Mocha vs RSpec

Free and open source

Free and open source

Free and open source. You pay in engineering time and CI minutes.

Free and open source. You pay in engineering time and CI minutes.

Everything, self-hosted

Everything, self-hosted

Widely used

OpenJS Foundation · since 2011

Widely used

RSpec Team · since 2005

• Small, stable and predictable — it does one job and has done it the same way for years.
• Pick your own assertions, mocks and coverage rather than accepting a bundle.
• Excellent async and reporter support.

• The output reads as documentation of intended behaviour.
• Shared examples and contexts keep large Rails suites organised.
• Deep integration with the Rails ecosystem — Capybara, FactoryBot, VCR.

• No built-in mocking, snapshots, coverage or parallel-by-default execution.
• Assembling and documenting the stack is work every new project repeats.
• Fewer new projects adopt it; momentum sits with Vitest and Jest.

• Deeply nested contexts with let and before hooks become very hard to follow.
• The DSL is a language of its own to learn.
• Rails suites tend towards slowness; expect to invest in parallelisation.

Node.js services where you want explicit control over every part of the test stack.

Ruby and Rails applications.