refactor: Consolidate repeated ModuleResult assertion patterns (#1579, #1569)

Issue #1579: Replace repeated ModuleResultType.Success assertion blocks
with calls to ModuleResultAssertions helper methods across test files:
- CommandTests.cs: Use AssertSuccessWithValue and AssertCommandOutput
- DotNetTests.cs: Use AssertSuccessWithValue
- GitTests.cs: Use AssertSuccessWithValue
- NodeTests.cs: Use AssertSuccessWithValue
- ZipTests.cs: Use AssertSuccess (no value check needed)

Issue #1569: Further consolidate EncodingTests.cs by:
- Removing duplicate test data provider methods
- Combining "Has_Not_Errored" and "Output_Is_Correct" tests into single tests
- Reducing 18 tests to 9 tests with same coverage
- Removing unused module class definitions

Also updated ModuleResultAssertions.AssertSuccessWithValue<T> to accept
nullable types (ModuleResult<T?>) to work with module return types.

Net reduction: 212 lines of test code while maintaining full coverage.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: thomhurst

test/ModularPipelines.TestHelpers/Assertions/ModuleResultAssertions.cs

@@ -12,7 +12,7 @@ public static class ModuleResultAssertions
     /// Asserts that a module result represents a successful execution with a non-null value.
     /// Checks: ModuleResultType is Success, Exception is null, Value is not null.
     /// </summary>
-    public static async Task AssertSuccessWithValue<T>(ModuleResult<T> moduleResult)
+    public static async Task AssertSuccessWithValue<T>(ModuleResult<T?> moduleResult)
         where T : class
     {
         using (Assert.Multiple())
@@ -27,7 +27,8 @@ public static async Task AssertSuccessWithValue<T>(ModuleResult<T> moduleResult)
     /// Asserts that a module result represents a successful execution.
     /// Checks: ModuleResultType is Success, Exception is null.
     /// </summary>
-    public static async Task AssertSuccess<T>(ModuleResult<T> moduleResult)
+    public static async Task AssertSuccess<T>(ModuleResult<T?> moduleResult)
+        where T : class
     {
         using (Assert.Multiple())
         {

test/ModularPipelines.UnitTests/Helpers/CommandTests.cs

@@ -5,6 +5,7 @@
 using ModularPipelines.Modules;
 using ModularPipelines.Options;
 using ModularPipelines.TestHelpers;
+using ModularPipelines.TestHelpers.Assertions;
 
 namespace ModularPipelines.UnitTests.Helpers;
 
@@ -37,34 +38,22 @@ public async Task Has_Not_Errored()
     {
         var moduleResult = await await RunModule<CommandEchoModule>();
 
-        using (Assert.Multiple())
-        {
-            await Assert.That(moduleResult.ModuleResultType).IsEqualTo(ModuleResultType.Success);
-            await Assert.That(moduleResult.Exception).IsNull();
-            await Assert.That(moduleResult.Value).IsNotNull();
-        }
+        await ModuleResultAssertions.AssertSuccessWithValue(moduleResult);
     }
 
     [Test]
     public async Task Standard_Output_Equals_Foo_Bar()
     {
         var moduleResult = await await RunModule<CommandEchoModule>();
 
-        using (Assert.Multiple())
-        {
-            await Assert.That(moduleResult.Value!.StandardError).IsNull().Or.IsEmpty();
-            await Assert.That(moduleResult.Value.StandardOutput.Trim()).IsEqualTo(TestConstants.TestString);
-        }
+        await ModuleResultAssertions.AssertCommandOutput(moduleResult, TestConstants.TestString);
     }
 
     [Test]
     public async Task Standard_Output_Equals_Foo_Bar_With_Timeout()
     {
         var moduleResult = await await RunModule<CommandEchoTimeoutModule>();
 
-        using (Assert.Multiple())
-        {
-            await Assert.That(moduleResult.Value!.Trim()).IsEqualTo(TestConstants.TestString);
-        }
+        await Assert.That(moduleResult.Value!.Trim()).IsEqualTo(TestConstants.TestString);
     }
 }

test/ModularPipelines.UnitTests/Helpers/DotNetTests.cs

@@ -6,6 +6,7 @@
 using ModularPipelines.Models;
 using ModularPipelines.Modules;
 using ModularPipelines.TestHelpers;
+using ModularPipelines.TestHelpers.Assertions;
 
 namespace ModularPipelines.UnitTests.Helpers;
 
@@ -41,12 +42,7 @@ public async Task Has_Not_Errored()
     {
         var moduleResult = await await RunModule<DotNetVersionModule>();
 
-        using (Assert.Multiple())
-        {
-            await Assert.That(moduleResult.ModuleResultType).IsEqualTo(ModuleResultType.Success);
-            await Assert.That(moduleResult.Exception).IsNull();
-            await Assert.That(moduleResult.Value).IsNotNull();
-        }
+        await ModuleResultAssertions.AssertSuccessWithValue(moduleResult);
     }
 
     [Test]
@@ -55,11 +51,6 @@ public async Task Format_Has_Not_Errored()
     {
         var moduleResult = await await RunModule<DotNetFormatModule>();
 
-        using (Assert.Multiple())
-        {
-            await Assert.That(moduleResult.ModuleResultType).IsEqualTo(ModuleResultType.Success);
-            await Assert.That(moduleResult.Exception).IsNull();
-            await Assert.That(moduleResult.Value).IsNotNull();
-        }
+        await ModuleResultAssertions.AssertSuccessWithValue(moduleResult);
     }
-}
+}