Improve error handling, fix base URL comparison bug (#28)

- Improve error handling (no more ambiguous NullPointerException when there's no matching recording in a cassette)
- Fix bug with comparing base URLs

Author: nwithan8

src/main/java/com/easypost/easyvcr/MatchRules.java

@@ -3,6 +3,7 @@
 import com.easypost.easyvcr.internal.Utilities;
 import com.easypost.easyvcr.requestelements.Request;
 
+import java.net.URI;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -50,13 +51,30 @@ private void by(BiFunction<Request, Request, Boolean> rule) {
      */
     public MatchRules byBaseUrl() {
         by((received, recorded) -> {
-            String receivedUri = received.getUri().getPath();
-            String recordedUri = recorded.getUri().getPath();
+            String receivedUri = getBaseUrl(received.getUri());
+            String recordedUri = getBaseUrl(recorded.getUri());
             return receivedUri.equalsIgnoreCase(recordedUri);
         });
         return this;
     }
 
+    /**
+     * Extract the base URL from a URI.
+     *
+     * @param url The URI to extract the base URL from.
+     * @return The base URL.
+     */
+    private static String getBaseUrl(URI url) {
+        String baseUrl = url.getScheme() + "://" + url.getHost();
+        if (url.getPort() != -1) {
+            baseUrl += ":" + url.getPort();
+        }
+        if (url.getPath() != null) {
+            baseUrl += url.getPath();
+        }
+        return baseUrl;
+    }
+
     /**
      * Add a rule to compare the bodies of the requests.
      *

src/main/java/com/easypost/easyvcr/clients/httpurlconnection/RecordableHttpURLConnection.java

@@ -144,6 +144,17 @@ public RecordableHttpURLConnection(URL url, Cassette cassette, Mode mode)
         this(url, cassette, mode, new AdvancedSettings());
     }
 
+    /**
+     * Throws an exception if a matching interaction has not been cached.
+     *
+     * @throws VCRException If the interaction has not been cached.
+     */
+    private void cachedInteractionExistsOtherwiseError() throws VCRException {
+        if (this.cachedInteraction == null) {
+            throw new VCRException("No matching interaction found.");
+        }
+    }
+
     /**
      * Get an object from the cache.
      *
@@ -725,6 +736,8 @@ Based on this Sun source code for HttpURLConnection (seen below):
         try {
             buildCache();
 
+            cachedInteractionExistsOtherwiseError();
+
             if (this.cachedInteraction.getResponse().getStatus().getCode() >= 400) {
                 // Client Error 4xx and Server Error 5xx
                 return createInputStream(this.cachedInteraction.getResponse().getBody());
@@ -1297,6 +1310,7 @@ public InputStream getInputStream() throws IOException {
         }
         try {
             buildCache();
+            cachedInteractionExistsOtherwiseError();
             return createInputStream(this.cachedInteraction.getResponse().getBody());
         } catch (VCRException | RecordingExpirationException e) {
             throw new RuntimeException(e);

src/main/java/com/easypost/easyvcr/clients/httpurlconnection/RecordableHttpsURLConnection.java

@@ -149,6 +149,17 @@ public RecordableHttpsURLConnection(URL url, Cassette cassette, Mode mode)
         this(url, cassette, mode, new AdvancedSettings());
     }
 
+    /**
+     * Throws an exception if a matching interaction has not been cached.
+     *
+     * @throws VCRException If the interaction has not been cached.
+     */
+    private void cachedInteractionExistsOtherwiseError() throws VCRException {
+        if (this.cachedInteraction == null) {
+            throw new VCRException("No matching interaction found.");
+        }
+    }
+
     /**
      * Get an object from the cache.
      *
@@ -728,6 +739,8 @@ Based on this Sun source code for HttpURLConnection (seen below):
         try {
             buildCache();
 
+            cachedInteractionExistsOtherwiseError();
+
             if (this.cachedInteraction.getResponse().getStatus().getCode() >= 400) {
                 // Client Error 4xx and Server Error 5xx
                 return createInputStream(this.cachedInteraction.getResponse().getBody());
@@ -1300,6 +1313,7 @@ public InputStream getInputStream() throws IOException {
         }
         try {
             buildCache();
+            cachedInteractionExistsOtherwiseError();
             return createInputStream(this.cachedInteraction.getResponse().getBody());
         } catch (VCRException | RecordingExpirationException e) {
             throw new RuntimeException(e);

src/test/java/HttpUrlConnectionTest.java

@@ -9,6 +9,7 @@
 import com.easypost.easyvcr.Mode;
 import com.easypost.easyvcr.RecordingExpirationException;
 import com.easypost.easyvcr.TimeFrame;
+import com.easypost.easyvcr.VCRException;
 import com.easypost.easyvcr.clients.httpurlconnection.RecordableHttpsURLConnection;
 import com.google.gson.JsonParseException;
 import org.junit.Assert;
@@ -534,4 +535,42 @@ public void testReplayHttpError() throws Exception {
         Assert.assertNotNull(clientAfterRequest);
         Assert.assertNotNull(clientAfterRequest.getErrorStream());
     }
+
+    @Test
+    public void testCachedInteractionDoesNotExist() throws Exception {
+        Cassette cassette = TestUtils.getCassette("test_cached_interaction_does_not_exist");
+        cassette.erase(); // Erase cassette before recording
+
+        final String url = "https://google.com/path/to/endpoint";
+
+        // make connection using Mode.Record
+        RecordableHttpsURLConnection connection =
+                (RecordableHttpsURLConnection) HttpClients.newClient(HttpClientType.HttpsUrlConnection,
+                        url, cassette, Mode.Record);
+        // make HTTP call (record to cassette)
+        connection.connect();
+        Assert.assertTrue(cassette.numInteractions() > 0); // make sure we recorded something
+
+        // Attempt to replay a cached interaction that does not exist
+        // need to use strict matching to ensure we don't match a different interaction
+        AdvancedSettings advancedSettings = new AdvancedSettings();
+        advancedSettings.matchRules = MatchRules.strict();
+
+        connection = (RecordableHttpsURLConnection) HttpClients.newClient(HttpClientType.HttpsUrlConnection,
+                url + "1", cassette, Mode.Replay, advancedSettings);
+        // make HTTP call (attempt replay from cassette)
+        connection.connect();
+
+        // Attempt to pull data (e.g. body) from the response (via the input stream)
+        // this throws a RuntimeException because of the way the exceptions are coalesced internally
+        try {
+            connection.getInputStream();
+            // if we get here, the exception was not thrown as expected
+            Assert.fail();
+        } catch (Exception e) {
+            Assert.assertTrue(e instanceof RuntimeException);
+            Assert.assertTrue(e.getCause() instanceof VCRException);
+            Assert.assertEquals(e.getCause().getMessage(), "No matching interaction found.");
+        }
+    }
 }