArgumentError('Invalid capabilities. Specify either app or appTopLevelWindow.');
             }
+            if (caps.appEnvironment) {
+                const invalidKeys = Object.entries(caps.appEnvironment as Record<string, unknown>)
+                    .filter(([, v]) => typeof v !== 'string')
+                    .map(([k]) => k);
+                if (invalidKeys.length > 0) {
+                    throw new errors.InvalidArgumentError(
+                        `Invalid capabilities. 'appEnvironment' values must be strings. Invalid keys: ${invalidKeys.join(', ')}`
+                    );
+                }
+            }
             if (this.caps.shouldCloseApp === undefined) {
                 this.caps.shouldCloseApp = true; // set default value
             }