Phase 0 WP-0.2–0.9: Implement Commons (types, entities, interfaces, messages, protocol, tests)

- WP-0.2: Namespace/folder skeleton (26 directories)
- WP-0.3: Shared data types (6 enums, RetryPolicy, Result<T>)
- WP-0.4: 24 domain entity POCOs across 10 domain areas
- WP-0.5: 7 repository interfaces with full CRUD signatures
- WP-0.6: IAuditService cross-cutting interface
- WP-0.7: 26 message contract records across 8 concern areas
- WP-0.8: IDataConnection protocol abstraction with batch ops
- WP-0.9: 8 architectural constraint enforcement tests
All 40 tests pass, zero warnings.

tests/ScadaLink.Commons.Tests/Types/EnumTests.cs

@@ -0,0 +1,36 @@
+using ScadaLink.Commons.Types.Enums;
+
+namespace ScadaLink.Commons.Tests.Types;
+
+public class EnumTests
+{
+    [Theory]
+    [InlineData(typeof(DataType), new[] { "Boolean", "Int32", "Float", "Double", "String", "DateTime", "Binary" })]
+    [InlineData(typeof(InstanceState), new[] { "Enabled", "Disabled" })]
+    [InlineData(typeof(DeploymentStatus), new[] { "Pending", "InProgress", "Success", "Failed" })]
+    [InlineData(typeof(AlarmState), new[] { "Active", "Normal" })]
+    [InlineData(typeof(AlarmTriggerType), new[] { "ValueMatch", "RangeViolation", "RateOfChange" })]
+    [InlineData(typeof(ConnectionHealth), new[] { "Connected", "Disconnected", "Connecting", "Error" })]
+    public void Enum_ShouldHaveExpectedValues(Type enumType, string[] expectedNames)
+    {
+        var actualNames = Enum.GetNames(enumType);
+        Assert.Equal(expectedNames, actualNames);
+    }
+
+    [Theory]
+    [InlineData(typeof(DataType))]
+    [InlineData(typeof(InstanceState))]
+    [InlineData(typeof(DeploymentStatus))]
+    [InlineData(typeof(AlarmState))]
+    [InlineData(typeof(AlarmTriggerType))]
+    [InlineData(typeof(ConnectionHealth))]
+    public void Enum_ShouldBeSingularNamed(Type enumType)
+    {
+        // Singular names should not end with 's' (except 'Status' which is singular)
+        var name = enumType.Name;
+        Assert.False(name.EndsWith("es") && !name.EndsWith("Status"),
+            $"Enum {name} appears to be plural (ends with 'es').");
+        Assert.False(name.EndsWith("s") && !name.EndsWith("ss") && !name.EndsWith("us"),
+            $"Enum {name} appears to be plural (ends with 's').");
+    }
+}

tests/ScadaLink.Commons.Tests/Types/ResultTests.cs

@@ -0,0 +1,75 @@
+using ScadaLink.Commons.Types;
+
+namespace ScadaLink.Commons.Tests.Types;
+
+public class ResultTests
+{
+    [Fact]
+    public void Success_ShouldCreateSuccessfulResult()
+    {
+        var result = Result<int>.Success(42);
+
+        Assert.True(result.IsSuccess);
+        Assert.False(result.IsFailure);
+        Assert.Equal(42, result.Value);
+    }
+
+    [Fact]
+    public void Failure_ShouldCreateFailedResult()
+    {
+        var result = Result<int>.Failure("something went wrong");
+
+        Assert.True(result.IsFailure);
+        Assert.False(result.IsSuccess);
+        Assert.Equal("something went wrong", result.Error);
+    }
+
+    [Fact]
+    public void Value_OnFailure_ShouldThrow()
+    {
+        var result = Result<int>.Failure("error");
+
+        Assert.Throws<InvalidOperationException>(() => result.Value);
+    }
+
+    [Fact]
+    public void Error_OnSuccess_ShouldThrow()
+    {
+        var result = Result<int>.Success(42);
+
+        Assert.Throws<InvalidOperationException>(() => result.Error);
+    }
+
+    [Fact]
+    public void Match_OnSuccess_ShouldCallOnSuccess()
+    {
+        var result = Result<int>.Success(42);
+
+        var output = result.Match(
+            v => $"value={v}",
+            e => $"error={e}");
+
+        Assert.Equal("value=42", output);
+    }
+
+    [Fact]
+    public void Match_OnFailure_ShouldCallOnFailure()
+    {
+        var result = Result<int>.Failure("bad");
+
+        var output = result.Match(
+            v => $"value={v}",
+            e => $"error={e}");
+
+        Assert.Equal("error=bad", output);
+    }
+
+    [Fact]
+    public void Success_WithNullableReferenceType_ShouldWork()
+    {
+        var result = Result<string>.Success("hello");
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal("hello", result.Value);
+    }
+}

tests/ScadaLink.Commons.Tests/Types/RetryPolicyTests.cs

@@ -0,0 +1,35 @@
+using ScadaLink.Commons.Types;
+
+namespace ScadaLink.Commons.Tests.Types;
+
+public class RetryPolicyTests
+{
+    [Fact]
+    public void RetryPolicy_ShouldBeImmutableRecord()
+    {
+        var policy = new RetryPolicy(3, TimeSpan.FromSeconds(5));
+
+        Assert.Equal(3, policy.MaxRetries);
+        Assert.Equal(TimeSpan.FromSeconds(5), policy.Delay);
+    }
+
+    [Fact]
+    public void RetryPolicy_WithExpression_ShouldCreateNewInstance()
+    {
+        var original = new RetryPolicy(3, TimeSpan.FromSeconds(5));
+        var modified = original with { MaxRetries = 5 };
+
+        Assert.Equal(3, original.MaxRetries);
+        Assert.Equal(5, modified.MaxRetries);
+        Assert.Equal(original.Delay, modified.Delay);
+    }
+
+    [Fact]
+    public void RetryPolicy_EqualValues_ShouldBeEqual()
+    {
+        var a = new RetryPolicy(3, TimeSpan.FromSeconds(5));
+        var b = new RetryPolicy(3, TimeSpan.FromSeconds(5));
+
+        Assert.Equal(a, b);
+    }
+}