feat(conductor): Source/JS CSE machine evaluators and plugin

package.json

@@ -31,6 +31,9 @@
   "dependencies": {
     "@babel/parser": "^7.19.4",
     "@commander-js/extra-typings": "^14.0.0",
+    "@sourceacademy/common-cse-machine": "^0.1.0",
+    "@sourceacademy/conductor": "https://github.com/source-academy/conductor.git#0.5.0",
+    "@sourceacademy/runner-cse-machine": "^1.0.0",
     "@ts-morph/bootstrap": "^0.18.0",
     "acorn": "^8.8.2",
     "acorn-class-fields": "^1.0.0",
@@ -45,6 +48,7 @@
   "scripts": {
     "build": "yarn docs && yarn build:slang",
     "build:slang": "tsc --project tsconfig.prod.json",
+    "build:evaluators": "node scripts/build-evaluators.mjs",
     "eslint": "eslint --concurrency=auto src scripts",
     "format": "prettier --write \"src/**/*.{ts,tsx}\"",
     "format:ci": "prettier --list-different \"src/**/*.{ts,tsx}\"",
@@ -59,6 +63,12 @@
     "prepare": "husky"
   },
   "devDependencies": {
+    "@rollup/plugin-alias": "^5.1.1",
+    "@rollup/plugin-commonjs": "^28.0.3",
+    "@rollup/plugin-json": "^6.1.0",
+    "@rollup/plugin-node-resolve": "^16.0.1",
+    "@rollup/plugin-replace": "^6.0.3",
+    "@rollup/plugin-terser": "^1.0.0",
     "@types/estree": "^1.0.5",
     "@types/lodash": "^4.14.202",
     "@types/node": "^24.12.2",
@@ -67,13 +77,18 @@
     "@vitest/ui": "^4.0.4",
     "ace-builds": "~1.17.0",
     "coveralls": "^3.1.0",
+    "esbuild": "^0.25.0",
     "eslint": "^9.39.1",
     "eslint-plugin-import": "^2.32.0",
     "globals": "^17.0.0",
     "husky": "^9.0.0",
     "jsdoc": "4.0.5",
     "jsdom": "^29.0.0",
+    "path-browserify": "^1.0.1",
     "prettier": "^3.6.2",
+    "rollup": "^4.59.0",
+    "rollup-plugin-esbuild": "^6.2.1",
+    "rollup-plugin-polyfill-node": "^0.13.0",
     "typescript": "^6.0.2",
     "typescript-eslint": "^8.46.3",
     "vitest": "^4.0.4"

rollup.config.evaluator.mjs

@@ -0,0 +1,79 @@
+import alias from '@rollup/plugin-alias';
+import commonjs from '@rollup/plugin-commonjs';
+import json from '@rollup/plugin-json';
+import nodeResolve from '@rollup/plugin-node-resolve';
+import replace from '@rollup/plugin-replace';
+import terser from '@rollup/plugin-terser';
+import { fileURLToPath } from 'node:url';
+import esbuild from 'rollup-plugin-esbuild';
+import nodePolyfills from 'rollup-plugin-polyfill-node';
+
+const EVALUATOR = process.env.EVALUATOR;
+if (!EVALUATOR) {
+  throw new Error('EVALUATOR env var must be set. Use scripts/build-evaluators.mjs.');
+}
+
+const shim = name => fileURLToPath(new URL(`./scripts/evaluator-shims/${name}`, import.meta.url));
+
+// js-slang has a few inline `require('<literal>')` calls inside ES modules that
+// @rollup/plugin-commonjs cannot rewrite (it skips modules its acorn parser rejects as TS).
+// This transform rewrites those static requires into hoisted ESM imports first.
+function rewriteStaticRequires(modules) {
+  const pattern = new RegExp(`require\\((['"])(${modules.join('|')})\\1\\)`, 'g');
+  return {
+    name: 'rewrite-static-requires',
+    transform(code) {
+      if (!pattern.test(code)) return null;
+      pattern.lastIndex = 0;
+      const imports = new Map();
+      const replaced = code.replace(pattern, (_match, _quote, name) => {
+        const local = `__req_${name.replace(/[^a-zA-Z0-9]/g, '_')}`;
+        imports.set(name, local);
+        return local;
+      });
+      const header = [...imports].map(([name, local]) => `import ${local} from '${name}';`).join('\n');
+      return { code: `${header}\n${replaced}`, map: null };
+    },
+  };
+}
+
+function plugins() {
+  return [
+    rewriteStaticRequires(['acorn-class-fields']),
+    replace({
+      preventAssignment: true,
+      values: { __EVALUATOR__: EVALUATOR },
+    }),
+    alias({
+      entries: [
+        { find: 'path', replacement: shim('path.mjs') },
+        { find: 'inspector', replacement: shim('empty.mjs') },
+      ],
+    }),
+    esbuild({ target: 'es2020', sourceMap: true }),
+    commonjs({ transformMixedEsModules: true }),
+    json(),
+    nodeResolve({ preferBuiltins: false, browser: true }),
+    nodePolyfills(),
+    terser({ compress: { dead_code: true, passes: 2 } }),
+  ];
+}
+
+export default {
+  treeshake: { moduleSideEffects: false },
+  input: 'src/conductor/initialise.ts',
+  output: {
+    file: `dist/${EVALUATOR}.js`,
+    format: 'iife',
+    name: 'JsSlangWorker',
+    sourcemap: true,
+    banner: [
+      'var global = typeof globalThis !== "undefined" ? globalThis : self;',
+      'var process = (typeof globalThis !== "undefined" && globalThis.process) || ' +
+        '{ env: { NODE_ENV: "production" }, argv: [], platform: "browser", version: "", ' +
+        'versions: {}, nextTick: function (f) { Promise.resolve().then(f); }, ' +
+        'cwd: function () { return "/"; }, browser: true };',
+    ].join('\n'),
+  },
+  plugins: plugins(),
+};

scripts/build-evaluators.mjs

@@ -0,0 +1,28 @@
+#!/usr/bin/env node
+import { spawn } from 'node:child_process';
+
+// Keep in sync with exports in src/conductor/index.ts.
+const targets = ['SourceEvaluator1', 'JSCseEvaluator3', 'JSCseEvaluator4'];
+
+function buildTarget(target) {
+  console.log(`\nBuilding ${target}...\n`);
+  return new Promise((resolve, reject) => {
+    const child = spawn(
+      process.execPath,
+      ['--max-old-space-size=4096', 'node_modules/rollup/dist/bin/rollup', '-c', 'rollup.config.evaluator.mjs'],
+      {
+        env: { ...process.env, EVALUATOR: target },
+        stdio: 'inherit',
+        shell: false,
+      },
+    );
+    child.on('close', code => {
+      if (code === 0) resolve();
+      else reject(new Error(`Build failed for ${target} (exit ${code})`));
+    });
+  });
+}
+
+for (const target of targets) {
+  await buildTarget(target);
+}

scripts/evaluator-shims/empty.mjs

@@ -0,0 +1 @@
+export default {};

scripts/evaluator-shims/path.mjs

@@ -0,0 +1,8 @@
+import pathBrowserify from 'path-browserify';
+
+const path = pathBrowserify.default ?? pathBrowserify;
+
+export default path;
+export const posix = path.posix ?? path;
+export const win32 = path.win32 ?? path;
+export const { basename, delimiter, dirname, extname, format, isAbsolute, join, normalize, parse, relative, resolve, sep } = path;