consider draft/prerelease and remember asset URL

cmd/selfupdate-example/main.go

@@ -10,6 +10,7 @@ import (
 const version = "1.2.3"
 
 func selfUpdate() error {
+	selfupdate.EnableLog()
 	up, err := selfupdate.TryUpdate(version, "go-github-selfupdate", nil)
 	if err != nil {
 		return err
@@ -29,7 +30,7 @@ func usage() {
 func main() {
 	help := flag.Bool("help", false, "Show this help")
 	ver := flag.Bool("version", false, "Show version")
-	selfupdate := flag.Bool("selfupdate", false, "Try go-github-selfupdate via GitHub")
+	update := flag.Bool("selfupdate", false, "Try go-github-selfupdate via GitHub")
 
 	flag.Usage = usage
 	flag.Parse()
@@ -44,7 +45,7 @@ func main() {
 		os.Exit(0)
 	}
 
-	if *selfupdate {
+	if *update {
 		if err := selfUpdate(); err != nil {
 			fmt.Fprintln(os.Stderr, err)
 			os.Exit(1)

selfupdate/detect.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"regexp"
+	"runtime"
 	"strings"
 )
 
@@ -20,6 +21,47 @@ type ReleaseDetector struct {
 	apiCtx context.Context
 }
 
+func findSuitableReleaseAndAsset(rels []*github.RepositoryRelease) (*github.RepositoryRelease, *github.ReleaseAsset, bool) {
+	// Generate candidates
+	cs := make([]string, 0, 8)
+	for _, sep := range []rune{'_', '-'} {
+		for _, ext := range []string{"zip", "tar.gz"} {
+			suffix := fmt.Sprintf("%s%c%s.%s", runtime.GOOS, sep, runtime.GOARCH, ext)
+			cs = append(cs, suffix)
+			if runtime.GOOS == "windows" {
+				suffix = fmt.Sprintf("%s%c%s.exe.%s", runtime.GOOS, sep, runtime.GOARCH, ext)
+				cs = append(cs, suffix)
+			}
+		}
+	}
+
+	for _, rel := range rels {
+		if rel.GetDraft() {
+			log.Println("Skip draft version", rel.GetTagName())
+			continue
+		}
+		if rel.GetPrerelease() {
+			log.Println("Skip pre-release version", rel.GetTagName())
+			continue
+		}
+		if !reVersion.MatchString(rel.GetTagName()) {
+			log.Println("Skip version not adopting semver", rel.GetTagName())
+			continue
+		}
+		for _, asset := range rel.Assets {
+			name := asset.GetName()
+			for _, c := range cs {
+				if strings.HasSuffix(name, c) {
+					return rel, &asset, true
+				}
+			}
+		}
+	}
+
+	log.Println("Could no find any release for", runtime.GOOS, "and", runtime.GOARCH)
+	return nil, nil, false
+}
+
 // NewDetector crates a new detector instance. It initializes GitHub API client.
 func NewDetector() *ReleaseDetector {
 	token := os.Getenv("GITHUB_TOKEN")
@@ -36,14 +78,14 @@ func NewDetector() *ReleaseDetector {
 }
 
 // DetectLatest tries to get the latest version of the repository on GitHub. 'slug' means 'owner/name' formatted string.
-func (d *ReleaseDetector) DetectLatest(slug string) (ver semver.Version, found bool, err error) {
+func (d *ReleaseDetector) DetectLatest(slug string) (release *Release, found bool, err error) {
 	repo := strings.Split(slug, "/")
 	if len(repo) != 2 || repo[0] == "" || repo[1] == "" {
 		err = fmt.Errorf("Invalid slug format. It should be 'owner/name': %s", slug)
 		return
 	}
 
-	rel, res, err := d.api.Repositories.GetLatestRelease(d.apiCtx, repo[0], repo[1])
+	rels, res, err := d.api.Repositories.ListReleases(d.apiCtx, repo[0], repo[1], nil)
 	if err != nil {
 		log.Println("API returned an error response:", err)
 		if res.StatusCode == 404 {
@@ -55,23 +97,27 @@ func (d *ReleaseDetector) DetectLatest(slug string) (ver semver.Version, found b
 		return
 	}
 
+	rel, asset, found := findSuitableReleaseAndAsset(rels)
+	if !found {
+		return
+	}
+
 	tag := rel.GetTagName()
-	log.Println("Successfully fetched the latest release. tag:", tag, ", name:", rel.GetName(), ", URL:", rel.GetURL())
+	url := asset.GetBrowserDownloadURL()
+	log.Println("Successfully fetched the latest release. tag:", tag, ", name:", rel.GetName(), ", URL:", rel.GetURL(), ", Asset:", url)
 
 	// Strip version prefix
 	if indices := reVersion.FindStringIndex(tag); indices != nil && indices[0] > 0 {
+		log.Println("Strip prefix of version:", tag[:indices[0]])
 		tag = tag[indices[0]:]
 	}
 
-	ver, err = semver.Make(tag)
-	if err == nil {
-		found = true
-	}
-
+	release = &Release{AssetURL: url}
+	release.Version, err = semver.Make(tag)
 	return
 }
 
 // DetectLatest detects the latest release of the slug (owner/repo).
-func DetectLatest(slug string) (semver.Version, bool, error) {
+func DetectLatest(slug string) (*Release, bool, error) {
 	return NewDetector().DetectLatest(slug)
 }

selfupdate/detect_test.go

@@ -3,6 +3,7 @@ package selfupdate
 import (
 	"github.com/blang/semver"
 	"os"
+	"strings"
 	"testing"
 )
 
@@ -15,15 +16,21 @@ func TestGitHubTokenEnv(t *testing.T) {
 }
 
 func TestDetectReleaseWithVersionPrefix(t *testing.T) {
-	v, ok, err := DetectLatest("rhysd/github-clone-all")
+	r, ok, err := DetectLatest("rhysd/github-clone-all")
 	if err != nil {
 		t.Fatal("Fetch failed:", err)
 	}
 	if !ok {
 		t.Fatal("Failed to detect latest")
 	}
-	if v.LE(semver.MustParse("2.0.0")) {
-		t.Fatal("Incorrect version:", v)
+	if r == nil {
+		t.Fatal("Release detected but nil returned for it")
+	}
+	if r.Version.LE(semver.MustParse("2.0.0")) {
+		t.Fatal("Incorrect version:", r.Version)
+	}
+	if !strings.HasSuffix(r.AssetURL, ".zip") && !strings.HasSuffix(r.AssetURL, ".tar.gz") {
+		t.Fatal("Incorrect URL for asset:", r.AssetURL)
 	}
 }
 

selfupdate/log.go

@@ -6,8 +6,8 @@ import (
 	"os"
 )
 
-var log = stdlog.New(os.Stderr, "", stdlog.Ltime)
-var logEnabled = true
+var log = stdlog.New(ioutil.Discard, "", stdlog.Ltime)
+var logEnabled = false
 
 // EnableLog enables to output logging messages in library
 func EnableLog() {

selfupdate/release.go

@@ -0,0 +1,11 @@
+package selfupdate
+
+import (
+	"github.com/blang/semver"
+)
+
+// Release represents a release asset for current OS and arch.
+type Release struct {
+	Version  semver.Version
+	AssetURL string
+}