test(cluster): HOCON parses, role parser truth table

tests/Core/ZB.MOM.WW.OtOpcUa.Cluster.Tests/RoleParserTests.cs

@@ -0,0 +1,52 @@
+using Shouldly;
+using Xunit;
+
+namespace ZB.MOM.WW.OtOpcUa.Cluster.Tests;
+
+public sealed class RoleParserTests
+{
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    public void Empty_input_yields_empty_array(string? raw)
+    {
+        RoleParser.Parse(raw).ShouldBeEmpty();
+    }
+
+    [Fact]
+    public void Single_role_admin()
+    {
+        RoleParser.Parse("admin").ShouldBe(new[] { "admin" });
+    }
+
+    [Fact]
+    public void Two_roles_csv()
+    {
+        RoleParser.Parse("admin,driver").ShouldBe(new[] { "admin", "driver" });
+    }
+
+    [Fact]
+    public void Whitespace_tolerant()
+    {
+        RoleParser.Parse(" admin , driver ").ShouldBe(new[] { "admin", "driver" });
+    }
+
+    [Fact]
+    public void Case_insensitive_normalizes_to_lower()
+    {
+        RoleParser.Parse("ADMIN,Driver").ShouldBe(new[] { "admin", "driver" });
+    }
+
+    [Fact]
+    public void Duplicate_roles_deduped()
+    {
+        RoleParser.Parse("admin,admin,driver").ShouldBe(new[] { "admin", "driver" });
+    }
+
+    [Fact]
+    public void Unknown_role_throws()
+    {
+        Should.Throw<ArgumentException>(() => RoleParser.Parse("admin,master"));
+    }
+}