which handles broken symlink & unit test added (actions#2150) (action…

…s#2196) * which handles broken symlink & unit test added (actions#2150) * Update src/Runner.Sdk/Util/WhichUtil.cs Co-authored-by: Ferenc Hammerl <[email protected]> * fix pr comments * trace log added, in case we find a symlink that is broken * add check in case the target of the symlink is a relative path; added test that check symlink that targets a full path; added test that check symlink that targets a relative path; * fix tests * fix tests for linux --------- Co-authored-by: Eli Entelis <[email protected]> Co-authored-by: Eli Entelis <[email protected]> Co-authored-by: Ferenc Hammerl <[email protected]>
aj377183 · Apr 7, 2023 · 2ecd7d2 · 2ecd7d2
1 parent 0484afe
commit 2ecd7d2
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diff --git a/src/Runner.Sdk/Util/WhichUtil.cs b/src/Runner.Sdk/Util/WhichUtil.cs
@@ -60,7 +60,7 @@ public static string Which(string command, bool require = false, ITraceWriter tr
                             trace?.Verbose(ex.ToString());
                         }
 
-                        if (matches != null && matches.Length > 0)
+                        if (matches != null && matches.Length > 0 && IsPathValid(matches.First(), trace))
                         {
                             trace?.Info($"Location: '{matches.First()}'");
                             return matches.First();
@@ -86,7 +86,7 @@ public static string Which(string command, bool require = false, ITraceWriter tr
                             for (int i = 0; i < pathExtSegments.Length; i++)
                             {
                                 string fullPath = Path.Combine(pathSegment, $"{command}{pathExtSegments[i]}");
-                                if (matches.Any(p => p.Equals(fullPath, StringComparison.OrdinalIgnoreCase)))
+                                if (matches.Any(p => p.Equals(fullPath, StringComparison.OrdinalIgnoreCase)) && IsPathValid(fullPath, trace))
                                 {
                                     trace?.Info($"Location: '{fullPath}'");
                                     return fullPath;
@@ -105,7 +105,7 @@ public static string Which(string command, bool require = false, ITraceWriter tr
                         trace?.Verbose(ex.ToString());
                     }
 
-                    if (matches != null && matches.Length > 0)
+                    if (matches != null && matches.Length > 0 && IsPathValid(matches.First(), trace))
                     {
                         trace?.Info($"Location: '{matches.First()}'");
                         return matches.First();
@@ -128,5 +128,15 @@ public static string Which(string command, bool require = false, ITraceWriter tr
 
