improve behavior when no arguments are provided

Signed-off-by: Alex Goodman <[email protected]>

README.md

@@ -11,8 +11,16 @@
 A fast changelog generator that sources changes from GitHub PRs and issues, organized by labels.
 
 ```bash
+# create a changelog from the last GitHib release until the current git HEAD tag/commit
+# for the git repo in the current directory
+chronicle 
+
+# create a changelog with all changes from v0.16.0 until current git HEAD tag/commit
+# for the git repo in the current directory
 chronicle --since-tag v0.16.0
-chronicle --since-tag v0.16.0 --until-tag v0.18.0
+
+# create a changelog between two specific tags for a repo at the given path
+chronicle --since-tag v0.16.0 --until-tag v0.18.0 ./path/to/git/repo
 ```
 
 ## Installation

cmd/create_github_worker.go

@@ -32,24 +32,14 @@ func createChangelogFromGithub() (*release.Description, error) {
 	}
 	log.Infof("since ref=%q date=%q", lastRelease.Version, lastRelease.Date)
 
-	releaseVersion := appConfig.UntilTag
-	releaseDisplayVersion := releaseVersion
-	if releaseVersion == "" {
-		releaseVersion = "(Unreleased)"
-		releaseDisplayVersion = releaseVersion
-		// check if the current commit is tagged, then use that
-		releaseTag, err := git.HeadTagOrCommit(appConfig.CliOptions.RepoPath)
-		if err != nil {
-			return nil, fmt.Errorf("problem while attempting to find head tag: %w", err)
-		}
-		if releaseTag != "" {
-			releaseVersion = releaseTag
-		}
+	releaseVersion, releaseDisplayVersion, err := getCurrentReleaseInfo(appConfig.UntilTag, appConfig.CliOptions.RepoPath)
+	if err != nil {
+		return nil, err
 	}
 
 	log.Infof("until ref=%q", releaseVersion)
 
-	changes, err := summer.Changes(lastRelease.Version, appConfig.UntilTag)
+	changes, err := summer.Changes(lastRelease.Version, releaseVersion)
 	if err != nil {
 		return nil, fmt.Errorf("unable to summarize changes: %w", err)
 	}
@@ -70,9 +60,32 @@ func createChangelogFromGithub() (*release.Description, error) {
 			Date:    time.Now(),
 		},
 		VCSTagURL:        summer.TagURL(lastRelease.Version),
-		VCSChangesURL:    summer.ChangesURL(lastRelease.Version, appConfig.UntilTag),
+		VCSChangesURL:    summer.ChangesURL(lastRelease.Version, releaseVersion),
 		Changes:          changes,
 		SupportedChanges: supportedChanges,
 		Notice:           "", // TODO...
 	}, nil
 }
+
+func getCurrentReleaseInfo(explicitReleaseVersion, repoPath string) (string, string, error) {
+	if explicitReleaseVersion != "" {
+		return explicitReleaseVersion, explicitReleaseVersion, nil
+	}
+
+	// check if the current commit is tagged, then use that
+	releaseTag, err := git.HeadTag(repoPath)
+	if err != nil {
+		return "", "", fmt.Errorf("problem while attempting to find head tag: %w", err)
+	}
+	if releaseTag != "" {
+		return releaseTag, releaseTag, nil
+	}
+
+	// fallback to referencing the commit directly
+	commitRef, err := git.HeadCommit(repoPath)
+	if err != nil {
+		return "", "", fmt.Errorf("problem while attempting to find head ref: %w", err)
+	}
+
+	return commitRef, "(Unreleased)", nil
+}

