Ensure messages are non-null

Checks
1. error.message()
2. logMessage
3. 'No message'

2nd commit

src/main/java/com/squareup/squash/SquashEntry.java

@@ -53,11 +53,11 @@ public class SquashEntry {
   final String message;
   final String log_message;
 
-  public SquashEntry(String client, String apiKey, String message, Throwable error,
+  public SquashEntry(String client, String apiKey, String logMessage, Throwable error,
       String appVersion, int versionCode, String buildSha, String deviceId, String endpoint,
       String userId, String environment) {
     this.client = client;
-    this.log_message = message;
+    this.log_message = logMessage;
     this.version = appVersion;
     this.revision = buildSha;
     this.build = "" + versionCode;
@@ -68,9 +68,22 @@ public SquashEntry(String client, String apiKey, String message, Throwable error
     SquashBacktrace.populateNestedExceptions(parent_exceptions, error);
     this.ivars = SquashBacktrace.getIvars(error);
     this.class_name = error == null ? null : error.getClass().getName();
-    this.message = error == null ? null : error.getMessage();
+    this.message = createMessage(error, logMessage);
     this.api_key = apiKey;
     this.user_id = userId;
     this.occurred_at = DATE_FORMAT_THREAD_LOCAL.get().format(new Date());
   }
+
+  // Squash requires a non-empty message field.
+  private static String createMessage(Throwable error, String logMessage) {
+    String message;
+    if (error != null && error.getMessage() != null) {
+      message = error.getMessage();
+    } else if (logMessage != null) {
+      message = logMessage;
+    } else {
+      message = "No message";
+    }
+    return message;
+  }
 }

src/test/java/com/squareup/squash/SquashEntryTest.java

@@ -72,6 +72,41 @@ private SquashEntry serializeAndDeserialize(SquashEntry logEntry) throws IOExcep
     assertThat(deserialized.class_name).isEqualTo(exception.getClass().getName());
   }
 
+  @Test public void testExceptionWithNoMessage() throws Exception {
+    final Throwable exception = mock(Throwable.class);
+
+    StackTraceElement s0 = new StackTraceElement("com.jake", "CantProgram",
+        "core-android/src/com/jake/Brain.java", 50);
+    StackTraceElement s1 = new StackTraceElement("com.jake", "IsDrunk",
+        "core-android/src/com/jake/Status.java", 510);
+    StackTraceElement[] stackTrace = { s0, s1 };
+
+    when(exception.getMessage()).thenReturn(null);
+    when(exception.getStackTrace()).thenReturn(stackTrace);
+
+    String logMessage = "Jake can't program";
+    final SquashEntry logEntry = factory.create(logMessage, exception);
+    SquashEntry deserialized = serializeAndDeserialize(logEntry);
+    assertThat(deserialized.message).isEqualTo(logMessage);
+  }
+
+  @Test public void testExceptionWithNoMessageOrLogMessage() throws Exception {
+    final Throwable exception = mock(Throwable.class);
+
+    StackTraceElement s0 = new StackTraceElement("com.jake", "CantProgram",
+        "core-android/src/com/jake/Brain.java", 50);
+    StackTraceElement s1 = new StackTraceElement("com.jake", "IsDrunk",
+        "core-android/src/com/jake/Status.java", 510);
+    StackTraceElement[] stackTrace = { s0, s1 };
+
+    when(exception.getMessage()).thenReturn(null);
+    when(exception.getStackTrace()).thenReturn(stackTrace);
+
+    final SquashEntry logEntry = factory.create(null, exception);
+    SquashEntry deserialized = serializeAndDeserialize(logEntry);
+    assertThat(deserialized.message).isEqualTo("No message");
+  }
+
   private void assertBacktracesMatch(StackTraceElement[] myLittleStackTrace,
       List<SquashBacktrace.StackElement> stackElements) {
     for (int i = 0, stackElementsSize = stackElements.size(); i < stackElementsSize; i++) {

test.txt

@@ -0,0 +1,3 @@
+this is our 3rd class on git
+git is version control tool
+