fix: prevent duplicate empty args in generated completions

.changeset/fast-lamps-march.md

@@ -0,0 +1,5 @@
+---
+'@bomb.sh/tab': patch
+---
+
+prevent duplicate empty args in generated completions

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
         run: pnpm install
 
       - name: Run tests
-        run: pnpm test
+        run: pnpm test:unit
 
   typecheck:
     name: Lint and Type Check

.github/workflows/shell-completions.yml

@@ -0,0 +1,58 @@
+name: Shell Completions
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  shell-argv-protocol:
+    name: Shell argv protocol
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install shell dependencies
+        shell: bash
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y zsh fish wget apt-transport-https software-properties-common
+
+      - name: Install PowerShell
+        shell: bash
+        run: |
+          source /etc/os-release
+          wget -q https://packages.microsoft.com/config/ubuntu/$VERSION_ID/packages-microsoft-prod.deb
+          sudo dpkg -i packages-microsoft-prod.deb
+          rm packages-microsoft-prod.deb
+          sudo apt-get update
+          sudo apt-get install -y powershell
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4.0.0
+
+      - name: Set node version to 20
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          registry-url: https://registry.npmjs.org/
+          cache: pnpm
+
+      - name: Install deps
+        run: pnpm install
+
+      - name: Print shell versions
+        shell: bash
+        run: |
+          bash --version
+          zsh --version
+          fish --version
+          pwsh --version
+
+      - name: Run shell argv protocol tests
+        run: pnpm test tests/shell-empty-argv.test.ts

examples/demo.t.ts

@@ -120,17 +120,26 @@ t.command('lint', 'Lint project').argument(
   true
 ); // Variadic argument for multiple files
 
+const supportedShells = ['zsh', 'bash', 'fish', 'powershell'];
+const completeUsage = 'Usage: vite complete <shell> | vite complete -- <argv>';
+
+function printCompleteUsageAndExit() {
+  console.error(completeUsage);
+  process.exit(1);
+}
+
 // Handle completion command
 if (process.argv[2] === 'complete') {
-  const shell = process.argv[3];
-  if (shell && ['zsh', 'bash', 'fish', 'powershell'].includes(shell)) {
-    t.setup('vite', 'pnpm tsx examples/demo.t.ts', shell);
+  const mode = process.argv[3];
+
+  if (mode === '--') {
+    // Runtime completion request from the generated shell script.
+    t.parse(process.argv.slice(4));
+  } else if (mode && supportedShells.includes(mode)) {
+    // Shell script generation.
+    t.setup('vite', 'pnpm tsx examples/demo.t.ts', mode);
   } else {
-    // Parse completion arguments (everything after --)
-    const separatorIndex = process.argv.indexOf('--');
-    const completionArgs =
-      separatorIndex !== -1 ? process.argv.slice(separatorIndex + 1) : [];
-    t.parse(completionArgs);
+    printCompleteUsageAndExit();
   }
 } else {
   // Regular CLI usage (just show help for demo)

package.json

@@ -7,6 +7,8 @@
   },
   "scripts": {
     "test": "vitest run",
+    "test:unit": "vitest run --exclude tests/shell-empty-argv.test.ts",
+    "test:shell": "vitest run tests/shell-empty-argv.test.ts",
     "type-check": "tsc --noEmit",
     "format": "prettier --write .",
     "format:check": "prettier --check .",

src/powershell.ts

@@ -93,8 +93,10 @@ export function generate(name: string, exec: string): string {
         # Remove the flag part
         $Flag, $WordToComplete = $WordToComplete.Split("=", 2)
     }
-
-    if ( $WordToComplete -eq "" -And ( -Not $IsEqualFlag )) {
+    $HasTrailingEmptyArg = $QuotedArgs -match "(^| )''$"
+    __${name}_debug "HasTrailingEmptyArg: $HasTrailingEmptyArg"
+
+    if ( $WordToComplete -eq "" -And ( -Not $IsEqualFlag ) -And ( -Not $HasTrailingEmptyArg )) {
         # If the last parameter is complete (there is a space following it)
         # We add an extra empty parameter so we can indicate this to the go method.
         __${name}_debug "Adding extra empty parameter"

src/zsh.ts

@@ -48,7 +48,7 @@ _${name}() {
 
     # Prepare the command to obtain completions, ensuring arguments are quoted for eval
     local -a args_to_quote=("\${(@)words[2,-1]}")
-    if [ "\${lastChar}" = "" ]; then
+    if [ "\${lastChar}" = "" ] && [ "\${args_to_quote[-1]}" != "" ]; then
         # If the last parameter is complete (there is a space following it)
         # We add an extra empty parameter so we can indicate this to the go completion code.
         __${name}_debug "Adding extra empty parameter"