feat!: add Parser and New method

Author: muthukrishnan24

commit.go

@@ -56,7 +56,7 @@ func (c *Commit) Notes() []Note {
 	return c.notes
 }
 
-// IsBreakingChange returns true if breaking change
+// IsBreakingChange returns true if commit is breaking change
 func (c *Commit) IsBreakingChange() bool {
 	return c.isBreakingChange
 }

example_test.go

@@ -17,7 +17,8 @@ Ref #123
 Date: 01-01-2021
 By: John Doe`
 
-	commit, err := parser.Parse(msg)
+	p := parser.New()
+	commit, err := p.Parse(msg)
 	if err != nil {
 		fmt.Printf("Error: %s", err.Error())
 	}

parser.go

@@ -18,28 +18,28 @@ const (
 	footRegExStr = `^(?:(BREAKING[- ]CHANGE|(?:[A-Za-z-])+): |((?:[A-Za-z-])+) #)(.+)$`
 )
 
-var defParser = newParser()
-
-// Parse attempts to parse a commit message to a conventional commit
-func Parse(message string) (*Commit, error) {
-	return defParser.parse(message)
-}
-
-type parser struct {
+// Parser represent a conventional commit message parser
+type Parser struct {
 	headerRegex, footerRegex *regexp.Regexp
 }
 
-func newParser() *parser {
+// New returns a new parser
+func New() *Parser {
 	headerRegex := regexp.MustCompile(headRegExStr)
 	footerRegex := regexp.MustCompile(footRegExStr)
 
-	return &parser{
+	return &Parser{
 		headerRegex: headerRegex,
 		footerRegex: footerRegex,
 	}
 }
 
-func (p *parser) parse(message string) (*Commit, error) {
+// Parse attempts to parse a commit message to a conventional commit
+func (p *Parser) Parse(message string) (*Commit, error) {
+	return p.parse(message)
+}
+
+func (p *Parser) parse(message string) (*Commit, error) {
 	c := &Commit{
 		message: message,
 	}
@@ -124,7 +124,7 @@ func (p *parser) parse(message string) (*Commit, error) {
 
 // parseLineAsFooter attempts to parse the given line as a footer, returning both the key and the value of the header.
 // If the line cannot be parsed then isFooter is false
-func (p *parser) parseLineAsFooter(line string) (key, value string, isFooter bool) {
+func (p *Parser) parseLineAsFooter(line string) (key, value string, isFooter bool) {
 	matches := p.footerRegex.FindStringSubmatch(line)
 	if len(matches) != 4 {
 		return "", "", false
@@ -137,7 +137,7 @@ func (p *parser) parseLineAsFooter(line string) (key, value string, isFooter boo
 }
 
 // parseHeader attempts to parse the commit description line and set the appropriate values in the the given commit
-func (p *parser) parseHeader(c *Commit, header string) error {
+func (p *Parser) parseHeader(c *Commit, header string) error {
 	matches := p.headerRegex.FindStringSubmatch(header)
 	if matches == nil {
 		return errHeader

parser_bench_test.go

@@ -31,9 +31,11 @@ By: John Doe`
 
 var dumpRes *Commit
 
+var p = New()
+
 func BenchmarkParser(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		r, err := Parse(sampleCommit)
+		r, err := p.Parse(sampleCommit)
 		if err != nil {
 			b.Error(err)
 			return

parser_header_test.go

@@ -19,7 +19,7 @@ func TestParseHeaderValid(t *testing.T) {
 		"1245#feat1234(@scope/scope1,scope2): description, \n\n body 1 2, 3 and 4?",
 	}
 
-	p := newParser()
+	p := New()
 
 	for index, validCase := range validCases {
 
@@ -50,7 +50,7 @@ func TestParseHeaderInvalid(t *testing.T) {
 		`feat(scope))!: A description with name.txt`,
 	}
 
-	p := newParser()
+	p := New()
 
 	for index, validCase := range validCases {
 		testName := "case#" + strconv.Itoa(index+1)

parser_test.go

@@ -224,7 +224,8 @@ func TestParserErrNoBlankLine(t *testing.T) {
 		t.Error(err)
 	}
 
-	_, err = Parse(commitMsg)
+	p := New()
+	_, err = p.Parse(commitMsg)
 	if err == nil {
 		t.Errorf("no error: test file %v passed", fileName)
 		return
@@ -243,7 +244,8 @@ func TestParserErrHeaderLine(t *testing.T) {
 		t.Error(err)
 	}
 
-	_, err = Parse(commitMsg)
+	p := New()
+	_, err = p.Parse(commitMsg)
 	if err == nil {
 		t.Errorf("no error: test file %v passed", fileName)
 		return
@@ -261,7 +263,8 @@ func parseMsgAndCompare(t *testing.T, fileName string, expectedCommit *Commit) {
 		return
 	}
 
-	actualCommit, err := Parse(commitMsg)
+	p := New()
+	actualCommit, err := p.Parse(commitMsg)
 	if err != nil {
 		t.Errorf("Received unexpected error:\n%+v", err)
 		return