Parameter Swap

parameter-swap is a go/analysis-based tool that identifies mismatches between named arguments and named function parameters. This may be legit, but is often a cause for concern.

Example messages

Given the following source code example.go:

     1  package example
     2
     3  func foo(one, two int) int {
     4      return one + two
     5  }
     6
     7  func main() {
     8      one, two := 1, 2
     9      foo(two, one)
    10  }

parameter-swap will report the following:

$ parameter-swap ./...
.../example.go:9:6: passes 'two' as 'one' in call to func foo(one int, two int) int (position 0 vs 1)
.../example.go:9:11: passes 'one' as 'two' in call to func foo(one int, two int) int (position 1 vs 0)
exit status 3

Usage

Run from source with go run github.com/mutility/parameter-swap@latest or install with go install github.com/mutility/parameter-swap@latest and run parameter-swap from GOPATH/bin.

You can configure behvior at the command line by passing the flags below, or in library use by setting fields on pswap.Analyzer().

Flag	Field	Meaning
-exact	ExactTypeOnly	Suppress reports of mismatched parameters of mismatching types
-gen	IncludeGeneratedFiles	Include reports from generated files

Bug reports and feature contributions

parameter-swap is developed in spare time, so while bug reports and feature contributions are welcomed, it may take a while for them to be reviewed. If possible, try to find a minimal reproduction before reporting a bug. Bugs that are difficult or impossible to reproduce will likely be closed.

All bug fixes will include tests to help ensure no regression; correspondingly all contributions should include such tests.

Mutility Analyzers

parameter-swap is part of mutility-analyzers.