feat: add detect-tools utility and Gemini sync with tests

src/sync/gemini.ts

@@ -0,0 +1,76 @@
+import fs from "fs/promises"
+import path from "path"
+import type { ClaudeHomeConfig } from "../parsers/claude-home"
+import type { ClaudeMcpServer } from "../types/claude"
+import { forceSymlink, isValidSkillName } from "../utils/symlink"
+
+type GeminiMcpServer = {
+  command?: string
+  args?: string[]
+  url?: string
+  env?: Record<string, string>
+  headers?: Record<string, string>
+}
+
+export async function syncToGemini(
+  config: ClaudeHomeConfig,
+  outputRoot: string,
+): Promise<void> {
+  const skillsDir = path.join(outputRoot, "skills")
+  await fs.mkdir(skillsDir, { recursive: true })
+
+  for (const skill of config.skills) {
+    if (!isValidSkillName(skill.name)) {
+      console.warn(`Skipping skill with invalid name: ${skill.name}`)
+      continue
+    }
+    const target = path.join(skillsDir, skill.name)
+    await forceSymlink(skill.sourceDir, target)
+  }
+
+  if (Object.keys(config.mcpServers).length > 0) {
+    const settingsPath = path.join(outputRoot, "settings.json")
+    const existing = await readJsonSafe(settingsPath)
+    const converted = convertMcpForGemini(config.mcpServers)
+    const existingMcp =
+      existing.mcpServers && typeof existing.mcpServers === "object"
+        ? (existing.mcpServers as Record<string, unknown>)
+        : {}
+    const merged = {
+      ...existing,
+      mcpServers: { ...existingMcp, ...converted },
+    }
+    await fs.writeFile(settingsPath, JSON.stringify(merged, null, 2), { mode: 0o600 })
+  }
+}
+
+async function readJsonSafe(filePath: string): Promise<Record<string, unknown>> {
+  try {
+    const content = await fs.readFile(filePath, "utf-8")
+    return JSON.parse(content) as Record<string, unknown>
+  } catch (err) {
+    if ((err as NodeJS.ErrnoException).code === "ENOENT") {
+      return {}
+    }
+    throw err
+  }
+}
+
+function convertMcpForGemini(
+  servers: Record<string, ClaudeMcpServer>,
+): Record<string, GeminiMcpServer> {
+  const result: Record<string, GeminiMcpServer> = {}
+  for (const [name, server] of Object.entries(servers)) {
+    const entry: GeminiMcpServer = {}
+    if (server.command) {
+      entry.command = server.command
+      if (server.args && server.args.length > 0) entry.args = server.args
+      if (server.env && Object.keys(server.env).length > 0) entry.env = server.env
+    } else if (server.url) {
+      entry.url = server.url
+      if (server.headers && Object.keys(server.headers).length > 0) entry.headers = server.headers
+    }
+    result[name] = entry
+  }
+  return result
+}

src/utils/detect-tools.ts

@@ -0,0 +1,46 @@
+import os from "os"
+import path from "path"
+import { pathExists } from "./files"
+
+export type DetectedTool = {
+  name: string
+  detected: boolean
+  reason: string
+}
+
+export async function detectInstalledTools(
+  home: string = os.homedir(),
+  cwd: string = process.cwd(),
+): Promise<DetectedTool[]> {
+  const checks: Array<{ name: string; paths: string[] }> = [
+    { name: "opencode", paths: [path.join(home, ".config", "opencode"), path.join(cwd, ".opencode")] },
+    { name: "codex", paths: [path.join(home, ".codex")] },
+    { name: "droid", paths: [path.join(home, ".factory")] },
+    { name: "cursor", paths: [path.join(cwd, ".cursor"), path.join(home, ".cursor")] },
+    { name: "pi", paths: [path.join(home, ".pi")] },
+    { name: "gemini", paths: [path.join(cwd, ".gemini"), path.join(home, ".gemini")] },
+  ]
+
+  const results: DetectedTool[] = []
+  for (const check of checks) {
+    let detected = false
+    let reason = "not found"
+    for (const p of check.paths) {
+      if (await pathExists(p)) {
+        detected = true
+        reason = `found ${p}`
+        break
+      }
+    }
+    results.push({ name: check.name, detected, reason })
+  }
+  return results
+}
+
+export async function getDetectedTargetNames(
+  home: string = os.homedir(),
+  cwd: string = process.cwd(),
+): Promise<string[]> {
+  const tools = await detectInstalledTools(home, cwd)
+  return tools.filter((t) => t.detected).map((t) => t.name)
+}

