diff --git a/test/unit/local-branch-file-classifiers.test.ts b/test/unit/local-branch-file-classifiers.test.ts
new file mode 100644
index 0000000000..310ed41239
--- /dev/null
+++ b/test/unit/local-branch-file-classifiers.test.ts
@@ -0,0 +1,137 @@
+import { describe, expect, it } from "vitest";
+
+import { isCodeFile, isTestFile } from "../../src/signals/local-branch";
+
+describe("isTestFile", () => {
+  it("matches test/spec directories anywhere in the path", () => {
+    for (const path of [
+      "test/example.ts",
+      "tests/example.ts",
+      "spec/example.rb",
+      "__tests__/component.tsx",
+      "packages/api/test/helper.go",
+      "services/worker/tests/worker.py",
+      "app/models/spec/user.rb",
+      "frontend/src/__tests__/button.jsx",
+    ]) {
+      expect(isTestFile(path)).toBe(true);
+    }
+  });
+
+  it("matches the src/test convention", () => {
+    for (const path of [
+      "src/test/setup.ts",
+      "packages/core/src/test/fixtures.ts",
+    ]) {
+      expect(isTestFile(path)).toBe(true);
+    }
+  });
+
+  it("matches go/python/ruby _test suffix files", () => {
+    for (const path of [
+      "handler_test.go",
+      "pkg/server/router_test.go",
+      "service_test.py",
+      "app/jobs/cleanup_test.py",
+      "models/account_test.rb",
+      "HANDLER_TEST.GO",
+    ]) {
+      expect(isTestFile(path)).toBe(true);
+    }
+  });
+
+  it("matches ruby _spec suffix files", () => {
+    for (const path of ["user_spec.rb", "spec/models/user_spec.rb"]) {
+      expect(isTestFile(path)).toBe(true);
+    }
+  });
+
+  it("matches dotted .test/.spec source files across supported extensions", () => {
+    for (const path of [
+      "math.test.ts",
+      "Button.spec.tsx",
+      "client.test.js",
+      "widget.spec.jsx",
+      "calc.test.py",
+      "user.spec.rb",
+      "engine.test.rs",
+      "Engine.Test.TS",
+    ]) {
+      expect(isTestFile(path)).toBe(true);
+    }
+  });
+
+  it("does not flag production sources or lookalike directory names", () => {
+    for (const path of [
+      "src/index.ts",
+      "src/signals/local-branch.ts",
+      "README.md",
+      "testing/util.ts",
+      "contest/entry.ts",
+      "specs/openapi.ts",
+    ]) {
+      expect(isTestFile(path)).toBe(false);
+    }
+  });
+
+  it("does not flag near-miss suffixes that fall outside the patterns", () => {
+    for (const path of [
+      "helper_test.ts",
+      "helper_test.js",
+      "config_spec.py",
+      "foo.testing.ts",
+      "notes.test.md",
+    ]) {
+      expect(isTestFile(path)).toBe(false);
+    }
+  });
+});
+
+describe("isCodeFile", () => {
+  it("matches supported programming-language extensions", () => {
+    for (const path of [
+      "src/index.ts",
+      "components/Button.tsx",
+      "scripts/build.js",
+      "pages/home.jsx",
+      "service/main.py",
+      "lib/parser.rb",
+      "engine/core.rs",
+      "android/App.kt",
+      "etl/Job.scala",
+      "server/Main.java",
+      "cmd/server/main.go",
+      "migrations/0001_init.sql",
+      "helper_test.ts",
+    ]) {
+      expect(isCodeFile(path)).toBe(true);
+    }
+  });
+
+  it("excludes files that are themselves test files even with code extensions", () => {
+    for (const path of [
+      "math.test.ts",
+      "Button.spec.tsx",
+      "handler_test.go",
+      "service_test.py",
+      "models/account_test.rb",
+      "__tests__/component.jsx",
+    ]) {
+      expect(isCodeFile(path)).toBe(false);
+    }
+  });
+
+  it("excludes non-code assets and extensionless files", () => {
+    for (const path of [
+      "README.md",
+      "package.json",
+      "assets/logo.png",
+      "styles/site.css",
+      "docs/notes.txt",
+      "Dockerfile",
+      "config.yaml",
+    ]) {
+      expect(isCodeFile(path)).toBe(false);
+    }
+  });
+});