Merge branch 'master' into sergio.prada/task-improve-int-tests

* master:
  Fix getEnhancedMetricTags on local env (#87)
  When headers is set to null return undefined (#86)

Author: Czechh

src/metrics/enhanced-metrics.spec.ts

@@ -14,6 +14,7 @@ const mockContext = ({
 } as any) as Context;
 const mockContextLocal = ({
   functionName: "my-test-lambda",
+  functionVersion: "1.0.0",
   memoryLimitInMB: "128",
 } as any) as Context;
 

src/metrics/enhanced-metrics.ts

@@ -45,10 +45,8 @@ export function getRuntimeTag(): string | null {
 
 export function getEnhancedMetricTags(context: Context): string[] {
   let arnTags = [`functionname:${context.functionName}`];
-  if (context.functionVersion) {
+  if (context.invokedFunctionArn) {
     arnTags = parseTagsFromARN(context.invokedFunctionArn, context.functionVersion);
-  } else if (context.invokedFunctionArn) {
-    arnTags = parseTagsFromARN(context.invokedFunctionArn);
   }
   const tags = [...arnTags, getColdStartTag(), `memorysize:${context.memoryLimitInMB}`];
 

src/trace/context.spec.ts

@@ -226,6 +226,10 @@ describe("readTraceFromEvent", () => {
     const result = readTraceFromEvent({});
     expect(result).toBeUndefined();
   });
+  it("returns undefined when headers is null", () => {
+    const result = readTraceFromEvent("some-value");
+    expect(result).toBeUndefined();
+  });
   it("returns undefined when event isn't object", () => {
     const result = readTraceFromEvent("some-value");
     expect(result).toBeUndefined();

src/trace/context.ts

@@ -147,7 +147,8 @@ export function readTraceFromEvent(event: any): TraceContext | undefined {
   }
   const headers = event.headers;
 
-  if (typeof headers !== "object") {
+  // e.g. When lambda is invoked synchronously, headers can be set to null by the caller
+  if (!headers || typeof headers !== "object") {
     return;
   }