1 files changed, 46 insertions, 0 deletions
diff --git a/test/bun.js/concat.test.js b/test/bun.js/concat.test.js
new file mode 100644
index 000000000..a965fdb94
--- /dev/null
+++ b/test/bun.js/concat.test.js
@@ -0,0 +1,46 @@
+import { describe, it, expect } from "bun:test";
+import { gcTick } from "./gc";
+import { concatArrayBuffers } from "bun";
+
+describe("concat", () => {
+  function polyfill(chunks) {
+    var size = 0;
+    for (const chunk of chunks) {
+      size += chunk.byteLength;
+    }
+    var buffer = new ArrayBuffer(size);
+    var view = new Uint8Array(buffer);
+    var offset = 0;
+    for (const chunk of chunks) {
+      view.set(chunk, offset);
+      offset += chunk.byteLength;
+    }
+    return buffer;
+  }
+
+  function concatToString(chunks) {
+    return Array.from(new Uint8Array(concatArrayBuffers(chunks))).join("");
+  }
+
+  function polyfillToString(chunks) {
+    return Array.from(new Uint8Array(polyfill(chunks))).join("");
+  }
+
+  it("works with one element", () => {
+    expect(concatToString([new Uint8Array([123])])).toBe(
+      polyfillToString([new Uint8Array([123])])
+    );
+  });
+
+  it("works with two elements", () => {
+    expect(
+      concatToString([Uint8Array.from([123]), Uint8Array.from([456])])
+    ).toBe(polyfillToString([Uint8Array.from([123]), Uint8Array.from([456])]));
+  });
+
+  it("works with mix of ArrayBuffer and TypedArray elements", () => {
+    expect(
+      concatToString([Uint8Array.from([123]).buffer, Uint8Array.from([456])])
+    ).toBe(polyfillToString([Uint8Array.from([123]), Uint8Array.from([456])]));
+  });
+});