ifacecapture

README

ifacecapture

Go linter that tries to find possibly unintentional usage of captured variables implementing an inner-scoped parameter's interface.

This linter was originally designed to try and find mistakes like the following in code implementing database transactions:

type Database interface {
    Transaction(tx Database)
    DoQuery()
}

func doDatabaseStuff(db Database) {
    db.Transaction(func(tx Database) { // tx is a transaction handle
        db.DoQuery() 
        // the programmer probably meant to use the transaction handle "tx", but
        // accidentally used the outer scope variable "db"
    })
}

It searches for functions taking a callback, which itself takes one or parameters which are of some interface type. It then searches for captures of outer scope variables which implement that interface.

This linter may help you find similar patterns, where you have a callback function intended to aid safe usage of an interface. Unintentional captures of an outer scope variable that also implements that interface often means that there was a mistake.

How to test

go test ./... -cover -race

How to release

You can build releases for all platforms with GoReleaser:

rm -rf ./dist
goreleaser build

To do a release using CI:

1. Tag a commit on the main branch (should be tagged according to semver). git tag v0.x.x.
2. Push tags to GitHub. git push --tags

TODO:

• More tests
• Check multiple interface parameters
• Cleaner code
• Configurability