feat(core-eslint): workspace helper for conformance rules

packages/core-eslint/rules/_workspace.test.js

@@ -0,0 +1,34 @@
+import { describe, it, expect } from "vitest";
+import path from "node:path";
+import os from "node:os";
+import fs from "node:fs";
+import { readWorkspacePackages } from "./_workspace.js";
+
+function writeWorkspaceYaml(contents) {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "workspace-"));
+  const filepath = path.join(dir, "pnpm-workspace.yaml");
+  fs.writeFileSync(filepath, contents);
+  return { dir, filepath };
+}
+
+describe("_workspace", () => {
+  it("returns the list of declared package globs", () => {
+    const { dir } = writeWorkspaceYaml(
+      `packages:
+  - "apps/*"
+  - "packages/*"
+`,
+    );
+    expect(readWorkspacePackages(dir)).toEqual(["apps/*", "packages/*"]);
+  });
+
+  it("returns [] when pnpm-workspace.yaml is missing", () => {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), "workspace-"));
+    expect(readWorkspacePackages(dir)).toEqual([]);
+  });
+
+  it("returns [] when packages key is absent", () => {
+    const { dir } = writeWorkspaceYaml(`# empty\n`);
+    expect(readWorkspacePackages(dir)).toEqual([]);
+  });
+});