From 65358990c26ae95301127a73613f4b11867412a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Jare=C5=A1?= <me@jakubjares.com>
Date: Fri, 31 Jul 2026 21:04:10 +0200
Subject: [PATCH] Fix #2923: resolve code coverage ReportRoot and RepoRoot
 during configuration validation
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CodeCoverage.ReportRoot and Run.RepoRoot were resolved to absolute paths
only in Get-ReportRoot, which runs when the report is written at the very
end of the run. A test can change the current location (Set-Location), so
a relative ReportRoot/RepoRoot resolved then would use whatever directory
the last test left behind (#2921 comment).

Resolve both to absolute in Resolve-CodeCoverageConfiguration, which runs
during plugin setup while the current location still points at the
directory Invoke-Pester was called from, next to the OutputPath resolution
added in #2892. Paths already absolute are unaffected.

🤖
---
 src/functions/Coverage.Plugin.ps1 | 12 +++++++
 tst/functions/Coverage.Tests.ps1  | 54 +++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/src/functions/Coverage.Plugin.ps1 b/src/functions/Coverage.Plugin.ps1
index da5b00ce8..0a2aeaad1 100644
--- a/src/functions/Coverage.Plugin.ps1
+++ b/src/functions/Coverage.Plugin.ps1
@@ -246,4 +246,16 @@ function Resolve-CodeCoverageConfiguration {
     # test can change the current location (e.g. Set-Location), so a relative path would resolve
     # against the wrong directory, or one that no longer exists (#2641).
     $PesterPreference.CodeCoverage.OutputPath = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($PesterPreference.CodeCoverage.OutputPath.Value)
+
+    # Resolve the report root to an absolute path now, for the same reason. Get-ReportRoot uses it
+    # (or its Run.RepoRoot fallback) to strip the prefix off the absolute file paths when the report
+    # is written. That also happens after all tests ran, so resolving a relative ReportRoot/RepoRoot
+    # only then would use the location the last test left behind (#2923).
+    if (-not [string]::IsNullOrEmpty($PesterPreference.CodeCoverage.ReportRoot.Value)) {
+        $PesterPreference.CodeCoverage.ReportRoot = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($PesterPreference.CodeCoverage.ReportRoot.Value)
+    }
+
+    if (-not [string]::IsNullOrEmpty($PesterPreference.Run.RepoRoot.Value)) {
+        $PesterPreference.Run.RepoRoot = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($PesterPreference.Run.RepoRoot.Value)
+    }
 }
diff --git a/tst/functions/Coverage.Tests.ps1 b/tst/functions/Coverage.Tests.ps1
index dda93ff78..34ae0db91 100644
--- a/tst/functions/Coverage.Tests.ps1
+++ b/tst/functions/Coverage.Tests.ps1
@@ -1440,4 +1440,58 @@ InPesterModuleScope {
             Get-RelativePath -Path $absFile -RelativeTo (Get-ReportRoot) | Should -Be $expected
         }
     }
+
+    Describe 'Resolve-CodeCoverageConfiguration report root resolution (#2923)' {
+        # A relative ReportRoot (or its Run.RepoRoot fallback) must be captured against the
+        # location Invoke-Pester was called from, during configuration validation, not against
+        # whatever location a test leaves behind. The report is written after all tests ran, so
+        # resolving only then (in Get-ReportRoot) would break when a test changes the location.
+        BeforeAll {
+            $invocationDir = (New-Item -ItemType Directory -Path (Join-Path $TestDrive 'invocation-dir') -Force).FullName
+            $elsewhere = (New-Item -ItemType Directory -Path (Join-Path $TestDrive 'elsewhere') -Force).FullName
+        }
+
+        It 'captures a relative CodeCoverage.ReportRoot at configuration time so a later location change does not move it' {
+            $PesterPreference = [PesterConfiguration]::Default
+            $PesterPreference.CodeCoverage.ReportRoot = '.'
+
+            Push-Location -Path $invocationDir
+            try {
+                Resolve-CodeCoverageConfiguration
+            }
+            finally {
+                Pop-Location
+            }
+
+            # A test changed the current location before the report is written.
+            Push-Location -Path $elsewhere
+            try {
+                Get-ReportRoot | Should -Be $invocationDir
+            }
+            finally {
+                Pop-Location
+            }
+        }
+
+        It 'captures a relative Run.RepoRoot fallback at configuration time so a later location change does not move it' {
+            $PesterPreference = [PesterConfiguration]::Default
+            $PesterPreference.Run.RepoRoot = '.'
+
+            Push-Location -Path $invocationDir
+            try {
+                Resolve-CodeCoverageConfiguration
+            }
+            finally {
+                Pop-Location
+            }
+
+            Push-Location -Path $elsewhere
+            try {
+                Get-ReportRoot | Should -Be $invocationDir
+            }
+            finally {
+                Pop-Location
+            }
+        }
+    }
 }