functions/Remove-DbaAgentJob.ps1

function Remove-DbaAgentJob {
    <#
        .SYNOPSIS
            Remove-DbaAgentJob removes a job.
 
        .DESCRIPTION
            Remove-DbaAgentJob removes a a job in the SQL Server Agent.
 
        .PARAMETER SqlInstance
            The SQL Server instance. Server version must be SQL Server version 2012 or higher.
 
        .PARAMETER SqlCredential
            Allows you to login to servers using SQL Logins instead of Windows Authentication (AKA Integrated or Trusted).
         
        .PARAMETER Job
            The name of the job. Can be null if the the job id is being used.
 
        .PARAMETER KeepHistory
            Specifies to keep the history for the job. By default is history is deleted.
 
        .PARAMETER KeepUnusedSchedule
            Specifies to keep the schedules attached to this job if they are not attached to any other job.
            By default the unused schedule is deleted.
 
        .PARAMETER WhatIf
            If this switch is enabled, no actions are performed but informational messages will be displayed that explain what would happen if the command were to run.
 
        .PARAMETER Confirm
            If this switch is enabled, you will be prompted for confirmation before executing any operations that change state.
 
        .PARAMETER Silent
            If this switch is enabled, the internal messaging functions will be silenced.
 
        .NOTES
            Original Author: Sander Stad (@sqlstad, sqlstad.nl)
            Tags: Agent, Job
                 
            Website: https://dbatools.io
            Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
            License: GNU GPL v3 https://opensource.org/licenses/GPL-3.0
 
        .LINK
            https://dbatools.io/Remove-DbaAgentJob
 
        .EXAMPLE
            Remove-DbaAgentJob -SqlInstance sql1 -Job Job1
 
            Removes the job from the instance with the name Job1.
 
        .EXAMPLE
            Remove-DbaAgentJob -SqlInstance sql1 -Job Job1 -KeepHistory
 
            Removes the job but keeps the history.
 
        .EXAMPLE
            Remove-DbaAgentJob -SqlInstance sql1 -Job Job1 -KeepUnusedSchedule
 
            Removes the job but keeps the unused schedules.
 
        .EXAMPLE
            Remove-DbaAgentJob -SqlInstance sql1, sql2, sql3 -Job Job1
 
            Removes the job from multiple servers.
 
        .EXAMPLE
            sql1, sql2, sql3 | Remove-DbaAgentJob -Job Job1
 
            Removes the job from multiple servers using pipe line
 
    #>

    [CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = "Low")]

    param(
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [Alias("ServerInstance", "SqlServer")]
        [object[]]$SqlInstance,

        [Parameter(Mandatory = $false)]
        [PSCredential]$SqlCredential,
        
        [Parameter(Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [object[]]$Job,
        
        [Parameter(Mandatory = $false)]
        [switch]$KeepHistory,
        
        [Parameter(Mandatory = $false)]
        [switch]$KeepUnusedSchedule,
        
        [Parameter(Mandatory = $false)]
        [switch]$Silent
    )

    process {

        foreach ($instance in $sqlinstance) {

            # Try connecting to the instance
            Write-Message -Message "Attempting to connect to $instance" -Level Verbose
            try {
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }
        
            foreach ($j in $Job) {

                # Check if the job exists
                if ($Server.JobServer.Jobs.Name -notcontains $j) {
                    Write-Message -Message "Job $j doesn't exists on $instance" -Warning
                }
                else {   
                    # Get the job
                    try {
                        $currentjob = $Server.JobServer.Jobs[$j] 
                    }
                    catch {
                        Stop-Function -Message "Something went wrong creating the job. `n$($_.Exception.Message)" -Target $instance -Continue
                    }

                    # Delete the history
                    if (-not $KeepHistory) {
                        Write-Message -Message "Purging job history" -Level Verbose
                        $currentjob.PurgeHistory()
                    }

                    # Execute
                    if ($PSCmdlet.ShouldProcess($instance, "Removing the job on $instance")) {
                        try {
                            Write-Message -Message "Removing the job" -Level Output

                            if ($KeepUnusedSchedule) {
                                # Drop the job keeping the unused schedules
                                Write-Message -Message "Removing job keeping unused schedules" -Level Verbose
                                $currentjob.Drop($true) 
                            }
                            else {
                                # Drop the job removing the unused schedules
                                Write-Message -Message "Removing job removing unused schedules" -Level Verbose
                                $currentjob.Drop($false) 
                            }
                    
                        }
                        catch {
                            Stop-Function -Message  "Something went wrong removing the job. `n$($_.Exception.Message)" -Target $instance -Continue
                        }
                    } 
                }

            } # foreach object job
        } # forech object instance
    } # process

    end {
        Write-Message -Message "Finished removing jobs(s)." -Level Output
    }
}