Ekklesia/core/tests/module-discovery.test.ts

import { mkdir, mkdtemp, rm, symlink, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";
import { afterEach, describe, expect, it } from "vitest";
import {
  discoverModules,
  ModuleDiscoveryError,
  type ModuleDiscoveryIssueCode,
} from "../src/modules/index.js";

interface ModuleFixtureOptions {
  directory?: string;
  manifest?: Record<string, unknown>;
  packageJson?: Record<string, unknown>;
  serverSource?: string;
  /** Extra package-relative files to write before discovery runs, so a fixture can publish a
   * compiled UI artifact (or a deliberately uncompiled one) alongside its server entrypoint. */
  extraFiles?: Record<string, string>;
}

const temporaryDirectories: string[] = [];

afterEach(async () => {
  await Promise.all(
    temporaryDirectories.splice(0).map((directory) => rm(directory, { recursive: true })),
  );
});

async function createModulesDirectory(): Promise<string> {
  const directory = await mkdtemp(path.join(tmpdir(), "ekklesia-modules-"));
  temporaryDirectories.push(directory);
  return directory;
}

function manifestFor(id: string): Record<string, unknown> {
  return {
    manifestVersion: 4,
    id,
    name: `${id} module`,
    version: "0.1.0",
    compatibility: {
      platform: "^0.1.0",
      moduleSdk: "^0.1.0",
    },
    capabilities: [{ id: `${id}.records`, version: "1.0.0" }],
    permissions: [
      { id: `${id}.records.read`, baseline: "restricted", description: "Read records." },
    ],
    entrypoints: {
      server: "./dist/server/index.js",
    },
  };
}

async function createModule(
  modulesDirectory: string,
  id: string,
  options: ModuleFixtureOptions = {},
): Promise<void> {
  const directoryName = options.directory ?? id;
  const moduleDirectory = path.join(modulesDirectory, directoryName);
  const manifest = options.manifest ?? manifestFor(id);
  const packageJson = options.packageJson ?? {
    name: `@test/module-${id}`,
    version: "0.1.0",
    type: "module",
    ekklesia: { layer: "module" },
  };

  await mkdir(path.join(moduleDirectory, "dist/server"), { recursive: true });
  await Promise.all([
    writeFile(path.join(moduleDirectory, "package.json"), JSON.stringify(packageJson)),
    writeFile(path.join(moduleDirectory, "ekklesia.module.json"), JSON.stringify(manifest)),
    writeFile(
      path.join(moduleDirectory, "dist/server/index.js"),
      options.serverSource ?? `export default { id: ${JSON.stringify(id)}, version: "0.1.0" };`,
    ),
  ]);

  for (const [relativePath, contents] of Object.entries(options.extraFiles ?? {})) {
    const target = path.join(moduleDirectory, relativePath);
    await mkdir(path.dirname(target), { recursive: true });
    await writeFile(target, contents);
  }
}

async function discoveryError(
  modulesDirectory: string,
  versions: { moduleSdkVersion?: string; platformVersion?: string } = {},
): Promise<ModuleDiscoveryError> {
  try {
    await discoverModules({
      moduleSdkVersion: versions.moduleSdkVersion ?? "0.1.0",
      modulesDirectory,
      platformVersion: versions.platformVersion ?? "0.1.0",
    });
  } catch (error) {
    if (error instanceof ModuleDiscoveryError) {
      return error;
    }
    throw error;
  }
  throw new Error("Expected module discovery to fail.");
}

function issueCodes(error: ModuleDiscoveryError): ModuleDiscoveryIssueCode[] {
  return error.issues.map((issue) => issue.code);
}

describe("module discovery", () => {
  it("treats a missing or empty modules directory as zero installed modules", async () => {
    const parent = await createModulesDirectory();
    const missing = path.join(parent, "missing");

    await expect(
      discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory: missing,
        platformVersion: "0.1.0",
      }),
    ).resolves.toEqual([]);
    await expect(
      discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory: parent,
        platformVersion: "0.1.0",
      }),
    ).resolves.toEqual([]);
  });

