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

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)
+  })
+})