Reusing or sharing tasks about invoke-build

[pwm1234-sri]

Thank you for your detailed answer!
At the moment as I am just getting started, my needs are rather simple, so I will use imported tasks.
If my needs grow (and my powershell scripting skills improve) I will move to a module.

[nightroman]

Here is the most straightforward and idiomatic way (but not always best, see next comment).

(1) Compose your shared tasks in a separate script, example: Shared.tasks.ps1

Invoke-Build/Tests/Shared.tasks.ps1

Lines 11 to 19 in 545f37f

	# Synopsis: Just writes a string.
	task SharedTask1 {
	'In SharedTask1'
	}
	# Synopsis: Calls SharedTask1 and writes another string.
	task SharedTask2 SharedTask1, {
	'In SharedTask2'
	}

(2) Import tasks into a build script. Two ways.

(2.1) If the task script contains just tasks with no script scope variables
(e.g. SharedTask1, SharedTask2) then simply invoke the task script from
a build script:

Invoke-Build/Tests/.build.ps1

Lines 40 to 42 in 0151787

	# In order to import more tasks, simply invoke a script with them.
	# *.tasks.ps1 files play the same role as MSBuild *.targets files.
	.\Shared.tasks.ps1

(2.2) If shared tasks use script scope variables (e.g. Sleep uses
$SleepMilliseconds) then dot-source the task script:

. .\Shared.tasks.ps1 5000

Granted, this is not a typical example, the variable is also a parameter.
Dot-sourcing is needed if a task file declares and assigns script variables.
If you just invoke (&) such a script then variables are gone after the call.
But if you invoke by . then variables get into and stay in the calling scope.

One way or another, by invoking the task script from a build script, you get
the shared tasks added (note that task is just an alias of Add-BuildTask)
to other tasks defined (added) in the build script.

Another existing example

Task script: https://github.com/nightroman/FarNet/blob/master/FarNet/FarNet.tasks.ps1

This task script is imported into (invoked from) several build scripts:

• https://github.com/nightroman/FarNet/blob/master/FarNet/FarNet.Tools/.build.ps1
• https://github.com/nightroman/FarNet/blob/master/FarNet/FarNet.Works.Config/.build.ps1
• a few more projects

https://github.com/nightroman/Invoke-Build/tree/master/Tasks/Import
Note that in this example actual build scripts are almost "empty", they all
basically consists of the imported tasks. But they use different environments
(script variables).

(Update)

Another example, including tasks in modules

https://github.com/nightroman/Invoke-Build/tree/master/Tasks/Import

[nightroman]

Or is the right way to put the reusable logic into a function in a script or module that is imported in a typical powershell way?

This is another absolutely right way. You share the usual PowerShell functions / scripts / modules that run some actions. Then you call them from build script tasks. Tasks are just thin wrappers of that calls.

Which way to use? You decide which is better in a particular case. I use both and kind of prefer imported tasks in relatively simple cases, when tasks do not require parameters / script variables or use just a few of them.

With many parameters / variables, especially different for different tasks, the shared tasks are less attractive, more messy. Then I use shared functions / scripts / modules and call them from thin tasks.

[nightroman]

Oh, I completely forgot :) There is the whole article about this, with examples, including shared tasks in modules.
https://github.com/nightroman/Invoke-Build/tree/master/Tasks/Import

[pwm1234-sri]

Thank you! Now that I am understanding invoke-build a little better, I believe there are a number of goodies in the Tasks folder that I should study. Thanks again!!!