  it("discovers static manifests and orders dependencies deterministically", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "calendar", {
      manifest: {
        ...manifestFor("calendar"),
        dependencies: {
          modules: { required: { people: "^0.1.0" } },
          capabilities: { required: { "people.records": "^2.0.0" } },
        },
        storage: { buckets: [{ id: "assets" }, { id: "exports" }] },
      },
      serverSource: 'throw new Error("discovery must never execute server code");',
    });
    await createModule(modulesDirectory, "people", {
      manifest: {
        ...manifestFor("people"),
        capabilities: [{ id: "people.records", version: "2.1.0" }],
      },
    });

    const modules = await discoverModules({
      moduleSdkVersion: "0.1.0",
      modulesDirectory,
      platformVersion: "0.1.0",
    });

    expect(modules.map((module) => module.manifest.id)).toEqual(["people", "calendar"]);
    expect(modules[1]?.manifest.storage.buckets.map((bucket) => bucket.id)).toEqual([
      "assets",
      "exports",
    ]);
    expect(Object.isFrozen(modules[1]?.manifest)).toBe(true);
    const mutableBuckets = modules[1]?.manifest.storage.buckets as unknown as Array<{ id: string }>;
    expect(() => mutableBuckets.push({ id: "tampered" })).toThrow(TypeError);

    expect(modules[1]?.manifest.permissions).toEqual([
      { id: "calendar.records.read", baseline: "restricted", description: "Read records." },
    ]);
    expect(Object.isFrozen(modules[1]?.manifest.permissions)).toBe(true);
    expect(Object.isFrozen(modules[1]?.manifest.permissions[0])).toBe(true);
    const mutablePermissions = modules[1]?.manifest.permissions as unknown as Array<{
      id: string;
    }>;
    expect(() => mutablePermissions.push({ id: "tampered" })).toThrow(TypeError);
  });

  it("aggregates malformed packages and manifests without partial discovery", async () => {
    const modulesDirectory = await createModulesDirectory();
    await mkdir(path.join(modulesDirectory, "missing"));
    await createModule(modulesDirectory, "invalid", {
      manifest: { ...manifestFor("invalid"), renderers: ["not-allowed"] },
      packageJson: {
        name: "@test/module-invalid",
        version: "not-semver",
        type: "commonjs",
      },
    });

    const error = await discoveryError(modulesDirectory);

    expect(issueCodes(error)).toEqual(
      expect.arrayContaining([
        "MODULE_MANIFEST_INVALID",
        "MODULE_MANIFEST_MISSING",
        "MODULE_PACKAGE_INVALID",
        "MODULE_PACKAGE_MISSING",
      ]),
    );
  });

  it("aggregates malformed JSON without exposing machine-specific paths", async () => {
    const modulesDirectory = await createModulesDirectory();
    const moduleDirectory = path.join(modulesDirectory, "broken-json");
    await mkdir(moduleDirectory);
    await Promise.all([
      writeFile(path.join(moduleDirectory, "package.json"), "{"),
      writeFile(path.join(moduleDirectory, "ekklesia.module.json"), "["),
    ]);

    const error = await discoveryError(modulesDirectory);
    expect(issueCodes(error)).toEqual(
      expect.arrayContaining(["MODULE_MANIFEST_INVALID", "MODULE_PACKAGE_INVALID"]),
    );
    expect(error.issues.every((issue) => !issue.message.includes(modulesDirectory))).toBe(true);
  });

  it("requires package and manifest versions to match", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "mismatch", {
      packageJson: {
        name: "@test/module-mismatch",
        version: "0.2.0",
        type: "module",
        ekklesia: { layer: "module" },
      },
    });

    const error = await discoveryError(modulesDirectory);
    expect(issueCodes(error)).toContain("MODULE_VERSION_MISMATCH");
  });

