create GetDiff

repository/mocks.go

@@ -103,6 +103,37 @@ func CreateTestRepository(tmp_path string, repo string, file string, content str
 	return cleanup, err
 }
 
+func CreateCommitOnTestRepository(tmpPath string, repo string, file string, content string) ([]byte, error) {
+	testPath := path.Join(tmpPath, repo+".git")
+	gitPath, err := exec.LookPath("git")
+	if err != nil {
+		return nil, err
+	}
+	err = ioutil.WriteFile(path.Join(testPath, file), []byte(content), 0644)
+	if err != nil {
+		return nil, err
+	}
+	cmd := exec.Command(gitPath, "add", ".")
+	cmd.Dir = testPath
+	err = cmd.Run()
+	if err != nil {
+		return nil, err
+	}
+	cmd = exec.Command(gitPath, "commit", "-m", content, "--allow-empty-message")
+	cmd.Dir = testPath
+	err = cmd.Run()
+	if err != nil {
+		return nil, err
+	}
+	cmd = exec.Command(gitPath, "log", "--pretty=format:%H", "-1")
+	cmd.Dir = testPath
+	out, err := cmd.Output()
+	if err !=nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 func CreateBranchesOnTestRepository(tmp_path string, repo string, file string, content string, branches ...string) error {
 	testPath := path.Join(tmp_path, repo+".git")
 	gitPath, err := exec.LookPath("git")
@@ -182,3 +213,13 @@ func (r *MockContentRetriever) GetBranch(repo string) ([]map[string]string, erro
 	}
 	return r.Refs, nil
 }
+
+func (r *MockContentRetriever) GetDiff(repo, previousCommit, lastCommit string) ([]byte, error) {
+	if r.LookPathError != nil {
+		return nil, r.LookPathError
+	}
+	if r.OutputError != nil {
+		return nil, r.OutputError
+	}
+	return r.ResultContents, nil
+}

repository/repository.go

@@ -251,6 +251,7 @@ type ContentRetriever interface {
 	GetTree(repo, ref, path string) ([]map[string]string, error)
 	GetForEachRef(repo, pattern string) ([]map[string]string, error)
 	GetBranch(repo string) ([]map[string]string, error)
+	GetDiff(repo, lastCommit, previousCommit string) ([]byte, error)
 }
 
 var Retriever ContentRetriever
@@ -411,6 +412,25 @@ func (*GitContentRetriever) GetBranch(repo string) ([]map[string]string, error)
 	return branches, err
 }
 
+func (*GitContentRetriever) GetDiff(repo, previousCommit, lastCommit string) ([]byte, error) {
+	gitPath, err := exec.LookPath("git")
+	if err != nil {
+		return nil, fmt.Errorf("Error when trying to obtain diff with commits %s and %s of repository %s (%s).", lastCommit, previousCommit, repo, err)
+	}
+	cwd := barePath(repo)
+	repoExists, err := exists(cwd)
+	if err != nil || !repoExists {
+		return nil, fmt.Errorf("Error when trying to obtain diff with commits %s and %s of repository %s (Repository does not exist).", lastCommit, previousCommit, repo)
+	}
+	cmd := exec.Command(gitPath, "diff", previousCommit, lastCommit)
+	cmd.Dir = cwd
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return nil, fmt.Errorf("Error when trying to obtain diff with commits %s and %s of repository %s (%s).", lastCommit, previousCommit, repo, err)
+	}
+	return out, nil
+}
+
 func retriever() ContentRetriever {
 	if Retriever == nil {
 		Retriever = &GitContentRetriever{}
@@ -441,3 +461,7 @@ func GetForEachRef(repo, pattern string) ([]map[string]string, error) {
 func GetBranch(repo string) ([]map[string]string, error) {
 	return retriever().GetBranch(repo)
 }
+
+func GetDiff(repo, previousCommit, lastCommit string) ([]byte, error) {
+	return retriever().GetDiff(repo, previousCommit, lastCommit)
+}

repository/repository_test.go

@@ -876,3 +876,67 @@ func (s *S) TestGetBranchIntegrationEmptySubject(c *gocheck.C) {
 	c.Assert(branches[1]["authorEmail"], gocheck.Equals, "<much@email.com>")
 	c.Assert(branches[1]["subject"], gocheck.Equals, "")
 }
+
+func (s *S) TestGetDiffIntegration(c *gocheck.C) {
+	oldBare := bare
+	bare = "/tmp"
+	repo := "gandalf-test-repo"
+	file := "README"
+	content := "Just a regular readme."
+	object1 := "You should read this README"
+	object2 := "Seriously, read this file!"
+	cleanUp, errCreate := CreateTestRepository(bare, repo, file, content)
+	defer func() {
+		cleanUp()
+		bare = oldBare
+	}()
+	c.Assert(errCreate, gocheck.IsNil)
+	firstCommit, err := CreateCommitOnTestRepository(bare, repo, file, object1)
+	c.Assert(err, gocheck.IsNil)
+	secondCommit, err := CreateCommitOnTestRepository(bare, repo, file, object2)
+	c.Assert(err, gocheck.IsNil)
+	diff, err := GetDiff(repo, string(firstCommit), string(secondCommit))
+	c.Assert(err, gocheck.IsNil)
+	c.Assert(string(diff), gocheck.Matches, `(?s).*-You should read this README.*\+Seriously, read this file!.*`)
+}
+
+func (s *S) TestGetDiffIntegrationWhenInvalidRepo(c *gocheck.C) {
+	oldBare := bare
+	bare = "/tmp"
+	repo := "gandalf-test-repo"
+	file := "README"
+	content := "Just a regular readme."
+	object1 := "You should read this README"
+	object2 := "Seriously, read this file!"
+	cleanUp, errCreate := CreateTestRepository(bare, repo, file, content)
+	defer func() {
+		cleanUp()
+		bare = oldBare
+	}()
+	c.Assert(errCreate, gocheck.IsNil)
+	firstCommit, err := CreateCommitOnTestRepository(bare, repo, file, object1)
+	c.Assert(err, gocheck.IsNil)
+	secondCommit, err := CreateCommitOnTestRepository(bare, repo, file, object2)
+	c.Assert(err, gocheck.IsNil)
+	_, err = GetDiff("invalid-repo", string(firstCommit), string(secondCommit))
+	c.Assert(err.Error(), gocheck.Equals, fmt.Sprintf("Error when trying to obtain diff with commits %s and %s of repository invalid-repo (Repository does not exist).", secondCommit, firstCommit))
+}
+
+func (s *S) TestGetDiffIntegrationWhenInvalidCommit(c *gocheck.C) {
+	oldBare := bare
+	bare = "/tmp"
+	repo := "gandalf-test-repo"
+	file := "README"
+	content := "Just a regular readme."
+	object1 := "You should read this README"
+	cleanUp, errCreate := CreateTestRepository(bare, repo, file, content)
+	defer func() {
+		cleanUp()
+		bare = oldBare
+	}()
+	c.Assert(errCreate, gocheck.IsNil)
+	firstCommit, err := CreateCommitOnTestRepository(bare, repo, file, object1)
+	c.Assert(err, gocheck.IsNil)
+	_, err = GetDiff(repo, "12beu23eu23923ey32eiyeg2ye", string(firstCommit))
+	c.Assert(err.Error(), gocheck.Equals, fmt.Sprintf("Error when trying to obtain diff with commits %s and 12beu23eu23923ey32eiyeg2ye of repository %s (exit status 128).", firstCommit, repo))
+}