Validate WritingSystemIds on creation

backend/FwLite/FwLiteProjectSync.Tests/Fixtures/MultiStringOverride.cs

@@ -1,4 +1,4 @@
-using MiniLcm.Models;
+using MiniLcm.Models;
 using Soenneker.Utils.AutoBogus.Context;
 using Soenneker.Utils.AutoBogus.Override;
 
@@ -16,7 +16,8 @@ public override void Generate(AutoFakerOverrideContext context)
         var wordsArray = context.Faker.Random.WordsArray(1, 4);
         foreach (var word in wordsArray)
         {
-            target[context.Faker.Random.String(2, 'a', 'z')] = word;
+            var ws = context.Faker.Random.ArrayElement(MiniLcm.Tests.WritingSystemCodes.ValidTwoLetterCodes);
+            target[ws] = word;
         }
     }
 }

backend/FwLite/LcmCrdt.Tests/DataModelSnapshotTests.cs

@@ -10,6 +10,7 @@
 using SIL.Harmony.Changes;
 using SIL.Harmony.Entities;
 using Soenneker.Utils.AutoBogus;
+using Soenneker.Utils.AutoBogus.Config;
 
 namespace LcmCrdt.Tests;
 
@@ -76,7 +77,10 @@ public async Task VerifyIObjectWithIdModels()
     [Fact]
     public void VerifyIObjectWithIdsMatchAdapterGetObjectTypeName()
     {
-        var faker = new AutoFaker();
+        var faker = new AutoFaker(new AutoFakerConfig()
+        {
+            Overrides = [new MultiStringOverride()]
+        });
         var jsonSerializerOptions = _crdtConfig.JsonSerializerOptions;
         var types = jsonSerializerOptions.GetTypeInfo(typeof(IObjectWithId)).PolymorphismOptions?.DerivedTypes ?? [];
         using (new AssertionScope())

backend/FwLite/LcmCrdt.Tests/EntityCopyMethodTests.cs

@@ -8,7 +8,11 @@ namespace LcmCrdt.Tests;
 
 public class EntityCopyMethodTests
 {
-    private readonly AutoFaker _autoFaker = new(new AutoFakerConfig());
+    private readonly AutoFaker _autoFaker = new(new AutoFakerConfig()
+    {
+        Overrides = [new MultiStringOverride()]
+    });
+
     public static IEnumerable<object[]> GetEntityTypes()
     {
         var crdtConfig = new CrdtConfig();

backend/FwLite/LcmCrdt.Tests/MultiStringOverride.cs

@@ -1,4 +1,4 @@
-using MiniLcm.Models;
+using MiniLcm.Models;
 using Soenneker.Utils.AutoBogus.Context;
 using Soenneker.Utils.AutoBogus.Override;
 
@@ -16,7 +16,8 @@ public override void Generate(AutoFakerOverrideContext context)
         var wordsArray = context.Faker.Random.WordsArray(1, 4);
         foreach (var word in wordsArray)
         {
-            target[context.Faker.Random.String(2, 'a', 'z')] = word;
+            var ws = context.Faker.Random.ArrayElement(WritingSystemCodes.ValidTwoLetterCodes);
+            target[ws] = word;
         }
     }
 }

