Add --prerelease-suffix flag

Dockerfile

@@ -4,7 +4,7 @@ WORKDIR /build
 COPY ./ /build/
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build .
 
-FROM scratch
+FROM alpine
 COPY --from=builder /build/git-describe-semver /bin/git-describe-semver
 WORKDIR /workdir
 ENTRYPOINT ["/bin/git-describe-semver"]

README.md

@@ -16,20 +16,21 @@ none | fail | `v0.0.0-dev.23.gabc1234`
 
 * Flag `--fallback v0.0.0`: Fallback to given tag name if no tag is available
 * Flag `--drop-prefix`: Drop any present prefix (like `v`) from the output
+* Flag `--prerelease-suffix`: Adds a dash-separated suffix to the prerelease part
 
 ### Binary
 
 ```bash
 cd my-git-directory
-wget -q https://github.com/choffmeister/git-describe-semver/releases/download/v0.2.0/git-describe-semver-linux-amd64
+wget -q https://github.com/choffmeister/git-describe-semver/releases/download/v0.2.1/git-describe-semver-linux-amd64
 chmod +x git-describe-semver-linux-amd64
-./git-describe-semver-linux-amd64 --fallback v0.0.0
+./git-describe-semver-linux-amd64
 ```
 
 ### Docker
 
 ```bash
 cd my-git-directory
-docker pull choffmeister/git-describe-semver:v0.2.0
-docker run --rm -v $PWD:/workdir choffmeister/git-describe-semver:v0.2.0 --fallback v0.0.0
+docker pull choffmeister/git-describe-semver:v0.2.1
+docker run --rm -v $PWD:/workdir choffmeister/git-describe-semver:v0.2.1
 ```

main.go

@@ -14,48 +14,49 @@ import (
 type GenerateVersionOptions struct {
 	FallbackTagName string
 	DropTagNamePrefix bool
+	PrereleaseSuffix string
 }
 
 // GenerateVersion ...
 func GenerateVersion(tagName string, counter int, headHash string, opts GenerateVersionOptions) (*string, error) {
-	devPreRelease := []string{"dev", strconv.Itoa(counter), "g" + (headHash)[0:7]}
+	devPrerelease := []string{"dev", strconv.Itoa(counter), "g" + (headHash)[0:7]}
+	if opts.PrereleaseSuffix != "" {
+		devPrerelease[len(devPrerelease) - 1] = devPrerelease[len(devPrerelease) - 1] + "-" + opts.PrereleaseSuffix
+	}
+	version := &SemVer{}
 	if tagName == "" {
-		version := SemVerParse(opts.FallbackTagName)
+		version = SemVerParse(opts.FallbackTagName)
 		if version == nil {
 			return nil, fmt.Errorf("unable to parse fallback tag")
 		}
-		version.PreRelease = devPreRelease
-		if opts.DropTagNamePrefix {
-			version.Prefix = ""
+		version.Prerelease = devPrerelease
+	} else {
+		version = SemVerParse(tagName)
+		if version == nil {
+			return nil, fmt.Errorf("unable to parse tag")
 		}
-		result := version.String()
-		return &result, nil
-	}
-	version := SemVerParse(tagName)
-	if version == nil {
-		return nil, fmt.Errorf("unable to parse tag")
-	}
-	if counter == 0 {
-		result := version.String()
-		return &result, nil
-	}
-	if len(version.PreRelease) > 0 {
-		version = &SemVer{
-			Prefix:        version.Prefix,
-			Major:         version.Major,
-			Minor:         version.Minor,
-			Patch:         version.Patch,
-			PreRelease:    append(version.PreRelease, devPreRelease...),
-			BuildMetadata: append([]string{}, version.BuildMetadata...),
+		if counter == 0 {
+			result := version.String()
+			return &result, nil
 		}
-	} else {
-		version = &SemVer{
-			Prefix:        version.Prefix,
-			Major:         version.Major,
-			Minor:         version.Minor,
-			Patch:         version.Patch + 1,
-			PreRelease:    devPreRelease,
-			BuildMetadata: append([]string{}, version.BuildMetadata...),
+		if len(version.Prerelease) > 0 {
+			version = &SemVer{
+				Prefix:        version.Prefix,
+				Major:         version.Major,
+				Minor:         version.Minor,
+				Patch:         version.Patch,
+				Prerelease:    append(version.Prerelease, devPrerelease...),
+				BuildMetadata: append([]string{}, version.BuildMetadata...),
+			}
+		} else {
+			version = &SemVer{
+				Prefix:        version.Prefix,
+				Major:         version.Major,
+				Minor:         version.Minor,
+				Patch:         version.Patch + 1,
+				Prerelease:    devPrerelease,
+				BuildMetadata: append([]string{}, version.BuildMetadata...),
+			}
 		}
 	}
 	if opts.DropTagNamePrefix {
@@ -85,6 +86,7 @@ func Run(dir string, opts GenerateVersionOptions) (*string, error) {
 func main() {
 	fallback := flag.String("fallback", "", "The first version to fallback to should there be no tag")
 	dropPrefix := flag.Bool("drop-prefix", false, "Drop prefix from output")
+	prereleaseSuffix := flag.String("prerelease-suffix", "", "Suffix to add to prereleases")
 	flag.Parse()
 
