Merge pull request #3 from go-git/pr-1248

git.LogOptions: add `PathFilter func(string) bool` 

4 files changed, 117 insertions, 16 deletions

diff --git a/options.go b/options.go
index cc8f9c5..9a03560 100644
--- a/options.go
+++ b/options.go
@@ -343,8 +343,15 @@ type LogOptions struct {
 
 	// Show only those commits in which the specified file was inserted/updated.
 	// It is equivalent to running `git log -- <file-name>`.
+	// this field is kept for compatility, it can be replaced with PathFilter
 	FileName *string
 
+	// Filter commits based on the path of files that are updated
+	// takes file path as argument and should return true if the file is desired
+	// It can be used to implement `git log -- <path>`
+	// either <path> is a file path, or directory path, or a regexp of file/directory path
+	PathFilter func(string) bool
+
 	// Pretend as if all the refs in refs/, along with HEAD, are listed on the command line as <commit>.
 	// It is equivalent to running `git log --all`.
 	// If set on true, the From option will be ignored.
diff --git a/plumbing/object/commit_walker_file.go b/plumbing/object/commit_walker_path.go
index b73e4ce..6a49fd1 100644
--- a/plumbing/object/commit_walker_file.go
+++ b/plumbing/object/commit_walker_path.go
@@ -8,27 +8,39 @@ import (
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 )
 
-type commitFileIter struct {
-	fileName      string
+type commitPathIter struct {
+	pathFilter    func(string) bool
 	sourceIter    CommitIter
 	currentCommit *Commit
 	checkParent   bool
 }
 
-// NewCommitFileIterFromIter returns a commit iterator which performs diffTree between
+// NewCommitPathIterFromIter returns a commit iterator which performs diffTree between
 // successive trees returned from the commit iterator from the argument. The purpose of this is
 // to find the commits that explain how the files that match the path came to be.
 // If checkParent is true then the function double checks if potential parent (next commit in a path)
 // is one of the parents in the tree (it's used by `git log --all`).
-func NewCommitFileIterFromIter(fileName string, commitIter CommitIter, checkParent bool) CommitIter {
-	iterator := new(commitFileIter)
+// pathFilter is a function that takes path of file as argument and returns true if we want it
+func NewCommitPathIterFromIter(pathFilter func(string) bool, commitIter CommitIter, checkParent bool) CommitIter {
+	iterator := new(commitPathIter)
 	iterator.sourceIter = commitIter
-	iterator.fileName = fileName
+	iterator.pathFilter = pathFilter
 	iterator.checkParent = checkParent
 	return iterator
 }
 
-func (c *commitFileIter) Next() (*Commit, error) {
+// this function is kept for compatibilty, can be replaced with NewCommitPathIterFromIter
+func NewCommitFileIterFromIter(fileName string, commitIter CommitIter, checkParent bool) CommitIter {
+	return NewCommitPathIterFromIter(
+		func(path string) bool {
+			return path == fileName
+		},
+		commitIter,
+		checkParent,
+	)
+}
+
+func (c *commitPathIter) Next() (*Commit, error) {
 	if c.currentCommit == nil {
 		var err error
 		c.currentCommit, err = c.sourceIter.Next()
@@ -45,7 +57,7 @@ func (c *commitFileIter) Next() (*Commit, error) {
 	return commit, commitErr
 }
 
-func (c *commitFileIter) getNextFileCommit() (*Commit, error) {
+func (c *commitPathIter) getNextFileCommit() (*Commit, error) {
 	for {
 		// Parent-commit can be nil if the current-commit is the initial commit
 		parentCommit, parentCommitErr := c.sourceIter.Next()
@@ -96,9 +108,9 @@ func (c *commitFileIter) getNextFileCommit() (*Commit, error) {
 	}
 }
 
-func (c *commitFileIter) hasFileChange(changes Changes, parent *Commit) bool {
+func (c *commitPathIter) hasFileChange(changes Changes, parent *Commit) bool {
 	for _, change := range changes {
-		if change.name() != c.fileName {
+		if !c.pathFilter(change.name()) {
 			continue
 		}
 
@@ -125,7 +137,7 @@ func isParentHash(hash plumbing.Hash, commit *Commit) bool {
 	return false
 }
 
-func (c *commitFileIter) ForEach(cb func(*Commit) error) error {
+func (c *commitPathIter) ForEach(cb func(*Commit) error) error {
 	for {
 		commit, nextErr := c.Next()
 		if nextErr == io.EOF {
@@ -144,6 +156,6 @@ func (c *commitFileIter) ForEach(cb func(*Commit) error) error {
 	return nil
 }
 
