Commands index page comparison to Commands in dbatools module (cmdlet and function)

Find-MissingCommands.ps1

function Find-MissingCommands {
    <#
    .SYNOPSIS
    Find missing commands between the dbatools.io/commands and dbatools Module public functions

    .PARAMETER ModulePath
    Path to dbatools local repository

    .PARAMETER CommandPagePath
    Full path to the index.html commands page (e.g. c:\git\web\commands\index.html)

    .PARAMETER Reverse
    Compare commands found in the CommandPagePath to those in the module

    .EXAMPLE
    Find-MissingCommands

    Returns string list of the commands not found in the Commands page.
    #>
    [cmdletbinding()]
    param(
        [string]
        $ModulePath = 'C:\git\dbatools',

        [string]
        $CommandPagePath = 'C:\git\web\commands\index.html',

        [switch]
        $Reverse
    )
    $commandPage = Get-Content $CommandPagePath

    if (-not (Get-Module dbatools)) {
        Import-Module $ModulePath
    }
    $commands = Get-Command -Module dbatools -CommandType Cmdlet, Function | Where-Object Name -NotIn 'Where-DbaObject','New-DbaTeppCompletionResult' | Select-Object -Expand Name

    if ($Reverse) {
        $commandRefs = $commandPage | Select-String '<a href="http://docs.dbatools.io/' | ForEach-Object { $_.ToString().Trim() }
        $commandRefList = foreach ($ref in $commandRefs) {
            $ref.ToString().SubString(0,$ref.ToString().IndexOf('">')).TrimStart('<a href="http://docs.dbatools.io/')
        }
        $commandRefList | Where-Object { $_ -notin $commands }
    } else {
        #find missing
        $notFound = $commands | ForEach-Object -ThrottleLimit 10 -Parallel { $foundIt = $using:commandPage | Select-String -Pattern $_; if (-not $foundIt) { $_ } }

        # found
        $found = $commands | ForEach-Object -ThrottleLimit 10 -Parallel { $foundIt = $using:commandPage | Select-String -Pattern $_; if ($foundIt) { $_ } }

        Write-Host "Tally: Total Commands ($($commands.Count)) | Found ($($found.Count)) | Missing ($($notFound.Count))"
        $notFound
    }
}

I think this function should work as expected now. I would just recommend verifying that the returns look correct.

 function Find-MissingCommands {
    <#
    .SYNOPSIS
    Find missing commands between the dbatools.io/commands and dbatools Module public functions
    .PARAMETER ModulePath
    Path to dbatools local repository
    .PARAMETER CommandPage
    Full path to the index.html commands page (e.g. c:\git\web\commands\index.html)
    .EXAMPLE
    Find-MissingCommands
    Returns string list of the commands not found in the Commands page.
    #>
    [cmdletbinding()]
    param(
        [string]
        $ModulePath = 'E:\Development\Powershell\dbatools',

        [string]
        $CommandPage = 'E:\Development\Powershell\web\commands\index.html',

        [Switch]
        $Reverse
    )
    # Changed to $CommandPageContent because $CommandPage is statically typed to [String] which breaks the code. 
    $CommandPageContent = Get-Content $CommandPage

    if (-not (Get-Module dbatools)) {
        Import-Module $ModulePath
    }
    $commands = Get-Command -Module dbatools -CommandType Cmdlet, Function | Where-Object Name -NotIn 'Where-DbaObject', 'New-DbaTeppCompletionResult' | Select-Object -Expand Name

    If ($Reverse) {
        # This takes advantage of Select-String returning a MatchInfo object and allows us to extract that information directly using Regex Capture groups.
        # The pattern is as follows.
            # Capture anything that might exist before <a href ....
            # Capture <a href...
            # Capture 0 or more any characters, as few as possible (lazy quantifier) until
            # Capture "> literals
            # Capture 0 or more any characters, as few as possible (lazy quantifier) but record the group, until
            # Capture literal </a>
        $commandRefList = $CommandPageContent | Select-String -Pattern '.*<a href="http://docs.dbatools.io/.*?">(.*?)</a>' | ForEach-Object {$_.Matches[0].Groups[1].Value}
        $commandRefList | Where-Object { $_ -notin $commands }
    }
    else {
        #find missing
        $notFound = $commands | ForEach-Object -ThrottleLimit 10 -Parallel { $foundIt = $using:commandPage | Select-String -Pattern $_; if (-not $foundIt) { $_ } }

        # found
        $found = $commands | ForEach-Object -ThrottleLimit 10 -Parallel { $foundIt = $using:commandPage | Select-String -Pattern $_; if ($foundIt) { $_ } }

        Write-Host "Tally: Total Commands ($($commands.Count)) | Found ($($found.Count)) | Missing ($($notFound.Count))"
        $notFound
    }
}

That change truncates the command names found in the index:

I've updated Gist with the current version that returns the expected content: