fix(powershell-generator): remove trailing comma from last entry

src/core/completions/generators/powershell-generator.ts

@@ -8,6 +8,11 @@ import { POWERSHELL_DYNAMIC_HELPERS } from '../templates/powershell-templates.js
 export class PowerShellGenerator implements CompletionGenerator {
   readonly shell = 'powershell' as const;
 
+  private stripTrailingCommaFromLastLine(lines: string[]): void {
+    if (lines.length === 0) return;
+    lines[lines.length - 1] = lines[lines.length - 1].replace(/,\s*$/, '');
+  }
+
   /**
    * Generate a PowerShell completion script
    *
@@ -20,6 +25,7 @@ export class PowerShellGenerator implements CompletionGenerator {
     for (const cmd of commands) {
       commandLines.push(`            @{Name="${cmd.name}"; Description="${this.escapeDescription(cmd.description)}"},`);
     }
+    this.stripTrailingCommaFromLastLine(commandLines);
     const topLevelCommands = commandLines.join('\n');
 
     // Build command cases using push() for loop clarity
@@ -88,6 +94,7 @@ Register-ArgumentCompleter -CommandName openspec -ScriptBlock $openspecCompleter
             lines.push(`${indent}        @{Name="${longFlag}"; Description="${this.escapeDescription(flag.description)}"},`);
           }
         }
+        this.stripTrailingCommaFromLastLine(lines);
         lines.push(`${indent}    )`);
         lines.push(`${indent}    $flags | Where-Object { $_.Name -like "$wordToComplete*" } | ForEach-Object {`);
         lines.push(`${indent}        [System.Management.Automation.CompletionResult]::new($_.Name, $_.Name, "ParameterName", $_.Description)`);
@@ -103,6 +110,7 @@ Register-ArgumentCompleter -CommandName openspec -ScriptBlock $openspecCompleter
       for (const subcmd of cmd.subcommands) {
         lines.push(`${indent}        @{Name="${subcmd.name}"; Description="${this.escapeDescription(subcmd.description)}"},`);
       }
+      this.stripTrailingCommaFromLastLine(lines);
       lines.push(`${indent}    )`);
       lines.push(`${indent}    $subcommands | Where-Object { $_.Name -like "$wordToComplete*" } | ForEach-Object {`);
       lines.push(`${indent}        [System.Management.Automation.CompletionResult]::new($_.Name, $_.Name, "ParameterValue", $_.Description)`);
@@ -148,6 +156,7 @@ Register-ArgumentCompleter -CommandName openspec -ScriptBlock $openspecCompleter
           lines.push(`${indent}        @{Name="${longFlag}"; Description="${this.escapeDescription(flag.description)}"},`);
         }
       }
+      this.stripTrailingCommaFromLastLine(lines);
       lines.push(`${indent}    )`);
       lines.push(`${indent}    $flags | Where-Object { $_.Name -like "$wordToComplete*" } | ForEach-Object {`);
       lines.push(`${indent}        [System.Management.Automation.CompletionResult]::new($_.Name, $_.Name, "ParameterName", $_.Description)`);

test/core/completions/generators/powershell-generator.test.ts

@@ -1,6 +1,6 @@
-import {describe, it, expect, beforeEach} from 'vitest';
-import {PowerShellGenerator} from '../../../../src/core/completions/generators/powershell-generator.js';
-import {CommandDefinition} from '../../../../src/core/completions/types.js';
+import { describe, it, expect, beforeEach } from 'vitest';
+import { PowerShellGenerator } from '../../../../src/core/completions/generators/powershell-generator.js';
+import { CommandDefinition } from '../../../../src/core/completions/types.js';
 
 describe('PowerShellGenerator', () => {
 	let generator: PowerShellGenerator;
@@ -444,6 +444,34 @@ describe('PowerShellGenerator', () => {
 			expect(script).toContain('Get-OpenSpecSpecs');
 		});
 
+		it('should not emit trailing commas in @() arrays', () => {
+			const commands: CommandDefinition[] = [
+				{
+					name: 'config',
+					description: 'Manage configuration',
+					flags: [
+						{
+							name: 'scope',
+							short: 's',
+							description: 'Configuration scope',
+						},
+					],
+					subcommands: [
+						{
+							name: 'get',
+							description: 'Get a config value',
+							flags: [],
+						},
+					],
+				},
+			];
+
+			const script = generator.generate(commands);
+
+			// PowerShell array literals (@(...)) can't have a trailing comma on the last element.
+			expect(script).not.toMatch(/\},\s*\r?\n\s*\)/);
+		});
+
 		it('should handle empty command list', () => {
 			const commands: CommandDefinition[] = [];