             return null;
         }
+
+        // checks if the file is a symlink and if the symlink`s target exists.
+        private static bool IsPathValid(string path, ITraceWriter trace = null)
+        {
+            var fileInfo = new FileInfo(path);
+            var linkTargetFullPath = fileInfo.Directory?.FullName + Path.DirectorySeparatorChar + fileInfo.LinkTarget;
+            if(fileInfo.LinkTarget == null || File.Exists(linkTargetFullPath) || File.Exists(fileInfo.LinkTarget)) return true;
+            trace?.Info($"the target '{fileInfo.LinkTarget}' of the symbolic link '{path}', does not exist");
+            return false;
+        }
     }
 }
diff --git a/src/Test/L0/Util/WhichUtilL0.cs b/src/Test/L0/Util/WhichUtilL0.cs
@@ -1,4 +1,4 @@
-using GitHub.Runner.Common.Util;
+using GitHub.Runner.Common.Util;
 using GitHub.Runner.Sdk;
 using System;
 using System.IO;
@@ -89,5 +89,128 @@ public void WhichHandleFullyQualifiedPath()
                 Assert.Equal(gitPath, gitPath2);
             }
         }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void WhichHandlesSymlinkToTargetFullPath()
+        {
+            // Arrange
+            using TestHostContext hc = new TestHostContext(this);
+            Tracing trace = hc.GetTrace();
+            string oldValue = Environment.GetEnvironmentVariable(PathUtil.PathVariable);
+#if OS_WINDOWS
+            string newValue = oldValue + @$";{Path.GetTempPath()}";
+            string symlinkName = $"symlink-{Guid.NewGuid()}";
+            string symlink = Path.GetTempPath() + $"{symlinkName}.exe";
+            string target = Path.GetTempPath() + $"target-{Guid.NewGuid()}.exe";
+#else
+            string newValue = oldValue + @$":{Path.GetTempPath()}";
+            string symlinkName = $"symlink-{Guid.NewGuid()}";
+            string symlink = Path.GetTempPath() + $"{symlinkName}";
+            string target = Path.GetTempPath() + $"target-{Guid.NewGuid()}";
+#endif
+
+            Environment.SetEnvironmentVariable(PathUtil.PathVariable, newValue);
+
+
+            using (File.Create(target))
+            {
+                File.CreateSymbolicLink(symlink, target);
+
+                // Act.
+                var result = WhichUtil.Which(symlinkName, require: true, trace: trace);
+
+                // Assert
+                Assert.True(!string.IsNullOrEmpty(result) && File.Exists(result), $"Unable to find symlink through: {nameof(WhichUtil.Which)}");
+
+            }
+
+
+            // Cleanup
+            File.Delete(symlink);
+            File.Delete(target);
+            Environment.SetEnvironmentVariable(PathUtil.PathVariable, oldValue);
+
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void WhichHandlesSymlinkToTargetRelativePath()
+        {
+            // Arrange
+            using TestHostContext hc = new TestHostContext(this);
+            Tracing trace = hc.GetTrace();
+            string oldValue = Environment.GetEnvironmentVariable(PathUtil.PathVariable);
+#if OS_WINDOWS
+            string newValue = oldValue + @$";{Path.GetTempPath()}";
+            string symlinkName = $"symlink-{Guid.NewGuid()}";
+            string symlink = Path.GetTempPath() + $"{symlinkName}.exe";
+            string targetName = $"target-{Guid.NewGuid()}.exe";
+            string target = Path.GetTempPath() + targetName;
+#else
+            string newValue = oldValue + @$":{Path.GetTempPath()}";
+            string symlinkName = $"symlink-{Guid.NewGuid()}";
+            string symlink = Path.GetTempPath() + $"{symlinkName}";
+            string targetName = $"target-{Guid.NewGuid()}";
+            string target = Path.GetTempPath() + targetName;
+#endif
+            Environment.SetEnvironmentVariable(PathUtil.PathVariable, newValue);
+
+
+            using (File.Create(target))
+            {
+                File.CreateSymbolicLink(symlink, targetName);
+
+                // Act.
+                var result = WhichUtil.Which(symlinkName, require: true, trace: trace);
+
+                // Assert
+                Assert.True(!string.IsNullOrEmpty(result) && File.Exists(result), $"Unable to find {symlinkName} through: {nameof(WhichUtil.Which)}");
+            }
+
+            // Cleanup
+            File.Delete(symlink);
+            File.Delete(target);
+            Environment.SetEnvironmentVariable(PathUtil.PathVariable, oldValue);
+
+        }
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void WhichThrowsWhenSymlinkBroken()
+        {
+            // Arrange
+            using TestHostContext hc = new TestHostContext(this);
+            Tracing trace = hc.GetTrace();
+            string oldValue = Environment.GetEnvironmentVariable(PathUtil.PathVariable);
+
+#if OS_WINDOWS
+            string newValue = oldValue + @$";{Path.GetTempPath()}";
+            string brokenSymlinkName = $"broken-symlink-{Guid.NewGuid()}";
+            string brokenSymlink = Path.GetTempPath() + $"{brokenSymlinkName}.exe";
+#else
+            string newValue = oldValue + @$":{Path.GetTempPath()}";
+            string brokenSymlinkName = $"broken-symlink-{Guid.NewGuid()}";
+            string brokenSymlink = Path.GetTempPath() + $"{brokenSymlinkName}";
+#endif
+
+
+            string target = "no-such-file-cf7e351f";
+            Environment.SetEnvironmentVariable(PathUtil.PathVariable, newValue);
+
+            File.CreateSymbolicLink(brokenSymlink, target);
+
+            // Act.
+            var exception = Assert.Throws<FileNotFoundException>(()=>WhichUtil.Which(brokenSymlinkName, require: true, trace: trace));
+
+            // Assert
+            Assert.Equal(brokenSymlinkName, exception.FileName);
+
+            // Cleanup
+            File.Delete(brokenSymlink);
+            Environment.SetEnvironmentVariable(PathUtil.PathVariable, oldValue);
+        }
     }
 }