From 3117df1c1486daf524cd7dd71eef5250e9d89689 Mon Sep 17 00:00:00 2001
From: Danijel Martinek <danijel@fraqtal.xyz>
Date: Tue, 12 May 2026 23:22:43 +0200
Subject: [PATCH] feat(core-eslint): required-cores-installed rule

---
 .../rules/required-cores-installed.js         | 68 +++++++++++++
 .../rules/required-cores-installed.test.js    | 95 +++++++++++++++++++
 2 files changed, 163 insertions(+)
 create mode 100644 packages/core-eslint/rules/required-cores-installed.js
 create mode 100644 packages/core-eslint/rules/required-cores-installed.test.js

diff --git a/packages/core-eslint/rules/required-cores-installed.js b/packages/core-eslint/rules/required-cores-installed.js
new file mode 100644
index 0000000..202264a
--- /dev/null
+++ b/packages/core-eslint/rules/required-cores-installed.js
@@ -0,0 +1,68 @@
+import fs from "node:fs";
+import path from "node:path";
+import { readManifestSource } from "./_manifest-source.js";
+import { readWorkspacePackages } from "./_workspace.js";
+
+/**
+ * Check whether `packages/core-<name>` exists under any of the workspace
+ * globs. The glob set is small and predictable (e.g. ["apps/*", "packages/*"]);
+ * we simulate matching by checking each glob's directory portion + verifying
+ * `core-<name>` exists in that directory.
+ */
+function coreExistsInWorkspace(coreName, repoRoot, packageGlobs) {
+  for (const glob of packageGlobs) {
+    const slashStar = glob.endsWith("/*") ? glob.slice(0, -2) : null;
+    if (!slashStar) continue;
+    const candidate = path.join(repoRoot, slashStar, `core-${coreName}`);
+    if (fs.existsSync(candidate)) return true;
+  }
+  return false;
+}
+
+/** @type {import("eslint").Rule.RuleModule} */
+export default {
+  meta: {
+    type: "problem",
+    docs: {
+      description:
+        "Cores declared in a feature.manifest.ts's requiredCores must exist as core-<name> packages within a workspace glob.",
+    },
+    schema: [
+      {
+        type: "object",
+        properties: {
+          repoRoot: { type: "string" },
+        },
+        additionalProperties: false,
+      },
+    ],
+    messages: {
+      coreNotInstalled:
+        "Manifest declares requiredCores: [..., \"{{core}}\", ...] but `core-{{core}}` is not present in any workspace glob. Run `pnpm turbo gen core-package {{core}}` or drop the entry.",
+    },
+  },
+  create(context) {
+    const opts = context.options[0] ?? {};
+    const repoRoot = opts.repoRoot ?? context.cwd ?? process.cwd();
+    return {
+      Program(node) {
+        const filename = context.filename;
+        if (!filename.endsWith("/feature.manifest.ts") && !filename.endsWith("\\feature.manifest.ts")) {
+          return;
+        }
+        const manifest = readManifestSource(filename);
+        if (!manifest) return;
+        const globs = readWorkspacePackages(repoRoot);
+        for (const core of manifest.requiredCores) {
+          if (!coreExistsInWorkspace(core, repoRoot, globs)) {
+            context.report({
+              node,
+              messageId: "coreNotInstalled",
+              data: { core },
+            });
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/packages/core-eslint/rules/required-cores-installed.test.js b/packages/core-eslint/rules/required-cores-installed.test.js
new file mode 100644
index 0000000..0725306
--- /dev/null
+++ b/packages/core-eslint/rules/required-cores-installed.test.js
@@ -0,0 +1,95 @@
+import { describe, it } from "vitest";
+import { RuleTester } from "eslint";
+import path from "node:path";
+import os from "node:os";
+import fs from "node:fs";
+import rule from "./required-cores-installed.js";
+
+function makeFixture({ workspacePackages, manifestCores }) {
+  const repoRoot = fs.mkdtempSync(path.join(os.tmpdir(), "rci-"));
+  fs.writeFileSync(
+    path.join(repoRoot, "pnpm-workspace.yaml"),
+    `packages:\n${workspacePackages.map((p) => `  - "${p}"`).join("\n")}\n`,
+  );
+  const manifestDir = path.join(repoRoot, "packages", "demo", "src");
+  fs.mkdirSync(manifestDir, { recursive: true });
+  // We also need each declared core to exist as a package directory for the glob to resolve.
+  for (const core of manifestCores) {
+    fs.mkdirSync(path.join(repoRoot, "packages", `core-${core}`), { recursive: true });
+  }
+  const manifest = path.join(manifestDir, "feature.manifest.ts");
+  fs.writeFileSync(
+    manifest,
+    `export const demoManifest = defineFeature({
+  name: "demo",
+  requiredCores: [${manifestCores.map((c) => `"${c}"`).join(", ")}],
+  useCases: {},
+  realtimeChannels: [],
+  jobs: [],
+} as const);`,
+  );
+  return { repoRoot, manifest };
+}
+
+const tester = new RuleTester({ languageOptions: { ecmaVersion: "latest", sourceType: "module" } });
+
+describe("required-cores-installed", () => {
+  it("passes when all declared cores are present as core-<x> packages under a workspace glob", () => {
+    const { repoRoot, manifest } = makeFixture({
+      workspacePackages: ["packages/*"],
+      manifestCores: ["audit", "events"],
+    });
+    tester.run("required-cores-installed", rule, {
+      valid: [
+        {
+          filename: manifest,
+          code: fs.readFileSync(manifest, "utf8"),
+          options: [{ repoRoot }],
+        },
+      ],
+      invalid: [],
+    });
+  });
+
+  it("fires for any declared core that has no matching package", () => {
+    const repoRoot = fs.mkdtempSync(path.join(os.tmpdir(), "rci-"));
+    fs.writeFileSync(path.join(repoRoot, "pnpm-workspace.yaml"), `packages:\n  - "packages/*"\n`);
+    const manifestDir = path.join(repoRoot, "packages", "demo", "src");
+    fs.mkdirSync(manifestDir, { recursive: true });
+    // NB: do NOT create packages/core-realtime — that's the missing one.
+    fs.mkdirSync(path.join(repoRoot, "packages", "core-audit"), { recursive: true });
+    const manifest = path.join(manifestDir, "feature.manifest.ts");
+    fs.writeFileSync(
+      manifest,
+      `export const demoManifest = defineFeature({
+  name: "demo",
+  requiredCores: ["audit", "realtime"],
+  useCases: {},
+  realtimeChannels: [],
+  jobs: [],
+} as const);`,
+    );
+
+    tester.run("required-cores-installed", rule, {
+      valid: [],
+      invalid: [
+        {
+          filename: manifest,
+          code: fs.readFileSync(manifest, "utf8"),
+          options: [{ repoRoot }],
+          errors: [{ messageId: "coreNotInstalled", data: { core: "realtime" } }],
+        },
+      ],
+    });
+  });
+
+  it("is a no-op for files that are not feature.manifest.ts", () => {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), "rci-"));
+    const other = path.join(dir, "not-a-manifest.ts");
+    fs.writeFileSync(other, `export const x = 1;`);
+    tester.run("required-cores-installed", rule, {
+      valid: [{ filename: other, code: fs.readFileSync(other, "utf8"), options: [{ repoRoot: dir }] }],
+      invalid: [],
+    });
+  });
+});