If modelHash is null pass emptyString to logger which requires non-null modelHash (#3941)

Author: kabeer-uber

firebase-ml-modeldownloader/src/main/java/com/google/firebase/ml/modeldownloader/internal/CustomModelDownloadService.java

@@ -176,7 +176,9 @@ public Task<CustomModel> getCustomModelDetails(
                 exceptionCode = FirebaseMlException.NO_NETWORK_CONNECTION;
               }
               eventLogger.logDownloadFailureWithReason(
-                  new CustomModel(modelName, modelHash, 0, 0L), false, errorCode.getValue());
+                  new CustomModel(modelName, modelHash != null ? modelHash : "", 0, 0L),
+                  false,
+                  errorCode.getValue());
               return Tasks.forException(new FirebaseMlException(errorMessage, exceptionCode));
             }
 

firebase-ml-modeldownloader/src/test/java/com/google/firebase/ml/modeldownloader/internal/CustomModelDownloadServiceTest.java

@@ -20,6 +20,7 @@
 import static com.github.tomakehurst.wiremock.client.WireMock.getRequestedFor;
 import static com.github.tomakehurst.wiremock.client.WireMock.stubFor;
 import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
+import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertWithMessage;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
@@ -52,6 +53,7 @@
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.robolectric.RobolectricTestRunner;
@@ -708,6 +710,38 @@ public void downloadService_unauthenticatedToken() {
             any(), eq(false), eq(ErrorCode.MODEL_INFO_DOWNLOAD_CONNECTION_FAILED.getValue()));
   }
 
+  @Test
+  public void downloadService_nullModelHashPassedUnauthenticatedToken() {
+    when(installationsApiMock.getToken(anyBoolean()))
+        .thenReturn(Tasks.forException(new IllegalArgumentException("bad request")));
+
+    CustomModelDownloadService service =
+        new CustomModelDownloadService(
+            ApplicationProvider.getApplicationContext(),
+            installationsApiMock,
+            directExecutor,
+            API_KEY,
+            PACKAGE_FINGERPRINT_HASH,
+            TEST_ENDPOINT,
+            mockEventLogger);
+
+    Task<CustomModel> modelTask = service.getCustomModelDetails(PROJECT_ID, MODEL_NAME, null);
+
+    Assert.assertTrue(modelTask.getException() instanceof FirebaseMlException);
+    Assert.assertEquals(
+        ((FirebaseMlException) modelTask.getException()).getCode(),
+        FirebaseMlException.UNAUTHENTICATED);
+    Assert.assertTrue(modelTask.getException().getMessage().contains("authentication error"));
+
+    ArgumentCaptor<CustomModel> captor = ArgumentCaptor.forClass(CustomModel.class);
+    verify(mockEventLogger, times(1))
+        .logDownloadFailureWithReason(
+            captor.capture(),
+            eq(false),
+            eq(ErrorCode.MODEL_INFO_DOWNLOAD_CONNECTION_FAILED.getValue()));
+    assertThat(captor.getValue().getModelHash()).isNotNull();
+  }
+
   @Test
   public void downloadService_malFormedUrl() {
     CustomModelDownloadService service =