1 files changed, 69 insertions, 0 deletions
diff --git a/core/runtime/encode_decode_test.js b/core/runtime/encode_decode_test.js
new file mode 100644
index 000000000..0f4668765
--- /dev/null
+++ b/core/runtime/encode_decode_test.js
@@ -0,0 +1,69 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+"use strict";
+function assert(cond) {
+  if (!cond) {
+    throw Error("assert");
+  }
+}
+
+function assertArrayEquals(a1, a2) {
+  if (a1.length !== a2.length) throw Error("assert");
+
+  for (const index in a1) {
+    if (a1[index] !== a2[index]) {
+      throw Error("assert");
+    }
+  }
+}
+
+function main() {
+  // deno-fmt-ignore
+  const fixture1 = [
+    0xf0, 0x9d, 0x93, 0xbd,
+    0xf0, 0x9d, 0x93, 0xae,
+    0xf0, 0x9d, 0x94, 0x81,
+    0xf0, 0x9d, 0x93, 0xbd
+  ];
+  // deno-fmt-ignore
+  const fixture2 = [
+    72, 101, 108, 108,
+    111, 32, 239, 191,
+    189, 239, 191, 189,
+    32, 87, 111, 114,
+    108, 100
+  ];
+
+  const empty = Deno.core.ops.op_encode("");
+  if (empty.length !== 0) throw new Error("assert");
+
+  assertArrayEquals(
+    Array.from(Deno.core.ops.op_encode("𝓽𝓮𝔁𝓽")),
+    fixture1,
+  );
+  assertArrayEquals(
+    Array.from(Deno.core.ops.op_encode("Hello \udc12\ud834 World")),
+    fixture2,
+  );
+
+  const emptyBuf = Deno.core.ops.op_decode(new Uint8Array(0));
+  if (emptyBuf !== "") throw new Error("assert");
+
+  assert(Deno.core.ops.op_decode(new Uint8Array(fixture1)) === "𝓽𝓮𝔁𝓽");
+  assert(
+    Deno.core.ops.op_decode(new Uint8Array(fixture2)) ===
+      "Hello �� World",
+  );
+
+  // See https://github.com/denoland/deno/issues/6649
+  let thrown = false;
+  try {
+    Deno.core.ops.op_decode(new Uint8Array(2 ** 29));
+  } catch (e) {
+    thrown = true;
+    assert(e instanceof RangeError);
+    assert(e.message === "string too long");
+  }
+  assert(thrown);
+}
+
+main();