From 8ee0decd2f9e4d73e28a6a6fa1da33940313b582 Mon Sep 17 00:00:00 2001
From: Martin Tirion <mtirion@microsoft.com>
Date: Tue, 27 Aug 2024 16:52:58 +0200
Subject: [PATCH] Added validation of root-reference with ~

---
 .../DocLinkChecker.Test/HyperlinkTests.cs     | 46 +++++++++++++++++++
 .../DocLinkChecker/Models/Hyperlink.cs        |  1 -
 .../Services/LinkValidatorService.cs          | 42 ++++++++++++-----
 3 files changed, 77 insertions(+), 12 deletions(-)

diff --git a/src/DocLinkChecker/DocLinkChecker.Test/HyperlinkTests.cs b/src/DocLinkChecker/DocLinkChecker.Test/HyperlinkTests.cs
index 6a22fc1..5a76892 100644
--- a/src/DocLinkChecker/DocLinkChecker.Test/HyperlinkTests.cs
+++ b/src/DocLinkChecker/DocLinkChecker.Test/HyperlinkTests.cs
@@ -303,6 +303,52 @@ public async void ValidateLocalLinkNonExistingHeadingShouldHaveErrors()
             headingError.Severity.Should().Be(Enums.MarkdownErrorSeverity.Warning);
         }
 
+        [Theory]
+        [InlineData("~/general/images/nature.jpeg")]
+        [InlineData("~\\general\\images\\nature.jpeg")]
+        public async void ValidateRootLinkShouldHaveNoErrors(string path)
+        {
+            // Arrange
+            _config.DocumentationFiles.SourceFolder = _fileServiceMock.Root;
+            string sourceDoc = $"{_fileServiceMock.Root}\\general\\another-sample.md";
+
+            LinkValidatorService service = new LinkValidatorService(_serviceProvider, _config, _fileService, _console);
+
+            //Act
+            int line = 499;
+            int column = 75;
+            Hyperlink link = new Hyperlink(sourceDoc, line, column, path);
+            await service.VerifyHyperlink(link);
+
+            // Assert
+            service.Errors.Should().BeEmpty();
+        }
+
+        [Theory]
+        [InlineData("~/general/images/NON_EXISTING.jpeg")]
+        [InlineData("~\\NON_EXISTING\\images\\nature.jpeg")]
+        public async void ValidateInvalidRootLinkShouldHaveErrors(string path)
+        {
+            // Arrange
+            _config.DocumentationFiles.SourceFolder = _fileServiceMock.Root;
+            string sourceDoc = $"{_fileServiceMock.Root}\\general\\another-sample.md";
+
+            LinkValidatorService service = new LinkValidatorService(_serviceProvider, _config, _fileService, _console);
+
+            //Act
+            int line = 499;
+            int column = 75;
+            Hyperlink link = new Hyperlink(sourceDoc, line, column, path);
+            await service.VerifyHyperlink(link);
+
+            // Assert
+            service.Errors.Should().NotBeEmpty();
+            var linkError = service.Errors.FirstOrDefault(x => x.Message.Contains("Not found"));
+            linkError.Line.Should().Be(line);
+            linkError.Column.Should().Be(column);
+            linkError.Severity.Should().Be(MarkdownErrorSeverity.Error);
+        }
+
         [Fact]
         public async void ValidateLocalLinkWithFullPathShouldHaveErrors()
         {
diff --git a/src/DocLinkChecker/DocLinkChecker/Models/Hyperlink.cs b/src/DocLinkChecker/DocLinkChecker/Models/Hyperlink.cs
index 7ab906d..53d2381 100644
--- a/src/DocLinkChecker/DocLinkChecker/Models/Hyperlink.cs
+++ b/src/DocLinkChecker/DocLinkChecker/Models/Hyperlink.cs
@@ -1,6 +1,5 @@
 namespace DocLinkChecker.Models
 {
-    using System.Diagnostics;
     using System.IO;
     using DocLinkChecker.Enums;
 
diff --git a/src/DocLinkChecker/DocLinkChecker/Services/LinkValidatorService.cs b/src/DocLinkChecker/DocLinkChecker/Services/LinkValidatorService.cs
index 1233c7c..f60ae1a 100644
--- a/src/DocLinkChecker/DocLinkChecker/Services/LinkValidatorService.cs
+++ b/src/DocLinkChecker/DocLinkChecker/Services/LinkValidatorService.cs
@@ -272,18 +272,38 @@ private Task VerifyLocalHyperlink(Hyperlink hyperlink)
                 return Task.CompletedTask;
             }
 
-            // compute link of the url relative to the path of the file.
-            if (!_fileService.ExistsFileOrDirectory(hyperlink.UrlFullPath))
+            if (hyperlink.Url.StartsWith("~"))
             {
-                // referenced file doesn't exist
-                _errors.Enqueue(
-                    new MarkdownError(
-                        hyperlink.FilePath,
-                        hyperlink.Line,
-                        hyperlink.Column,
-                        MarkdownErrorSeverity.Error,
-                        $"Not found: {hyperlink.Url}"));
-                return Task.CompletedTask;
+                // special case for a reference to the root of the docs. Calculate full path differently.
+                string url = hyperlink.Url.Replace("~", _config.DocumentationFiles.SourceFolder);
+                if (!_fileService.ExistsFileOrDirectory(url))
+                {
+                    // referenced file doesn't exist
+                    _errors.Enqueue(
+                        new MarkdownError(
+                            hyperlink.FilePath,
+                            hyperlink.Line,
+                            hyperlink.Column,
+                            MarkdownErrorSeverity.Error,
+                            $"Not found: {hyperlink.Url}"));
+                    return Task.CompletedTask;
+                }
+            }
+            else
+            {
+                // compute link of the url relative to the path of the file.
+                if (!_fileService.ExistsFileOrDirectory(hyperlink.UrlFullPath))
+                {
+                    // referenced file doesn't exist
+                    _errors.Enqueue(
+                        new MarkdownError(
+                            hyperlink.FilePath,
+                            hyperlink.Line,
+                            hyperlink.Column,
+                            MarkdownErrorSeverity.Error,
+                            $"Not found: {hyperlink.Url}"));
+                    return Task.CompletedTask;
+                }
             }
 
             switch (_config.DocLinkChecker.RelativeLinkStrategy)