-func (c *commitFileIter) Close() {
+func (c *commitPathIter) Close() {
 	c.sourceIter.Close()
 }
diff --git a/repository.go b/repository.go
index 11269ef..1e3e339 100644
--- a/repository.go
+++ b/repository.go
@@ -1067,6 +1067,9 @@ func (r *Repository) Log(o *LogOptions) (object.CommitIter, error) {
 		// for `git log --all` also check parent (if the next commit comes from the real parent)
 		it = r.logWithFile(*o.FileName, it, o.All)
 	}
+	if o.PathFilter != nil {
+		it = r.logWithPathFilter(o.PathFilter, it, o.All)
+	}
 
 	if o.Since != nil || o.Until != nil {
 		limitOptions := object.LogLimitOptions{Since: o.Since, Until: o.Until}
@@ -1099,7 +1102,21 @@ func (r *Repository) logAll(commitIterFunc func(*object.Commit) object.CommitIte
 }
 
 func (*Repository) logWithFile(fileName string, commitIter object.CommitIter, checkParent bool) object.CommitIter {
-	return object.NewCommitFileIterFromIter(fileName, commitIter, checkParent)
+	return object.NewCommitPathIterFromIter(
+		func(path string) bool {
+			return path == fileName
+		},
+		commitIter,
+		checkParent,
+	)
+}
+
+func (*Repository) logWithPathFilter(pathFilter func(string) bool, commitIter object.CommitIter, checkParent bool) object.CommitIter {
+	return object.NewCommitPathIterFromIter(
+		pathFilter,
+		commitIter,
+		checkParent,
+	)
 }
 
 func (*Repository) logWithLimit(commitIter object.CommitIter, limitOptions object.LogLimitOptions) object.CommitIter {
diff --git a/repository_test.go b/repository_test.go
index e85311f..06b748a 100644
--- a/repository_test.go
+++ b/repository_test.go
@@ -10,6 +10,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"testing"
 	"time"
@@ -1676,6 +1677,70 @@ func (s *RepositorySuite) TestLogFileWithError(c *C) {
 	c.Assert(err, NotNil)
 }
 
+func (s *RepositorySuite) TestLogPathWithError(c *C) {
+	fileName := "README"
+	pathIter := func(path string) bool {
+		return path == fileName
+	}
+	cIter := object.NewCommitPathIterFromIter(pathIter, &mockErrCommitIter{}, false)
+	defer cIter.Close()
+
+	err := cIter.ForEach(func(commit *object.Commit) error {
+		return nil
+	})
+	c.Assert(err, NotNil)
+}
+
+func (s *RepositorySuite) TestLogPathRegexpWithError(c *C) {
+	pathRE := regexp.MustCompile("R.*E")
+	pathIter := func(path string) bool {
+		return pathRE.MatchString(path)
+	}
+	cIter := object.NewCommitPathIterFromIter(pathIter, &mockErrCommitIter{}, false)
+	defer cIter.Close()
+
+	err := cIter.ForEach(func(commit *object.Commit) error {
+		return nil
+	})
+	c.Assert(err, NotNil)
+}
+
+func (s *RepositorySuite) TestLogPathFilterRegexp(c *C) {
+	pathRE := regexp.MustCompile(".*\\.go")
+	pathIter := func(path string) bool {
+		return pathRE.MatchString(path)
+	}
+
+	r, _ := Init(memory.NewStorage(), nil)
+	err := r.clone(context.Background(), &CloneOptions{
+		URL: s.GetBasicLocalRepositoryURL(),
+	})
+	c.Assert(err, IsNil)
+
+	expectedCommitIDs := []string{
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
+		"918c48b83bd081e863dbe1b80f8998f058cd8294",
+	}
+	commitIDs := []string{}
+
+	cIter, err := r.Log(&LogOptions{
+		PathFilter: pathIter,
+		From:       plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"),
+	})
+	c.Assert(err, IsNil)
+	defer cIter.Close()
+
+	cIter.ForEach(func(commit *object.Commit) error {
+		commitIDs = append(commitIDs, commit.ID().String())
+		return nil
+	})
+	c.Assert(
+		strings.Join(commitIDs, ", "),
+		Equals,
+		strings.Join(expectedCommitIDs, ", "),
+	)
+}
+
 func (s *RepositorySuite) TestLogLimitNext(c *C) {
 	r, _ := Init(memory.NewStorage(), nil)
 	err := r.clone(context.Background(), &CloneOptions{
@@ -2615,9 +2680,9 @@ func (s *RepositorySuite) TestResolveRevisionWithErrors(c *C) {
 	c.Assert(err, IsNil)
 
 	datas := map[string]string{
-		"efs/heads/master~": "reference not found",
-		"HEAD^3":            `Revision invalid : "3" found must be 0, 1 or 2 after "^"`,
-		"HEAD^{/whatever}":  `No commit message match regexp : "whatever"`,
+		"efs/heads/master~":                        "reference not found",
+		"HEAD^3":                                   `Revision invalid : "3" found must be 0, 1 or 2 after "^"`,
+		"HEAD^{/whatever}":                         `No commit message match regexp : "whatever"`,
 		"4e1243bd22c66e76c2ba9eddc1f91394e57f9f83": "reference not found",
 	}