Fixes for git head in tests microsoft#1801 (microsoft#1802)

docs/CHANGELOG-v3.md

@@ -45,6 +45,8 @@ What's changed since pre-release v3.0.0-B0153:
 - Bug fixes:
   - Fixed discovery of installed modules in CLI by @BernieWhite.
     [#1779](https://github.com/microsoft/PSRule/issues/1779)
+  - Fixed for git head in tests by @BernieWhite.
+    [#1801](https://github.com/microsoft/PSRule/issues/1801)
 
 ## v3.0.0-B0153 (pre-release)
 

docs/deprecations.md

@@ -43,6 +43,17 @@ The following execution options have been deprecated and will be removed from _v
     You do not need to configure both options.
     If you have the deprecated option configured, switch to the new option.
 
+### Git Head input object
+
+Previously when the `Input.Format` option was set to `File` the `.git/HEAD` file was emitted as an input object.
+The original purpose of this feature was to allow conventions to run once against the root of the repository.
+Subsequent changes to PSRule have made this feature redundant by adding support for the `-Initialize` block.
+
+From _v3_ the `.git/HEAD` file will no longer be emitted as an input object.
+
+Consider adding or updating a convention that uses the `-Initialize` block to emit run initialization logic.
+Yon can also use the `-Initialize` block to emit a custom object to the pipeline by using the `$PSRule.ImportWithType` method.
+
 ### Rule output object
 
 Several properties of the rule object have been renamed to improve consistency with other objects.

docs/upgrade-notes.md

@@ -29,18 +29,15 @@ To resolve any issue caused by this change, you can:
   [1]: https://aka.ms/ps-rule/options#bindingtargetname
   [2]: https://aka.ms/ps-rule/options#suppression
 
-### Using PowerShell 7.3 or later
+### Using PowerShell 7.4 or later
 
 From _v3.0.0_, PSRule requires:
 
 - Windows PowerShell 5.1 for running as a PowerShell module. _OR_
-- PowerShell 7.3 or later for development, building locally, or running as a PowerShell module.
+- PowerShell 7.4 or later for development, building locally, or running as a PowerShell module.
 
 Support for Windows PowerShell 5.1 is deprecated and will be removed in a future release of PSRule (v4).
-We recommend upgrading to PowerShell 7.3 or later.
-
-At the time of writing, PowerShell 7.3 is the most recent version of PowerShell.
-PowerShell 7.4 is expected, and PSRule v4 will aim to support the latest version of PowerShell as the minimum requirement.
+We recommend upgrading to PowerShell 7.4 or later.
 
 ### Changes to CLI commands
 

src/PSRule/Common/GitHelper.cs

@@ -16,7 +16,8 @@ internal static class GitHelper
 {
     private const string GIT_HEAD = "HEAD";
     private const string GIT_REF_PREFIX = "ref: ";
-    private const string GIT_DEFAULT_PATH = ".git/";
+    private const string GIT_GITDIR_PREFIX = "gitdir: ";
+    private const string GIT_DEFAULT_PATH = ".git";
     private const string GIT_REF_HEAD = "refs/heads/";
 
     private const string GITHUB_BASE_URL = "https://github.com/";
@@ -44,7 +45,7 @@ internal static class GitHelper
     /// <summary>
     /// The get HEAD ref.
     /// </summary>
-    public static bool TryHeadRef(out string value, string path = null)
+    public static bool TryHeadRef(out string value)
     {
         // Try PSRule
         if (Environment.TryString(ENV_PSRULE_REPO_REF, out value) ||
@@ -61,22 +62,22 @@ public static bool TryHeadRef(out string value, string path = null)
             return true;
 
         // Try .git/
-        return TryReadHead(path, out value);
+        return TryReadHead(out value);
     }
 
     /// <summary>
     /// Get the HEAD branch name.
     /// </summary>
-    public static bool TryHeadBranch(out string value, string path = null)
+    public static bool TryHeadBranch(out string value)
     {
-        value = TryHeadRef(out value, path) && value.StartsWith(GIT_REF_HEAD) ? value.Substring(11) : value;
+        value = TryHeadRef(out value) && value.StartsWith(GIT_REF_HEAD) ? value.Substring(11) : value;
         return !string.IsNullOrEmpty(value);
     }
 
     /// <summary>
     /// Get the target ref.
     /// </summary>
-    public static bool TryBaseRef(out string value, string path = null)
+    public static bool TryBaseRef(out string value)
     {
         // Try PSRule
         if (Environment.TryString(ENV_PSRULE_REPO_BASEREF, out value))
@@ -91,10 +92,10 @@ public static bool TryBaseRef(out string value, string path = null)
             return true;
 
         // Try .git/
-        return TryReadHead(path, out value);
+        return TryReadHead(out value);
     }
 
-    public static bool TryRevision(out string value, string path = null)
+    public static bool TryRevision(out string value)
     {
         // Try PSRule
         if (Environment.TryString(ENV_PSRULE_REPO_REVISION, out value))
@@ -109,7 +110,7 @@ public static bool TryRevision(out string value, string path = null)
             return true;
 
