Add context overwrite option (#240)

Author: nazoking

README.md

@@ -72,6 +72,7 @@ Executes a lambda given the `options` object, which is a dictionary where the ke
 | `callback`|optional, lambda third parameter [callback][1]. When left out a Promise is returned|
 | `onInvocationEnd`|optional. called once the invocation ended. useful when awslambda.streamifyResponse is used to distinguish between end of response stream and end of invocation. |
 | `clientContext`|optional, used to populated clientContext property of lambda second parameter (context)
+| `contextOverwrite`| optional, a function that overwrites the context object. It can get and overwrite the values of the context (such as awsRequestId). |
 
 #### `lambdaLocal.setLogger(logger)`
 #### `lambdaLocal.getLogger()`

src/lambdalocal.ts

@@ -187,6 +187,7 @@ function _executeSync(opts) {
         timeoutMs = opts.timeoutMs || 3000,
         verboseLevel = opts.verboseLevel,
         callback = opts.callback,
+        contextOverwrite = opts.contextOverwrite,
         onInvocationEnd = opts.onInvocationEnd,
         clientContext = null;
 
@@ -304,6 +305,8 @@ function _executeSync(opts) {
 
     var ctx = context.generate_context();
 
+    if(contextOverwrite) opts.contextOverwrite(ctx);
+
     const executeLambdaFunc = lambdaFunc => {
         try {
             //load event

test/test.js

@@ -301,6 +301,26 @@ describe("- Testing lambdalocal.js", function () {
             });
         });
     });
+    describe('* Context overwrite', function () {
+        it("Should overwrite context", function(cb){
+            var lambdalocal = require(lambdalocal_path);
+            lambdalocal.execute({
+                event: require(path.join(__dirname, "./events/test-event.js")),
+                lambdaPath: path.join(__dirname, "./functs/test-func.js"),
+                lambdaHandler: functionName,
+                contextOverwrite: function (ctx){
+                    ctx.awsRequestId = "test id";
+                    ctx.functionName = "test function";
+                },
+                callback: function (err, done) {
+                    assert.equal(done.result, "testvar");
+                    assert.equal(done.context.awsRequestId, "test id");
+                    assert.equal(done.context.functionName, "test function");
+                    cb();
+                }
+            });
+        });
+    });
     describe('* Nested Run', function () {
         it("Should handle nested calls properly (context singleton)", function (cb) {
             var lambdalocal = require(lambdalocal_path);