  it("rejects duplicate module IDs and package names", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "one", {
      manifest: {
        ...manifestFor("one"),
        id: "shared",
        capabilities: [{ id: "shared.records", version: "1.0.0" }],
        permissions: [
          { id: "shared.records.read", baseline: "restricted", description: "Read records." },
        ],
      },
      packageJson: {
        name: "@test/duplicate",
        version: "0.1.0",
        type: "module",
        ekklesia: { layer: "module" },
      },
    });
    await createModule(modulesDirectory, "two", {
      manifest: {
        ...manifestFor("two"),
        id: "shared",
        capabilities: [{ id: "shared.records", version: "1.0.0" }],
        permissions: [
          { id: "shared.records.read", baseline: "restricted", description: "Read records." },
        ],
      },
      packageJson: {
        name: "@test/duplicate",
        version: "0.1.0",
        type: "module",
        ekklesia: { layer: "module" },
      },
    });

    const error = await discoveryError(modulesDirectory);

    expect(issueCodes(error)).toEqual(
      expect.arrayContaining(["MODULE_ID_DUPLICATE", "MODULE_PACKAGE_NAME_DUPLICATE"]),
    );
  });

  it("enforces platform and Module SDK compatibility", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "future", {
      manifest: {
        ...manifestFor("future"),
        compatibility: { platform: ">=1.0.0", moduleSdk: ">=2.0.0" },
      },
    });

    const error = await discoveryError(modulesDirectory);

    expect(issueCodes(error)).toEqual(
      expect.arrayContaining(["MODULE_PLATFORM_INCOMPATIBLE", "MODULE_SDK_INCOMPATIBLE"]),
    );
  });

  it("allows missing optional dependencies but rejects missing required dependencies", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "optional-consumer", {
      manifest: {
        ...manifestFor("optional-consumer"),
        dependencies: { modules: { optional: { absent: "^1.0.0" } } },
      },
    });

    await expect(
      discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory,
        platformVersion: "0.1.0",
      }),
    ).resolves.toHaveLength(1);

    await createModule(modulesDirectory, "required-consumer", {
      manifest: {
        ...manifestFor("required-consumer"),
        dependencies: { modules: { required: { absent: "^1.0.0" } } },
      },
    });
    const error = await discoveryError(modulesDirectory);
    expect(issueCodes(error)).toContain("MODULE_DEPENDENCY_MISSING");
  });

  it("rejects installed dependencies with incompatible versions", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "people");
    await createModule(modulesDirectory, "calendar", {
      manifest: {
        ...manifestFor("calendar"),
        dependencies: { modules: { optional: { people: "^2.0.0" } } },
      },
    });

    const error = await discoveryError(modulesDirectory);
    expect(issueCodes(error)).toContain("MODULE_DEPENDENCY_INCOMPATIBLE");
  });

  it("allows absent optional capabilities but rejects missing required capabilities", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "optional-consumer", {
      manifest: {
        ...manifestFor("optional-consumer"),
        dependencies: { capabilities: { optional: { "people.records": "^1.0.0" } } },
      },
    });
    await expect(
      discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory,
        platformVersion: "0.1.0",
      }),
    ).resolves.toHaveLength(1);

    await createModule(modulesDirectory, "consumer", {
      manifest: {
        ...manifestFor("consumer"),
        dependencies: { capabilities: { required: { "people.records": "^1.0.0" } } },
      },
    });
    const error = await discoveryError(modulesDirectory);
    expect(issueCodes(error)).toContain("MODULE_CAPABILITY_MISSING");
  });

  it("rejects incompatible installed required and optional capabilities", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "people");
    await createModule(modulesDirectory, "required-consumer", {
      manifest: {
        ...manifestFor("required-consumer"),
        dependencies: { capabilities: { required: { "people.records": "^2.0.0" } } },
      },
    });
    await createModule(modulesDirectory, "optional-consumer", {
      manifest: {
        ...manifestFor("optional-consumer"),
        dependencies: { capabilities: { optional: { "people.records": "^3.0.0" } } },
      },
    });

