fix(management-service): resolve ManagementService-004,006,007,013 — PipeTo dispatch, JsonDocument disposal, unified serialization, endpoint tests; re-triage MS-009

tests/ScadaLink.ManagementService.Tests/ManagementEndpointsTests.cs

@@ -0,0 +1,65 @@
+using ScadaLink.Commons.Messages.Management;
+using ScadaLink.ManagementService;
+
+namespace ScadaLink.ManagementService.Tests;
+
+/// <summary>
+/// Tests for <see cref="ManagementEndpoints"/> request-body parsing
+/// (findings ManagementService-006 / -013).
+/// </summary>
+public class ManagementEndpointsTests
+{
+    [Fact]
+    public void ParseCommand_WithExplicitPayload_DeserializesIntoCommandType()
+    {
+        var json = """{ "command": "CreateSite", "payload": { "name": "Site1", "siteIdentifier": "SITE1", "description": "Desc" } }""";
+
+        var result = ManagementEndpoints.ParseCommand(json);
+
+        Assert.True(result.Success);
+        var command = Assert.IsType<CreateSiteCommand>(result.Command);
+        Assert.Equal("Site1", command.Name);
+        Assert.Equal("SITE1", command.SiteIdentifier);
+        Assert.Equal("Desc", command.Description);
+    }
+
+    [Fact]
+    public void ParseCommand_WithMissingPayload_DeserializesParameterlessCommand()
+    {
+        // No "payload" field at all -- the fallback must not allocate a throwaway
+        // JsonDocument and must still produce a valid parameterless command.
+        var json = """{ "command": "ListTemplates" }""";
+
+        var result = ManagementEndpoints.ParseCommand(json);
+
+        Assert.True(result.Success);
+        Assert.IsType<ListTemplatesCommand>(result.Command);
+    }
+
+    [Fact]
+    public void ParseCommand_WithInvalidJson_ReturnsFailure()
+    {
+        var result = ManagementEndpoints.ParseCommand("{ not json");
+
+        Assert.False(result.Success);
+        Assert.Equal("BAD_REQUEST", result.ErrorCode);
+    }
+
+    [Fact]
+    public void ParseCommand_WithMissingCommandField_ReturnsFailure()
+    {
+        var result = ManagementEndpoints.ParseCommand("""{ "payload": {} }""");
+
+        Assert.False(result.Success);
+        Assert.Equal("BAD_REQUEST", result.ErrorCode);
+    }
+
+    [Fact]
+    public void ParseCommand_WithUnknownCommand_ReturnsFailure()
+    {
+        var result = ManagementEndpoints.ParseCommand("""{ "command": "NoSuchCommand" }""");
+
+        Assert.False(result.Success);
+        Assert.Equal("BAD_REQUEST", result.ErrorCode);
+    }
+}