# pester/Pester

Pester is the ubiquitous test and mock framework for PowerShell.

Repository: https://github.com/pester/Pester
Canonical: https://ross.abutalabs.com/products/pester
Homepage: https://pester.dev/
Language: PowerShell
License: NOASSERTION
License Family: other
Topics: powershell, pester-tests, powershell-tests, assertions, mocking, mock, testing, tdd, bdd, tdd-framework, bdd-framework
Last push: 2026-08-25T17:32:58+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 97, longevity 100
- inputs: {"age_days": 5722, "days_push": 8, "days_rel": 22, "gap_med": 6, "n_releases_24m": 8}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3326, forks 478 (observed 2026-08-28T04:07:56.446549+00:00)

## What it is
Pester is the ubiquitous test and mock framework for PowerShell, providing a Describe/Context/It DSL with Should assertions and powerful command mocking. It supports unit and integration testing, code coverage, and test result reporting for CI pipelines.

## Use cases
- write unit tests for powershell functions
- mock cmdlets in powershell tests
- run powershell tests in ci pipeline
- measure code coverage of powershell module
- test infrastructure and deployment configurations
- bdd-style testing in powershell
- assert powershell script output

## When to choose
- you are writing or maintaining PowerShell modules or scripts and need automated tests
- you need mocking of PowerShell commands without dependency injection
- you want code coverage and test result artifacts for CI pipelines

## When to avoid
- you are testing code in languages other than PowerShell
- you need a general-purpose test runner outside the PowerShell ecosystem

## Facets
- artifact type: library
- maturity: active
- function: testing, mocking, e2e-testing, benchmarking
- domain: testing, developer-tools
- platform: windows, cross-platform, cli
- tags: powershell, bdd, tdd, assertions, code-coverage, unit-testing, ci-integration, automation, devops, linux, macos

## Member repositories
- pester/Pester (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:56.446549+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:41:47.149400+00:00, confidence not recorded.
  - readme: https://github.com/pester/Pester (fetched 2026-08-28T04:07:56.446549+00:00, sha 079c594992d2)
  - homepage: https://pester.dev/ (fetched 2026-08-29T09:34:47.246108+00:00, sha 5820bcd4437e)
  - site_page: https://pester.dev/docs/quick-start (fetched 2026-08-29T09:34:47.255339+00:00, sha 6c3cacf956e4)
  - site_page: https://pester.dev/docs/commands/Add-ShouldOperator (fetched 2026-08-29T09:34:47.257727+00:00, sha 81bdca5e3658)
  - site_page: https://pester.dev/docs/introduction/installation (fetched 2026-08-29T09:34:47.259403+00:00, sha af2fd8762d5f)
- Data as of 2026-08-30T08:39:29.467469+00:00.