tests/detect-tools.test.ts

@@ -0,0 +1,96 @@
+import { describe, expect, test } from "bun:test"
+import { promises as fs } from "fs"
+import path from "path"
+import os from "os"
+import { detectInstalledTools, getDetectedTargetNames } from "../src/utils/detect-tools"
+
+describe("detectInstalledTools", () => {
+  test("detects tools when config directories exist", async () => {
+    const tempHome = await fs.mkdtemp(path.join(os.tmpdir(), "detect-tools-"))
+    const tempCwd = await fs.mkdtemp(path.join(os.tmpdir(), "detect-tools-cwd-"))
+
+    // Create directories for some tools
+    await fs.mkdir(path.join(tempHome, ".codex"), { recursive: true })
+    await fs.mkdir(path.join(tempCwd, ".cursor"), { recursive: true })
+    await fs.mkdir(path.join(tempCwd, ".gemini"), { recursive: true })
+
+    const results = await detectInstalledTools(tempHome, tempCwd)
+
+    const codex = results.find((t) => t.name === "codex")
+    expect(codex?.detected).toBe(true)
+    expect(codex?.reason).toContain(".codex")
+
+    const cursor = results.find((t) => t.name === "cursor")
+    expect(cursor?.detected).toBe(true)
+    expect(cursor?.reason).toContain(".cursor")
+
+    const gemini = results.find((t) => t.name === "gemini")
+    expect(gemini?.detected).toBe(true)
+    expect(gemini?.reason).toContain(".gemini")
+
+    // Tools without directories should not be detected
+    const opencode = results.find((t) => t.name === "opencode")
+    expect(opencode?.detected).toBe(false)
+
+    const droid = results.find((t) => t.name === "droid")
+    expect(droid?.detected).toBe(false)
+
+    const pi = results.find((t) => t.name === "pi")
+    expect(pi?.detected).toBe(false)
+  })
+
+  test("returns all tools with detected=false when no directories exist", async () => {
+    const tempHome = await fs.mkdtemp(path.join(os.tmpdir(), "detect-empty-"))
+    const tempCwd = await fs.mkdtemp(path.join(os.tmpdir(), "detect-empty-cwd-"))
+
+    const results = await detectInstalledTools(tempHome, tempCwd)
+
+    expect(results.length).toBe(6)
+    for (const tool of results) {
+      expect(tool.detected).toBe(false)
+      expect(tool.reason).toBe("not found")
+    }
+  })
+
+  test("detects home-based tools", async () => {
+    const tempHome = await fs.mkdtemp(path.join(os.tmpdir(), "detect-home-"))
+    const tempCwd = await fs.mkdtemp(path.join(os.tmpdir(), "detect-home-cwd-"))
+
+    await fs.mkdir(path.join(tempHome, ".config", "opencode"), { recursive: true })
+    await fs.mkdir(path.join(tempHome, ".factory"), { recursive: true })
+    await fs.mkdir(path.join(tempHome, ".pi"), { recursive: true })
+
+    const results = await detectInstalledTools(tempHome, tempCwd)
+
+    expect(results.find((t) => t.name === "opencode")?.detected).toBe(true)
+    expect(results.find((t) => t.name === "droid")?.detected).toBe(true)
+    expect(results.find((t) => t.name === "pi")?.detected).toBe(true)
+  })
+})
+
+describe("getDetectedTargetNames", () => {
+  test("returns only names of detected tools", async () => {
+    const tempHome = await fs.mkdtemp(path.join(os.tmpdir(), "detect-names-"))
+    const tempCwd = await fs.mkdtemp(path.join(os.tmpdir(), "detect-names-cwd-"))
+
+    await fs.mkdir(path.join(tempHome, ".codex"), { recursive: true })
+    await fs.mkdir(path.join(tempCwd, ".gemini"), { recursive: true })
+
+    const names = await getDetectedTargetNames(tempHome, tempCwd)
+
+    expect(names).toContain("codex")
+    expect(names).toContain("gemini")
+    expect(names).not.toContain("opencode")
+    expect(names).not.toContain("droid")
+    expect(names).not.toContain("pi")
+    expect(names).not.toContain("cursor")
+  })
+
+  test("returns empty array when nothing detected", async () => {
+    const tempHome = await fs.mkdtemp(path.join(os.tmpdir(), "detect-none-"))
+    const tempCwd = await fs.mkdtemp(path.join(os.tmpdir(), "detect-none-cwd-"))
+
+    const names = await getDetectedTargetNames(tempHome, tempCwd)
+    expect(names).toEqual([])
+  })
+})