    const error = await discoveryError(modulesDirectory);
    const incompatibilities = error.issues.filter(
      (issue) => issue.code === "MODULE_CAPABILITY_INCOMPATIBLE",
    );
    expect(incompatibilities).toHaveLength(2);
    expect(incompatibilities).toEqual(
      expect.arrayContaining([
        expect.objectContaining({
          message: "Capability people.records 1.0.0 does not satisfy ^2.0.0.",
          path: "dependencies.capabilities.required.people.records",
        }),
        expect.objectContaining({
          message: "Capability people.records 1.0.0 does not satisfy ^3.0.0.",
          path: "dependencies.capabilities.optional.people.records",
        }),
      ]),
    );
  });

  it("detects dependency cycles", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "one", {
      manifest: {
        ...manifestFor("one"),
        dependencies: { modules: { required: { two: "^0.1.0" } } },
      },
    });
    await createModule(modulesDirectory, "two", {
      manifest: {
        ...manifestFor("two"),
        dependencies: { modules: { required: { one: "^0.1.0" } } },
      },
    });
    await createModule(modulesDirectory, "three", {
      manifest: {
        ...manifestFor("three"),
        dependencies: { modules: { required: { two: "^0.1.0" } } },
      },
    });

    const error = await discoveryError(modulesDirectory);
    expect(issueCodes(error)).toContain("MODULE_DEPENDENCY_CYCLE");
    expect(error.issues.find((issue) => issue.code === "MODULE_DEPENDENCY_CYCLE")?.message).toBe(
      "Module dependency cycle contains: one, two.",
    );
  });

  it("rejects missing entrypoint targets and invalid caller versions", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "missing-server", {
      manifest: {
        ...manifestFor("missing-server"),
        entrypoints: {
          server: "./dist/server/missing.js",
          schema: "./dist/schema/missing.js",
        },
      },
    });

    let error = await discoveryError(modulesDirectory);
    expect(error.issues.filter((issue) => issue.code === "MODULE_ENTRYPOINT_MISSING")).toHaveLength(
      2,
    );

    error = await discoveryError(modulesDirectory, { platformVersion: "invalid" });
    expect(issueCodes(error)).toContain("DISCOVERY_CONFIGURATION_INVALID");
  });

  it("rejects source TypeScript server entrypoints", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "source-server", {
      manifest: {
        ...manifestFor("source-server"),
        entrypoints: { server: "./src/server/index.ts" },
      },
    });

    const error = await discoveryError(modulesDirectory);
    expect(error.issues).toContainEqual(
      expect.objectContaining({
        code: "MODULE_ENTRYPOINT_INVALID",
        message: "server must reference compiled ESM JavaScript with a .js or .mjs extension.",
        path: "entrypoints.server",
      }),
    );
  });

  it.each([
    "./src/schema/index.ts",
    "./dist/schema/index.cjs",
  ])("rejects non-ESM schema entrypoint %s", async (schemaEntrypoint) => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "schema-source", {
      manifest: {
        ...manifestFor("schema-source"),
        entrypoints: {
          server: "./dist/server/index.js",
          schema: schemaEntrypoint,
        },
      },
    });

    const error = await discoveryError(modulesDirectory);
    expect(error.issues).toContainEqual(
      expect.objectContaining({
        code: "MODULE_ENTRYPOINT_INVALID",
        message: "schema must reference compiled ESM JavaScript with a .js or .mjs extension.",
        path: "entrypoints.schema",
      }),
    );
  });

  it("accepts an optional compiled ESM schema entrypoint", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "compiled-schema", {
      manifest: {
        ...manifestFor("compiled-schema"),
        entrypoints: {
          server: "./dist/server/index.js",
          schema: "./dist/schema/index.mjs",
        },
      },
    });
    const schemaDirectory = path.join(modulesDirectory, "compiled-schema", "dist/schema");
    await mkdir(schemaDirectory, { recursive: true });
    await writeFile(path.join(schemaDirectory, "index.mjs"), "export default {};\n");

