feat: add first-class pi target with mcporter/subagent compatibility

tests/pi-writer.test.ts

@@ -0,0 +1,99 @@
+import { describe, expect, test } from "bun:test"
+import { promises as fs } from "fs"
+import path from "path"
+import os from "os"
+import { writePiBundle } from "../src/targets/pi"
+import type { PiBundle } from "../src/types/pi"
+
+async function exists(filePath: string): Promise<boolean> {
+  try {
+    await fs.access(filePath)
+    return true
+  } catch {
+    return false
+  }
+}
+
+describe("writePiBundle", () => {
+  test("writes prompts, skills, extensions, mcporter config, and AGENTS.md block", async () => {
+    const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "pi-writer-"))
+    const outputRoot = path.join(tempRoot, ".pi")
+
+    const bundle: PiBundle = {
+      prompts: [{ name: "workflows-plan", content: "Prompt content" }],
+      skillDirs: [
+        {
+          name: "skill-one",
+          sourceDir: path.join(import.meta.dir, "fixtures", "sample-plugin", "skills", "skill-one"),
+        },
+      ],
+      generatedSkills: [{ name: "repo-research-analyst", content: "---\nname: repo-research-analyst\n---\n\nBody" }],
+      extensions: [{ name: "compound-engineering-compat.ts", content: "export default function () {}" }],
+      mcporterConfig: {
+        mcpServers: {
+          context7: { baseUrl: "https://mcp.context7.com/mcp" },
+        },
+      },
+    }
+
+    await writePiBundle(outputRoot, bundle)
+
+    expect(await exists(path.join(outputRoot, "prompts", "workflows-plan.md"))).toBe(true)
+    expect(await exists(path.join(outputRoot, "skills", "skill-one", "SKILL.md"))).toBe(true)
+    expect(await exists(path.join(outputRoot, "skills", "repo-research-analyst", "SKILL.md"))).toBe(true)
+    expect(await exists(path.join(outputRoot, "extensions", "compound-engineering-compat.ts"))).toBe(true)
+    expect(await exists(path.join(outputRoot, "compound-engineering", "mcporter.json"))).toBe(true)
+
+    const agentsPath = path.join(outputRoot, "AGENTS.md")
+    const agentsContent = await fs.readFile(agentsPath, "utf8")
+    expect(agentsContent).toContain("BEGIN COMPOUND PI TOOL MAP")
+    expect(agentsContent).toContain("MCPorter")
+  })
+
+  test("writes to ~/.pi/agent style roots without nesting under .pi", async () => {
+    const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "pi-agent-root-"))
+    const outputRoot = path.join(tempRoot, "agent")
+
+    const bundle: PiBundle = {
+      prompts: [{ name: "workflows-work", content: "Prompt content" }],
+      skillDirs: [],
+      generatedSkills: [],
+      extensions: [],
+    }
+
+    await writePiBundle(outputRoot, bundle)
+
+    expect(await exists(path.join(outputRoot, "prompts", "workflows-work.md"))).toBe(true)
+    expect(await exists(path.join(outputRoot, ".pi"))).toBe(false)
+  })
+
+  test("backs up existing mcporter config before overwriting", async () => {
+    const tempRoot = await fs.mkdtemp(path.join(os.tmpdir(), "pi-backup-"))
+    const outputRoot = path.join(tempRoot, ".pi")
+    const configPath = path.join(outputRoot, "compound-engineering", "mcporter.json")
+
+    await fs.mkdir(path.dirname(configPath), { recursive: true })
+    await fs.writeFile(configPath, JSON.stringify({ previous: true }, null, 2))
+
+    const bundle: PiBundle = {
+      prompts: [],
+      skillDirs: [],
+      generatedSkills: [],
+      extensions: [],
+      mcporterConfig: {
+        mcpServers: {
+          linear: { baseUrl: "https://mcp.linear.app/mcp" },
+        },
+      },
+    }
+
+    await writePiBundle(outputRoot, bundle)
+
+    const files = await fs.readdir(path.dirname(configPath))
+    const backupFileName = files.find((file) => file.startsWith("mcporter.json.bak."))
+    expect(backupFileName).toBeDefined()
+
+    const currentConfig = JSON.parse(await fs.readFile(configPath, "utf8")) as { mcpServers: Record<string, unknown> }
+    expect(currentConfig.mcpServers.linear).toBeDefined()
+  })
+})