1 files changed, 48 insertions, 0 deletions
diff --git a/toolkit/components/uniffi-bindgen-gecko-js/fixtures/tests/xpcshell/test_arithmetic.js b/toolkit/components/uniffi-bindgen-gecko-js/fixtures/tests/xpcshell/test_arithmetic.js
new file mode 100644
index 0000000000..a221abc39f
--- /dev/null
+++ b/toolkit/components/uniffi-bindgen-gecko-js/fixtures/tests/xpcshell/test_arithmetic.js
@@ -0,0 +1,48 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const Arithmetic = ChromeUtils.importESModule(
+  "resource://gre/modules/RustArithmetic.sys.mjs"
+);
+
+add_task(async function () {
+  Assert.ok(Arithmetic.IntegerOverflow);
+  Assert.equal(await Arithmetic.add(2, 4), 6);
+  Assert.equal(await Arithmetic.add(4, 8), 12);
+  // For other backends we would have this test:
+  // await Assert.rejects(
+  //     Arithmetic.add(18446744073709551615, 1),
+  //     Arithmetic.IntegerOverflow,
+  //     "add() should throw IntegerOverflow")
+  //
+  // However, this doesn't work because JS number values are actually 64-bit
+  // floats, and that number is greater than the maximum "safe" integer.
+  //
+  // Instead, let's test that we reject numbers that are that big
+  await Assert.rejects(
+    Arithmetic.add(Number.MAX_SAFE_INTEGER + 1, 0),
+    /TypeError/,
+    "add() should throw TypeError when an input is > MAX_SAFE_INTEGER"
+  );
+
+  Assert.equal(await Arithmetic.sub(4, 2), 2);
+  Assert.equal(await Arithmetic.sub(8, 4), 4);
+  await Assert.rejects(
+    Arithmetic.sub(0, 1),
+    Arithmetic.IntegerOverflow,
+    "sub() should throw IntegerOverflow"
+  );
+
+  Assert.equal(await Arithmetic.div(8, 4), 2);
+  // Can't test this, because we don't allow Rust panics in FF
+  // Assert.rejects(
+  //     Arithmetic.div(8, 0),
+  //     (e) => Assert.equal(e, Arithmetic.UniFFIInternalError),
+  //     "Divide by 0 should throw UniFFIInternalError")
+  //
+  Assert.ok(await Arithmetic.equal(2, 2));
+  Assert.ok(await Arithmetic.equal(4, 4));
+
+  Assert.ok(!(await Arithmetic.equal(2, 4)));
+  Assert.ok(!(await Arithmetic.equal(4, 8)));
+});