PowerShell Pester — Lesson 2: Assertions and Function Testing

Learning Objectives

• Use Should assertions for values, collections, errors, files, and types
• Test parameters, pipeline input, output, and edge cases
• Create positive, negative, boundary, and failure tests

Detailed Topics

• Use Should assertions for values: Use Should assertions for values, collections, errors, files, and types
• Test parameters: Test parameters, pipeline input, output, and edge cases
• Create positive: Create positive, negative, boundary, and failure tests

Guided Demonstration

1. Review the requirement, environment, dependencies, roles, risks, and expected outcome.
2. Demonstrate the relevant configuration, analysis, code, or administration workflow step by step.
3. Capture settings, outputs, logs, screenshots, calculations, or test evidence.
4. Compare the observed result with the stated acceptance criteria.

Hands-On Activity

Develop comprehensive tests for a parameterized PowerShell function.

• Document assumptions and the planned sequence before making changes.
• Complete the activity and preserve evidence of normal and exception behavior.
• Record issues, corrective actions, and reusable operational or development notes.

Troubleshooting Focus

• Separate symptoms from causes and collect evidence before applying a fix.
• Check configuration, permissions, data, dependencies, capacity, connectivity, and recent changes.
• Validate rollback, recovery, support ownership, and user or business impact.

Validation Checklist

• The requirement and expected outcome are clear.
• The selected configuration, design, query, code, or process is documented.
• Normal, boundary, failure, security, and operational conditions are reviewed.
• The result is supported by evidence and the next improvement is prioritized.

Lesson Outcome

Learners can explain and apply Assertions and Function Testing in a realistic scenario and validate the result with documented evidence.