Gracefully handle schema missing InitialCatalog (#772)

Author: SimonCropp

src/Tests/Tests.cs

@@ -833,6 +833,15 @@ await Verify(connection)
             .SchemaIncludes(DbObjects.Tables);
     }
 
+    [Test]
+    public async Task SchemaMissingInitialCatalog()
+    {
+        var connection = new SqlConnection("Server=localhost");
+        var exception = Assert.ThrowsAsync<Exception>(
+            async () => await Verify(connection));
+        Assert.That(exception!.Message, Does.Contain("Initial Catalog"));
+    }
+
     [Test]
     public async Task SchemaIncludesAndFilter()
     {

src/Verify.SqlServer/SchemaValidation/SqlScriptBuilder.cs

@@ -48,13 +48,19 @@ public string BuildContent(SqlConnection connection)
 
     string BuildContent(Server server, SqlConnectionStringBuilder builder)
     {
+        var initialCatalog = builder.InitialCatalog;
+        if (string.IsNullOrWhiteSpace(initialCatalog))
+        {
+            throw new("The connection string must specify an Initial Catalog (database name) for schema verification.");
+        }
+
         server.SetDefaultInitFields(typeof(Table), "Name", "IsSystemObject");
         server.SetDefaultInitFields(typeof(View), "Name", "IsSystemObject");
         server.SetDefaultInitFields(typeof(StoredProcedure), "Name", "IsSystemObject");
         server.SetDefaultInitFields(typeof(UserDefinedFunction), "Name", "IsSystemObject");
         server.SetDefaultInitFields(typeof(Trigger), "Name", "IsSystemObject");
         server.SetDefaultInitFields(typeof(Synonym), "Name");
-        var database = server.Databases[builder.InitialCatalog];
+        var database = server.Databases[initialCatalog];
         database.Tables.Refresh();
 
         return GetScriptingObjects(database);