Merge pull request #74 from DataDog/darcy.rayner/handler-test

Add default 'handler'

Author: DarcyRaynerDD

src/handler.ts

@@ -0,0 +1,13 @@
+import { datadog, datadogHandlerEnvVar, lambdaTaskRootEnvVar, getEnvValue } from "./index";
+// We reuse the function loading logic already inside the lambda runtime.
+// tslint:disable-next-line:no-var-requires
+const { load } = require("/var/runtime/UserFunction") as any;
+
+if (getEnvValue("DD_TRACE_ENABLED", "true").toLowerCase() === "true") {
+  // tslint:disable-next-line:no-var-requires
+  require("dd-trace").init();
+}
+
+const taskRootEnv = getEnvValue(lambdaTaskRootEnvVar, "");
+const handlerEnv = getEnvValue(datadogHandlerEnvVar, "");
+export const handler = datadog(load(taskRootEnv, handlerEnv) as any);

src/index.ts

@@ -9,18 +9,19 @@ import {
 } from "./metrics";
 import { TraceConfig, TraceHeaders, TraceListener } from "./trace";
 import { logError, LogLevel, Logger, setColdStart, setLogLevel, setLogger, wrap } from "./utils";
-
 export { TraceHeaders } from "./trace";
 
-const apiKeyEnvVar = "DD_API_KEY";
-const apiKeyKMSEnvVar = "DD_KMS_API_KEY";
-const siteURLEnvVar = "DD_SITE";
-const logLevelEnvVar = "DD_LOG_LEVEL";
-const logForwardingEnvVar = "DD_FLUSH_TO_LOG";
-const logInjectionEnvVar = "DD_LOGS_INJECTION";
-const enhancedMetricsEnvVar = "DD_ENHANCED_METRICS";
-
-const defaultSiteURL = "datadoghq.com";
+export const apiKeyEnvVar = "DD_API_KEY";
+export const apiKeyKMSEnvVar = "DD_KMS_API_KEY";
+export const siteURLEnvVar = "DD_SITE";
+export const logLevelEnvVar = "DD_LOG_LEVEL";
+export const logForwardingEnvVar = "DD_FLUSH_TO_LOG";
+export const logInjectionEnvVar = "DD_LOGS_INJECTION";
+export const enhancedMetricsEnvVar = "DD_ENHANCED_METRICS";
+export const datadogHandlerEnvVar = "DD_LAMBDA_HANDLER";
+export const lambdaTaskRootEnvVar = "LAMBDA_TASK_ROOT";
+export const mergeXrayTracesEnvVar = "DD_MERGE_XRAY_TRACES";
+export const defaultSiteURL = "datadoghq.com";
 
 interface GlobalConfig {
   /**
@@ -79,7 +80,8 @@ export function datadog<TEvent, TResult>(
 ): Handler<TEvent, TResult> {
   const finalConfig = getConfig(config);
   const metricsListener = new MetricsListener(new KMSService(), finalConfig);
-  const handlerName = getEnvValue("_HANDLER", "handler");
+  const handlerName = getEnvValue(datadogHandlerEnvVar, getEnvValue("_HANDLER", "handler"));
+
   const traceListener = new TraceListener(finalConfig, handlerName);
   const listeners = [metricsListener, traceListener];
 
@@ -207,6 +209,10 @@ function getConfig(userConfig?: Partial<Config>): Config {
     const result = getEnvValue(enhancedMetricsEnvVar, "true").toLowerCase();
     config.enhancedMetrics = result === "true";
   }
+  if (userConfig === undefined || userConfig.mergeDatadogXrayTraces === undefined) {
+    const result = getEnvValue(mergeXrayTracesEnvVar, "false").toLowerCase();
+    config.mergeDatadogXrayTraces = result === "true";
+  }
 
   return config;
 }

src/utils/handler.spec.ts

@@ -196,7 +196,11 @@ describe("wrap", () => {
 
     let calledOriginalHandler = false;
 
-    const wrappedHandler = wrap(handler, () => {}, async () => {});
+    const wrappedHandler = wrap(
+      handler,
+      () => {},
+      async () => {},
+    );
 
     const result = await wrappedHandler({}, mockContext, () => {
       calledOriginalHandler = true;
@@ -216,7 +220,11 @@ describe("wrap", () => {
 
     let calledOriginalHandler = false;
 
-    const wrappedHandler = wrap(handler, () => {}, async () => {});
+    const wrappedHandler = wrap(
+      handler,
+      () => {},
+      async () => {},
+    );
 
     const result = await wrappedHandler({}, mockContext, () => {
       calledOriginalHandler = true;