    const modules = await discoverModules({
      moduleSdkVersion: "0.1.0",
      modulesDirectory,
      platformVersion: "0.1.0",
    });
    expect(modules[0]?.entrypoints.schema).toBe(path.join(schemaDirectory, "index.mjs"));
  });

  it("requires executable entrypoints to be files and migrations to be a directory", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "wrong-entrypoint-kind", {
      manifest: {
        ...manifestFor("wrong-entrypoint-kind"),
        entrypoints: {
          server: "./dist/server.js",
          schema: "./dist/schema.js",
          migrations: "./dist/server/index.js",
        },
      },
    });
    await Promise.all([
      mkdir(path.join(modulesDirectory, "wrong-entrypoint-kind", "dist/server.js")),
      mkdir(path.join(modulesDirectory, "wrong-entrypoint-kind", "dist/schema.js")),
    ]);

    const error = await discoveryError(modulesDirectory);
    expect(error.issues.filter((issue) => issue.code === "MODULE_ENTRYPOINT_INVALID")).toHaveLength(
      3,
    );
  });

  it("rejects schema entrypoint links that escape the module directory", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "linked-schema", {
      manifest: {
        ...manifestFor("linked-schema"),
        entrypoints: {
          server: "./dist/server/index.js",
          schema: "./dist/schema/index.js",
        },
      },
    });
    const schemaDirectory = path.join(modulesDirectory, "linked-schema", "dist/schema");
    const externalSchema = path.join(modulesDirectory, "external-schema.js");
    await mkdir(schemaDirectory, { recursive: true });
    await writeFile(externalSchema, "export default {};\n");
    await symlink("../../../external-schema.js", path.join(schemaDirectory, "index.js"));

    const error = await discoveryError(modulesDirectory);
    expect(error.issues).toContainEqual(
      expect.objectContaining({
        code: "MODULE_ENTRYPOINT_INVALID",
        path: "entrypoints.schema",
      }),
    );
  });

  it("rejects package metadata links that escape the module directory", async () => {
    const modulesDirectory = await createModulesDirectory();
    await createModule(modulesDirectory, "linked");
    const externalManifest = path.join(modulesDirectory, "external-manifest.json");
    const linkedManifest = path.join(modulesDirectory, "linked", "ekklesia.module.json");
    await writeFile(externalManifest, JSON.stringify(manifestFor("linked")));
    await rm(linkedManifest);
    await symlink("../external-manifest.json", linkedManifest);

    const error = await discoveryError(modulesDirectory);
    expect(issueCodes(error)).toContain("MODULE_MANIFEST_INVALID");
  });

  it("rejects symbolic links masquerading as installed module directories", async () => {
    const modulesDirectory = await createModulesDirectory();
    const externalModules = await createModulesDirectory();
    await createModule(externalModules, "outside");
    await symlink(
      path.join(externalModules, "outside"),
      path.join(modulesDirectory, "linked-module"),
      "dir",
    );

    const error = await discoveryError(modulesDirectory);
    expect(issueCodes(error)).toContain("MODULE_DIRECTORY_INVALID");
  });

  it("produces stable diagnostics independent of the absolute modules path", async () => {
    const firstModulesDirectory = await createModulesDirectory();
    const secondModulesDirectory = await createModulesDirectory();
    await mkdir(path.join(firstModulesDirectory, "broken"));
    await mkdir(path.join(secondModulesDirectory, "broken"));

    const [firstError, secondError] = await Promise.all([
      discoveryError(firstModulesDirectory),
      discoveryError(secondModulesDirectory),
    ]);

    expect(firstError.issues).toEqual(secondError.issues);
  });

  describe("compiled jobs entrypoint", () => {
    function manifestWithJobs(id: string, jobs: string): Record<string, unknown> {
      const manifest = manifestFor(id);
      manifest.entrypoints = { server: "./dist/server/index.js", jobs };
      return manifest;
    }

