Add --result as legacy alias for --results argument

docs/design/sonar-mark/cli/context.md

@@ -50,3 +50,16 @@ Using `IDisposable` rather than a finalizer is appropriate because the resource
 - `SonarMark-Validation-JUnitFormat` — JUnit XML file extension is accepted by `ResultsFile`
 - `SonarMark-Enforce-Mode` — `Enforce` flag is parsed and stored
 - `SonarMark-Enforce-ExitCode` — `ExitCode` returns 1 when `_hasErrors` is true
+- `SonarMark-Context-ResultAlias` — `--result` is accepted as a legacy alias for `--results`
+
+## Backward Compatibility
+
+### Legacy `--result` Alias
+
+The `ArgumentParser` accepts `--result` as a fall-through case immediately before `--results`
+in the switch statement. Both spellings invoke the same `GetRequiredStringArgument` call and
+set the same `ResultsFile` property, so downstream code is unaffected.
+
+This alias is intentionally omitted from help text and user-facing documentation because it
+exists only to avoid breaking existing automation scripts that pre-date the canonical
+`--results` spelling. New users and new scripts should always use `--results`.

docs/reqstream/sonar-mark/cli/context.yaml

@@ -57,3 +57,14 @@ sections:
         tests:
           - Context_Create_ResultsFile_SetsResultsProperty
           - Context_Create_MissingResultsFilename_ThrowsException
+
+      - id: SonarMark-Context-ResultAlias
+        title: The tool shall accept --result as a legacy alias for --results to preserve backward compatibility.
+        justification: |
+          Existing automation scripts and CI pipelines may use --result (without the trailing 's') from
+          before the canonical --results spelling was established. Accepting the alias prevents breakage
+          for those consumers without requiring a coordinated migration, while new users are directed to
+          the canonical --results flag via documentation and help text.
+        tests:
+          - Context_Create_ResultAlias_SetsResultsProperty
+          - Context_Create_MissingResultAliasFilename_ThrowsException

src/DemaConsulting.SonarMark/Cli/Context.cs

@@ -337,6 +337,8 @@ private int ParseArgument(string arg, string[] args, int index)
                     Branch = GetRequiredStringArgument(arg, args, index, "a branch name argument");
                     return index + 1;
 
+                // Accept --result as a legacy alias so older scripts continue working
+                case "--result":
                 case "--results":
                     ResultsFile = GetRequiredStringArgument(arg, args, index, "a results filename argument");
                     return index + 1;

test/DemaConsulting.SonarMark.Tests/Cli/ContextTests.cs

@@ -461,4 +461,29 @@ public void Context_Create_MissingResultsFilename_ThrowsException()
         var ex = Assert.ThrowsExactly<ArgumentException>(() => Context.Create(["--results"]));
         Assert.Contains("--results requires a results filename argument", ex.Message);
     }
+
+    /// <summary>
+    ///     Test that --result (legacy alias) sets the ResultsFile property.
+    /// </summary>
+    [TestMethod]
+    public void Context_Create_ResultAlias_SetsResultsProperty()
+    {
+        // Act
+        using var context = Context.Create(["--result", "results.trx"]);
+
+        // Assert
+        Assert.AreEqual("results.trx", context.ResultsFile);
+        Assert.AreEqual(0, context.ExitCode);
+    }
+
+    /// <summary>
+    ///     Test that --result (legacy alias) requires a filename argument.
+    /// </summary>
+    [TestMethod]
+    public void Context_Create_MissingResultAliasFilename_ThrowsException()
+    {
+        // Act/Assert
+        var ex = Assert.ThrowsExactly<ArgumentException>(() => Context.Create(["--result"]));
+        Assert.Contains("--result requires a results filename argument", ex.Message);
+    }
 }