feat: Add --next-tag flag (experimental)

chglog.go

@@ -16,6 +16,7 @@ import (
 // Options is an option used to process commits
 type Options struct {
 	Processor            Processor
+	NextTag              string              // Treat unreleased commits as specified tags (EXPERIMENTAL)
 	CommitFilters        map[string][]string // Filter by using `Commit` properties and values. Filtering is not done by specifying an empty value
 	CommitSortBy         string              // Property name to use for sorting `Commit` (e.g. `Scope`)
 	CommitGroupBy        string              // Property name of `Commit` to be grouped into `CommitGroup` (e.g. `Type`)
@@ -150,18 +151,30 @@ func (gen *Generator) Generate(w io.Writer, query string) error {
 }
 
 func (gen *Generator) readVersions(tags []*Tag, first string) ([]*Version, error) {
+	next := gen.config.Options.NextTag
 	versions := []*Version{}
 
 	for i, tag := range tags {
-		var rev string
+		var (
+			isNext = next == tag.Name
+			rev    string
+		)
 
-		if i+1 < len(tags) {
-			rev = tags[i+1].Name + ".." + tag.Name
-		} else {
-			if first != "" {
-				rev = first + ".." + tag.Name
+		if isNext {
+			if tag.Previous != nil {
+				rev = tag.Previous.Name + "..HEAD"
 			} else {
-				rev = tag.Name
+				rev = "HEAD"
+			}
+		} else {
+			if i+1 < len(tags) {
+				rev = tags[i+1].Name + ".." + tag.Name
+			} else {
+				if first != "" {
+					rev = first + ".." + tag.Name
+				} else {
+					rev = tag.Name
+				}
 			}
 		}
 
@@ -180,12 +193,21 @@ func (gen *Generator) readVersions(tags []*Tag, first string) ([]*Version, error
 			RevertCommits: revertCommits,
 			NoteGroups:    noteGroups,
 		})
+
+		// Instead of `getTags()`, assign the date to the tag
+		if isNext {
+			tag.Date = commits[0].Author.Date
+		}
 	}
 
 	return versions, nil
 }
 
 func (gen *Generator) readUnreleased(tags []*Tag) (*Unreleased, error) {
+	if gen.config.Options.NextTag != "" {
+		return &Unreleased{}, nil
+	}
+
 	rev := "HEAD"
 
 	if len(tags) > 0 {
@@ -216,6 +238,33 @@ func (gen *Generator) getTags(query string) ([]*Tag, string, error) {
 		return nil, "", err
 	}
 
+	next := gen.config.Options.NextTag
+	if next != "" {
+		for _, tag := range tags {
+			if next == tag.Name {
+				return nil, "", fmt.Errorf("\"%s\" tag already exists", next)
+			}
+		}
+
+		var previous *RelateTag
+		if len(tags) > 0 {
+			previous = &RelateTag{
+				Name:    tags[0].Name,
+				Subject: tags[0].Subject,
+				Date:    tags[0].Date,
+			}
+		}
+
+		// Assign the date with `readVersions()`
+		tags = append([]*Tag{
+			&Tag{
+				Name:     next,
+				Subject:  next,
+				Previous: previous,
+			},
+		}, tags...)
+	}
+
 	if len(tags) == 0 {
 		return nil, "", errors.New("git-tag does not exist")
 	}

chglog_test.go

@@ -13,8 +13,9 @@ import (
 )
 
 var (
-	cwd          string
-	testRepoRoot = ".tmp"
+	cwd                string
+	testRepoRoot       = ".tmp"
+	internalTimeFormat = "2006-01-02 15:04:05"
 )
 
