Powershell script to read a file line by line, pass the lines which start with a particular string to a function

Question

I'm trying to get code coverage using Sonarqube. The coverage report is generated by karma. For some reason, the coverage file generated by Karma changes the case of 22 files inside the report. As a result, I'm unable to get coverage for those 22 files. I use a PowerShell script in my Jenkins to generate a canonical path. Below is the script. My script should perform the below steps:

1. Access the coverage report (unit-tests-lcov.info)
2. Read the report line by line
3. Use every file inside unit-tests-lcov.info starting with 'SF' and pass it to the canonical function
4. Save the file

I'm unable to write a script for the 3rd step. Can anyone make necessary changes to my script below?

$getPathNameSignature = @'
[DllImport("kernel32.dll", SetLastError=true, CharSet=CharSet.Auto)]
public static extern uint GetLongPathName(
    string shortPath, 
    StringBuilder sb, 
    int bufferSize);

[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError=true)]
public static extern uint GetShortPathName(
   string longPath,
   StringBuilder shortPath,
   uint bufferSize);
'@
$getPathNameType = Add-Type -MemberDefinition $getPathNameSignature -Name GetPathNameType -UsingNamespace System.Text -PassThru


function Get-PathCanonicalCase
{
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]
        # Gets the real case of a path
        $Path
    )

    if( -not (Test-Path $Path) )
    {
        Write-Error "Path '$Path' doesn't exist."
        return
    }

    $shortBuffer = New-Object Text.StringBuilder ($Path.Length * 2)
    [void] $getPathNameType::GetShortPathName( $Path, $shortBuffer, $shortBuffer.Capacity )

    $longBuffer = New-Object Text.StringBuilder ($Path.Length * 2)
    [void] $getPathNameType::GetLongPathName( $shortBuffer.ToString(), $longBuffer, $longBuffer.Capacity )

    return $longBuffer.ToString()
}

$file3 = "$env:WORKSPACE\UIArtifacts\unit-tests-lcov.info"           
$text = (Get-Content -Path $file3 -ReadCount 0) -join "`n"  
$ran = $text -Includes 'SF'                                  
Get-PathCanonicalCase($text) | Set-Content -Path $file3    

A part of the input file looks like: I need to pass the file paths to the Get-Canonical function. PS. Part of the file paths is the environment variable.

TN:
c:\sysapps\hudson\.jenkins\jobs\CropObsUi-Metrics\workspace\encirca\encConf.js
FNF:0
FNH:0
DA:10,1
DA:14,1
DA:30,1
DA:31,1
DA:32,1
DA:33,1
DA:34,1
DA:35,1
DA:36,1
DA:37,1
DA:39,1
LF:11
LH:11
BRF:0
BRH:0
end_of_record
TN:
c:\sysapps\hudson\.jenkins\jobs\CropObsUi-Metrics\workspace\encirca\common\util\data.js
FN:25,(anonymous_1)
FN:57,(anonymous_2)
FN:87,(anonymous_3)
FN:149,(anonymous_4)
FNF:4
FNH:0
FNDA:0,(anonymous_1)
FNDA:0,(anonymous_2)
FNDA:0,(anonymous_3)
FNDA:0,(anonymous_4)

Answer 1

Ok, short list of issues. I see no reason for the -join command. Normally the Get-Content cmdlet will read a text file in as an array of strings, with each line being one string. When you join them it is then converted to one multi-line string. That is totally opposed to your purposes.

$text = Get-Content -Path $file3

You can filter the lines using a Where statement, and the -like operator.

$ran = $text | Where{$_ -like "SF*"}

When you call a function the correct format is normally:

FunctionName -Parameter Value [-AdditionalParameters AdditionalValues]

You can leave out the parameter names and just put the values in order in most cases. So your last line should be:

Get-PathCanonicalCase $ran | Set-Content -Path $file3

That would only output the lines that started with SF though, and I'm not sure how that's going to work since I don't think a path is going to start with SF. I have a feeling that there is more to the line, and this is not going to deal with your problem like you expect it to. That function expects the string that is passed to it to be a path, and only a path. It does not expect to have to parse a path out of a longer string.

OK to pass to the function:

c:\temp\somefile.csv

Not OK to pass to the function:

SF: c:\temp\somefile.csv <8,732 KB> 11/3/2015 08:16:32.6635

I have no idea what your lines look like in your file, so I just randomly made that up, but the point is that the function is not going to work if your path is a substring of what you are passing to the function. I think you are going to need some additional logic to make this work.

But, this does answer your question as to how to pass each line of the file that starts with SF to the function.

Edit2: Ok, I think you were probably better off before you remove the SF: from the lines with a path in them. Here's why... SF: makes it easy to know what lines need to be passed to the function, while the others can be simply passed through. Trimming the "SF: " off the beginning is easy. So, we're going to use RegEx to replace the path with the updated path that the function provides. We're going to use the 'SF: ' to figure out where the paths are. Here we go...

First import the file just like you were, but don't -join it (explained above).

$text = Get-Content -Path $file3

Then we're going to skip the whole $ran = bit, because there's no need for it. Instead we pipe $text into a ForEach loop, and in that loop look at the line. If the line starts with SF: we replace it with "SF:" followed by the output of the function. For the function we send it a substring starting at the 4th character for the current line, so it skips the 'SF:' and only gets the path. If it isn't a SF: line we simply output the line unchanged.

$text |%{If($_ -like "SF:*"){"SF:$(Get-PathCanonicalCase $_.substring(3))"}else{$_}} | Out-File $file3