test: Introduce Hermes CI workflow

.github/workflows/ci.yml

@@ -213,6 +213,41 @@ jobs:
       - name: Run yarn test262
         run: exit 0 # TODO remove test262 from required tests for CI
 
+  test-hermes:
+    name: test-hermes
+
+    # begin macro
+
+    runs-on: ${{ matrix.platform }}
+    strategy:
+      fail-fast: false
+      matrix:
+        platform: [ubuntu-latest]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      # without this, setup-node errors on mismatched yarn versions
+      - run: corepack enable
+
+      - name: Use Node.js 22.x
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22.x
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --immutable
+
+      # end macro
+
+      - name: Run yarn build
+        run: yarn build
+
+      - name: Run SES/Hermes smoke test
+        run: cd packages/ses && yarn test:hermes
+
   viable-release:
     name: viable-release
 

packages/ses/package.json

@@ -82,6 +82,7 @@
     "prepare": "npm run clean && npm run build",
     "qt": "ava",
     "test": "tsd && ava",
+    "test:hermes": "./scripts/hermes-test.sh",
     "test:xs": "xst dist/ses.umd.js test/_lockdown-safe.js",
     "postpack": "git clean -f '*.d.ts*' '*.tsbuildinfo'"
   },
@@ -101,6 +102,7 @@
     "eslint-config-prettier": "^9.1.0",
     "eslint-plugin-eslint-comments": "^3.2.0",
     "eslint-plugin-import": "^2.29.1",
+    "hermes-engine-cli": "^0.12.0",
     "prettier": "^3.3.3",
     "terser": "^5.16.6",
     "tsd": "^0.31.2",

packages/ses/scripts/hermes-test.sh

@@ -0,0 +1,55 @@
+#!/bin/bash
+
+# Creates a JS smoke test to be compiled into Hermes bytecode (hbc).
+#
+# Usage: scripts/hermes-test.sh
+
+set -ueo pipefail
+
+DIR=$(dirname -- "${BASH_SOURCE[0]}")
+cd "$DIR/.."
+
+OS="$(uname -s)"
+
+case "$OS" in
+    Linux*)
+        OS_DIR="linux64-bin"
+        ;;
+    Darwin*)
+        OS_DIR="osx-bin"
+        ;;
+    CYGWIN*|MINGW*|MSYS*)
+        OS_DIR="win64-bin"
+        ;;
+    *)
+        echo "Unsupported OS: $OS"
+        exit 1
+        ;;
+esac
+
+HERMESC="../../node_modules/hermes-engine-cli/$OS_DIR/hermesc"
+HERMES="../../node_modules/hermes-engine-cli/$OS_DIR/hermes"
+
+echo "Concatenating: dist/ses-hermes.cjs + test/_hermes-smoke.js"
+cat dist/ses-hermes.cjs test/_hermes-smoke.js > test/_hermes-smoke-dist.js
+echo "Generated: test/_hermes-smoke-dist.js"
+
+# Errors on async arrow functions and async generators
+# Both are unsupported on Hermes
+echo "Executing: test/_hermes-smoke-dist.js on Hermes compiler"
+$HERMESC test/_hermes-smoke-dist.js -emit-binary -out test/_hermes-smoke-dist.hbc
+echo "Generated: test/_hermes-smoke-dist.hbc"
+echo "Hermes compiler done"
+
+# TODO: Disabled until https://github.com/endojs/endo/issues/1891 complete
+# echo "Executing generated bytecode file on Hermes VM"
+# $HERMES -b test/_hermes-smoke-dist.hbc
+# echo "Hermes VM done"
+echo "Skipping: Hermes VM"
+
+echo "Hermes tests complete"
+
+echo "Removing: test/_hermes-smoke-dist.js"
+rm test/_hermes-smoke-dist.js
+echo "Removing: test/_hermes-smoke-dist.hbc"
+rm test/_hermes-smoke-dist.hbc

packages/ses/test/_hermes-smoke.js

@@ -0,0 +1,49 @@
+// Hermes doesn't support native I/O,
+// so we concat the SES shim above,
+// when running this test on Hermes.
+
+/**
+ * Test calling SES lockdown.
+ */
+const testLockdown = () => {
+  lockdown();
+};
+
+/**
+ * TODO: Test creating a new Compartment.
+ */
+// eslint-disable-next-line no-unused-vars
+const testCompartment = () => {
+  // eslint-disable-next-line no-unused-vars
+  const c = new Compartment();
+};
+
+/**
+ * TODO: Test Compartment import hook and resolve hook.
+ */
+// eslint-disable-next-line no-unused-vars
+async function testCompartmentHooks() {
+  const resolveHook = a => a;
+
+  async function importHook() {
+    return {
+      imports: [],
+      exports: ['meaning'],
+      execute(exports) {
+        exports.meaning = 42;
+      },
+    };
+  }
+
+  const compartment = new Compartment({}, {}, { resolveHook, importHook });
+
+  const module = compartment.module('.');
+
+  const {
+    namespace: { _meaning },
+  } = await compartment.import('.');
+
+  assert(module);
+}
+
+testLockdown();