         // Try .git/
-        return TryReadCommit(path, out value);
+        return TryReadCommit(out value);
     }
 
     public static bool TryRepository(out string value, string path = null)
@@ -151,6 +152,14 @@ public static bool TryGetChangedFiles(string baseRef, string filter, string opti
         return true;
     }
 
+    #region Helper methods
+
+    internal static bool TryReadHead(out string value, string path = null)
+    {
+        value = null;
+        return TryGitFile(GIT_HEAD, out var filePath, path) && TryReadRef(filePath, out value, out _);
+    }
+
     private static string GetGitBinary()
     {
         return RuntimeInformation.IsOSPlatform(OSPlatform.OSX) ||
@@ -162,43 +171,76 @@ private static string GetDiffArgs(string target, string source, string filter, s
         return $"diff --diff-filter={filter} --ignore-submodules=all --name-only --no-renames {target}";
     }
 
-    internal static bool TryReadHead(string path, out string value)
+    private static bool TryReadCommit(out string value)
     {
         value = null;
-        return TryGitFile(path, GIT_HEAD, out var filePath) && TryCommit(filePath, out value, out _);
+        if (!TryGitFile(GIT_HEAD, out var filePath))
+            return false;
+
+        while (TryReadRef(filePath, out value, out var isRef) && isRef)
+            TryGitFile(value, out filePath);
+
+        return value != null;
+    }
+
+    private static bool TryGitFile(string file, out string filePath, string path = null)
+    {
+        var gitPath = GetGitDir(path);
+        filePath = Path.Combine(gitPath, file);
+        return File.Exists(filePath);
     }
 
-    internal static bool TryReadCommit(string path, out string value)
+    private static string GetGitDir(string path)
+    {
+        var gitDir = Environment.GetRootedBasePath(path ?? GIT_DEFAULT_PATH);
+
+        // Try the case of a submodule.
+        if (File.Exists(path) && TryReadGitDir(path, out gitDir))
+            return gitDir;
+
+        // Try the simple case of .git/.
+        return gitDir;
+    }
+
+    private static bool TryReadGitDir(string path, out string value)
     {
         value = null;
-        if (!TryGitFile(path, GIT_HEAD, out var filePath))
+        if (!TryReadFirstLineFromGitFile(path, out var line))
             return false;
 
-        while (TryCommit(filePath, out value, out var isRef) && isRef)
-            TryGitFile(path, value, out filePath);
+        if (!line.StartsWith(GIT_GITDIR_PREFIX, StringComparison.OrdinalIgnoreCase))
+            return false;
 
-        return value != null;
+        value = Environment.GetRootedBasePath(line.Substring(8));
+        return true;
     }
 
-    private static bool TryGitFile(string path, string file, out string filePath)
+    private static bool TryReadRef(string path, out string value, out bool isRef)
     {
-        filePath = Path.Combine(Environment.GetRootedBasePath(path ?? GIT_DEFAULT_PATH), file);
-        return File.Exists(filePath);
+        value = null;
+        isRef = false;
+        if (!TryReadFirstLineFromGitFile(path, out var line))
+            return false;
+
+        isRef = line.StartsWith(GIT_REF_PREFIX, StringComparison.OrdinalIgnoreCase);
+        value = isRef ? line.Substring(5) : line;
+        return true;
     }
 
-    private static bool TryCommit(string path, out string value, out bool isRef)
+    /// <summary>
+    /// Read the first line of a git file.
+    /// </summary>
+    private static bool TryReadFirstLineFromGitFile(string path, out string value)
     {
         value = null;
-        isRef = false;
         if (!File.Exists(path))
             return false;
 
         var lines = File.ReadAllLines(path);
         if (lines == null || lines.Length == 0)
             return false;
 
-        isRef = lines[0].StartsWith(GIT_REF_PREFIX, StringComparison.OrdinalIgnoreCase);
-        value = isRef ? lines[0].Substring(5) : lines[0];
+        value = lines[0];
         return true;
     }
 
@@ -235,4 +277,6 @@ private static string GetWorktreeConfigArgs()
     {
         return "config --worktree --list";
     }
+
+    #endregion Helper methods
 }

src/PSRule/Pipeline/GetTargetPipelineBuilder.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation.
+// Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
 using PSRule.Configuration;
@@ -99,13 +99,6 @@ protected override PipelineInputStream PrepareReader()
                 return PipelineReceiverActions.ConvertFromPowerShellData(sourceObject, next);
             });
         }
-        else if (Option.Input.Format == InputFormat.File)
-        {
-            AddVisitTargetObjectAction((sourceObject, next) =>
-            {
-                return PipelineReceiverActions.ConvertFromGitHead(sourceObject, next);
-            });
-        }
         else if (Option.Input.Format == InputFormat.Detect && _InputPath != null)
         {
             AddVisitTargetObjectAction((sourceObject, next) =>

