internal/function: implement commit_file_stats

Signed-off-by: Miguel Molina <miguel@erizocosmi.co>

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added `commit_file_stats` function.
 - Added documentation about `commit_stats`.
 
 ### Changed
@@ -17,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - internal/function: take into account if repository is resolved in commit_stats ([#863](https://github.com/src-d/gitbase/pull/863))
+- internal/function: `Files` field in `commit_stats` contains now proper results.
 
 ### Changed
 

docs/using-gitbase/functions.md

@@ -6,7 +6,8 @@ To make some common tasks easier for the user, there are some functions to inter
 
 |     Name     |                                               Description                                                                      |
 |:-------------|:-------------------------------------------------------------------------------------------------------------------------------|
-|`commit_stats(repository_id, [from_commit_hash], to_commit_hash)`|returns the stats between two commits for a repository. If from is empty, it will compare the given `to_commit_hash` with its parent commit|
+|`commit_stats(repository_id, [from_commit_hash], to_commit_hash)`|returns the stats between two commits for a repository. If from is empty, it will compare the given `to_commit_hash` with its parent commit. Vendored files stats are not included in the result of this function.|
+|`commit_file_stats(repository_id, [from_commit_hash], to_commit_hash)`|returns an array with the stats of each file in `to_commit_hash` since the given `from_commit_hash`. If from is not given, the parent commit will be used. Vendored files stats are not included in the result of this function.|
 |`is_remote(reference_name)bool`| check if the given reference name is from a remote one                                                          |
 |`is_tag(reference_name)bool`| check if the given reference name is a tag                                                                         |
 |`is_vendor(file_path)bool`| check if the given file name is a vendored file                                                                         |

internal/commitstats/commit.go

@@ -0,0 +1,60 @@
+package commitstats
+
+import (
+	"fmt"
+
+	"gopkg.in/src-d/go-git.v4"
+	"gopkg.in/src-d/go-git.v4/plumbing/object"
+)
+
+// CommitStats represents the stats for a commit.
+type CommitStats struct {
+	// Files add/modified/removed by this commit.
+	Files int
+	// Code stats of the code lines.
+	Code KindStats
+	// Comment stats of the comment lines.
+	Comment KindStats
+	// Blank stats of the blank lines.
+	Blank KindStats
+	// Other stats of files that are not from a recognized or format language.
+	Other KindStats
+	// Total the sum of the previous stats.
+	Total KindStats
+}
+
+func (s *CommitStats) String() string {
+	return fmt.Sprintf("Code (+%d/-%d)\nComment (+%d/-%d)\nBlank (+%d/-%d)\nOther (+%d/-%d)\nTotal (+%d/-%d)\nFiles (%d)\n",
+		s.Code.Additions, s.Code.Deletions,
+		s.Comment.Additions, s.Comment.Deletions,
+		s.Blank.Additions, s.Blank.Deletions,
+		s.Other.Additions, s.Other.Deletions,
+		s.Total.Additions, s.Total.Deletions,
+		s.Files,
+	)
+}
+
+// Calculate calculates the CommitStats for from commit to another.
+// if from is nil the first parent is used, if the commit is orphan the stats
+// are compared against a empty commit.
+func Calculate(r *git.Repository, from, to *object.Commit) (*CommitStats, error) {
+	fs, err := CalculateByFile(r, from, to)
+	if err != nil {
+		return nil, err
+	}
+
+	return commitStatsFromCommitFileStats(fs), nil
+}
+
+func commitStatsFromCommitFileStats(fs []CommitFileStats) *CommitStats {
+	var s CommitStats
+	for _, f := range fs {
+		s.Blank.Add(f.Blank)
+		s.Comment.Add(f.Comment)
+		s.Code.Add(f.Code)
+		s.Other.Add(f.Other)
+		s.Total.Add(f.Total)
+		s.Files++
+	}
+	return &s
+}