Add Message to DocumentStatus, improve DocumentTranslationException m…

…essage

CHANGELOG.md

@@ -5,6 +5,17 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
+## [Unreleased]
+### Added
+* Add `ErrorMessage` property to `DocumentStatus` that contains a short
+  description of document translation error, if available.
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+
 ## [1.0.5] - 2022-04-12
 ### Added
 * Add support for `TextTranslateOptions.TagHandling = "html"`. No code changes
@@ -50,6 +61,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 Initial release.
 
 
+[Unreleased]: https://github.com/DeepLcom/deepl-dotnet/compare/v1.0.5..HEAD
 [1.0.5]: https://github.com/DeepLcom/deepl-dotnet/compare/v1.0.4..v1.0.5
 [1.0.4]: https://github.com/DeepLcom/deepl-dotnet/compare/v1.0.3..v1.0.4
 [1.0.3]: https://github.com/DeepLcom/deepl-dotnet/compare/v1.0.2..v1.0.3

DeepL/Model/DocumentStatus.cs

@@ -35,15 +35,16 @@ public enum StatusCode {
     ///   Number of characters billed for the translation of this document, only included
     ///   after document translation is finished and the state is done.
     /// </param>
+    /// <param name="errorMessage">Short description of the error, if available.</param>
     /// <remarks>
     ///   The constructor for this class (and all other Model classes) should not be used by library users. Ideally it
     ///   would be marked <see langword="internal" />, but needs to be <see langword="public" /> for JSON deserialization.
     ///   In future this function may have backwards-incompatible changes.
     /// </remarks>
     [JsonConstructor]
-    public DocumentStatus(string documentId, StatusCode status, int? secondsRemaining, int? billedCharacters) {
-      (DocumentId, Status, SecondsRemaining, BilledCharacters) =
-            (documentId, status, secondsRemaining, billedCharacters);
+    public DocumentStatus(string documentId, StatusCode status, int? secondsRemaining, int? billedCharacters, string? errorMessage) {
+      (DocumentId, Status, SecondsRemaining, BilledCharacters, ErrorMessage) =
+            (documentId, status, secondsRemaining, billedCharacters, errorMessage);
     }
 
     /// <summary>Document ID of the associated document.</summary>
@@ -64,6 +65,9 @@ public DocumentStatus(string documentId, StatusCode status, int? secondsRemainin
     /// </summary>
     public int? BilledCharacters { get; }
 
+    /// <summary>Short description of the error, if available.</summary>
+    public string? ErrorMessage { get; }
+
     /// <summary><c>true</c> if no error has occurred during document translation, otherwise <c>false</c>.</summary>
     public bool Ok => Status != StatusCode.Error;
 

DeepL/Translator.cs

@@ -380,7 +380,7 @@ public async Task TranslateDocumentWaitUntilDoneAsync(
       }
 
       if (!status.Ok) {
-        throw new DeepLException("Document translation resulted in an error");
+        throw new DeepLException(status.ErrorMessage ?? "Unknown error");
       }
     }
 

DeepLTests/TranslateDocumentTest.cs

@@ -93,7 +93,7 @@ await translator.TranslateDocumentAsync(
     }
 
     [MockServerOnlyFact]
-    public async Task TestTranslateDocument() {
+    public async Task TestTranslateLargeDocument() {
       var translator = CreateTestTranslator();
       using var outputStream = new MemoryStream();
       var inputFile = new FileInfo(ExampleLargeDocumentPath());
@@ -136,19 +136,22 @@ await translator.TranslateDocumentAsync(
       }
     }
 
-    [MockServerOnlyFact]
-    public async Task TestDocumentFailure() {
-      var translator = CreateTestTranslatorWithMockSession(
-            nameof(TestDocumentFailure),
-            new SessionOptions { DocumentFailure = 1 });
+    [Fact]
+    public async Task TestDocumentFailureDuringTranslation() {
+      var translator = CreateTestTranslator();
       var outputDocumentPath = OutputDocumentPath();
 
-      await Assert.ThrowsAsync<DocumentTranslationException>(
+      // Translating text from DE to DE will trigger error
+      var inputDocumentPath = ExampleDocumentPath(ExampleText(LanguageCode.German));
+
+      var exception = await Assert.ThrowsAsync<DocumentTranslationException>(
             async () => await translator.TranslateDocumentAsync(
-                  new FileInfo(ExampleDocumentPath()),
+                  new FileInfo(inputDocumentPath),
                   new FileInfo(outputDocumentPath),
-                  "EN",
+                  null,
                   "DE"));
+
+      Assert.Contains("Source and target language", exception.Message);
     }
 
     [Fact]