When using go generate, genny does not remove the original go generate comment.

[ammario]

When using go generate, genny does not remove the original go generate comment causing subsequent go generates to fail after a gen-gen-file.go is created. This creates the nuisance of having to manually remove the go generate line in generated files.

[xiegeo]

I don't run in to this problem.
With:

package ...

import (
    "bytes"
    "encoding/binary"
    "github.com/cheekybits/genny/generic"
)

//go:generate genny -in=$GOFILE -out=gen_$GOFILE gen "ValueType=int16,int32,float32"

type ValueType generic.Type

func ...

go generate produces:

// This file was automatically generated by genny.
// Any changes will be lost if this file is regenerated.
// see https://github.com/cheekybits/genny

package ...

import (
    "bytes"
    "encoding/binary"
)

func ...

Can you show a simplified version of your file so others can reproduce it?

[ammario]

This is what I'm using

package util
//go:generate $GOPATH/bin/genny -in=$GOFILE -out=gen-$GOFILE gen "valueType=Thread"


import (
        "sync"

        "github.com/cheekybits/genny/generic"
)

type valueType generic.Type

//valueTypeSlice is a synchronizable slice that supports easy deletion of indices.
type valueTypeSlice struct {
        Slice []valueType
        sync.Mutex
}

//Delete deletes an index from a slice by replacing the value at the end with the last index then reslicing to prune the last element.
//A call to delete must be synchronized via the built in mutex.
//Delete does not check bounds and will panic if index is outside the bounds of the slice.
func (s *valueTypeSlice) Delete(index int) {
        s.Slice[index] = s.Slice[len(s.Slice)-1]
        if len(s.Slice) > 0 {
                s.Slice = s.Slice[:len(s.Slice)-1]
        }

}

go generate (1.6.2) produces

// This file was automatically generated by genny.
// Any changes will be lost if this file is regenerated.
// see https://github.com/cheekybits/genny

package util

import "sync"

//go:generate $GOPATH/bin/genny -in=$GOFILE -out=gen-$GOFILE gen "Thread=Thread"

//ThreadSlice is a synchronizable slice that supports easy deletion of indices.
type ThreadSlice struct {
        Slice []Thread
        sync.Mutex
}

//Delete deletes an index from a slice by replacing the deleted value with the last value of the slice and pruning.
//A call to delete must be synchronized via the built in mutex.
//Delete does not check bounds and will panic if index is outside the bounds of the slice.
func (s *ThreadSlice) Delete(index int) {
        s.Slice[index] = s.Slice[len(s.Slice)-1]
        if len(s.Slice) > 0 {
                s.Slice = s.Slice[:len(s.Slice)-1]
        }

}

[xiegeo]

I can reproduce now.

Change $GOPATH/bin/genny to genny will fix it. After putting $GOPATH/bin/ in your path, and delete any existing gen_* files.

It looks like genny only recognize //go:generate genny ... as a genny command to be removed from the output, and not when the full path is specified.

[ammario]

Thanks, would this still be considered a bug?

A part of me feels like there should never be //go:generate's lingering?

[loren-osborn]

Just as a related comment $GOPATH/bin/genny should probably not be used as GOPATH can contain multiple paths separated by colons, but it would be nice if genny could register itself as a “tool” known by the compiler.

I personally have never put the //go:generate in the generic file before as it seems the client calling the generic should usually be the one specifying how it’s expanded.