Setup wat compile

package.json

@@ -33,11 +33,11 @@
   "scripts": {
     "lint": "eslint src",
     "start": "discovery",
-    "build": "npm run build-app && npm run build-report-template",
-    "build-wasm": "wat2wasm app/prepare/build-trees.wat -o app/prepare/build-trees.wasm",
+    "build": "npm run build-wasm && npm run build-app && npm run build-report-template",
+    "build-wasm": "node scripts/wat-compile.js",
     "build-app": "discovery-build --clean --config .discoveryrc.app.js --single-file --no-data --entry-names \"app\"",
     "build-report-template": "discovery-build --single-file --no-data --no-model-data-upload --entry-names \"report\"",
-    "build-gh-pages": "discovery-build --config .discoveryrc.app.js --single-file --no-data -o .gh-pages",
+    "build-gh-pages": "npm run build-wasm && discovery-build --config .discoveryrc.app.js --single-file --no-data -o .gh-pages",
     "prepublishOnly": "npm run build"
   },
   "dependencies": {
@@ -51,6 +51,7 @@
     "@discoveryjs/discovery": "^1.0.0-beta.81",
     "@typescript-eslint/eslint-plugin": "^5.21.0",
     "@typescript-eslint/parser": "^5.21.0",
-    "eslint": "^8.7.0"
+    "eslint": "^8.7.0",
+    "wabt": "^1.0.32"
   }
 }

scripts/wat-compile.js

@@ -0,0 +1,37 @@
+/* eslint-env node */
+const path = require('path');
+const fs = require('fs');
+const wabtPromise = require('wabt')();
+
+const files = [
+    '../app/prepare/build-trees.wat'
+].map(relpath => path.join(__dirname, relpath));
+
+async function compileWatToWasm() {
+    console.log('Compile WAT into WASM');
+    console.log();
+
+    const wabt = await wabtPromise;
+
+    for (let filepath of files) {
+        process.stdout.write(path.relative(process.cwd(), filepath) + '...');
+
+        const destPath = filepath.replace(/\.wat$/, '.wasm');
+        const watFileContent = fs.readFileSync(filepath, 'utf8');
+        const wasmModule = wabt.parseWat(filepath, watFileContent);
+        const { buffer } = wasmModule.toBinary({});
+
+        fs.writeFileSync(destPath, buffer);
+
+        console.log('OK');
+        console.log('  Written to', path.relative(process.cwd(), destPath));
+    }
+}
+
+if (module === require.main) {
+    compileWatToWasm();
+}
+
+module.exports = {
+    compileWatToWasm
+};