Add ability to start from user specified hash.

This feature can be useful for repositories with already established versioning, but
having hundreds of commits which could potentially produce really weird results due
to lack of previous rules on wording.

cmd/main.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	git "github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/go-git/go-git/v5/plumbing/object"
 	"github.com/lithammer/fuzzysearch/fuzzy"
 	"github.com/lukaszraczylo/zero"
@@ -44,9 +45,10 @@ type Wording struct {
 }
 
 type Force struct {
-	Patch int
-	Minor int
-	Major int
+	Patch  int
+	Minor  int
+	Major  int
+	Commit string
 }
 
 type SemVer struct {
@@ -107,7 +109,13 @@ func (s *Setup) CalculateSemver() SemVer {
 }
 
 func (s *Setup) ListCommits() ([]CommitDetails, error) {
-	ref, err := s.RepositoryHandler.Head()
+	var ref *plumbing.Reference
+	var err error
+	if zero.IsZero(s.Force.Commit) {
+		ref, err = s.RepositoryHandler.Head()
+	} else {
+		ref = plumbing.NewHashReference("start_commit", plumbing.NewHash(s.Force.Commit))
+	}
 	if err != nil {
 		return []CommitDetails{}, err
 	}

cmd/main_test.go

@@ -285,11 +285,23 @@ func (suite *Tests) TestSetup_ListCommits() {
 			noCommits: true,
 			wantErr:   true,
 		},
+		{
+			name: "List commits starting with certain hash",
+			fields: fields{
+				RepositoryName: "https://github.com/lukaszraczylo/simple-gql-client",
+				Force: Force{
+					Commit: "69fbe2df696f40281b9104ff073d26186cde1024",
+				},
+			},
+			noCommits: false,
+			wantErr:   false,
+		},
 	}
 	for _, tt := range tests {
 		suite.T().Run(tt.name, func(t *testing.T) {
 			s := &Setup{
 				RepositoryName: tt.fields.RepositoryName,
+				Force:          tt.fields.Force,
 			}
 			s.Prepare()
 			listOfCommits, err := s.ListCommits()
@@ -306,6 +318,7 @@ func (suite *Tests) TestSetup_ListCommits() {
 func (suite *Tests) TestSetup_CalculateSemver() {
 	type fields struct {
 		RepositoryName string
+		Force          Force
 	}
 	type wantSemver struct {
 		Major int
@@ -328,6 +341,20 @@ func (suite *Tests) TestSetup_CalculateSemver() {
 				Patch: 1,
 			},
 		},
+		{
+			name: "Test on existing repository, starting with certain hash",
+			fields: fields{
+				RepositoryName: "https://github.com/lukaszraczylo/simple-gql-client",
+				Force: Force{
+					Commit: "69fbe2df696f40281b9104ff073d26186cde1024",
+				},
+			},
+			wantSemver: wantSemver{
+				Major: 3,
+				Minor: 0,
+				Patch: 5,
+			},
+		},
 		{
 			name: "Test on non-existing repository",
 			fields: fields{
@@ -344,6 +371,7 @@ func (suite *Tests) TestSetup_CalculateSemver() {
 		suite.T().Run(tt.name, func(t *testing.T) {
 			s := &Setup{
 				RepositoryName: tt.fields.RepositoryName,
+				Force:          tt.fields.Force,
 			}
 			s.ReadConfig("../config.yaml")
 			s.Prepare()