feat: Add support for http events in invoke local (#264)

Author: CorentinDoue

invokeLocal/googleInvokeLocal.js

@@ -29,7 +29,7 @@ class GoogleInvokeLocal {
 
   async invokeLocal() {
     const functionObj = this.serverless.service.getFunction(this.options.function);
-    this.validateEventsProperty(functionObj, this.options.function, ['event']); // Only event is currently supported
+    this.validateEventsProperty(functionObj, this.options.function);
 
     const runtime = this.provider.getRuntime(functionObj);
     if (!runtime.startsWith('nodejs')) {

invokeLocal/googleInvokeLocal.test.js

@@ -165,9 +165,7 @@ describe('GoogleInvokeLocal', () => {
 
     it('should validate the function configuration', async () => {
       await googleInvokeLocal.invokeLocal();
-      expect(
-        validateEventsPropertyStub.calledOnceWith(functionObj, functionName, ['event'])
-      ).toEqual(true);
+      expect(validateEventsPropertyStub.calledOnceWith(functionObj, functionName)).toEqual(true);
     });
 
     it('should get the runtime', async () => {

invokeLocal/lib/httpReqRes.js

@@ -0,0 +1,30 @@
+'use strict';
+
+const express = require('express');
+const http = require('http');
+const net = require('net');
+
+// The getReqRes method create an express request and an express response
+// as they are created in an express server before being passed to the middlewares
+// Google use express 4.17.1 to run http cloud function
+// https://cloud.google.com/functions/docs/writing/http#http_frameworks
+const app = express();
+
+module.exports = {
+  getReqRes() {
+    const req = new http.IncomingMessage(new net.Socket());
+    const expressRequest = Object.assign(req, { app });
+    Object.setPrototypeOf(expressRequest, express.request);
+
+    const res = new http.ServerResponse(req);
+    const expressResponse = Object.assign(res, { app, req: expressRequest });
+    Object.setPrototypeOf(expressResponse, express.response);
+
+    expressRequest.res = expressResponse;
+
+    return {
+      expressRequest,
+      expressResponse,
+    };
+  },
+};

invokeLocal/lib/nodeJs.js

@@ -3,6 +3,7 @@
 const chalk = require('chalk');
 const path = require('path');
 const _ = require('lodash');
+const { getReqRes } = require('./httpReqRes');
 
 const tryToRequirePaths = (paths) => {
   let loaded;
@@ -19,10 +20,10 @@ const tryToRequirePaths = (paths) => {
   return loaded;
 };
 
+const jsonContentType = 'application/json';
+
 module.exports = {
   async invokeLocalNodeJs(functionObj, event, customContext) {
-    let hasResponded = false;
-
     // index.js and function.js are the two files supported by default by a cloud-function
     // TODO add the file pointed by the main key of the package.json
     const paths = ['index.js', 'function.js'].map((fileName) =>
@@ -41,27 +42,41 @@ module.exports = {
 
     this.addEnvironmentVariablesToProcessEnv(functionObj);
 
-    function handleError(err) {
-      let errorResult;
-      if (err instanceof Error) {
-        errorResult = {
-          errorMessage: err.message,
-          errorType: err.constructor.name,
-          stackTrace: err.stack && err.stack.split('\n'),
-        };
-      } else {
-        errorResult = {
-          errorMessage: err,
-        };
-      }
+    const eventType = Object.keys(functionObj.events[0])[0];
 
-      this.serverless.cli.consoleLog(chalk.red(JSON.stringify(errorResult, null, 4)));
-      process.exitCode = 1;
+    switch (eventType) {
+      case 'event':
+        return this.handleEvent(cloudFunction, event, customContext);
+      case 'http':
+        return this.handleHttp(cloudFunction, event, customContext);
+      default:
+        throw new Error(`${eventType} is not supported`);
     }
+  },
+  handleError(err, resolve) {
+    let errorResult;
+    if (err instanceof Error) {
+      errorResult = {
+        errorMessage: err.message,
+        errorType: err.constructor.name,
+        stackTrace: err.stack && err.stack.split('\n'),
+      };
+    } else {
+      errorResult = {
+        errorMessage: err,
+      };
+    }
+
+    this.serverless.cli.consoleLog(chalk.red(JSON.stringify(errorResult, null, 4)));
+    resolve();
+    process.exitCode = 1;
+  },
+  handleEvent(cloudFunction, event, customContext) {
+    let hasResponded = false;
 
     function handleResult(result) {
       if (result instanceof Error) {
-        handleError.call(this, result);
+        this.handleError.call(this, result);
         return;
       }
       this.serverless.cli.consoleLog(JSON.stringify(result, null, 4));
@@ -72,26 +87,68 @@ module.exports = {
         if (!hasResponded) {
           hasResponded = true;
           if (err) {
-            handleError.call(this, err);
+            this.handleError(err, resolve);
           } else if (result) {
             handleResult.call(this, result);
           }
+          resolve();
         }
-        resolve();
       };
 
       let context = {};
 
       if (customContext) {
         context = customContext;
       }
-
-      const maybeThennable = cloudFunction(event, context, callback);
-      if (maybeThennable) {
-        return Promise.resolve(maybeThennable).then(callback.bind(this, null), callback.bind(this));
+      try {
+        const maybeThennable = cloudFunction(event, context, callback);
+        if (maybeThennable) {
+          Promise.resolve(maybeThennable).then(callback.bind(this, null), callback.bind(this));
+        }
+      } catch (error) {
+        this.handleError(error, resolve);
       }
+    });
+  },
+  handleHttp(cloudFunction, event) {
+    const { expressRequest, expressResponse: response } = getReqRes();
+    const request = Object.assign(expressRequest, event);
+
+    return new Promise((resolve) => {
+      const endCallback = (data) => {
+        if (data && Buffer.isBuffer(data)) {
+          data = data.toString();
+        }
+        const headers = response.getHeaders();
+        const bodyIsJson =
+          headers['content-type'] && headers['content-type'].includes(jsonContentType);
+        if (data && bodyIsJson) {
+          data = JSON.parse(data);
+        }
+        this.serverless.cli.consoleLog(
+          JSON.stringify(
+            {
+              status: response.statusCode,
+              headers,
+              body: data,
+            },
+            null,
+            4
+          )
+        );
+        resolve();
+      };
 
-      return maybeThennable;
+      Object.assign(response, { end: endCallback }); // Override of the end method which is always called to send the response of the http request
+
+      try {
+        const maybeThennable = cloudFunction(request, response);
+        if (maybeThennable) {
+          Promise.resolve(maybeThennable).catch((error) => this.handleError(error, resolve));
+        }
+      } catch (error) {
+        this.handleError(error, resolve);
+      }
     });
   },