Testing#

Practice: Pester tests for every function. Files named *.Tests.ps1. Structure: Describe → Context → It. Use BeforeAll/AfterAll for setup.

Why: Tests are the executable specification (TDD). They catch regressions before production (Shift Left) and give contributors confidence to refactor. Consistent naming lets CI, pre-commit hooks, and editors discover tests automatically (Testable locally, Validatable in PRs).

How:

# Good
Describe 'Get-UserAccount' {
    Context 'When user exists' {
        It 'Should return user object' {
            $result = Get-UserAccount -UserId '123'
            $result | Should -Not -BeNullOrEmpty
            $result.UserId | Should -Be '123'
        }
    }

    Context 'When user does not exist' {
        It 'Should throw' {
            { Get-UserAccount -UserId '999' } | Should -Throw
        }
    }
}