fix: handle empty PowerShell profiles (#29)

Author: JacobOptimiza

installer/ProfileIntegration.ps1

@@ -15,12 +15,11 @@ $startMarker = '# >>> DevNav >>>'
 $endMarker = '# <<< DevNav <<<'
 $importLine = "Import-Module '$($ModulePath.Replace("'", "''"))'"
 $block = @($startMarker, $importLine, $endMarker)
-$content = if (Test-Path -LiteralPath $profilePath -PathType Leaf) {
-    @(Get-Content -LiteralPath $profilePath)
-}
-else {
-    @()
-}
+$content = @(
+    if (Test-Path -LiteralPath $profilePath -PathType Leaf) {
+        Get-Content -LiteralPath $profilePath
+    }
+)
 
 $start = [Array]::IndexOf($content, $startMarker)
 $end = [Array]::IndexOf($content, $endMarker)

tests/powershell/ProfileIntegration.Tests.ps1

@@ -0,0 +1,103 @@
+BeforeAll {
+    $repositoryRoot = Split-Path -Parent (Split-Path -Parent $PSScriptRoot)
+    $scriptPath = Join-Path $repositoryRoot 'installer\ProfileIntegration.ps1'
+    $realProfilePath = $PROFILE.CurrentUserCurrentHost
+    $realProfileSnapshot = if (Test-Path -LiteralPath $realProfilePath -PathType Leaf) {
+        [pscustomobject]@{ Exists = $true; Hash = (Get-FileHash -LiteralPath $realProfilePath -Algorithm SHA256).Hash }
+    }
+    else {
+        [pscustomobject]@{ Exists = $false; Hash = $null }
+    }
+    Set-Item Function:\global:Invoke-ProfileIntegrationRegression {
+        param([switch] $Install, [string] $ModulePath)
+        $arguments = @{ Install = $Install; ModulePath = $ModulePath }
+        & $global:profileIntegrationScriptPath @arguments
+        [pscustomobject]@{
+            Content = @($global:profileSetContent)
+            Encoding = $global:profileSetEncoding
+            NewItemPaths = @($global:profileNewItemPaths)
+        }
+    }
+}
+
+AfterAll {
+    $currentSnapshot = if (Test-Path -LiteralPath $realProfilePath -PathType Leaf) {
+        [pscustomobject]@{ Exists = $true; Hash = (Get-FileHash -LiteralPath $realProfilePath -Algorithm SHA256).Hash }
+    }
+    else {
+        [pscustomobject]@{ Exists = $false; Hash = $null }
+    }
+    $currentSnapshot.Exists | Should -Be $realProfileSnapshot.Exists
+    $currentSnapshot.Hash | Should -Be $realProfileSnapshot.Hash
+    Remove-Item Function:\global:Invoke-ProfileIntegrationRegression -ErrorAction SilentlyContinue
+}
+
+Describe 'ProfileIntegration.ps1 regression behavior' {
+    BeforeEach {
+        $global:profileIntegrationScriptPath = $scriptPath
+        $global:profileExists = $true
+        $global:profileExistingContent = @()
+        $global:profileSetContent = $null
+        $global:profileSetEncoding = $null
+        $global:profileNewItemPaths = [System.Collections.Generic.List[string]]::new()
+
+        Mock Test-Path {
+            param($LiteralPath, $PathType)
+            if ($LiteralPath -eq $PROFILE.CurrentUserCurrentHost) { return $global:profileExists }
+            return $false
+        }
+        Mock Get-Content {
+            param($LiteralPath)
+            if ($LiteralPath -eq $PROFILE.CurrentUserCurrentHost) { return $global:profileExistingContent }
+            throw "Unexpected Get-Content path: $LiteralPath"
+        }
+        Mock New-Item {
+            param($Path)
+            [void] $global:profileNewItemPaths.Add($Path)
+            [pscustomobject]@{ FullName = $Path }
+        }
+        Mock Set-Content {
+            param($LiteralPath, $Value, $Encoding)
+            $global:profileSetContent = @($Value | ForEach-Object { $_ })
+            $global:profileSetEncoding = $Encoding
+        }
+        Mock Remove-Item { param($LiteralPath) }
+    }
+
+    It 'installs successfully when the profile does not exist' {
+        $global:profileExists = $false
+        $modulePath = 'C:\Program Files\DevNav\DevNav.psm1'
+        $result = Invoke-ProfileIntegrationRegression -Install -ModulePath $modulePath
+
+        $result.Encoding | Should -BeOfType ([System.Text.UTF8Encoding])
+        $result.Encoding.GetPreamble().Length | Should -Be 0
+        $result.Content | Should -Contain '# >>> DevNav >>>'
+        $result.Content | Should -Contain "Import-Module '$modulePath'"
+        $result.Content | Should -Contain '# <<< DevNav <<<'
+        @($result.Content | Where-Object { $_ -eq '# >>> DevNav >>>' }).Count | Should -Be 1
+        @($result.Content | Where-Object { $_ -eq '# <<< DevNav <<<' }).Count | Should -Be 1
+        Should -Invoke New-Item -Times 2 -Scope It
+        Should -Invoke Set-Content -Times 1 -Scope It
+    }
+
+    It 'preserves a single-line profile and appends one DevNav block' {
+        $global:profileExistingContent = @('Set-Alias foo bar')
+        $modulePath = 'C:\Program Files\DevNav\DevNav.psm1'
+        $result = Invoke-ProfileIntegrationRegression -Install -ModulePath $modulePath
+
+        $result.Content | Should -Contain 'Set-Alias foo bar'
+        @($result.Content | Where-Object { $_ -eq '# >>> DevNav >>>' }).Count | Should -Be 1
+        @($result.Content | Where-Object { $_ -eq '# <<< DevNav <<<' }).Count | Should -Be 1
+        $result.Content | Should -Contain "Import-Module '$modulePath'"
+    }
+
+    It 'preserves a small multi-line profile and appends one DevNav block' {
+        $global:profileExistingContent = @('line before', 'line after')
+        $result = Invoke-ProfileIntegrationRegression -Install -ModulePath 'C:\Program Files\DevNav\DevNav.psm1'
+
+        $result.Content | Should -Contain 'line before'
+        $result.Content | Should -Contain 'line after'
+        @($result.Content | Where-Object { $_ -eq '# >>> DevNav >>>' }).Count | Should -Be 1
+        @($result.Content | Where-Object { $_ -eq '# <<< DevNav <<<' }).Count | Should -Be 1
+    }
+}