fix(tests): move Pester pin to 6.0.1 and allow empty -ForEach collections

[tablackburn]

Why

Two problems, found and fixed first in PlexAutomationToolkit. Both were triggered by a GitHub-hosted runner image change, not by any commit — the images now ship Pester 6.0.1.

Problem A — Pester 5 pin collides with Pester 6 on the runner

PSDepend imports the pinned Pester 5.7.1, then PowerShellBuild's Test-PSBuildPester runs Import-Module Pester -MinimumVersion 5.0.0, which resolves to the highest installed version (6.0.1 from the runner image) and collides with the already-loaded 5.7.1 DLL:

Exception: An incompatible version of the Pester.dll assembly is already loaded.
The loaded dll version is 5.7.1.0, but at least version 6.0.1 is required

Problem B — empty -ForEach kills whole test files, silently

Applying the fix for A is what exposes B, so they ship together.

Pester 6 throws on a null/empty -ForEach by default (Run.FailOnNullOrEmptyForEach); Pester 5 quietly generated zero tests. The throw happens during discovery, so Pester fails the entire container (the whole file). A failed container does not increment FailedCount, and Test-PSBuildPester only throws on FailedCount — so the build passes while that file's tests never run.

What changed

• build.depend.psd1 — Pester pin 5.7.1 → 6.0.1
• tests/Help.tests.ps1 — -AllowNullOrEmptyForEach on $helpLinks, $commandParameters, $helpParameterNames
• tests/Manifest.tests.ps1 — -AllowNullOrEmptyForEach on $dependencies

Each of these is legitimately empty in a default module: no command declares an http(s) .LINK, a command may declare only common parameters, and RequiredModules is commented out by default.

Describe "Test help for <_.Name>" -ForEach $commands is deliberately left strict — an empty command list means the module failed to import and should fail loudly.

Verification

This repo's own CI never exercises these tests — CI.yaml gates Build and Test behind template_guard, which trips on the presence of CHANGELOG.template.md. So it was verified by rendering the template and running the real task:

./Initialize-Template.ps1 -ModuleName AuditProbe -Prefix Ap ... -NoGitInit -NoBootstrap
./build.ps1 -Task Test

	Tests Passed	Containers failed
before (Pester 6.0.1)	27	2 — Help.tests.ps1, Manifest.tests.ps1
after (Pester 6.0.1)	30	0

Before the fix, discovery aborted at Help.tests.ps1:164 and Manifest.tests.ps1:211 — the exact lines changed here.

No CHANGELOG.md entry: this is not user-facing.

🤖 Generated with Claude Code

https://claude.ai/code/session_015fsEPNYeL5LKdWLDNdv3T6

Summary by CodeRabbit

• Bug Fixes

  • Improved automated validation for modules with empty or missing help links, parameters, and dependency collections.
  • Prevented test discovery failures caused by empty test inputs.

• Tests

  • Updated test compatibility with the latest testing framework version.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: b10d0118-a38f-4768-9daf-7d1c4c1aa380

📥 Commits

Reviewing files that changed from the base of the PR and between d0f1ad8 and e9796f9.

📒 Files selected for processing (3)

• build.depend.psd1
• tests/Help.tests.ps1
• tests/Manifest.tests.ps1

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📝 Walkthrough

Walkthrough

The build dependency changes from Pester 5.7.1 to 6.0.1. Help and manifest tests now allow null or empty collections during -ForEach expansion.

Changes

Pester compatibility

Layer / File(s)	Summary
Pester dependency and test iteration updates build.depend.psd1, tests/Help.tests.ps1, tests/Manifest.tests.ps1	The build uses Pester 6.0.1. Test contexts permit null or empty collections during iteration. Test bodies and validation logic remain unchanged.

Estimated code review effort: 1 (Trivial) | ~5 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the Pester version update and the test changes for empty -ForEach collections.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/pester-6-empty-foreach

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[Copilot]

Pull request overview

This PR updates the template’s test toolchain to align with GitHub-hosted runner images that now ship Pester 6.0.1, and adjusts a few Pester -ForEach blocks so that legitimate empty collections no longer abort test discovery (silently skipping entire files).

Changes:

• Bump the build-time Pester dependency pin from 5.7.1 to 6.0.1.
• Add -AllowNullOrEmptyForEach to specific It/Context blocks in Help.tests.ps1 where empty collections are valid in a default template.
• Add -AllowNullOrEmptyForEach to the manifest dependency Context in Manifest.tests.ps1 where RequiredModules may be empty by default.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
build.depend.psd1	Pins Pester to 6.0.1 to avoid runner-provided Pester 6 colliding with a pinned Pester 5 in-session.
tests/Help.tests.ps1	Prevents discovery-time failures when .LINK entries or filtered parameter lists are empty by allowing empty -ForEach.
tests/Manifest.tests.ps1	Prevents discovery-time failure when RequiredModules is empty by allowing empty -ForEach for dependency checks.

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