Create new example sentence translation if needed (#1648)

* Create new example sentence translation if needed
* Add unit test reproducing the bug and fix
* Address review comments

Author: rmunn

backend/FwLite/FwDataMiniLcmBridge.Tests/MiniLcmTests/UpdateEntryTests.cs

@@ -44,4 +44,57 @@ public async Task UpdateEntry_WithNullLexemeFormOA_CreatesNewLexemeForm()
         updatedEntry.LexemeForm.Should().NotBeNull();
         updatedEntry.LexemeForm["en"].Should().Be("updated test");
     }
+
+    [Fact]
+    public async Task UpdateEntry_CanUpdateExampleSentenceTranslations_WhenNoTranslationObjectExists()
+    {
+        // Arrange
+        var entry = await Api.CreateEntry(new Entry
+        {
+            LexemeForm = { { "en", "test" } },
+            Note = { { "en", "this is a test note" } },
+            CitationForm = { { "en", "test" } },
+            LiteralMeaning = { { "en", "test" } },
+            Senses =
+            [
+                new Sense
+                {
+                    Gloss = { { "en", "test" } },
+                    Definition = { { "en", "test" } },
+                    ExampleSentences =
+                    [
+                        new ExampleSentence { Sentence = { { "en", "testing is good" } } }
+                    ]
+                }
+            ]
+        });
+
+        var fwApi = (FwDataMiniLcmApi)Api;
+        var lexEntry = fwApi.EntriesRepository.GetObject(entry.Id);
+        ArgumentNullException.ThrowIfNull(entry);
+        ArgumentNullException.ThrowIfNull(lexEntry);
+        lexEntry.SensesOS[0].ExamplesOS[0].TranslationsOC.Should().ContainSingle();
+        // Reproduce the bug
+        UndoableUnitOfWorkHelper.DoUsingNewOrCurrentUOW("Clear TranslationsOC",
+            "Restore TranslationsOC",
+            fwApi.Cache.ServiceLocator.ActionHandler,
+            () =>
+            {
+                lexEntry.SensesOS[0].ExamplesOS[0].TranslationsOC.Clear();
+            });
+        lexEntry.SensesOS[0].ExamplesOS[0].TranslationsOC.Should().BeEmpty();
+
+        var before = entry.Copy();
+        var exampleSentence = entry.Senses[0].ExampleSentences[0];
+        exampleSentence.Translation = new() { { "en", "updated" } };
+
+        // Act
+        var updatedEntry = await Api.UpdateEntry(before, entry);
+        var updatedExampleSentence = updatedEntry.Senses[0].ExampleSentences[0];
+
+        // Assert
+        updatedExampleSentence.Translation.Should().ContainSingle();
+        updatedExampleSentence.Translation["en"].Should().Be("updated");
+        updatedEntry.Should().BeEquivalentTo(entry, options => options);
+    }
 }

backend/FwLite/FwDataMiniLcmBridge/Api/FwDataMiniLcmApi.cs

@@ -1324,13 +1324,18 @@ internal void CreateExampleSentence(ILexSense lexSense, ExampleSentence exampleS
         var lexExampleSentence = LexExampleSentenceFactory.Create(exampleSentence.Id);
         InsertExampleSentence(lexSense, lexExampleSentence, between);
         UpdateLcmMultiString(lexExampleSentence.Example, exampleSentence.Sentence);
-        var freeTranslationType = CmPossibilityRepository.GetObject(CmPossibilityTags.kguidTranFreeTranslation);
-        var translation = CmTranslationFactory.Create(lexExampleSentence, freeTranslationType);
+        var translation = CreateExampleSentenceTranslation(lexExampleSentence);
         UpdateLcmMultiString(translation.Translation, exampleSentence.Translation);
         lexExampleSentence.Reference = TsStringUtils.MakeString(exampleSentence.Reference,
             lexExampleSentence.Reference.get_WritingSystem(0));
     }
 
+    public ICmTranslation CreateExampleSentenceTranslation(ILexExampleSentence parent)
+    {
+        var freeTranslationType = CmPossibilityRepository.GetObject(CmPossibilityTags.kguidTranFreeTranslation);
+        return CmTranslationFactory.Create(parent, freeTranslationType);
+    }
+
     public async Task<ExampleSentence> CreateExampleSentence(Guid entryId, Guid senseId, ExampleSentence exampleSentence, BetweenPosition? between = null)
     {
         if (exampleSentence.Id == default) exampleSentence.Id = Guid.NewGuid();

backend/FwLite/FwDataMiniLcmBridge/Api/UpdateProxy/UpdateExampleSentenceProxy.cs

@@ -1,10 +1,10 @@
-using MiniLcm.Models;
+using MiniLcm.Models;
 using SIL.LCModel;
 using SIL.LCModel.Core.Text;
 
 namespace FwDataMiniLcmBridge.Api.UpdateProxy;
 
-public class UpdateExampleSentenceProxy(ILexExampleSentence sentence, FwDataMiniLcmApi lexboxLcmApi): ExampleSentence
+public class UpdateExampleSentenceProxy(ILexExampleSentence sentence, FwDataMiniLcmApi lexboxLcmApi) : ExampleSentence
 {
     public override Guid Id
     {
@@ -23,7 +23,13 @@ public override RichMultiString Translation
         get
         {
             var firstTranslation = sentence.TranslationsOC.FirstOrDefault()?.Translation;
-            return firstTranslation is null ? new RichMultiString() : new UpdateRichMultiStringProxy(firstTranslation, lexboxLcmApi);
+            if (firstTranslation is null)
+            {
+                var translation = lexboxLcmApi.CreateExampleSentenceTranslation(sentence);
+                sentence.TranslationsOC.Add(translation);
+                firstTranslation = translation.Translation;
+            }
+            return new UpdateRichMultiStringProxy(firstTranslation, lexboxLcmApi);
         }
         set => throw new NotImplementedException();
     }