internal/function: use custom fixed struct as LOC result (#931)

internal/function: use custom fixed struct as LOC result

Author: ajnavarro

docs/using-gitbase/functions.md

@@ -169,6 +169,26 @@ Also, if you want to retrieve values from a non common property, you can pass it
 
 > uast_extract(nodes_column, 'some-property')
 
+## How to use `loc`
+
+`loc` will return statistics about the lines of code in a file, such as the code lines, comment lines, etc.
+
+It requires a file path and a file content.
+
+> loc(file_path, blob_content)
+
+The result of this function is a JSON document with the following shape:
+
+```
+{
+	"Code": code lines,
+	"Comment": comment lines,
+	"Blank": blank lines,
+	"Name": file name,
+	"Lang": language
+}
+```
+
 ## How to use `commit_file_stats`
 
 `commit_file_stats` will return statistics about the line changes in all files in the given range of commits classifying them in 4 categories: code, comments, blank lines and other.

internal/function/loc.go

@@ -52,6 +52,15 @@ func (f *LOC) WithChildren(children ...sql.Expression) (sql.Expression, error) {
 	return NewLOC(children...)
 }
 
+// LocFile is the result of the LOC function for each file.
+type LocFile struct {
+	Code     int32  `json:"Code"`
+	Comments int32  `json:"Comment"`
+	Blanks   int32  `json:"Blank"`
+	Name     string `json:"Name"`
+	Lang     string `json:"Language"`
+}
+
 // Eval implements the Expression interface.
 func (f *LOC) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 	span, ctx := ctx.Span("gitbase.LOC")
@@ -70,11 +79,19 @@ func (f *LOC) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 		return nil, nil
 	}
 
-	return gocloc.AnalyzeReader(
+	file := gocloc.AnalyzeReader(
 		path,
 		languages.Langs[lang],
 		bytes.NewReader(blob), &gocloc.ClocOptions{},
-	), nil
+	)
+
+	return LocFile{
+		Code:     file.Code,
+		Comments: file.Comments,
+		Blanks:   file.Blanks,
+		Name:     file.Name,
+		Lang:     file.Lang,
+	}, nil
 }
 
 func (f *LOC) getInputValues(ctx *sql.Context, row sql.Row) (string, []byte, error) {

internal/function/loc_test.go

@@ -3,11 +3,10 @@ package function
 import (
 	"testing"
 
-	"github.com/hhatto/gocloc"
-	"github.com/stretchr/testify/require"
-	"gopkg.in/src-d/go-errors.v1"
 	"github.com/src-d/go-mysql-server/sql"
 	"github.com/src-d/go-mysql-server/sql/expression"
+	"github.com/stretchr/testify/require"
+	"gopkg.in/src-d/go-errors.v1"
 )
 
 func TestLoc(t *testing.T) {
@@ -22,7 +21,7 @@ func TestLoc(t *testing.T) {
 		{"too few args given", sql.NewRow("foo.foobar"), nil, nil},
 		{"too many args given", sql.NewRow("foo.rb", "bar", "baz"), nil, sql.ErrInvalidArgumentNumber},
 		{"invalid blob type given", sql.NewRow("foo", 5), nil, sql.ErrInvalidType},
-		{"path and blob are given", sql.NewRow("foo", "#!/usr/bin/env python\n\nprint 'foo'"), &gocloc.ClocFile{
+		{"path and blob are given", sql.NewRow("foo", "#!/usr/bin/env python\n\nprint 'foo'"), LocFile{
 			Code: 2, Comments: 0, Blanks: 1, Name: "foo", Lang: "Python",
 		}, nil},
 	}