    it.each([
      ["./dist/jobs/index.js", "index.js"],
      ["./dist/jobs/index.mjs", "index.mjs"],
    ])("accepts the compiled jobs artifact %s", async (jobs, filename) => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "jobs-compiled", {
        manifest: manifestWithJobs("jobs-compiled", jobs),
        extraFiles: { [`dist/jobs/${filename}`]: "export default {};\n" },
      });

      const [discovered] = await discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory,
        platformVersion: "0.1.0",
      });

      expect(discovered?.entrypoints.jobs).toBe(
        path.join(discovered?.directory ?? "", "dist/jobs", filename),
      );
    });

    it.each([
      "./src/jobs/index.ts",
      "./src/jobs/index.tsx",
      "./dist/jobs/index.cjs",
    ])("rejects the uncompiled jobs entrypoint %s", async (jobs) => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "jobs-source", {
        manifest: manifestWithJobs("jobs-source", jobs),
        extraFiles: { [jobs.slice(2)]: "export default {};\n" },
      });

      const error = await discoveryError(modulesDirectory);
      expect(error.issues).toContainEqual(
        expect.objectContaining({
          code: "MODULE_ENTRYPOINT_INVALID",
          message: "jobs must reference compiled ESM JavaScript with a .js or .mjs extension.",
          path: "entrypoints.jobs",
        }),
      );
    });

    it("rejects a declared jobs artifact that does not exist", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "jobs-missing", {
        manifest: manifestWithJobs("jobs-missing", "./dist/jobs/index.js"),
      });

      const error = await discoveryError(modulesDirectory);
      expect(issueCodes(error)).toContain("MODULE_ENTRYPOINT_MISSING");
    });

    it("rejects a jobs entrypoint that resolves to a directory", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "jobs-directory", {
        manifest: manifestWithJobs("jobs-directory", "./dist/jobs.js"),
        extraFiles: { "dist/jobs.js/placeholder.txt": "not a file entrypoint" },
      });

      const error = await discoveryError(modulesDirectory);
      expect(error.issues).toContainEqual(
        expect.objectContaining({
          code: "MODULE_ENTRYPOINT_INVALID",
          message: "jobs must resolve to a file.",
          path: "entrypoints.jobs",
        }),
      );
    });

    it("rejects a jobs entrypoint linked outside its own module package", async () => {
      const modulesDirectory = await createModulesDirectory();
      const externalDirectory = await createModulesDirectory();
      const externalArtifact = path.join(externalDirectory, "foreign-jobs.js");
      await writeFile(externalArtifact, "export default {};\n");
      await createModule(modulesDirectory, "jobs-linked", {
        manifest: manifestWithJobs("jobs-linked", "./dist/jobs/index.js"),
      });
      await mkdir(path.join(modulesDirectory, "jobs-linked/dist/jobs"), { recursive: true });
      await symlink(
        externalArtifact,
        path.join(modulesDirectory, "jobs-linked/dist/jobs/index.js"),
      );

      const error = await discoveryError(modulesDirectory);
      expect(issueCodes(error)).toContain("MODULE_ENTRYPOINT_INVALID");
    });

    it("never imports a jobs artifact merely to discover it", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "jobs-inert", {
        manifest: manifestWithJobs("jobs-inert", "./dist/jobs/index.js"),
        // Discovery is inert. If it ever imported a jobs entrypoint this would reject rather than
        // discover successfully — `jobs` still has no runtime consumer.
        extraFiles: {
          "dist/jobs/index.js": "throw new Error('a jobs entrypoint must never be evaluated');",
        },
      });

      const discovered = await discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory,
        platformVersion: "0.1.0",
      });

      expect(discovered).toHaveLength(1);
      expect(discovered[0]?.entrypoints.jobs).toContain("dist/jobs/index.js");
    });
  });

