Move git diff codes from models to services/gitdiff (#7889)

* move git diff codes from models to services/gitdiff

* fix template

* fix test

* fix template

services/comments/comments.go

@@ -0,0 +1,69 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package comments
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/services/gitdiff"
+)
+
+// CreateCodeComment creates a plain code comment at the specified line / path
+func CreateCodeComment(doer *models.User, repo *models.Repository, issue *models.Issue, content, treePath string, line, reviewID int64) (*models.Comment, error) {
+	var commitID, patch string
+	pr, err := models.GetPullRequestByIssueID(issue.ID)
+	if err != nil {
+		return nil, fmt.Errorf("GetPullRequestByIssueID: %v", err)
+	}
+	if err := pr.GetBaseRepo(); err != nil {
+		return nil, fmt.Errorf("GetHeadRepo: %v", err)
+	}
+	gitRepo, err := git.OpenRepository(pr.BaseRepo.RepoPath())
+	if err != nil {
+		return nil, fmt.Errorf("OpenRepository: %v", err)
+	}
+
+	// FIXME validate treePath
+	// Get latest commit referencing the commented line
+	// No need for get commit for base branch changes
+	if line > 0 {
+		commit, err := gitRepo.LineBlame(pr.GetGitRefName(), gitRepo.Path, treePath, uint(line))
+		if err == nil {
+			commitID = commit.ID.String()
+		} else if !strings.Contains(err.Error(), "exit status 128 - fatal: no such path") {
+			return nil, fmt.Errorf("LineBlame[%s, %s, %s, %d]: %v", pr.GetGitRefName(), gitRepo.Path, treePath, line, err)
+		}
+	}
+
+	// Only fetch diff if comment is review comment
+	if reviewID != 0 {
+		headCommitID, err := gitRepo.GetRefCommitID(pr.GetGitRefName())
+		if err != nil {
+			return nil, fmt.Errorf("GetRefCommitID[%s]: %v", pr.GetGitRefName(), err)
+		}
+		patchBuf := new(bytes.Buffer)
+		if err := gitdiff.GetRawDiffForFile(gitRepo.Path, pr.MergeBase, headCommitID, gitdiff.RawDiffNormal, treePath, patchBuf); err != nil {
+			return nil, fmt.Errorf("GetRawDiffForLine[%s, %s, %s, %s]: %v", err, gitRepo.Path, pr.MergeBase, headCommitID, treePath)
+		}
+		patch = gitdiff.CutDiffAroundLine(patchBuf, int64((&models.Comment{Line: line}).UnsignedLine()), line < 0, setting.UI.CodeCommentLines)
+	}
+	return models.CreateComment(&models.CreateCommentOptions{
+		Type:      models.CommentTypeCode,
+		Doer:      doer,
+		Repo:      repo,
+		Issue:     issue,
+		Content:   content,
+		LineNum:   line,
+		TreePath:  treePath,
+		CommitSHA: commitID,
+		ReviewID:  reviewID,
+		Patch:     patch,
+	})
+}

