feat(tests): add line processing tests with various file sizes

Author: MariusStorhaug

guidance/Read-File.ps1

@@ -0,0 +1,87 @@
+# Function to simulate processing each line
+function Test-LineProcessing {
+    param([string]$InputText)
+    # Simulate some work by creating a simple string operation
+    $InputText.Length > 0
+}
+
+$tests = @{
+    'Get-Content + foreach'        = {
+        param($filePath)
+        $content = Get-Content -Path $filePath
+        foreach ($line in $content) {
+            Test-LineProcessing -InputText $line
+        }
+    }
+    'Get-Content | ForEach-Object' = {
+        param($filePath)
+        Get-Content -Path $filePath |
+            ForEach-Object -Process {
+                Test-LineProcessing -InputText $_
+            }
+    }
+    'StreamReader'                 = {
+        param($filePath)
+        $sr = New-Object -TypeName System.IO.StreamReader -ArgumentList $filePath
+        try {
+            while ($sr.Peek() -ge 0) {
+                $line = $sr.ReadLine()
+                Test-LineProcessing -InputText $line
+            }
+        } finally {
+            $sr.Dispose()
+        }
+    }
+    'Get-Content -ReadCount 1'     = {
+        param($filePath)
+        Get-Content -Path $filePath -ReadCount 1 |
+            ForEach-Object -Process {
+                Test-LineProcessing -InputText $_
+            }
+    }
+}
+
+# Create test files
+$testFiles = @{
+    'test-small.txt'  = (1..100 | ForEach-Object { "This is line $_ with some additional text to make it realistic." })
+    'test-medium.txt' = (1..5000 | ForEach-Object {
+            "This is line $_ with some additional text to make it realistic and longer for testing purposes."
+        })
+    'test-large.txt'  = (1..50000 | ForEach-Object {
+            "This is line $_ with some additional text to make it realistic and longer for testing purposes with even more content."
+        })
+}
+
+# Generate test files
+foreach ($file in $testFiles.GetEnumerator()) {
+    $file.Value | Out-File -FilePath $file.Key -Encoding UTF8
+}
+
+'test-small.txt', 'test-medium.txt', 'test-large.txt' | ForEach-Object {
+    $groupResult = foreach ($test in $tests.GetEnumerator()) {
+        $ms = (Measure-Command { & $test.Value $_ }).TotalMilliseconds
+
+        [pscustomobject]@{
+            TestFile          = $_
+            Test              = $test.Key
+            TotalMilliseconds = [math]::Round($ms, 2)
+        }
+
+        [GC]::Collect()
+        [GC]::WaitForPendingFinalizers()
+    }
+
+    $groupResult = $groupResult | Sort-Object TotalMilliseconds
+    $groupResult | Select-Object *, @{
+        Name       = 'RelativeSpeed'
+        Expression = {
+            $relativeSpeed = $_.TotalMilliseconds / $groupResult[0].TotalMilliseconds
+            [math]::Round($relativeSpeed, 2).ToString() + 'x'
+        }
+    }
+}
+
+# Cleanup test files
+'test-small.txt', 'test-medium.txt', 'test-large.txt' | ForEach-Object {
+    Remove-Item $_ -Force -ErrorAction SilentlyContinue
+}