feat: support commands completion (#32)

Add full shell tab-completion for opencli, supporting Bash, Zsh, and Fish.

Co-authored-by: RinChanNOWWW <rin_chan_now@outlook.com>

Co-authored-by: Claude <noreply@anthropic.com>

scripts/postinstall.js

@@ -0,0 +1,179 @@
+#!/usr/bin/env node
+
+/**
+ * postinstall script — automatically install shell completion files.
+ *
+ * Detects the user's default shell and writes the completion script to the
+ * standard system completion directory so that tab-completion works immediately
+ * after `npm install -g`.
+ *
+ * Supported shells: bash, zsh, fish.
+ *
+ * This script is intentionally plain Node.js (no TypeScript, no imports from
+ * the main source tree) so that it can run without a build step.
+ */
+
+import { mkdirSync, writeFileSync, existsSync, readFileSync, appendFileSync } from 'node:fs';
+import { join } from 'node:path';
+import { homedir } from 'node:os';
+
+
+// ── Completion script content ──────────────────────────────────────────────
+
+const BASH_COMPLETION = `# Bash completion for opencli (auto-installed)
+_opencli_completions() {
+  local cur words cword
+  _get_comp_words_by_ref -n : cur words cword
+
+  local completions
+  completions=$(opencli --get-completions --cursor "$cword" "\${words[@]:1}" 2>/dev/null)
+
+  COMPREPLY=( $(compgen -W "$completions" -- "$cur") )
+  __ltrim_colon_completions "$cur"
+}
+complete -F _opencli_completions opencli
+`;
+
+const ZSH_COMPLETION = `#compdef opencli
+# Zsh completion for opencli (auto-installed)
+_opencli() {
+  local -a completions
+  local cword=$((CURRENT - 1))
+  completions=(\${(f)"$(opencli --get-completions --cursor "$cword" "\${words[@]:1}" 2>/dev/null)"})
+  compadd -a completions
+}
+_opencli
+`;
+
+const FISH_COMPLETION = `# Fish completion for opencli (auto-installed)
+complete -c opencli -f -a '(
+  set -l tokens (commandline -cop)
+  set -l cursor (count (commandline -cop))
+  opencli --get-completions --cursor $cursor $tokens[2..] 2>/dev/null
+)'
+`;
+
+// ── Helpers ────────────────────────────────────────────────────────────────
+
+function detectShell() {
+  const shell = process.env.SHELL || '';
+  if (shell.includes('zsh')) return 'zsh';
+  if (shell.includes('bash')) return 'bash';
+  if (shell.includes('fish')) return 'fish';
+  return null;
+}
+
+function ensureDir(dir) {
+  if (!existsSync(dir)) {
+    mkdirSync(dir, { recursive: true });
+  }
+}
+
+/**
+ * Ensure fpath contains the custom completions directory in .zshrc
+ */
+function ensureZshFpath(completionsDir, zshrcPath) {
+  const fpathLine = `fpath=(${completionsDir} $fpath)`;
+  const autoloadLine = `autoload -Uz compinit && compinit`;
+
+  if (!existsSync(zshrcPath)) {
+    writeFileSync(zshrcPath, `${fpathLine}\n${autoloadLine}\n`, 'utf8');
+    return;
+  }
+
+  const content = readFileSync(zshrcPath, 'utf8');
+
+  // Check if completions dir is already in fpath
+  if (content.includes(completionsDir)) {
+    return; // already configured
+  }
+
+  // Append fpath configuration
+  let addition = `\n# opencli completion\n${fpathLine}\n`;
+  if (!content.includes('compinit')) {
+    addition += `${autoloadLine}\n`;
+  }
+  appendFileSync(zshrcPath, addition, 'utf8');
+}
+
+// ── Main ───────────────────────────────────────────────────────────────────
+
+function main() {
+  // Skip in CI environments
+  if (process.env.CI || process.env.CONTINUOUS_INTEGRATION) {
+    return;
+  }
+
+  // Only install completion for global installs and npm link
+  const isGlobal = process.env.npm_config_global === 'true';
+  if (!isGlobal) {
+    return;
+  }
+
+  const shell = detectShell();
+  if (!shell) {
+    // Cannot determine shell; silently skip
+    return;
+  }
+
+  const home = homedir();
+
+  try {
+    switch (shell) {
+      case 'zsh': {
+        const completionsDir = join(home, '.zsh', 'completions');
+        const completionFile = join(completionsDir, '_opencli');
+        ensureDir(completionsDir);
+        writeFileSync(completionFile, ZSH_COMPLETION, 'utf8');
+
+        // Ensure fpath is set up in .zshrc
+        const zshrcPath = join(home, '.zshrc');
+        ensureZshFpath(completionsDir, zshrcPath);
+
+        console.log(`✓ Zsh completion installed to ${completionFile}`);
+        console.log(`  Restart your shell or run: source ~/.zshrc`);
+        break;
+      }
+      case 'bash': {
+        // Try system-level first, fall back to user-level
+        const userCompDir = join(home, '.bash_completion.d');
+        const completionFile = join(userCompDir, 'opencli');
+        ensureDir(userCompDir);
+        writeFileSync(completionFile, BASH_COMPLETION, 'utf8');
+
+        // Ensure .bashrc sources the completion directory
+        const bashrcPath = join(home, '.bashrc');
+        if (existsSync(bashrcPath)) {
+          const content = readFileSync(bashrcPath, 'utf8');
+          if (!content.includes('.bash_completion.d/opencli')) {
+            appendFileSync(bashrcPath,
+              `\n# opencli completion\n[ -f "${completionFile}" ] && source "${completionFile}"\n`,
+              'utf8'
+            );
+          }
+        }
+
+        console.log(`✓ Bash completion installed to ${completionFile}`);
+        console.log(`  Restart your shell or run: source ~/.bashrc`);
+        break;
+      }
+      case 'fish': {
+        const completionsDir = join(home, '.config', 'fish', 'completions');
+        const completionFile = join(completionsDir, 'opencli.fish');
+        ensureDir(completionsDir);
+        writeFileSync(completionFile, FISH_COMPLETION, 'utf8');
+
+        console.log(`✓ Fish completion installed to ${completionFile}`);
+        console.log(`  Restart your shell to activate.`);
+        break;
+      }
+    }
+  } catch (err) {
+    // Completion install is best-effort; never fail the package install
+    if (process.env.OPENCLI_VERBOSE) {
+      console.error(`Warning: Could not install shell completion: ${err.message}`);
+    }
+  }
+}
+
+main();