GitHub - psapezhka/replacer: Replacer is a go generator to find-and-replace in go source files

Replacer

Replacer is a Go code generator that applies regex-based transformations to your source files. It is designed to work with Go's //go:generate directive, allowing you to automate repetitive code modifications.

Why?

I often need to repeat the same set of comments in my Go code. For example, I use swaggo to generate Swagger documentation for an API. My API endpoints always return the same headers, like X-API-Version or X-Request-ID. Unfortunately, there's no way to define common headers for all endpoints yet. Instead of manually copying and pasting these headers every time, I created replacer to automate this process. Now, I can simply write:

run go generate, which is a part of my build pipeline, and get:

// @Header       all {string} X-Request-ID "UUID of the request"
// @Header       all {string} X-API-Version "API version, e.g. v1alpha"
// @Header       all {int} X-Ratelimit-Limit "Rate limit value"
// @Header       all {int} X-Ratelimit-Remaining "Rate limit remaining"
// @Header       all {int} X-Ratelimit-Reset "Rate limit reset interval in seconds"

Why not use sed or awk?

In short, it's hard to maintain when you have a lot of transformations, rules look more complicated. Also, there is a huge issues with multi-platform support. Even, unix-like macos and linux have different versions of sed and awk.

IDE's snippets?

IDE's snippets are great, but it's hard to maintain them in a team. Also, it's hard to share them between different IDE's.

Features

• Full-featured regex (docs), including expands
• Automatically searches for a configuration file (.replacer.yml or .replacer.yaml) in the current directory and parent directories.
• Stops searching at the root directory or when a go.mod file is encountered.

Installation

To install replacer, run:

go install github.com/weastur/replacer/@latest

Make sure that $GOPATH/bin is in your $PATH.

Of course, you can also download the binary from the releases page

Usage

1. Create a configuration file (.replacer.yml or .replacer.yaml) in the root of your project or in the directory where you want to run replacer.

   ---
   rules:
   - regex: '(?m)^\/\/ MY RULE$'
     repl: |-
       // MY NEW AWESOME
       // MULTI-LINE REPLACEMENT
   - regex: '(?m)^\/\/ MY 2 RULE$'
     repl: |-
       // REPLACEMENT No2
   - regex: '(?m)^\/\/ (?P<group>\w+) are also work$'
     repl: |-
       // ${group} are great

2. Add a //go:generate directive to your source file. Despite config search mechanism, the transformation rules will be applied only to the file where the directive is placed.

3. Run go generate to apply the transformations.

   Pay attention that generate command will only work if you have the replacer binary in your $PATH.

   Also, the go build command doesn't run go generate automatically. You need to run it manually. Refer to go help generate for more information.

4. Optional Flags:

   • -config - specify the path to the configuration file.

     Example: //go:generate replacer -config my-replacer-config.yml

Configuration file search

If the -config flag is not provided, replacer will search for a configuration file in the following order:

1. The current directory.
2. Parent directories, moving up one level at a time.
3. Stops searching when it reaches the root directory or encounters a go.mod file.

Development

See CONTRIBUTING.md for information on how to contribute to replacer.

tl;dr

# fork/clone the repository
# install go
# put some config in .replacer.yml
task build
task test
GOFILE=my-test-file.go replacer
# commit/push/PR

Project structure

• main - the main command.
• config - handles configuration file parsing and validation.
• generator - applies regex-based transformations to source files.

Security

Refer to the SECURITY.md file for more information.

License

Mozilla Public License 2.0

Refer to the LICENSE file for more information.