 type commitFunc = func(date, subject, body string)
@@ -48,7 +49,7 @@ func setup(dir string, setupRepo func(commitFunc, tagFunc, gitcmd.Client)) {
 		if body != "" {
 			msg += "\n\n" + body
 		}
-		t, _ := time.Parse("2006-01-02 15:04:05", date)
+		t, _ := time.Parse(internalTimeFormat, date)
 		d := t.Format("Mon Jan 2 15:04:05 2006 +0000")
 		git.Exec("commit", "--allow-empty", "--date", d, "-m", msg)
 	}
@@ -298,3 +299,95 @@ Online breaking change message.
 [2.0.0-beta.0]: https://github.com/git-chglog/git-chglog/compare/1.1.0...2.0.0-beta.0
 [1.1.0]: https://github.com/git-chglog/git-chglog/compare/1.0.0...1.1.0`, strings.TrimSpace(buf.String()))
 }
+
+func TestGeneratorWithNextTag(t *testing.T) {
+	assert := assert.New(t)
+	testName := "type_scope_subject"
+
+	setup(testName, func(commit commitFunc, tag tagFunc, _ gitcmd.Client) {
+		commit("2018-01-01 00:00:00", "feat(core): version 1.0.0", "")
+		tag("1.0.0")
+
+		commit("2018-02-01 00:00:00", "feat(core): version 2.0.0", "")
+		tag("2.0.0")
+
+		commit("2018-03-01 00:00:00", "feat(core): version 3.0.0", "")
+	})
+
+	gen := NewGenerator(&Config{
+		Bin:        "git",
+		WorkingDir: filepath.Join(testRepoRoot, testName),
+		Template:   filepath.Join(cwd, "testdata", testName+".md"),
+		Info: &Info{
+			Title:         "CHANGELOG Example",
+			RepositoryURL: "https://github.com/git-chglog/git-chglog",
+		},
+		Options: &Options{
+			NextTag: "3.0.0",
+			CommitFilters: map[string][]string{
+				"Type": []string{
+					"feat",
+				},
+			},
+			CommitSortBy:      "Scope",
+			CommitGroupBy:     "Type",
+			CommitGroupSortBy: "Title",
+			CommitGroupTitleMaps: map[string]string{
+				"feat": "Features",
+			},
+			HeaderPattern: "^(\\w*)(?:\\(([\\w\\$\\.\\-\\*\\s]*)\\))?\\:\\s(.*)$",
+			HeaderPatternMaps: []string{
+				"Type",
+				"Scope",
+				"Subject",
+			},
+		},
+	})
+
+	buf := &bytes.Buffer{}
+	err := gen.Generate(buf, "")
+
+	assert.Nil(err)
+	assert.Equal(`<a name="unreleased"></a>
+## [Unreleased]
+
+
+<a name="3.0.0"></a>
+## [3.0.0] - 2018-03-01
+### Features
+- **core:** version 3.0.0
+
+
+<a name="2.0.0"></a>
+## [2.0.0] - 2018-02-01
+### Features
+- **core:** version 2.0.0
+
+
+<a name="1.0.0"></a>
+## 1.0.0 - 2018-01-01
+### Features
+- **core:** version 1.0.0
+
+
+[Unreleased]: https://github.com/git-chglog/git-chglog/compare/3.0.0...HEAD
+[3.0.0]: https://github.com/git-chglog/git-chglog/compare/2.0.0...3.0.0
+[2.0.0]: https://github.com/git-chglog/git-chglog/compare/1.0.0...2.0.0`, strings.TrimSpace(buf.String()))
+
+	buf = &bytes.Buffer{}
+	err = gen.Generate(buf, "3.0.0")
+
+	assert.Nil(err)
+	assert.Equal(`<a name="unreleased"></a>
+## [Unreleased]
+
+
+<a name="3.0.0"></a>
+## [3.0.0] - 2018-03-01
+### Features
+- **core:** version 3.0.0
+
+
+[Unreleased]: https://github.com/git-chglog/git-chglog/compare/3.0.0...HEAD
+[3.0.0]: https://github.com/git-chglog/git-chglog/compare/2.0.0...3.0.0`, strings.TrimSpace(buf.String()))
+}

cmd/git-chglog/config.go

@@ -257,6 +257,7 @@ func (config *Config) Convert(ctx *CLIContext) *chglog.Config {
 			RepositoryURL: info.RepositoryURL,
 		},
 		Options: &chglog.Options{
+			NextTag:              ctx.NextTag,
 			CommitFilters:        opts.Commits.Filters,
 			CommitSortBy:         opts.Commits.SortBy,
 			CommitGroupBy:        opts.CommitGroups.GroupBy,

cmd/git-chglog/context.go

@@ -15,6 +15,7 @@ type CLIContext struct {
 	NoColor    bool
 	NoEmoji    bool
 	Query      string
+	NextTag    string
 }
 
 // InitContext ...

cmd/git-chglog/main.go

@@ -89,6 +89,11 @@ func main() {
 			Usage: "output path and filename for the changelogs. If not specified, output to stdout",
 		},
 
+		cli.StringFlag{
+			Name:  "next-tag",
+			Usage: "treat unreleased commits as specified tags (EXPERIMENTAL)",
+		},
+
 		// silent
 		cli.BoolFlag{
 			Name:  "silent",
@@ -155,6 +160,7 @@ func main() {
 				NoColor:    c.Bool("no-color"),
 				NoEmoji:    c.Bool("no-emoji"),
 				Query:      c.Args().First(),
+				NextTag:    c.String("next-tag"),
 			},
 			fs,
 			NewConfigLoader(),