tests/sync-gemini.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, test } from "bun:test"
+import { promises as fs } from "fs"
+import path from "path"
+import os from "os"
+import { syncToGemini } from "../src/sync/gemini"
+import type { ClaudeHomeConfig } from "../src/parsers/claude-home"
+
+describe("syncToGemini", () => {
+  test("symlinks skills and writes settings.json", async () => {
+    const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "sync-gemini-"))
+    const fixtureSkillDir = path.join(import.meta.dir, "fixtures", "sample-plugin", "skills", "skill-one")
+
+    const config: ClaudeHomeConfig = {
+      skills: [
+        {
+          name: "skill-one",
+          sourceDir: fixtureSkillDir,
+          skillPath: path.join(fixtureSkillDir, "SKILL.md"),
+        },
+      ],
+      mcpServers: {
+        context7: { url: "https://mcp.context7.com/mcp" },
+        local: { command: "echo", args: ["hello"], env: { FOO: "bar" } },
+      },
+    }
+
+    await syncToGemini(config, tempRoot)
+
+    // Check skill symlink
+    const linkedSkillPath = path.join(tempRoot, "skills", "skill-one")
+    const linkedStat = await fs.lstat(linkedSkillPath)
+    expect(linkedStat.isSymbolicLink()).toBe(true)
+
+    // Check settings.json
+    const settingsPath = path.join(tempRoot, "settings.json")
+    const settings = JSON.parse(await fs.readFile(settingsPath, "utf8")) as {
+      mcpServers: Record<string, { url?: string; command?: string; args?: string[]; env?: Record<string, string> }>
+    }
+
+    expect(settings.mcpServers.context7?.url).toBe("https://mcp.context7.com/mcp")
+    expect(settings.mcpServers.local?.command).toBe("echo")
+    expect(settings.mcpServers.local?.args).toEqual(["hello"])
+    expect(settings.mcpServers.local?.env).toEqual({ FOO: "bar" })
+  })
+
+  test("merges existing settings.json", async () => {
+    const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "sync-gemini-merge-"))
+    const settingsPath = path.join(tempRoot, "settings.json")
+
+    await fs.writeFile(
+      settingsPath,
+      JSON.stringify({
+        theme: "dark",
+        mcpServers: { existing: { command: "node", args: ["server.js"] } },
+      }, null, 2),
+    )
+
+    const config: ClaudeHomeConfig = {
+      skills: [],
+      mcpServers: {
+        context7: { url: "https://mcp.context7.com/mcp" },
+      },
+    }
+
+    await syncToGemini(config, tempRoot)
+
+    const merged = JSON.parse(await fs.readFile(settingsPath, "utf8")) as {
+      theme: string
+      mcpServers: Record<string, { command?: string; url?: string }>
+    }
+
+    // Preserves existing settings
+    expect(merged.theme).toBe("dark")
+    // Preserves existing MCP servers
+    expect(merged.mcpServers.existing?.command).toBe("node")
+    // Adds new MCP servers
+    expect(merged.mcpServers.context7?.url).toBe("https://mcp.context7.com/mcp")
+  })
+
+  test("does not write settings.json when no MCP servers", async () => {
+    const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "sync-gemini-nomcp-"))
+    const fixtureSkillDir = path.join(import.meta.dir, "fixtures", "sample-plugin", "skills", "skill-one")
+
+    const config: ClaudeHomeConfig = {
+      skills: [
+        {
+          name: "skill-one",
+          sourceDir: fixtureSkillDir,
+          skillPath: path.join(fixtureSkillDir, "SKILL.md"),
+        },
+      ],
+      mcpServers: {},
+    }
+
+    await syncToGemini(config, tempRoot)
+
+    // Skills should still be symlinked
+    const linkedSkillPath = path.join(tempRoot, "skills", "skill-one")
+    const linkedStat = await fs.lstat(linkedSkillPath)
+    expect(linkedStat.isSymbolicLink()).toBe(true)
+
+    // But settings.json should not exist
+    const settingsExists = await fs.access(path.join(tempRoot, "settings.json")).then(() => true).catch(() => false)
+    expect(settingsExists).toBe(false)
+  })
+})