hydrate alert evidence from clickhouse

services/api/tests/alert-context.test.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from "bun:test";
+import { isAlertContextPath, parseAlertContextTraceIdPath } from "../src/alert-context";
+
+describe("alert context route helpers", () => {
+  it("extracts a valid alert trace id from the context endpoint path", () => {
+    expect(parseAlertContextTraceIdPath("/flow/alerts/alert%3Actx%2Fone/context")).toBe("alert:ctx/one");
+  });
+
+  it("returns null for unrelated alert paths", () => {
+    expect(isAlertContextPath("/flow/alerts")).toBe(false);
+    expect(parseAlertContextTraceIdPath("/flow/alerts/alert:ctx")).toBeNull();
+  });
+
+  it("rejects malformed trace ids safely", () => {
+    expect(() => parseAlertContextTraceIdPath("/flow/alerts/%20/context")).toThrow();
+    expect(() => parseAlertContextTraceIdPath("/flow/alerts/%24bad/context")).toThrow();
+  });
+});