change == to .equals (#24)

* change == to .equals

* Add tests for this env var

Author: agocs

build.gradle

@@ -35,6 +35,7 @@ dependencies {
     testImplementation 'junit:junit:4.12'
     testImplementation 'org.apache.logging.log4j:log4j-api:2.13.3'
     testImplementation 'org.apache.logging.log4j:log4j-core:2.13.3'
+    testImplementation 'com.github.stefanbirkner:system-rules:1.19.0'
 }
 
 sourceCompatibility = 1.8

src/main/java/com/datadoghq/datadog_lambda_java/DDLambda.java

@@ -90,13 +90,13 @@ public DDLambda(Headerable req, Context cxt){
         MDC.put(MDC_TRACE_CONTEXT_FIELD, getTraceContextString());
     }
 
-    private boolean checkEnhanced(){
+    protected boolean checkEnhanced(){
         String sysEnhanced = System.getenv(ENHANCED_ENV);
         if (sysEnhanced == null){
             return true;
         }
 
-        if (sysEnhanced.toLowerCase() == "false"){
+        if (sysEnhanced.toLowerCase().equals("false")){
             return false;
         }
         return true;

src/main/java/com/datadoghq/datadog_lambda_java/Tracing.java

@@ -191,7 +191,7 @@ public String toJSONString(){
     }
 
     public boolean sendToXRay(){
-        if (this.id == null || this.id == "") {
+        if (this.id == null || this.id.equals("")) {
             return false;
         }
 
@@ -353,7 +353,7 @@ class XRayTraceContext{
     public XRayTraceContext(){
         //Root=1-5e41a79d-e6a0db584029dba86a594b7e;Parent=8c34f5ad8f92d510;Sampled=1
         String traceId = System.getenv("_X_AMZN_TRACE_ID");
-        if (traceId == null || traceId == ""){
+        if (traceId == null || traceId.equals("")){
             DDLogger.getLoggerImpl().debug("Unable to find _X_AMZN_TRACE_ID");
             return;
         }

src/test/java/com/datadoghq/datadog_lambda_java/LambdaInstrumenterTest.java

@@ -8,9 +8,14 @@
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
+import org.junit.Rule;
+import org.junit.contrib.java.lang.system.EnvironmentVariables;
 
 
 public class LambdaInstrumenterTest {
+    @Rule
+    public final EnvironmentVariables environmentVariables = new EnvironmentVariables();
+
     @Before
     public void setUp() throws Exception {
         ColdStart.resetColdStart();
@@ -109,6 +114,35 @@ public void setUp() throws Exception {
         Assert.assertTrue(pcm.tags.contains("cold_start:true"));
     }
 
+    @Test
+    public void EnhancedMetricsDeactivatedWithEnvVar(){
+        environmentVariables.set("DD_ENHANCED_METRICS", "false");
+        Context mc1 = new EnhancedMetricTest.MockContext();
+        DDLambda ddl = new DDLambda(mc1);
+        boolean isEnhanced = ddl.checkEnhanced();
+        Assert.assertFalse(isEnhanced);
+        environmentVariables.clear("DD_ENHANCED_METRICS");
+    }
+
+    @Test
+    public void EnhancedMetricsActivatedByDefault(){
+        System.out.println(System.getenv("DD_ENHANCED_METRICS"));
+        Context mc1 = new EnhancedMetricTest.MockContext();
+        DDLambda ddl = new DDLambda(mc1);
+        boolean isEnhanced = ddl.checkEnhanced();
+        Assert.assertTrue(isEnhanced);
+    }
+
+    @Test
+    public void EnhancedMetricsActivatedWithEnvVar(){
+        environmentVariables.set("DD_ENHANCED_METRICS", "true");
+        Context mc1 = new EnhancedMetricTest.MockContext();
+        DDLambda ddl = new DDLambda(mc1);
+        boolean isEnhanced = ddl.checkEnhanced();
+        Assert.assertTrue(isEnhanced);
+        environmentVariables.clear("DD_ENHANCED_METRICS");
+    }
+
     @After
     public void tearDown() throws Exception {
         ColdStart.resetColdStart();