Memory/QMD: robustly parse noisy qmd JSON output

src/memory/qmd-query-parser.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, it } from "vitest";
+import { parseQmdQueryJson } from "./qmd-query-parser.js";
+
+describe("parseQmdQueryJson", () => {
+  it("parses clean qmd JSON output", () => {
+    const results = parseQmdQueryJson('[{"docid":"abc","score":1,"snippet":"@@ -1,1\\none"}]', "");
+    expect(results).toEqual([
+      {
+        docid: "abc",
+        score: 1,
+        snippet: "@@ -1,1\none",
+      },
+    ]);
+  });
+
+  it("extracts embedded result arrays from noisy stdout", () => {
+    const results = parseQmdQueryJson(
+      `initializing
+{"payload":"ok"}
+[{"docid":"abc","score":0.5}]
+complete`,
+      "",
+    );
+    expect(results).toEqual([{ docid: "abc", score: 0.5 }]);
+  });
+
+  it("treats plain-text no-results from stderr as an empty result set", () => {
+    const results = parseQmdQueryJson("", "No results found\n");
+    expect(results).toEqual([]);
+  });
+
+  it("throws when stdout cannot be interpreted as qmd JSON", () => {
+    expect(() => parseQmdQueryJson("this is not json", "")).toThrow(
+      /qmd query returned invalid JSON/i,
+    );
+  });
+});