openapi-preprocessor VS espree

I use a mixed approach for OpenAPI, but not bidirectional.

I have OpenAPI pieces generated from my Go source code (comment, types, function signatures) as JSON.

I also have a manually-edited master YAML document that refers to generated bits via $ref links.

I then use openapi-preprocessor [1] (disclaimer: I wrote it) to produce a final openapi.json file which is committed in the repo.

When I want to extend the API in a spec-first process, I can add the new routes manually in the YAML file. When I do the implementation I replace the manual bits by the generated one when they are ready. When committing I can check the diff of openapi.json to verify I'm not losing in the process.

[1] https://github.com/dolmen-go/openapi-preprocessor

Bundling for OpenAPI specification has long been a need for authors to allow to reduce duplication, and to allow to split a big specification in multiples files, but publish a single one.

A few years ago I've written a tool to fit that niche: https://github.com/dolmen-go/openapi-preprocessor

https://github.com/dolmen-go/openapi-preprocessor

I have now to tweak it (well, it will be a major rewrite) to handle $ref relative to $id instead of the file location.

Focusing again on ESLint, the parser used by the linter is called Espree. This is an in-house parser built by the ESLint folks to fully support ECMAScript 6 and JSX on top of the already existing Esprima. The Espree module provide APIs for both tokenization and parsing that you can easily test out.

Why do we then have other JavaScript parsers like babel parser, swc parser, acorn, espree and the likes since JavaScript engines have their own internal parsers?

How does ESLint work? ESLint uses Espree for Javascript parsing. It uses an AST to evaluate patterns in code. It does all this before runtime.. meaning, without running your Javascript code it will find the bugs, syntax and stylistic errors.

ESLint doesn't process the code into the compiler phases, rather it provides an option to let you specify a Parser. By default, ESLint uses Espree which essentially converts JS source code to AST data structure, so in case you want to write a rule targeting TypeScript source code, you'll need to specify a different parser in your .eslintrc.json configuration file, same applies for different file extension, for HTML you might use this or creating your own parser!