Calling a local function from a dot sourced file - powershell

Question

I have a main script that I am running. What it does is read through a directory filled with other powershell scripts, dot includes them all and runs a predefined method in each made up of the first portion of the dot delimited file name. Example:
Run master.ps1
Master.ps1 dot sources .\resource\sub.ps1
Sub.ps1 has defined a function called 'dosub'
Master.ps1 runs 'dosub' using Invoke-Expression
Also defined in sub.ps1 is the function 'saysomething'. Implemented in'dosub' is a call to 'saysomething'.
My problem is I keep getting the error:
The term 'saysomething' is not recognized as the name of a cmdlet,
function, script file, or operable program. Check the spelling of the
name, or if a path was included, verify that the path is correct and
try again.
Why can't the method 'dosub' find the method 'saysomething' which is defined in the same file?
master.ps1:
$handlersDir = "handlers"
$handlers = #(Get-ChildItem $handlersDir)
foreach ( $handler in $handlers ) {
. .\$handlersDir\$handler
$fnParts = $handler.Name.split(".")
$exp = "do" + $fnParts[0]
Invoke-Expression $exp
}
sub.ps1:
function saysomething() {
Write-Host "I'm here to say something!"
}
function dosub() {
saysomething
Write-Host "In dosub!"
}

Answer 1

Your code works on my system. However you can simplify it a bit:
$handlersDir = "handlers"
$handlers = #(Get-ChildItem $handlersDir)
foreach ( $handler in $handlers )
{
. .\$handlersDir\$handler
$exp = "do" + $handler.BaseName
Write-Host "Calling $exp"
& $exp
}
Note the availability of the BaseName property. You also don't need to use Invoke-Expression. You can just call the named command ysing the call (&) operator.

Answer 2

What you have given works as needed. You probably don't have the directories etc proper on your machine. Or you are running something else and posting a different ( working!) code here.
You can also make following corrections:
. .\$handlersDir\$handler
instead of above you can do:
. $handler.fullname
Instead the splitting of the filename you can do:
$exp = "do" + $handler.basename