fix: Decode grep context arrays in fff-node (#321)

* fix: Decode grep context arrays in fff-node

* test: Normalize Windows paths in fff-node grep context e2e

Author: jzinno

packages/fff-node/src/ffi.ts

@@ -627,7 +627,7 @@ function readCStringArray(ptrArray: JsExternal, count: number): string[] {
     const elemPtr = ptrOffset(ptrArray, i * 8);
     const [charPtr] = restorePointer({
       retType: [DataType.External],
-      paramsValue: wrapPointer([elemPtr]),
+      paramsValue: [elemPtr],
     }) as unknown as [JsExternal];
     result.push(readCString(charPtr) ?? "");
   }

packages/fff-node/test/e2e.mjs

@@ -20,6 +20,7 @@ import { FileFinder, closeLibrary } from "../dist/src/index.js";
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const REPO_ROOT = resolve(__dirname, "..", "..", "..");
+const normalizePath = (p) => p.replace(/\\/g, "/");
 
 /** @type {import("../dist/src/finder.js").FileFinder | null} */
 let finder = null;
@@ -167,6 +168,31 @@ describe("fff-node", { concurrency: 1 }, () => {
       assert.ok(r.ok, `regex grep failed: ${!r.ok ? r.error : ""}`);
       assert.ok(r.value.items.length > 0);
     });
+
+    it("decodes before/after context lines", () => {
+      const r = finder.grep(
+        "match.contextBefore = readCStringArray(raw.context_before, raw.context_before_count);",
+        {
+          mode: "plain",
+          beforeContext: 1,
+          afterContext: 1,
+          maxMatchesPerFile: 5,
+        },
+      );
+      assert.ok(r.ok, `grep with context failed: ${!r.ok ? r.error : ""}`);
+
+      const match = r.value.items.find(
+        (m) => normalizePath(m.relativePath) === "packages/fff-node/src/ffi.ts",
+      );
+      assert.ok(
+        match,
+        `expected a match in packages/fff-node/src/ffi.ts, got: ${r.value.items
+          .map((m) => normalizePath(m.relativePath))
+          .join(", ")}`,
+      );
+      assert.deepEqual(match.contextBefore, ["  if (raw.context_before_count > 0) {"]);
+      assert.deepEqual(match.contextAfter, ["  }"]);
+    });
   });
 
   describe("multiGrep", { concurrency: 1 }, () => {