Marine-js: writing logs into stderr in nodejs env

marine-js/npm-package/src/FaaS.ts

@@ -108,6 +108,13 @@ export class FaaS {
 
                     const message = getStringFromWasm0(wasm, offset, size);
                     const str = `[marine service "${this._serviceId}"]: ${message}`;
+
+                    const nodeProcess = (globalThis as any).process ? (globalThis as any).process : undefined;
+                    if (nodeProcess && nodeProcess.stderr) {
+                        nodeProcess.stderr.write(str);
+                        return;
+                    }
+
                     if (level <= LEVEL_ERROR) {
                         console.error(str);
                     } else if (level === LEVEL_WARN) {

marine-js/npm-package/src/__test__/logging.nodejs.spec.ts

@@ -0,0 +1,36 @@
+import fs from 'fs';
+import path from 'path';
+import { FaaS } from '../FaaS';
+
+const examplesDir = path.join(__dirname, '../../../../examples');
+
+const loadWasmModule = async (waspPath: string) => {
+    const fullPath = path.join(waspPath);
+    const buffer = await fs.promises.readFile(fullPath);
+    const module = await WebAssembly.compile(buffer);
+    return module;
+};
+
+describe('WASM logging tests in nodejs', () => {
+    it('Testing logging level', async () => {
+        // arrange
+        // @ts-ignore
+        process.stderr.write = jest.fn();
+        const marine = await loadWasmModule(path.join(__dirname, '../../dist/marine-js.wasm'));
+        const greeting = await loadWasmModule(
+            path.join(examplesDir, './greeting_record/artifacts/greeting-record.wasm'),
+        );
+
+        const faas = new FaaS(marine, greeting, 'srv', undefined, { WASM_LOG: 'info' });
+        await faas.init();
+
+        // act
+        const res = faas.call('log_info', [], undefined);
+
+        // assert
+        // @ts-ignore
+        expect(process.stderr.write).toBeCalledTimes(1);
+        // @ts-ignore
+        expect(process.stderr.write).toHaveBeenNthCalledWith(1, '[marine service "srv"]: info');
+    });
+});

marine-js/npm-package/src/__test__/logging.web.spec.ts

@@ -11,6 +11,8 @@ const loadWasmModule = async (waspPath: string) => {
     return module;
 };
 
+(globalThis as any).process = undefined;
+
 describe.each([
     // force column layout
     ['error', 'error'],
@@ -18,7 +20,7 @@ describe.each([
     ['info', 'info'],
     ['debug', 'log'],
     ['trace', 'log'],
-])('WASM logging tests', (level, fn) => {
+])('WASM logging tests in web', (level, fn) => {
     it('Testing logging level', async () => {
         // arrange
         // @ts-ignore