  describe("module-owned UI entrypoint (ADR 0021)", () => {
    function manifestWithUi(id: string, ui: string): Record<string, unknown> {
      const manifest = manifestFor(id);
      manifest.entrypoints = { server: "./dist/server/index.js", ui };
      return manifest;
    }

    it("resolves a declared compiled UI entrypoint to a canonical path inside the package", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "announcements", {
        manifest: manifestWithUi("announcements", "./dist/ui/index.js"),
        extraFiles: { "dist/ui/index.js": "export default {};" },
      });

      const [discovered] = await discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory,
        platformVersion: "0.1.0",
      });

      expect(discovered?.entrypoints.ui).toBe(
        path.join(discovered?.directory ?? "", "dist/ui/index.js"),
      );
      expect(discovered?.entrypoints.server).toBeDefined();
    });

    it("omits the resolved UI entrypoint entirely for a backend-only module", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "roster");

      const [discovered] = await discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory,
        platformVersion: "0.1.0",
      });

      expect(discovered?.entrypoints.ui).toBeUndefined();
      expect(Object.hasOwn(discovered?.entrypoints ?? {}, "ui")).toBe(false);
    });

    it("rejects a source TypeScript UI entrypoint where compiled output is required", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "signage", {
        manifest: manifestWithUi("signage", "./src/ui/index.ts"),
        extraFiles: { "src/ui/index.ts": "export default {};" },
      });

      const error = await discoveryError(modulesDirectory);
      expect(issueCodes(error)).toContain("MODULE_ENTRYPOINT_INVALID");
      expect(error.issues.map((issue) => issue.path)).toContain("entrypoints.ui");
    });

    it("rejects a missing UI artifact rather than silently ignoring the declaration", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "video", {
        manifest: manifestWithUi("video", "./dist/ui/index.js"),
      });

      const error = await discoveryError(modulesDirectory);
      expect(issueCodes(error)).toContain("MODULE_ENTRYPOINT_MISSING");
    });

    it("rejects a UI entrypoint that resolves to a directory instead of a file", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "livestream", {
        manifest: manifestWithUi("livestream", "./dist/ui.js"),
        extraFiles: { "dist/ui.js/placeholder.txt": "not a file entrypoint" },
      });

      const error = await discoveryError(modulesDirectory);
      expect(issueCodes(error)).toContain("MODULE_ENTRYPOINT_INVALID");
    });

    it("rejects a UI entrypoint linked outside its own module package", async () => {
      const modulesDirectory = await createModulesDirectory();
      const externalDirectory = await createModulesDirectory();
      const externalArtifact = path.join(externalDirectory, "foreign-ui.js");
      await writeFile(externalArtifact, "export default {};");
      await createModule(modulesDirectory, "calendar", {
        manifest: manifestWithUi("calendar", "./dist/ui/index.js"),
      });
      await mkdir(path.join(modulesDirectory, "calendar/dist/ui"), { recursive: true });
      await symlink(externalArtifact, path.join(modulesDirectory, "calendar/dist/ui/index.js"));

      const error = await discoveryError(modulesDirectory);
      expect(issueCodes(error)).toContain("MODULE_ENTRYPOINT_INVALID");
    });

    it("never imports a UI artifact merely to discover it", async () => {
      const modulesDirectory = await createModulesDirectory();
      await createModule(modulesDirectory, "announcements", {
        manifest: manifestWithUi("announcements", "./dist/ui/index.js"),
        // Discovery is inert: a throwing artifact must not be evaluated. If discovery ever
        // imported a UI entrypoint, this would surface as a rejected promise rather than a
        // successfully discovered module.
        extraFiles: {
          "dist/ui/index.js": "throw new Error('a UI entrypoint must never be evaluated');",
        },
      });

      const discovered = await discoverModules({
        moduleSdkVersion: "0.1.0",
        modulesDirectory,
        platformVersion: "0.1.0",
      });

      expect(discovered).toHaveLength(1);
      expect(discovered[0]?.entrypoints.ui).toContain("dist/ui/index.js");
    });
  });
});