quickfix

README

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The goquickfix command quick fixes Go source that is well typed but
Go refuses to compile e.g. "x declared and not used".

== Installation

    go get github.com/motemen/go-quickfix/cmd/goquickfix

== Usage

    goquickfix [-w] [-revert] <path>...

    Flags:
      -revert=false: try to revert possible quickfixes introduced by goquickfix
      -w=false: write result to (source) file instead of stdout

== Description

While coding, sometimes you may write a Go program that is completely well typed
but `go build` (or `run` or `test`) refuses to build, like this:

[source,go]
----
package main

import (
	"fmt"
	"log"
)

func main() {
	nums := []int{3, 1, 4, 1, 5}
	for i, n := range nums {
		fmt.Println(n)
	}
}
----

The Go compiler will complain:

    eg.go:5: imported and not used: "log"

Or

    eg.go:9: i declared and not used

Do we have to bother to comment out the import line or remove
the unused identifier one by one for the Go compiler? Of course no,
`goquickfix` does the work instead of you.

Run

    goquickfix -w eg.go

and you will get the source rewritten so that Go compiles it well without
changing the semantics:

[source,go]
----
package main

import (
	"fmt"
	_ "log"
)

func main() {
	nums := []int{3, 1, 4, 1, 5}
	for i, n := range nums {
		fmt.Println(n)
		_ = i
	}
}
----

Now you can `go run` or `go test` your code safely.

== TODO

* `-d` option to show diffs
* `-hard=true` option to remove erroneous code rather than adding new code

Documentation

Overview

Package quickfix provides functions for fixing Go ASTs that are well typed but "go build" refuses to build.

Index

• func QuickFix(fset *token.FileSet, files []*ast.File) (err error)
• func RevertQuickFix(fset *token.FileSet, files []*ast.File) (err error)
• type ErrCouldNotLocate
  • func (e ErrCouldNotLocate) Error() string
• type ErrorList
  • func (errs ErrorList) Error() string

Functions

func QuickFix

func QuickFix(fset *token.FileSet, files []*ast.File) (err error)

QuickFix rewrites AST files of same package so that they pass go build. For example:

v declared but not used             -> append `_ = v`
"p" imported but not used           -> rewrite to `import _ "p"`
no new variables on left side of := -> rewrite `:=` to `=`

TODO implement hardMode, which removes errorneous code rather than adding

func RevertQuickFix

func RevertQuickFix(fset *token.FileSet, files []*ast.File) (err error)

RevertQuickFix reverts possible quickfixes introduced by QuickFix. This may result to non-buildable source, and cannot reproduce the original code before first QuickFix. For example:

`_ = v`        -> removed
`import _ "p"` -> rewritten to `import "p"`

Types

type ErrCouldNotLocate

type ErrCouldNotLocate struct {
	Err  types.Error
	Fset *token.FileSet
}

func (ErrCouldNotLocate) Error

func (e ErrCouldNotLocate) Error() string

type ErrorList

type ErrorList []error

func (ErrorList) Error

func (errs ErrorList) Error() string