├── README.md
├── go.mod
├── go.sum
└── main.go


/README.md:
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1 | # gomodmerge
2 | 
3 | Sometimes we'll have a project that uses Go modules but one of its dependencies do not. Updating your project when its dependencies change can be awkward because there's no easy way of merging dependency requirements from non-module build systems such as dep.
4 | 
5 | The `gomodmerge` tool makes it possible to do that. In your non-module dependency, run `go mod init` to create a module file for that dependency. Then in your project, run `gomodmerge $dependency/go.mod` to merge any versions that are newer.
6 | 


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/go.mod:
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1 | module github.com/rogpeppe/gomodmerge
2 | 
3 | require (
4 | 	github.com/rogpeppe/go-internal v1.0.0-alpha
5 | 	gopkg.in/errgo.v2 v2.1.0
6 | )
7 | 


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/go.sum:
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 1 | github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 2 | github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 3 | github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 4 | github.com/rogpeppe/go-internal v0.0.8 h1:AXvcOSBIr8szCL4Ml897LRBY33zaEJSpmdt3YEDTMmg=
 5 | github.com/rogpeppe/go-internal v1.0.0-alpha h1:zJtNjia0DW6sKVGzv5i+3TwGRJEJmaPnU9F12IRf/gI=
 6 | github.com/rogpeppe/go-internal v1.0.0-alpha/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 7 | gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 8 | gopkg.in/errgo.v2 v2.1.0 h1:0vLT13EuvQ0hNvakwLuFZ/jYrLp5F3kcWHXdRggjCE8=
 9 | gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
10 | 


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/main.go:
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  1 | package main
  2 | 
  3 | import (
  4 | 	"bytes"
  5 | 	"encoding/json"
  6 | 	"flag"
  7 | 	"fmt"
  8 | 	"io"
  9 | 	"io/ioutil"
 10 | 	"os"
 11 | 	"os/exec"
 12 | 	"path/filepath"
 13 | 	"sort"
 14 | 
 15 | 	"github.com/rogpeppe/go-internal/semver"
 16 | 	"gopkg.in/errgo.v2/fmt/errors"
 17 | )
 18 | 
 19 | func main() {
 20 | 	flag.Usage = func() {
 21 | 		fmt.Fprint(os.Stderr, `gomodmerge gomodfile
 22 | 
 23 | Update the local module's dependencies by merging them
 24 | from the dependencies implied by the argument go.mod file.
 25 | 
 26 | Dependencies that are older than the current module's dependencies
 27 | will be ignored.
 28 | `)
 29 | 		os.Exit(2)
 30 | 	}
 31 | 	flag.Parse()
 32 | 	if flag.NArg() != 1 {
 33 | 		flag.Usage()
 34 | 	}
 35 | 	if err := mergeMod(flag.Arg(0)); err != nil {
 36 | 		fmt.Fprintf(os.Stderr, "%v (%s)\n", err, errors.Details(err))
 37 | 		os.Exit(1)
 38 | 	}
 39 | }
 40 | 
 41 | func mergeMod(modfile string) error {
 42 | 	localVersions, err := moduleVersions("")
 43 | 	if err != nil {
 44 | 		return errors.Wrap(err)
 45 | 	}
 46 | 	dir, err := ioutil.TempDir("", "")
 47 | 	if err != nil {
 48 | 		return errors.Wrap(err)
 49 | 	}
 50 | 	defer os.RemoveAll(dir)
 51 | 	goMod, err := ioutil.ReadFile(modfile)
 52 | 	if err != nil {
 53 | 		return errors.Wrap(err)
 54 | 	}
 55 | 	if err := ioutil.WriteFile(filepath.Join(dir, "go.mod"), goMod, 0666); err != nil {
 56 | 		return errors.Wrap(err)
 57 | 	}
 58 | 	otherVersions, err := moduleVersions(dir)
 59 | 	if err != nil {
 60 | 		return errors.Wrap(err)
 61 | 	}
 62 | 	updates := make(map[string]string)
 63 | 	for mod, version := range otherVersions {
 64 | 		localVersion, ok := localVersions[mod]
 65 | 		if !ok || semver.Compare(version, localVersion) > 0 {
 66 | 			updates[mod] = version
 67 | 		}
 68 | 	}
 69 | 	if len(updates) == 0 {
 70 | 		fmt.Println("no updates required")
 71 | 		return nil
 72 | 	}
 73 | 	updateMods := make([]string, 0, len(updates))
 74 | 	for mod := range updates {
 75 | 		updateMods = append(updateMods, mod)
 76 | 	}
 77 | 	sort.Strings(updateMods)
 78 | 	editArgs := []string{"mod", "edit"}
 79 | 	for _, mod := range updateMods {
 80 | 		editArgs = append(editArgs, "-require="+mod+"@"+updates[mod])
 81 | 	}
 82 | 	c := exec.Command("go", editArgs...)
 83 | 	c.Stderr = os.Stderr
 84 | 	if err := c.Run(); err != nil {
 85 | 		return errors.Wrap(err)
 86 | 	}
 87 | 	for _, mod := range updateMods {
 88 | 		fmt.Printf("%s %s\n", mod, updates[mod])
 89 | 	}
 90 | 	return nil
 91 | }
 92 | 
 93 | type goMod struct {
 94 | 	Path    string
 95 | 	Version string
 96 | }
 97 | 
 98 | func moduleVersions(dir string) (map[string]string, error) {
 99 | 	var out bytes.Buffer
100 | 	c := exec.Command("go", "list", "-m", "-json", "all")
101 | 	c.Dir = dir
102 | 	c.Stderr = os.Stderr
103 | 	c.Stdout = &out
104 | 	if err := c.Run(); err != nil {
105 | 		return nil, errors.Wrap(err)
106 | 	}
107 | 	dec := json.NewDecoder(&out)
108 | 	mods := make(map[string]string)
109 | 	for {
110 | 		var m goMod
111 | 		if err := dec.Decode(&m); err != nil {
112 | 			if err == io.EOF {
113 | 				break
114 | 			}
115 | 			return nil, errors.Wrap(err)
116 | 		}
117 | 		if m.Version != "" {
118 | 			mods[m.Path] = m.Version
119 | 		}
120 | 	}
121 | 	return mods, nil
122 | }
123 | 


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