services/gitdiff/gitdiff_test.go

@@ -0,0 +1,197 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package gitdiff
+
+import (
+	"html/template"
+	"strings"
+	"testing"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/setting"
+
+	dmp "github.com/sergi/go-diff/diffmatchpatch"
+	"github.com/stretchr/testify/assert"
+)
+
+func assertEqual(t *testing.T, s1 string, s2 template.HTML) {
+	if s1 != string(s2) {
+		t.Errorf("%s should be equal %s", s2, s1)
+	}
+}
+
+func TestDiffToHTML(t *testing.T) {
+	assertEqual(t, "foo <span class=\"added-code\">bar</span> biz", diffToHTML([]dmp.Diff{
+		{Type: dmp.DiffEqual, Text: "foo "},
+		{Type: dmp.DiffInsert, Text: "bar"},
+		{Type: dmp.DiffDelete, Text: " baz"},
+		{Type: dmp.DiffEqual, Text: " biz"},
+	}, DiffLineAdd))
+
+	assertEqual(t, "foo <span class=\"removed-code\">bar</span> biz", diffToHTML([]dmp.Diff{
+		{Type: dmp.DiffEqual, Text: "foo "},
+		{Type: dmp.DiffDelete, Text: "bar"},
+		{Type: dmp.DiffInsert, Text: " baz"},
+		{Type: dmp.DiffEqual, Text: " biz"},
+	}, DiffLineDel))
+}
+
+const exampleDiff = `diff --git a/README.md b/README.md
+--- a/README.md
++++ b/README.md
+@@ -1,3 +1,6 @@
+ # gitea-github-migrator
++
++ Build Status
+- Latest Release
+ Docker Pulls
++ cut off
++ cut off`
+
+func TestCutDiffAroundLine(t *testing.T) {
+	result := CutDiffAroundLine(strings.NewReader(exampleDiff), 4, false, 3)
+	resultByLine := strings.Split(result, "\n")
+	assert.Len(t, resultByLine, 7)
+	// Check if headers got transferred
+	assert.Equal(t, "diff --git a/README.md b/README.md", resultByLine[0])
+	assert.Equal(t, "--- a/README.md", resultByLine[1])
+	assert.Equal(t, "+++ b/README.md", resultByLine[2])
+	// Check if hunk header is calculated correctly
+	assert.Equal(t, "@@ -2,2 +3,2 @@", resultByLine[3])
+	// Check if line got transferred
+	assert.Equal(t, "+ Build Status", resultByLine[4])
+
+	// Must be same result as before since old line 3 == new line 5
+	newResult := CutDiffAroundLine(strings.NewReader(exampleDiff), 3, true, 3)
+	assert.Equal(t, result, newResult, "Must be same result as before since old line 3 == new line 5")
+
+	newResult = CutDiffAroundLine(strings.NewReader(exampleDiff), 6, false, 300)
+	assert.Equal(t, exampleDiff, newResult)
+
+	emptyResult := CutDiffAroundLine(strings.NewReader(exampleDiff), 6, false, 0)
+	assert.Empty(t, emptyResult)
+
+	// Line is out of scope
+	emptyResult = CutDiffAroundLine(strings.NewReader(exampleDiff), 434, false, 0)
+	assert.Empty(t, emptyResult)
+}
+
+func BenchmarkCutDiffAroundLine(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		CutDiffAroundLine(strings.NewReader(exampleDiff), 3, true, 3)
+	}
+}
+
+func ExampleCutDiffAroundLine() {
+	const diff = `diff --git a/README.md b/README.md
+--- a/README.md
++++ b/README.md
+@@ -1,3 +1,6 @@
+ # gitea-github-migrator
++
++ Build Status
+- Latest Release
+ Docker Pulls
++ cut off
++ cut off`
+	result := CutDiffAroundLine(strings.NewReader(diff), 4, false, 3)
+	println(result)
+}
+
+func TestParsePatch(t *testing.T) {
+	var diff = `diff --git "a/README.md" "b/README.md"
+--- a/README.md
++++ b/README.md
+@@ -1,3 +1,6 @@
+ # gitea-github-migrator
++
++ Build Status
+- Latest Release
+ Docker Pulls
++ cut off
++ cut off`
+	result, err := ParsePatch(setting.Git.MaxGitDiffLines, setting.Git.MaxGitDiffLineCharacters, setting.Git.MaxGitDiffFiles, strings.NewReader(diff))
+	if err != nil {
+		t.Errorf("ParsePatch failed: %s", err)
+	}
+	println(result)
+
+	var diff2 = `diff --git "a/A \\ B" "b/A \\ B"
+--- "a/A \\ B"
++++ "b/A \\ B"
+@@ -1,3 +1,6 @@
+ # gitea-github-migrator
++
++ Build Status
+- Latest Release
+ Docker Pulls
++ cut off
++ cut off`
+	result, err = ParsePatch(setting.Git.MaxGitDiffLines, setting.Git.MaxGitDiffLineCharacters, setting.Git.MaxGitDiffFiles, strings.NewReader(diff2))
+	if err != nil {
+		t.Errorf("ParsePatch failed: %s", err)
+	}
+	println(result)
+
+	var diff3 = `diff --git a/README.md b/README.md
+--- a/README.md
++++ b/README.md
+@@ -1,3 +1,6 @@
+ # gitea-github-migrator
++
++ Build Status
+- Latest Release
+ Docker Pulls
++ cut off
++ cut off`
+	result, err = ParsePatch(setting.Git.MaxGitDiffLines, setting.Git.MaxGitDiffLineCharacters, setting.Git.MaxGitDiffFiles, strings.NewReader(diff3))
+	if err != nil {
+		t.Errorf("ParsePatch failed: %s", err)
+	}
+	println(result)
+}
+
+func setupDefaultDiff() *Diff {
+	return &Diff{
+		Files: []*DiffFile{
+			{
+				Name: "README.md",
+				Sections: []*DiffSection{
+					{
+						Lines: []*DiffLine{
+							{
+								LeftIdx:  4,
+								RightIdx: 4,
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+func TestDiff_LoadComments(t *testing.T) {
+	assert.NoError(t, models.PrepareTestDatabase())
+
+	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
+	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	diff := setupDefaultDiff()
+	assert.NoError(t, diff.LoadComments(issue, user))
+	assert.Len(t, diff.Files[0].Sections[0].Lines[0].Comments, 2)
+}
+
+func TestDiffLine_CanComment(t *testing.T) {
+	assert.False(t, (&DiffLine{Type: DiffLineSection}).CanComment())
+	assert.False(t, (&DiffLine{Type: DiffLineAdd, Comments: []*models.Comment{{Content: "bla"}}}).CanComment())
+	assert.True(t, (&DiffLine{Type: DiffLineAdd}).CanComment())
+	assert.True(t, (&DiffLine{Type: DiffLineDel}).CanComment())
+	assert.True(t, (&DiffLine{Type: DiffLinePlain}).CanComment())
+}
+
+func TestDiffLine_GetCommentSide(t *testing.T) {
+	assert.Equal(t, "previous", (&DiffLine{Comments: []*models.Comment{{Line: -3}}}).GetCommentSide())
+	assert.Equal(t, "proposed", (&DiffLine{Comments: []*models.Comment{{Line: 3}}}).GetCommentSide())
+}

services/gitdiff/main_test.go

@@ -0,0 +1,16 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package gitdiff
+
+import (
+	"path/filepath"
+	"testing"
+
+	"code.gitea.io/gitea/models"
+)
+
+func TestMain(m *testing.M) {
+	models.MainTest(m, filepath.Join("..", ".."))
+}