fix issue #133

scm/driver/bitbucket/git.go

@@ -35,6 +35,15 @@ func (s *gitService) FindBranch(ctx context.Context, repo, name string) (*scm.Re
 }
 
 func (s *gitService) FindCommit(ctx context.Context, repo, ref string) (*scm.Commit, *scm.Response, error) {
+	// github and gitlab permit fetching a commit by sha
+	// or branch. This code emulates the github and gitlab
+	// behavior for bitbucket by fetching the commit sha
+	// for the branch and using in the subsequent API call.
+	if scm.IsHash(ref) == false {
+		if branch, _, err := s.FindBranch(ctx, repo, scm.TrimRef(ref)); err == nil {
+			ref = branch.Sha // replace ref with sha
+		}
+	}
 	path := fmt.Sprintf("2.0/repositories/%s/commit/%s", repo, ref)
 	out := new(commit)
 	res, err := s.client.do(ctx, "GET", path, nil, out)
@@ -217,9 +226,9 @@ func convertDiffstat(from *diffstat) *scm.Change {
 		Deleted: from.Status == "removed",
 	}
 
-	if (response.Renamed) {
+	if response.Renamed {
 		response.PrevFilePath = from.Old.Path
-	} else if (response.Deleted) {
+	} else if response.Deleted {
 		response.Path = from.Old.Path
 	}
 

scm/driver/bitbucket/git_test.go

@@ -41,6 +41,37 @@ func TestGitFindCommit(t *testing.T) {
 	}
 }
 
+func TestGitFindCommitForBranch(t *testing.T) {
+	defer gock.Off()
+
+	gock.New("https://api.bitbucket.org").
+		Get("/2.0/repositories/atlassian/stash-example-plugin/commit/a6e5e7d797edf751cbd839d6bd4aef86c941eec9").
+		Reply(200).
+		Type("application/json").
+		File("testdata/commit.json")
+
+	gock.New("https://api.bitbucket.org").
+		Get("/2.0/repositories/atlassian/stash-example-plugin/refs/branches/master").
+		Reply(200).
+		Type("application/json").
+		File("testdata/branch.json")
+
+	client, _ := New("https://api.bitbucket.org")
+	got, _, err := client.Git.FindCommit(context.Background(), "atlassian/stash-example-plugin", "master")
+	if err != nil {
+		t.Error(err)
+	}
+
+	want := new(scm.Commit)
+	raw, _ := ioutil.ReadFile("testdata/commit.json.golden")
+	json.Unmarshal(raw, &want)
+
+	if diff := cmp.Diff(got, want); diff != "" {
+		t.Errorf("Unexpected Results")
+		t.Log(diff)
+	}
+}
+
 func TestGitCreateBranch(t *testing.T) {
 	defer gock.Off()
 

scm/util.go

@@ -14,6 +14,13 @@ import (
 // from the git ref (e.g. refs/pulls/{d}/head)
 var re = regexp.MustCompile("\\d+")
 
+// regular expressions to test whether or not a string is
+// a sha1 or sha256 commit hash.
+var (
+	sha1   = regexp.MustCompile("^([a-f0-9]{40})$")
+	sha256 = regexp.MustCompile("^([a-f0-9]{64})$")
+)
+
 // Split splits the full repository name into segments.
 func Split(s string) (owner, name string) {
 	parts := strings.SplitN(s, "/", 2)
@@ -78,3 +85,7 @@ func IsPullRequest(ref string) bool {
 		strings.HasPrefix(ref, "refs/merge-requests/")
 }
 
+// IsHash returns true if the string is a commit hash.
+func IsHash(s string) bool {
+	return sha1.MatchString(s) || sha256.MatchString(s)
+}

scm/util_test.go

@@ -193,3 +193,49 @@ func TestExtractPullRequest(t *testing.T) {
 		}
 	}
 }
+
+func TestIsHash(t *testing.T) {
+	tests := []struct {
+		name string
+		tag  bool
+	}{
+		{
+			name: "aacad6eca956c3a340ae5cd5856aa9c4a3755408",
+			tag:  true,
+		},
+		{
+			name: "3da541559918a808c2402bba5012f6c60b27661c",
+			tag:  true,
+		},
+		{
+			name: "f0e4c2f76c58916ec258f246851bea091d14d4247a2fc3e18694461b1816e13b",
+			tag:  true,
+		},
+		// not a sha
+		{
+			name: "aacad6e",
+			tag:  false,
+		},
+		{
+			name: "master",
+			tag:  false,
+		},
+		{
+			name: "refs/heads/master",
+			tag:  false,
+		},
+		{
+			name: "issue/42",
+			tag:  false,
+		},
+		{
+			name: "feature/foo",
+			tag:  false,
+		},
+	}
+	for _, test := range tests {
+		if got, want := IsHash(test.name), test.tag; got != want {
+			t.Errorf("Got IsHash %v, want %v", got, want)
+		}
+	}
+}