feat(core-eslint): usecase-must-have-test-file rule

packages/core-eslint/rules/usecase-must-have-test-file.js

@@ -0,0 +1,32 @@
+import fs from "node:fs";
+
+/** @type {import("eslint").Rule.RuleModule} */
+export default {
+  meta: {
+    type: "problem",
+    docs: {
+      description:
+        "Every *.use-case.ts file must have a sibling *.use-case.test.ts (TDD discipline).",
+    },
+    schema: [],
+    messages: {
+      missingTestFile:
+        "Use case {{filename}} has no sibling test file at {{expected}}. Write the red test first.",
+    },
+  },
+  create(context) {
+    return {
+      Program(node) {
+        const filename = context.filename;
+        if (!filename.endsWith(".use-case.ts")) return;
+        const expected = filename.replace(/\.use-case\.ts$/, ".use-case.test.ts");
+        if (fs.existsSync(expected)) return;
+        context.report({
+          node,
+          messageId: "missingTestFile",
+          data: { filename: filename.split("/").pop(), expected: expected.split("/").pop() },
+        });
+      },
+    };
+  },
+};