internal/git/head.go

@@ -33,3 +33,39 @@ func HeadTagOrCommit(repoPath string) (string, error) {
 
 	return ref.Hash().String(), nil
 }
+
+func HeadTag(repoPath string) (string, error) {
+	r, err := git.PlainOpen(repoPath)
+	if err != nil {
+		return "", fmt.Errorf("unable to open repo: %w", err)
+	}
+	ref, err := r.Head()
+	if err != nil {
+		return "", fmt.Errorf("unable fetch head: %w", err)
+	}
+	tagRefs, _ := r.Tags()
+	var tagName string
+
+	_ = tagRefs.ForEach(func(t *plumbing.Reference) error {
+		if t.Hash().String() == ref.Hash().String() {
+			tagName = t.Name().Short()
+			return fmt.Errorf("found")
+		}
+		return nil
+	})
+
+	// note: if there is no tag, then an empty value is returned
+	return tagName, nil
+}
+
+func HeadCommit(repoPath string) (string, error) {
+	r, err := git.PlainOpen(repoPath)
+	if err != nil {
+		return "", fmt.Errorf("unable to open repo: %w", err)
+	}
+	ref, err := r.Head()
+	if err != nil {
+		return "", fmt.Errorf("unable fetch head: %w", err)
+	}
+	return ref.Hash().String(), nil
+}

internal/git/head_test.go

@@ -6,23 +6,97 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestHeadTagOrCommit(t *testing.T) {
+	tests := []struct {
+		name          string
+		path          string
+		expects       string
+		expectsLength int
+	}{
+		{
+			name:    "head has tag",
+			path:    "test-fixtures/repos/tagged-repo",
+			expects: "v0.1.0",
+		},
+		{
+			name: "head has no tag",
+			path: "test-fixtures/repos/commit-in-repo",
+			// since we don't commit the exact fixture, we don't know what the value will be (but the length
+			// of a commit string is fixed and is a good proxy here)
+			expectsLength: 40,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			actual, err := HeadTagOrCommit(test.path)
+			assert.NoError(t, err)
+			if test.expects != "" {
+				assert.Equal(t, test.expects, actual)
+			}
+			if test.expectsLength != 0 {
+				assert.Len(t, actual, test.expectsLength)
+			}
+		})
+	}
+}
+
 func TestHeadTag(t *testing.T) {
 	tests := []struct {
 		name    string
 		path    string
 		expects string
 	}{
 		{
-			name:    "go case",
+			name:    "head has tag",
 			path:    "test-fixtures/repos/tagged-repo",
 			expects: "v0.1.0",
 		},
+		{
+			name: "head has no tag",
+			path: "test-fixtures/repos/commit-in-repo",
+		},
 	}
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			actual, err := HeadTagOrCommit(test.path)
+			actual, err := HeadTag(test.path)
 			assert.NoError(t, err)
 			assert.Equal(t, test.expects, actual)
 		})
 	}
 }
+
+func TestHeadCommit(t *testing.T) {
+	tests := []struct {
+		name          string
+		path          string
+		expects       string
+		expectsLength int
+	}{
+		{
+			name: "head has tag",
+			path: "test-fixtures/repos/tagged-repo",
+			// since we don't commit the exact fixture, we don't know what the value will be (but the length
+			// of a commit string is fixed and is a good proxy here)
+			expectsLength: 40,
+		},
+		{
+			name: "head has no tag",
+			path: "test-fixtures/repos/commit-in-repo",
+			// since we don't commit the exact fixture, we don't know what the value will be (but the length
+			// of a commit string is fixed and is a good proxy here)
+			expectsLength: 40,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			actual, err := HeadCommit(test.path)
+			assert.NoError(t, err)
+			if test.expects != "" {
+				assert.Equal(t, test.expects, actual)
+			}
+			if test.expectsLength != 0 {
+				assert.Len(t, actual, test.expectsLength)
+			}
+		})
+	}
+}

internal/git/test-fixtures/Makefile

@@ -1,9 +1,12 @@
 
 .PHONY: all
-all: repos/remote-repo repos/tagged-repo
+all: repos/remote-repo repos/tagged-repo repos/commit-in-repo
 
 repos/remote-repo:
 	./create-remote-repo.sh
 
 repos/tagged-repo:
-	./create-tagged-repo.sh
+	./create-tagged-repo.sh
+
+repos/commit-in-repo:
+	./create-commit-in-repo.sh

internal/git/test-fixtures/create-commit-in-repo.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -eux -o pipefail
+
+if [ -d "/path/to/dir" ]
+then
+    echo "fixture already exists!"
+    exit 0
+else
+    echo "creating fixture..."
+fi
+
+git init repos/commit-in-repo
+
+pushd repos/commit-in-repo
+
+git config --local user.email "[email protected]"
+git config --local user.name "nope"
+
+trap 'popd' EXIT
+
+git commit -m 'something' --allow-empty