wasm32 regression test

.github/workflows/ci.yml

@@ -35,3 +35,31 @@ jobs:
 
       - name: Test
         run: cargo test --manifest-path iKeySort/Cargo.toml ${{ matrix.feature_mode.features }}
+
+  wasm32-regression:
+    name: wasm32 regression (Node.js)
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: wasm32-unknown-unknown
+
+      - name: Cache cargo registry + build
+        uses: Swatinem/rust-cache@v2
+
+      - name: Build debug wasm module
+        run: cargo build --manifest-path iKeySort/tests/wasm32/Cargo.toml --target wasm32-unknown-unknown
+
+      - name: Run debug wasm module
+        run: node iKeySort/tests/wasm32/run.mjs iKeySort/tests/wasm32/target/wasm32-unknown-unknown/debug/wasm32_regression.wasm
+
+      - name: Build release wasm module
+        run: cargo build --manifest-path iKeySort/tests/wasm32/Cargo.toml --target wasm32-unknown-unknown --release
+
+      - name: Run release wasm module
+        run: node iKeySort/tests/wasm32/run.mjs iKeySort/tests/wasm32/target/wasm32-unknown-unknown/release/wasm32_regression.wasm

iKeySort/tests/wasm32/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "wasm32_regression"
+version = "0.0.0"
+edition = "2024"
+publish = false
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+i_key_sort = { path = "../.." }
+
+[profile.release]
+panic = "abort"

iKeySort/tests/wasm32/run.mjs

@@ -0,0 +1,11 @@
+import { readFile } from "node:fs/promises";
+
+const bytes = await readFile(process.argv[2]);
+const { instance } = await WebAssembly.instantiate(bytes, {});
+const result = instance.exports.run_i64_32bit_boundary_regression();
+
+if (result !== 0) {
+    throw new Error(`wasm32 i64 regression failed with code ${result}`);
+}
+
+console.log("wasm32 i64 regression passed");

iKeySort/tests/wasm32/src/lib.rs

@@ -0,0 +1,26 @@
+use i_key_sort::sort::one_key::OneKeySort;
+
+#[unsafe(no_mangle)]
+pub extern "C" fn run_i64_32bit_boundary_regression() -> i32 {
+    const BOUNDARY: i64 = 1i64 << 32;
+
+    let mut values = [
+        0,
+        BOUNDARY - 1,
+        BOUNDARY,
+        1,
+        BOUNDARY / 2,
+        BOUNDARY - 2,
+        123,
+        BOUNDARY - 123,
+    ]
+    .repeat(128);
+    values.reverse();
+
+    let mut expected = values.clone();
+    expected.sort_unstable();
+
+    values.sort_by_one_key(false, |value| *value);
+
+    i32::from(values != expected)
+}

iKeySort/tests/wasm32_i64.rs

@@ -0,0 +1,28 @@
+use i_key_sort::sort::one_key::OneKeySort;
+
+#[test]
+fn sort_i64_across_32_bit_boundary() {
+    const BOUNDARY: i64 = 1i64 << 32;
+
+    // On wasm32, the old implementation truncated the full distance to zero
+    // while the intermediate distance became `usize::MAX`, escaping the layout.
+    let mut values = [
+        0,
+        BOUNDARY - 1,
+        BOUNDARY,
+        1,
+        BOUNDARY / 2,
+        BOUNDARY - 2,
+        123,
+        BOUNDARY - 123,
+    ]
+    .repeat(128);
+    values.reverse();
+
+    let mut expected = values.clone();
+    expected.sort_unstable();
+
+    values.sort_by_one_key(false, |value| *value);
+
+    assert_eq!(values, expected);
+}