fix: 0 wildcard matches for --required-files is not an error

Agent-Logs-Url: https://github.com/304NotModified/SLNX-validator/sessions/df57f4d4-bd94-489f-94d0-3f0476a70eee

Co-authored-by: 304NotModified <5808377+304NotModified@users.noreply.github.com>

Author: Copilot

README.md

@@ -104,8 +104,7 @@ Always exits with code `0`, even when validation errors are found. Useful in CI
 
 Verify that a set of files or directories matching glob patterns exist on disk **and** are referenced as `<File>` entries in the solution file(s) being validated. Any failure is reported as a normal validation error (exit code `1`) that also appears in SonarQube reports.
 
-- **Disk check** — if no files match the glob patterns, a `SLNX020` (`RequiredFileDoesntExistOnSystem`) error is added to the solution result.
-- **Reference check** — for each matched file that is not referenced as `<File Path="...">` in the `.slnx`, a `SLNX021` (`RequiredFileNotReferencedInSolution`) error is added. The error message shows the exact `<File>` element that should be added.
+- **Reference check** — for each matched file that is not referenced as `<File Path="...">` in the `.slnx`, a `SLNX021` (`RequiredFileNotReferencedInSolution`) error is added. The error message shows the exact `<File>` element that should be added. If the pattern matches no files, the check is skipped silently (not an error).
 
 Relative paths in the `.slnx` are resolved relative to the solution file's location.
 
@@ -150,8 +149,8 @@ slnx-validator MySolution.slnx --required-files "appsettings.json;docs/"
 
 | Code | Description |
 |------|-------------|
-| `0`  | All patterns matched and all matched files are referenced in the solution. |
-| `1`  | Any validation error — including required files not existing or not referenced. |
+| `0`  | All matched files are referenced in the solution (or no files matched the pattern). |
+| `1`  | Any validation error — including required files not referenced. |
 
 ### Severity override flags
 
@@ -403,7 +402,6 @@ The following are **intentionally out of scope** because the toolchain already h
 | `SLNX011` | `ReferencedFileNotFound`  | A file referenced in `<File Path="...">` does not exist on disk. |
 | `SLNX012` | `InvalidWildcardUsage`    | A `<File Path="...">` contains a wildcard pattern (see [`examples/invalid-wildcard.slnx`](examples/invalid-wildcard.slnx)). |
 | `SLNX013` | `XsdViolation`            | The XML structure violates the schema, e.g. `<Folder>` inside `<Folder>` (see [`examples/invalid-xsd.slnx`](examples/invalid-xsd.slnx)). |
-| `SLNX020` | `RequiredFileDoesntExistOnSystem`   | A `--required-files` pattern matched no files on the file system. |
 | `SLNX021` | `RequiredFileNotReferencedInSolution` | A `--required-files` matched file exists on disk but is not referenced as a `<File>` element in the solution. |
 
 ## XSD Schema

src/SLNX-validator/RequiredFilesOptions.cs

@@ -6,7 +6,7 @@ namespace JulianVerdurmen.SlnxValidator;
 /// </summary>
 /// <param name="MatchedPaths">
 /// Absolute disk paths that were matched by <see cref="Pattern"/>.
-/// An empty list means the pattern matched no files.
+/// An empty list means the pattern matched no files — this is not an error (no files to check).
 /// <see langword="null"/> means the <c>--required-files</c> option was not used.
 /// </param>
 /// <param name="Pattern">The raw semicolon-separated pattern string supplied by the user.</param>

src/SLNX-validator/SlnxCollector.cs

@@ -61,13 +61,7 @@ public async Task<IReadOnlyList<FileValidationResult>> CollectAsync(
             if (requiredFilesOptions is not null)
             {
                 var matched = requiredFilesOptions.MatchedPaths;
-                if (matched is null || matched.Count == 0)
-                {
-                    allErrors.Add(new ValidationError(
-                        ValidationErrorCode.RequiredFileDoesntExistOnSystem,
-                        $"Required file does not exist on the system. No files matched: {requiredFilesOptions.Pattern}"));
-                }
-                else
+                if (matched is not null && matched.Count > 0)
                 {
                     var hasXsdErrors = allErrors.Any(e => e.Code == ValidationErrorCode.XsdViolation);
                     if (!hasXsdErrors)

tests/SLNX-validator.Tests/SlnxCollectorTests.cs

@@ -31,7 +31,7 @@ private static (SlnxCollector collector, IRequiredFilesChecker checker) CreateCo
     #region CollectAsync
 
     [Test]
-    public async Task CollectAsync_RequiredFilesPatternNoMatch_AddsRequiredFileDoesntExistOnSystemError()
+    public async Task CollectAsync_RequiredFilesPatternNoMatch_NoError()
     {
         // Arrange
         var (collector, _) = CreateCollector();
@@ -42,8 +42,7 @@ public async Task CollectAsync_RequiredFilesPatternNoMatch_AddsRequiredFileDoesn
 
         // Assert
         results.Should().HaveCount(1);
-        results[0].HasErrors.Should().BeTrue();
-        results[0].Errors.Should().ContainSingle(e => e.Code == ValidationErrorCode.RequiredFileDoesntExistOnSystem);
+        results[0].HasErrors.Should().BeFalse();
     }
 
     [Test]

tests/SLNX-validator.Tests/ValidatorRunnerTests.cs

@@ -125,14 +125,14 @@ public async Task RunAsync_RequiredFiles_AllMatchedAndReferenced_ReturnsZero()
     }
 
     [Test]
-    public async Task RunAsync_RequiredFiles_NoMatchOnDisk_ReturnsOne()
+    public async Task RunAsync_RequiredFiles_NoMatchOnDisk_ReturnsZero()
     {
         // Arrange
         var slnxPath = Path.GetFullPath("test.slnx");
 
         var checker = Substitute.For<IRequiredFilesChecker>();
         checker.ResolveMatchedPaths(Arg.Any<string>(), Arg.Any<string>())
-            .Returns([]); // nothing matched on disk
+            .Returns([]); // nothing matched on disk — no error expected
 
         var runner = CreateRunnerWithSlnx(slnxPath, "<Solution />", checker);
 
@@ -141,7 +141,7 @@ public async Task RunAsync_RequiredFiles_NoMatchOnDisk_ReturnsOne()
             Options(slnxPath, requiredFilesPattern: "nonexistent/**/*.md"), CancellationToken.None);
 
         // Assert
-        exitCode.Should().Be(1);
+        exitCode.Should().Be(0);
     }
 
     #endregion