Add "git blame" parser

blame.go

@@ -0,0 +1,128 @@
+package git
+
+import (
+	"bufio"
+	"bytes"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// BlameFile return map of line number and Commit that change that line
+func (r *Repository) BlameFile(file string) (map[int]*Commit, error) {
+	cmd := NewCommand("blame", "-p", file)
+	stdout, err := cmd.Run()
+	if err != nil {
+		return nil, err
+	}
+	return Blame(stdout)
+}
+
+// Blame parse content of `git blame` in porcelain format
+func Blame(content []byte) (map[int]*Commit, error) {
+	var commits = make(map[[20]byte]*Commit)
+	var commit = &Commit{}
+	var details = make(map[string]string)
+	var result = make(map[int]*Commit)
+	scanner := bufio.NewScanner(bytes.NewReader(content))
+	for scanner.Scan() {
+		line := scanner.Text()
+		if string(line[0]) != "\t" {
+			words := strings.Fields(line)
+			sha, err := NewIDFromString(words[0])
+			if err == nil {
+				// SHA and rows numbers line
+				commit = getCommit(sha, commits)
+				commit.fill(details)
+				details = make(map[string]string) // empty all details
+				i, err := strconv.Atoi(words[2])
+				if err != nil {
+					return nil, err
+				}
+				result[i] = commit
+			} else {
+				// commit details line
+				switch words[0] {
+				case "summary":
+					commit.Message = line[len(words[0])+1:]
+				case "previous":
+					commit.parents = []*SHA1{MustIDFromString(words[1])}
+				default:
+					if len(words) > 1 {
+						details[words[0]] = line[len(words[0])+1:]
+					}
+				}
+			}
+		} else {
+			// needed for last line in blame
+			commit.fill(details)
+		}
+	}
+
+	return result, nil
+}
+
+// Return commit from map or creates a new one
+func getCommit(sha *SHA1, commits map[[20]byte]*Commit) *Commit {
+	commit, ok := commits[sha.bytes]
+	if !ok {
+		commit = &Commit{
+			ID: sha,
+		}
+		commits[sha.bytes] = commit
+	}
+
+	return commit
+}
+
+func (c *Commit) fill(data map[string]string) {
+	author, ok := data["author"]
+	if ok && c.Author == nil {
+		t, err := parseBlameTime(data, "author")
+		if err != nil {
+			c.Author = &Signature{
+				Name:  author,
+				Email: data["author-mail"],
+			}
+		} else {
+			c.Author = &Signature{
+				Name:  author,
+				Email: data["author-mail"],
+				When:  t,
+			}
+		}
+	}
+	committer, ok := data["committer"]
+	if ok && c.Committer == nil {
+		t, err := parseBlameTime(data, "committer")
+		if err != nil {
+			c.Committer = &Signature{
+				Name:  committer,
+				Email: data["committer-mail"],
+			}
+		} else {
+			c.Committer = &Signature{
+				Name:  committer,
+				Email: data["committer-mail"],
+				When:  t,
+			}
+		}
+	}
+}
+
+func parseBlameTime(data map[string]string, prefix string) (time.Time, error) {
+	atoi, err := strconv.ParseInt(data[prefix+"-time"], 10, 64)
+	if err != nil {
+		return time.Time{}, err
+	}
+	t := time.Unix(atoi, 0)
+
+	if len(data["author-tz"]) == 5 {
+		hours, ok1 := strconv.ParseInt(data[prefix+"-tz"][:3], 10, 0)
+		mins, ok2 := strconv.ParseInt(data[prefix+"-tz"][3:5], 10, 0)
+		if ok1 == nil && ok2 == nil {
+			t = t.In(time.FixedZone("Fixed", int((hours*60+mins)*60)))
+		}
+	}
+	return t, nil
+}

blame_test.go

@@ -0,0 +1,101 @@
+package git
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+	"time"
+)
+
+var oneRowBlame = `2c49687c5b06776a44e2a8c0635428f647909472 3 3 4
+author ᴜɴᴋɴᴡᴏɴ
+author-mail <[email protected]>
+author-time 1585383299
+author-tz +0800
+committer GitHub
+committer-mail <[email protected]>
+committer-time 1585383299
+committer-tz +0800
+summary ci: migrate from Travis to GitHub Actions (#50)
+previous 0d17b78404b7432905a58a235d875e9d28969ee3 README.md
+filename README.md
+	[![GitHub Workflow Status](https://img.shields.io/github/workflow/status/gogs/git-module/Go?logo=github&style=for-the-badge)](https://github.com/gogs/git-module/actions?query=workflow%3AGo)
+`
+
+var twoRowsBlame = `f29bce1e3a666c02175d080892be185405dd3af4 1 1 2
+author Unknwon
+author-mail <[email protected]>
+author-time 1573967409
+author-tz -0800
+committer Unknwon
+committer-mail <[email protected]>
+committer-time 1573967409
+committer-tz -0800
+summary README:  update badges
+previous 065699e51f42559ab0c3ad22c1f2c789b2def8fb README.md
+filename README.md
+	# Git Module 
+f29bce1e3a666c02175d080892be185405dd3af4 2 2
+
+`
+
+var commit1 = &Commit{
+	ID:      MustIDFromString("f29bce1e3a666c02175d080892be185405dd3af4"),
+	Message: "README:  update badges",
+	Author: &Signature{
+		Name:  "Unknwon",
+		Email: "<[email protected]>",
+		When:  time.Unix(1573967409, 0).In(time.FixedZone("Fixed", -8*60*60)),
+	},
+	Committer: &Signature{
+		Name:  "Unknwon",
+		Email: "<[email protected]>",
+		When:  time.Unix(1573967409, 0).In(time.FixedZone("Fixed", -8*60*60)),
+	},
+	parents: []*SHA1{MustIDFromString("065699e51f42559ab0c3ad22c1f2c789b2def8fb")},
+}
+
+var commit2 = &Commit{
+	ID:      MustIDFromString("2c49687c5b06776a44e2a8c0635428f647909472"),
+	Message: "ci: migrate from Travis to GitHub Actions (#50)",
+	Author: &Signature{
+		Name:  "ᴜɴᴋɴᴡᴏɴ",
+		Email: "<[email protected]>",
+		When:  time.Unix(1585383299, 0).In(time.FixedZone("Fixed", 8*60*60)),
+	},
+	Committer: &Signature{
+		Name:  "GitHub",
+		Email: "<[email protected]>",
+		When:  time.Unix(1585383299, 0).In(time.FixedZone("Fixed", 8*60*60)),
+	},
+	parents: []*SHA1{MustIDFromString("0d17b78404b7432905a58a235d875e9d28969ee3")},
+}
+
+func TestOneRowBlame(t *testing.T) {
+	blame, _ := Blame([]byte(oneRowBlame))
+	var expect = make(map[int]*Commit)
+
+	expect[3] = commit2
+
+	assert.Equal(t, expect, blame)
+}
+
+func TestMultipleRowsBlame(t *testing.T) {
+	blame, _ := Blame([]byte(twoRowsBlame + oneRowBlame))
+	var expect = make(map[int]*Commit)
+
+	expect[1] = commit1
+	expect[2] = commit1
+	expect[3] = commit2
+
+	assert.Equal(t, expect, blame)
+}
+
+func TestRepository_BlameFile(t *testing.T) {
+	blame, _ := testrepo.BlameFile("README.md")
+	assert.Greater(t, len(blame), 0)
+}
+
+func TestRepository_BlameNotExistFile(t *testing.T) {
+	_, err := testrepo.BlameFile("0")
+	assert.Error(t, err)
+}