 	dir, err := os.Getwd()
@@ -94,6 +96,7 @@ func main() {
 	opts := GenerateVersionOptions{
 		FallbackTagName: *fallback,
 		DropTagNamePrefix: *dropPrefix,
+		PrereleaseSuffix: *prereleaseSuffix,
 	}
 	result, err := Run(dir, opts)
 	if err != nil {

main_test.go

@@ -14,7 +14,6 @@ func TestGenerateVersion(t *testing.T) {
 		actual, err := GenerateVersion(inputTagName, inputCounter, inputHeadHash, inputOpts)
 		if assert.NoError(err) {
 			assert.Equal(expected, *actual)
-
 		}
 	}
 
@@ -29,6 +28,10 @@ func TestGenerateVersion(t *testing.T) {
 	test("", 1, "abc1234", GenerateVersionOptions{FallbackTagName: "0.0.0"}, "0.0.0-dev.1.gabc1234")
 	test("", 1, "abc1234", GenerateVersionOptions{FallbackTagName: "v0.0.0"}, "v0.0.0-dev.1.gabc1234")
 	test("", 1, "abc1234", GenerateVersionOptions{FallbackTagName: "v0.0.0", DropTagNamePrefix: true}, "0.0.0-dev.1.gabc1234")
+
+	test("v0.0.0", 0, "abc1234", GenerateVersionOptions{PrereleaseSuffix: "SNAPSHOT"}, "v0.0.0")
+	test("v0.0.0", 1, "abc1234", GenerateVersionOptions{PrereleaseSuffix: "SNAPSHOT"}, "v0.0.1-dev.1.gabc1234-SNAPSHOT")
+
 	_, err := GenerateVersion("", 1, "abc1234", GenerateVersionOptions{})
 	assert.Error(err)
 }

semver.go

@@ -13,7 +13,7 @@ type SemVer struct {
 	Major         int
 	Minor         int
 	Patch         int
-	PreRelease    []string
+	Prerelease    []string
 	BuildMetadata []string
 }
 
@@ -24,15 +24,15 @@ func (v SemVer) Equal(v2 SemVer) bool {
 		v.Major == v2.Major &&
 		v.Minor == v2.Minor &&
 		v.Patch == v2.Patch &&
-		equalStringSlice(v.PreRelease, v2.PreRelease) &&
+		equalStringSlice(v.Prerelease, v2.Prerelease) &&
 		equalStringSlice(v.BuildMetadata, v2.BuildMetadata)
 }
 
 // String ...
 func (v SemVer) String() string {
 	str := fmt.Sprintf("%s%d.%d.%d", v.Prefix, v.Major, v.Minor, v.Patch)
-	if len(v.PreRelease) > 0 {
-		str = str + "-" + strings.Join(v.PreRelease, ".")
+	if len(v.Prerelease) > 0 {
+		str = str + "-" + strings.Join(v.Prerelease, ".")
 	}
 	if len(v.BuildMetadata) > 0 {
 		str = str + "+" + strings.Join(v.BuildMetadata, ".")
@@ -53,15 +53,15 @@ func SemVerParse(str string) *SemVer {
 	major, _ := strconv.Atoi(match[2])
 	minor, _ := strconv.Atoi(match[3])
 	patch, _ := strconv.Atoi(match[4])
-	preRelease := stringToSlice(match[5], ".")
+	prerelease := stringToSlice(match[5], ".")
 	buildMetadata := stringToSlice(match[6], ".")
 
