feat(cli): add install and uninstall commands for skills (#16377)

packages/cli/src/utils/skillUtils.ts

@@ -6,6 +6,12 @@
 
 import { SettingScope } from '../config/settings.js';
 import type { SkillActionResult } from './skillSettings.js';
+import { Storage, loadSkillsFromDir } from '@google/gemini-cli-core';
+import { cloneFromGit } from '../config/extensions/github.js';
+import extract from 'extract-zip';
+import * as fs from 'node:fs/promises';
+import * as path from 'node:path';
+import * as os from 'node:os';
 
 /**
  * Shared logic for building the core skill action message while allowing the
@@ -64,3 +70,129 @@ export function renderSkillActionFeedback(
   const s = formatScopeItem(totalAffectedScopes[0]);
   return `Skill "${skillName}" ${actionVerb} ${preposition} ${s} settings.`;
 }
+
+/**
+ * Central logic for installing a skill from a remote URL or local path.
+ */
+export async function installSkill(
+  source: string,
+  scope: 'user' | 'workspace',
+  subpath: string | undefined,
+  onLog: (msg: string) => void,
+): Promise<Array<{ name: string; location: string }>> {
+  let sourcePath = source;
+  let tempDirToClean: string | undefined = undefined;
+
+  const isGitUrl =
+    source.startsWith('git@') ||
+    source.startsWith('http://') ||
+    source.startsWith('https://');
+
+  const isSkillFile = source.toLowerCase().endsWith('.skill');
+
+  if (isGitUrl) {
+    tempDirToClean = await fs.mkdtemp(path.join(os.tmpdir(), 'gemini-skill-'));
+    sourcePath = tempDirToClean;
+
+    onLog(`Cloning skill from ${source}...`);
+    // Reuse existing robust git cloning utility from extension manager.
+    await cloneFromGit(
+      {
+        source,
+        type: 'git',
+      },
+      tempDirToClean,
+    );
+  } else if (isSkillFile) {
+    tempDirToClean = await fs.mkdtemp(path.join(os.tmpdir(), 'gemini-skill-'));
+    sourcePath = tempDirToClean;
+
+    onLog(`Extracting skill from ${source}...`);
+    await extract(path.resolve(source), { dir: tempDirToClean });
+  }
+
+  // If a subpath is provided, resolve it against the cloned/local root.
+  if (subpath) {
+    sourcePath = path.join(sourcePath, subpath);
+  }
+
+  sourcePath = path.resolve(sourcePath);
+
+  // Quick security check to prevent directory traversal out of temp dir when cloning
+  if (tempDirToClean && !sourcePath.startsWith(path.resolve(tempDirToClean))) {
+    if (tempDirToClean) {
+      await fs.rm(tempDirToClean, { recursive: true, force: true });
+    }
+    throw new Error('Invalid path: Directory traversal not allowed.');
+  }
+
+  onLog(`Searching for skills in ${sourcePath}...`);
+  const skills = await loadSkillsFromDir(sourcePath);
+
+  if (skills.length === 0) {
+    if (tempDirToClean) {
+      await fs.rm(tempDirToClean, { recursive: true, force: true });
+    }
+    throw new Error(
+      `No valid skills found in ${source}${subpath ? ` at path "${subpath}"` : ''}. Ensure a SKILL.md file exists with valid frontmatter.`,
+    );
+  }
+
+  const workspaceDir = process.cwd();
+  const storage = new Storage(workspaceDir);
+  const targetDir =
+    scope === 'workspace'
+      ? storage.getProjectSkillsDir()
+      : Storage.getUserSkillsDir();
+
+  await fs.mkdir(targetDir, { recursive: true });
+
+  const installedSkills: Array<{ name: string; location: string }> = [];
+
+  for (const skill of skills) {
+    const skillName = skill.name;
+    const skillDir = path.dirname(skill.location);
+    const destPath = path.join(targetDir, skillName);
+
+    const exists = await fs.stat(destPath).catch(() => null);
+    if (exists) {
+      onLog(`Skill "${skillName}" already exists. Overwriting...`);
+      await fs.rm(destPath, { recursive: true, force: true });
+    }
+
+    await fs.cp(skillDir, destPath, { recursive: true });
+    installedSkills.push({ name: skillName, location: destPath });
+  }
+
+  if (tempDirToClean) {
+    await fs.rm(tempDirToClean, { recursive: true, force: true });
+  }
+
+  return installedSkills;
+}
+
+/**
+ * Central logic for uninstalling a skill by name.
+ */
+export async function uninstallSkill(
+  name: string,
+  scope: 'user' | 'workspace',
+): Promise<{ location: string } | null> {
+  const workspaceDir = process.cwd();
+  const storage = new Storage(workspaceDir);
+  const targetDir =
+    scope === 'workspace'
+      ? storage.getProjectSkillsDir()
+      : Storage.getUserSkillsDir();
+
+  const skillPath = path.join(targetDir, name);
+
+  const exists = await fs.stat(skillPath).catch(() => null);
+
+  if (!exists) {
+    return null;
+  }
+
+  await fs.rm(skillPath, { recursive: true, force: true });
+  return { location: skillPath };
+}