Add tests for URLConnection wrappers (embrace-io#35)

## Goal

Add tests to verify that our network wrappers actually call the appropriate methods that they are wrapping. Along the way, added some more comments and did some renaming.

embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/internal/network/http/EmbraceHttpUrlConnection.java

@@ -17,6 +17,12 @@
 
 import javax.net.ssl.SSLPeerUnverifiedException;
 
+/**
+ * An interface that duplicates the functionality of HttpURLConnection whose implementation can then wrap an actual HttpURLConnection's
+ * implementation so calls can be forwarded from this interface's implementation to the wrapped HttpURLConnection implementation.
+ * Having this separate interface allows the actual wrappers ({@link EmbraceHttpUrlConnectionImpl}/{@link EmbraceHttpsUrlConnectionImpl})
+ * to share an implementation whilst exposing separate interfaces for what they're wrapping.
+ */
 interface EmbraceHttpUrlConnection {
 
     void addRequestProperty(@NonNull String key, @Nullable String value);

embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/internal/network/http/EmbraceHttpUrlConnectionImpl.java

@@ -12,6 +12,9 @@
 import java.util.List;
 import java.util.Map;
 
+/**
+ * An implementation of HttpURLConnection that forwards calls to an {@link EmbraceUrlConnectionDelegate}
+ */
 class EmbraceHttpUrlConnectionImpl<T extends HttpURLConnection> extends HttpURLConnection {
 
     private final EmbraceHttpUrlConnection embraceHttpUrlConnectionDelegate;
@@ -23,8 +26,12 @@ class EmbraceHttpUrlConnectionImpl<T extends HttpURLConnection> extends HttpURLC
      * @param enableWrapIoStreams true if we should transparently ungzip the response, else false
      */
     public EmbraceHttpUrlConnectionImpl(T connection, boolean enableWrapIoStreams) {
+        this(connection, new EmbraceUrlConnectionDelegate<>(connection, enableWrapIoStreams));
+    }
+
+    EmbraceHttpUrlConnectionImpl(T connection, EmbraceUrlConnectionDelegate<T> delegate) {
         super(connection.getURL());
-        embraceHttpUrlConnectionDelegate = new EmbraceUrlConnectionDelegate<>(connection, enableWrapIoStreams);
+        embraceHttpUrlConnectionDelegate = delegate;
     }
 
     @Override

embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/internal/network/http/EmbraceHttpsUrlConnection.java

@@ -10,7 +10,7 @@
 import javax.net.ssl.SSLSocketFactory;
 
 /**
- * Additional methods for HTTPS network calls
+ * {@link EmbraceHttpUrlConnection} plus additional methods for HTTPS network calls
  */
 interface EmbraceHttpsUrlConnection extends EmbraceHttpUrlConnection {
 

embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/internal/network/http/EmbraceHttpsUrlConnectionImpl.java

@@ -36,8 +36,12 @@ class EmbraceHttpsUrlConnectionImpl<T extends HttpsURLConnection> extends HttpsU
      * @param enableWrapIoStreams true if we should transparently ungzip the response, else false
      */
     public EmbraceHttpsUrlConnectionImpl(T connection, boolean enableWrapIoStreams) {
+        this(connection, new EmbraceUrlConnectionDelegate<>(connection, enableWrapIoStreams));
+    }
+
+    EmbraceHttpsUrlConnectionImpl(T connection, EmbraceUrlConnectionDelegate<T> delegate) {
         super(connection.getURL());
-        embraceHttpsUrlConnectionDelegate = new EmbraceUrlConnectionDelegate<>(connection, enableWrapIoStreams);
+        embraceHttpsUrlConnectionDelegate = delegate;
     }
 
     @Override
@@ -342,12 +346,12 @@ public void setHostnameVerifier(HostnameVerifier verifier) {
         this.embraceHttpsUrlConnectionDelegate.setHostnameVerifier(verifier);
     }
 
-
+    @Override
     public Principal getLocalPrincipal() {
         return embraceHttpsUrlConnectionDelegate.getLocalPrincipal();
     }
 
-
+    @Override
     public Principal getPeerPrincipal() throws SSLPeerUnverifiedException {
         return embraceHttpsUrlConnectionDelegate.getPeerPrincipal();
     }

embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/internal/network/http/EmbraceUrlConnectionDelegate.java

@@ -41,7 +41,7 @@
 import kotlin.jvm.functions.Function0;
 
 /**
- * Wraps @{link HttpUrlConnection} to log network calls to Embrace. The wrapper also wraps the
+ * Wraps {@link HttpURLConnection} to log network calls to Embrace. The wrapper also wraps the
  * InputStream to get an accurate count of bytes received if a Content-Length is not provided by
  * the server.
  * <p>