 	return &SemVer{
 		Prefix:        prefix,
 		Major:         major,
 		Minor:         minor,
 		Patch:         patch,
-		PreRelease:    preRelease,
+		Prerelease:    prerelease,
 		BuildMetadata: buildMetadata,
 	}
 }

semver_test.go

@@ -16,10 +16,10 @@ func TestSemVerString(t *testing.T) {
 	test(SemVer{}, "0.0.0")
 	test(SemVer{Prefix: "v"}, "v0.0.0")
 	test(SemVer{Major: 1, Minor: 2, Patch: 3}, "1.2.3")
-	test(SemVer{PreRelease: []string{"rc", "1"}}, "0.0.0-rc.1")
-	test(SemVer{PreRelease: []string{"alpha-version", "1"}}, "0.0.0-alpha-version.1")
+	test(SemVer{Prerelease: []string{"rc", "1"}}, "0.0.0-rc.1")
+	test(SemVer{Prerelease: []string{"alpha-version", "1"}}, "0.0.0-alpha-version.1")
 	test(SemVer{BuildMetadata: []string{"foo", "bar"}}, "0.0.0+foo.bar")
-	test(SemVer{Prefix: "v", Major: 1, Minor: 2, Patch: 3, PreRelease: []string{"rc", "1"}, BuildMetadata: []string{"foo", "bar"}}, "v1.2.3-rc.1+foo.bar")
+	test(SemVer{Prefix: "v", Major: 1, Minor: 2, Patch: 3, Prerelease: []string{"rc", "1"}, BuildMetadata: []string{"foo", "bar"}}, "v1.2.3-rc.1+foo.bar")
 }
 
 func TestSemVerParse(t *testing.T) {
@@ -32,10 +32,10 @@ func TestSemVerParse(t *testing.T) {
 	test("0.0.0", &SemVer{})
 	test("v0.0.0", &SemVer{Prefix: "v"})
 	test("1.2.3", &SemVer{Major: 1, Minor: 2, Patch: 3})
-	test("0.0.0-rc.1", &SemVer{PreRelease: []string{"rc", "1"}})
-	test("0.0.0-alpha-version.1", &SemVer{PreRelease: []string{"alpha-version", "1"}})
+	test("0.0.0-rc.1", &SemVer{Prerelease: []string{"rc", "1"}})
+	test("0.0.0-alpha-version.1", &SemVer{Prerelease: []string{"alpha-version", "1"}})
 	test("0.0.0+foo.bar", &SemVer{BuildMetadata: []string{"foo", "bar"}})
-	test("v1.2.3-rc.1+foo.bar", &SemVer{Prefix: "v", Major: 1, Minor: 2, Patch: 3, PreRelease: []string{"rc", "1"}, BuildMetadata: []string{"foo", "bar"}})
+	test("v1.2.3-rc.1+foo.bar", &SemVer{Prefix: "v", Major: 1, Minor: 2, Patch: 3, Prerelease: []string{"rc", "1"}, BuildMetadata: []string{"foo", "bar"}})
 	test("invalid", nil)
 }
 
@@ -50,10 +50,10 @@ func TestSemVerEqual(t *testing.T) {
 	test(SemVer{Major: 1}, SemVer{Major: 2}, false)
 	test(SemVer{Minor: 1}, SemVer{Minor: 2}, false)
 	test(SemVer{Patch: 1}, SemVer{Patch: 2}, false)
-	test(SemVer{PreRelease: []string{"foo"}}, SemVer{PreRelease: []string{"foo"}}, true)
-	test(SemVer{PreRelease: []string{"foo"}}, SemVer{PreRelease: []string{"bar"}}, false)
-	test(SemVer{PreRelease: []string{"foo"}}, SemVer{}, false)
-	test(SemVer{}, SemVer{PreRelease: []string{"bar"}}, false)
+	test(SemVer{Prerelease: []string{"foo"}}, SemVer{Prerelease: []string{"foo"}}, true)
+	test(SemVer{Prerelease: []string{"foo"}}, SemVer{Prerelease: []string{"bar"}}, false)
+	test(SemVer{Prerelease: []string{"foo"}}, SemVer{}, false)
+	test(SemVer{}, SemVer{Prerelease: []string{"bar"}}, false)
 	test(SemVer{BuildMetadata: []string{"foo"}}, SemVer{BuildMetadata: []string{"foo"}}, true)
 	test(SemVer{BuildMetadata: []string{"foo"}}, SemVer{BuildMetadata: []string{"bar"}}, false)
 	test(SemVer{BuildMetadata: []string{"foo"}}, SemVer{}, false)