Testing for Breaking Changes in Fastify APIs

This page summarizes the projects mentioned and recommended in the original post on dev.to

SurveyJS - JavaScript Form Builder with No-Code UI & Built-In JSON Schema Editor
Keep full control over the data you collect and tailor the form builder’s entire look and feel to your users’ needs. SurveyJS works with React, Angular, Vue 3, and is compatible with any backend or auth system. Learn more.
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Stream - Scalable APIs for Chat, Feeds, Moderation, & Video.
Stream helps developers build engaging apps that scale to millions with performant and flexible Chat, Feeds, Moderation, and Video APIs and SDKs powered by a global edge network and enterprise-grade infrastructure.
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  1. Optic

    OpenAPI linting, diffing and testing. Optic helps prevent breaking changes, publish accurate documentation and improve the design of your APIs.

    Recently I was approached by a team that needed help testing their Fastify API for breaking changes. Fastify was making it easy to quickly ship a lot of new functionality, but breaking changes were making it through Code Reviews. They were not finding out the changes were breaking until a consumer emailed them — not good. The developer who reached out saw my work on the Optic project and asked for help.

  2. SurveyJS

    JavaScript Form Builder with No-Code UI & Built-In JSON Schema Editor. Keep full control over the data you collect and tailor the form builder’s entire look and feel to your users’ needs. SurveyJS works with React, Angular, Vue 3, and is compatible with any backend or auth system. Learn more.

    SurveyJS logo
  3. fastify-swagger

    Swagger documentation generator for Fastify

    First let’s get our current OpenAPI specification out of Fastify and onto the file system. If you have not added the https://github.com/fastify/fastify-swagger plugin first go do that. Then use this simple script I called generate-spec.ts to write your OpenAPI specification to the filesystem.

  4. openapi-diff

    Utility for comparing two OpenAPI specifications.

    Now that we have a way to lookup our API’s behavior with Git, we can start testing for breaking changes between versions of our API. We’ll be using Optic (an open source tool I created) to do just that. If you are looking for other options I recommend https://github.com/OpenAPITools/openapi-diff or https://github.com/Tufin/oasdiff.

  5. oasdiff

    OpenAPI Diff and Breaking Changes

    Now that we have a way to lookup our API’s behavior with Git, we can start testing for breaking changes between versions of our API. We’ll be using Optic (an open source tool I created) to do just that. If you are looking for other options I recommend https://github.com/OpenAPITools/openapi-diff or https://github.com/Tufin/oasdiff.

NOTE: The number of mentions on this list indicates mentions on common posts plus user suggested alternatives. Hence, a higher number means a more popular project.

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