backend/FwLite/MiniLcm.Tests/WritingSystemCodes.cs

@@ -0,0 +1,190 @@
+namespace MiniLcm.Tests;
+
+public static class WritingSystemCodes
+{
+    public static string[] ValidTwoLetterCodes = [
+        "aa",
+        "ab",
+        "ae",
+        "af",
+        "ak",
+        "am",
+        "an",
+        "ar",
+        "as",
+        "av",
+        "ay",
+        "az",
+        "ba",
+        "be",
+        "bg",
+        "bi",
+        "bm",
+        "bn",
+        "bo",
+        "br",
+        "bs",
+        "ca",
+        "ce",
+        "ch",
+        "co",
+        "cr",
+        "cs",
+        "cu",
+        "cv",
+        "cy",
+        "da",
+        "de",
+        "dv",
+        "dz",
+        "ee",
+        "el",
+        "en",
+        "eo",
+        "es",
+        "et",
+        "eu",
+        "fa",
+        "ff",
+        "fi",
+        "fj",
+        "fo",
+        "fr",
+        "fy",
+        "ga",
+        "gd",
+        "gl",
+        "gn",
+        "gu",
+        "gv",
+        "ha",
+        "he",
+        "hi",
+        "ho",
+        "hr",
+        "ht",
+        "hu",
+        "hy",
+        "hz",
+        "{{",
+        "id",
+        "ie",
+        "ig",
+        "ii",
+        "ik",
+        "io",
+        "is",
+        "it",
+        "iu",
+        "ja",
+        "jv",
+        "ka",
+        "kg",
+        "ki",
+        "kj",
+        "kk",
+        "kl",
+        "km",
+        "kn",
+        "ko",
+        "kr",
+        "ks",
+        "ku",
+        "kv",
+        "kw",
+        "ky",
+        "la",
+        "lb",
+        "lg",
+        "li",
+        "ln",
+        "lo",
+        "lt",
+        "lu",
+        "lv",
+        "mg",
+        "mh",
+        "#m",
+        "mk",
+        "ml",
+        "mn",
+        "mr",
+        "ms",
+        "mt",
+        "my",
+        "na",
+        "#n",
+        "nd",
+        "ne",
+        "ng",
+        "nl",
+        "nn",
+        "no",
+        "nr",
+        "nv",
+        "ny",
+        "oc",
+        "oj",
+        "om",
+        "or",
+        "os",
+        "pa",
+        "pi",
+        "pl",
+        "ps",
+        "pt",
+        "qu",
+        "rm",
+        "rn",
+        "ro",
+        "ru",
+        "rw",
+        "sa",
+        "sc",
+        "sd",
+        "se",
+        "sg",
+        "si",
+        "sk",
+        "sl",
+        "sm",
+        "sn",
+        "so",
+        "sq",
+        "sr",
+        "ss",
+        "st",
+        "su",
+        "sv",
+        "sw",
+        "ta",
+        "te",
+        "tg",
+        "th",
+        "ti",
+        "tk",
+        "tl",
+        "tn",
+        "to",
+        "tr",
+        "ts",
+        "tt",
+        "tw",
+        "ty",
+        "ug",
+        "uk",
+        "ur",
+        "uz",
+        "ve",
+        "vi",
+        "#v",
+        "wa",
+        "wo",
+        "xh",
+        "yi",
+        "yo",
+        "za",
+        "zh",
+        "zu",
+    ];
+}

backend/FwLite/MiniLcm.Tests/WritingSystemTestsBase.cs

@@ -19,4 +19,32 @@ public async Task GetWritingSystems_ReturnsExemplars()
         var writingSystems = await Api.GetWritingSystems();
         writingSystems.Vernacular.Should().Contain(ws => ws.Exemplars.Any());
     }
+
+    [Theory]
+    [InlineData("en")]
+    [InlineData("th")]
+    [InlineData("en-Zxxx-x-audio")]
+    public void ValidWritingSystemId_ShouldNotThrow(string code)
+    {
+        var ws = new WritingSystemId(code);
+        ws.Should().NotBeNull();
+    }
+
+    [Theory]
+    [InlineData("gx")]
+    [InlineData("oo")]
+    [InlineData("eng")] // Three-letter codes not allowed when there's a valid two-letter code
+    [InlineData("eng-Zxxx-x-audio")]
+    [InlineData("nonsense")]
+    public void InvalidWritingSystemId_ShouldThrow(string code)
+    {
+        Assert.Throws<ArgumentException>(() => new WritingSystemId(code));
+    }
+
+    [Fact]
+    public void DefaultWritingSystemId_IsValid()
+    {
+        var ws = new WritingSystemId("default");
+        ws.Should().NotBeNull();
+    }
 }

backend/FwLite/MiniLcm/MiniLcm.csproj

@@ -9,6 +9,7 @@
     </PropertyGroup>
 
     <ItemGroup>
+      <PackageReference Include="SIL.WritingSystems" Version="14.2.0-beta*" />
       <PackageReference Include="System.Text.Json" Version="8.0.5" />
       <PackageReference Include="SystemTextJsonPatch" Version="3.2.1" />
     </ItemGroup>

backend/FwLite/MiniLcm/Models/WritingSystemId.cs

@@ -1,5 +1,6 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
+using SIL.WritingSystems;
 
 namespace MiniLcm.Models;
 
@@ -26,11 +27,26 @@ public override void WriteAsPropertyName(Utf8JsonWriter writer, WritingSystemId
 }
 
 [JsonConverter(typeof(WritingSystemIdJsonConverter))]
-public readonly record struct WritingSystemId(string Code): ISpanFormattable, ISpanParsable<WritingSystemId>
+public readonly record struct WritingSystemId: ISpanFormattable, ISpanParsable<WritingSystemId>
 {
+    public string Code { get; init; }
+
+    public WritingSystemId(string code)
+    {
+        if (code == "default" || IetfLanguageTag.IsValid(code))
+        {
+            Code = code;
+        }
+        else
+        {
+            throw new ArgumentException($"Invalid writing system ID {code}", nameof(code));
+        }
+    }
+
     public static implicit operator string(WritingSystemId ws) => ws.Code;
     public static implicit operator WritingSystemId(string code) => new(code);
     public static implicit operator WritingSystemId(ReadOnlySpan<char> code) => new(new string(code));
+
     public override string ToString()
     {
         return Code;