src/PSRule/Pipeline/InvokePipelineBuilder.cs

@@ -190,13 +190,6 @@ protected override PipelineInputStream PrepareReader()
                 return PipelineReceiverActions.ConvertFromPowerShellData(sourceObject, next);
             });
         }
-        else if (Option.Input.Format == InputFormat.File)
-        {
-            AddVisitTargetObjectAction((sourceObject, next) =>
-            {
-                return PipelineReceiverActions.ConvertFromGitHead(sourceObject, next);
-            });
-        }
         else if (Option.Input.Format == InputFormat.Detect && _InputPath != null)
         {
             AddVisitTargetObjectAction((sourceObject, next) =>

src/PSRule/Pipeline/PipelineReciever.cs

@@ -157,7 +157,7 @@ public static IEnumerable<TargetObject> ConvertFromPowerShellData(TargetObject t
     {
         // Only attempt to deserialize if the input is a string or a file
         if (!IsAcceptedType(targetObject))
-            return new TargetObject[] { targetObject };
+            return [targetObject];
 
         var data = ReadAsString(targetObject, out var sourceInfo);
         var ast = System.Management.Automation.Language.Parser.ParseInput(data, out _, out _);
@@ -175,16 +175,6 @@ public static IEnumerable<TargetObject> ConvertFromPowerShellData(TargetObject t
         return VisitItems(value, sourceInfo, next);
     }
 
-    public static IEnumerable<TargetObject> ConvertFromGitHead(TargetObject targetObject, VisitTargetObject next)
-    {
-        // Only attempt to convert if Git HEAD file
-        if (!IsGitHead(targetObject))
-            return new TargetObject[] { targetObject };
-
-        var value = PSObject.AsPSObject(GetRepositoryInfo(targetObject, out var sourceInfo));
-        return VisitItems(new PSObject[] { value }, sourceInfo, next);
-    }
-
     public static IEnumerable<TargetObject> ReadObjectPath(TargetObject targetObject, VisitTargetObject source, string objectPath, bool caseSensitive)
     {
         if (!ObjectHelper.GetPath(
@@ -206,7 +196,7 @@ public static IEnumerable<TargetObject> ReadObjectPath(TargetObject targetObject
         }
         else
         {
-            return new TargetObject[] { new(PSObject.AsPSObject(nestedObject), targetObject.Source) };
+            return [new(PSObject.AsPSObject(nestedObject), targetObject.Source)];
         }
     }
 
@@ -232,22 +222,6 @@ targetObject.Value.BaseObject is FileInfo ||
             targetObject.Value.BaseObject is Uri;
     }
 
-    private static bool IsGitHead(TargetObject targetObject)
-    {
-        return targetObject.Value.BaseObject is InputFileInfo info && info.DisplayName == InputFileInfo_GitHead;
-    }
-
-    private static RepositoryInfo GetRepositoryInfo(TargetObject targetObject, out TargetSourceInfo sourceInfo)
-    {
-        sourceInfo = null;
-        if (targetObject.Value.BaseObject is not InputFileInfo inputFileInfo)
-            return null;
-
-        sourceInfo = new TargetSourceInfo(inputFileInfo);
-        GitHelper.TryHeadRef(out var headRef, inputFileInfo.DirectoryName);
-        return new RepositoryInfo(inputFileInfo.BasePath, headRef);
-    }
-
     private static string ReadAsString(TargetObject targetObject, out TargetSourceInfo sourceInfo)
     {
         sourceInfo = null;

tests/PSRule.Tests/GitHelperTests.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
-using System.IO;
+using System.Runtime.InteropServices;
 
 namespace PSRule;
 
@@ -15,7 +15,7 @@ public void TryReadHead_WhenValidPath_ShouldReturnGitHead()
     {
         var expectedHead = GetGitOutput();
 
-        Assert.True(GitHelper.TryReadHead("../../../../../.git/", out var actualHead));
+        Assert.True(GitHelper.TryReadHead(out var actualHead, "../../../../../.git/"));
         Assert.Equal(expectedHead, NormalizeBranch(actualHead));
     }
 
@@ -28,7 +28,16 @@ private static string NormalizeBranch(string actualHead)
 
     private static string GetGitOutput()
     {
-        return File.ReadAllText("../../../../../.git/HEAD").Replace("ref: ", string.Empty).Replace("refs/heads/", string.Empty).Trim();
+        var bin = RuntimeInformation.IsOSPlatform(OSPlatform.OSX) || RuntimeInformation.IsOSPlatform(OSPlatform.Linux) ? "git" : "git.exe";
+        var git = ExternalTool.Get(null, bin);
+        git.WaitForExit("branch --show-current", out _);
+        var branch = git.GetOutput().Trim();
+        if (string.IsNullOrEmpty(branch))
+        {
+            git.WaitForExit("rev-parse HEAD", out _);
+            branch = git.GetOutput().Trim();
+        }
+        return branch;
     }
 
     #endregion Helper methods