Is there an existing convention for listing powershell modules required for a PowerShell project? An equivalent to Python's requirements.txt or Node's package.json, etc? Run command X to 'Install-Module' all requirements?
PowerShell modules specify their dependencies via their module manifests (*.psd1 files).
It is common for PowerShell modules to be self-contained, i.e. to come bundled with their dependencies.
However, intra-repository dependencies (on other modules) can be specified via the RequiredModules entry, and should be installed automatically when you use the obsolescent Install-Module command or its successor, Install-PSResource - see this answer for more information.
The presence of all dependencies is also enforced at import time, whether or not a given module is loaded explicitly, with Import-Module, or implicitly, via module autoloading.
To list the module and assembly dependencies of a given module (that is either currently loaded or is auto-discoverable, if specified by name only), use:
Get-Module -ListAvailable $someModule |
Select-Object RequiredModules, RequiredAssemblies
Note:
Unlike for dependent modules, there is no mechanism to auto-install dependent assemblies - the latter must be bundled via the module or exist in a well-known location on the system.
For a proposal to make working with NuGet packages (to consume .NET assemblies) easier in PowerShell, see GitHub issue #6724; that said, given that Install-PSResource is now focused on PowerShell resources only, this may never come to fruition.