CONTINUAL INTEGRATION

Part 1
Problem scenario:  You have a PowerShell function that should add two parameter numbers and display their sum.  It is displaying the input when it should not.  No sum is being displayed.  There are no error messages. What should you do?
Solution:  Your code may look like this:

function contint ($a, $b) {
    $c = $a + $b
    return $c}

$d = contint (5, 2)
echo $d

The solution is to change the "$d = contint" line to be like this:
$d = contint 5 2
#With just spaces between the function name and its positional parameters, the PowerShell function will be invoked properly.

Part 2
Problem scenario:  You have a PowerShell function that is not working.  When you run the script that invokes it, you get an error like this:

"Select-String : Cannot bind argument to parameter 'Pattern' because it is null.
At C:\temp\contint1.ps1:2 char:34
+     $ca = cat $a | select-string $b
+                                  ~~
    + CategoryInfo          : InvalidData: (:) [Select-String], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.SelectStr
   ingCommand"

Here is the function in the script:
function contint ($a, $b) {
    $ca = cat $a | select-string $b
    return $c}

$d = contint ('C:\temp\foo.txt', 'alphaString')
echo $d

Solution:  The solution is to call the function without parentheses and without the comma like this:
function contint ($a, $b) {
    $ca = cat $a | select-string $b
    return $ca}

$d = contint 'C:\temp\foo.txt' 'alphaString'
echo $d
#  The single quotes on the string arguments are optional. 
# There can be no commas between the arguments when calling the function.

Goal:  To use a diskpart.exe script (a file of commands that could be ran interactively in sequence).
Problem:  When you run this command via PowerShell it does not work:  diskpart /s C:\Full\Path\script.txt
The result says something like "Microsoft DiskPart ..." and there is a list of alphabetic diskpart subcommands (ACTIVE to RECOVER).  There is no explicit error.  The diskpart command and script does no work.
Background:  When a PowerShell redirect (>) command is used to save a file, the default encoding is usually Unicode.  This encoding will not work for a diskpart script file (e.g., a .txt file of commands that could run interactively in sequence once diskpart is entered). 
Solution:  To resolve this, open the script, go to Save As, change the "Encoding" from "Unicode" to "ANSI."  Alternatively, if the diskpart script you are using is generated via PowerShell on an ongoing basis, use the Out-File and Encoding flags to designate the file to be ASCII.