1 files changed, 24 insertions, 7 deletions
diff --git a/integration/bunjs-only-snippets/response.file.test.js b/integration/bunjs-only-snippets/response.file.test.js
index 7b818405a..ed4844876 100644
--- a/integration/bunjs-only-snippets/response.file.test.js
+++ b/integration/bunjs-only-snippets/response.file.test.js
@@ -7,22 +7,39 @@ it("Response.file", async () => {
 });
 
 it("Response.file as a blob", async () => {
-  const file = path.join(import.meta.url, "../fetch.js.txt");
-  var response = Response.file(file);
+  const filePath = path.join(import.meta.url, "../fetch.js.txt");
+  const fixture = fs.readFileSync(filePath, "utf8");
+  // this is a Response object with the same interface as the one returned by fetch
+  // internally, instead of a byte array, it stores the file path!
+  // this enables several performance optimizations
+  var response = Response.file(filePath);
+
+  // at this point, it's still just a file path
   var blob = await response.blob();
+  // no size because we haven't read it from disk yet
   expect(blob.size).toBe(0);
-  expect(await blob.text()).toBe(fs.readFileSync(file, "utf8"));
-  expect(blob.size).toBe(1256);
-  expect(await blob.text()).toBe(fs.readFileSync(file, "utf8"));
+  // now it reads "./fetch.js.txt" from the filesystem
+  // it's lazy, only loads once we ask for it
+  // if it fails, the promise will reject at this point
+  expect(await blob.text()).toBe(fixture);
+  // now that it's loaded, the size updates
+  expect(blob.size).toBe(fixture.length);
+  // and it only loads once for _all_ blobs pointing to that file path
+  // until all references are released
+  expect((await blob.arrayBuffer()).byteLength).toBe(fixture.length);
 
   const array = new Uint8Array(await blob.arrayBuffer());
-  const text = fs.readFileSync(file, "utf8");
+  const text = fixture;
   for (let i = 0; i < text.length; i++) {
     expect(array[i]).toBe(text.charCodeAt(i));
   }
-  expect(blob.size).toBe(1256);
+  expect(blob.size).toBe(fixture.size);
   blob = null;
   response = null;
   Bun.gc(true);
   await new Promise((resolve) => setTimeout(resolve, 1));
+  // now we're back
+  var response = Response.file(file);
+  var blob = await response.blob();
+  expect(blob.size).toBe(0);
 });