query and show commits by branch

This allows the same SHA to have different builds on different branches, each
separately viewable. This is useful for expressing a "pipeline" in terms of
branches, e.g. a commit starts on branch A and progress through B and C to
master, with the build script switching on branch name.

Previously viewing each build would arbitrarily choose which branch's commit
to show.

pkg/database/testing/commits_test.go

@@ -44,6 +44,32 @@ func TestGetCommit(t *testing.T) {
 	}
 }
 
+func TestGetCommitBranchHash(t *testing.T) {
+	Setup()
+	defer Teardown()
+
+	commit, err := database.GetCommitBranchHash("develop", "5f32ec7b08dfe3a097c1a5316de5b5069fb35ff9", 2)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if commit.ID != 5 {
+		t.Errorf("Exepected ID %d, got %d", 5, commit.ID)
+	}
+
+	if commit.Branch != "develop" {
+		t.Errorf("Exepected Branch %s, got %s", "develop", commit.Branch)
+	}
+
+	if commit.Hash != "5f32ec7b08dfe3a097c1a5316de5b5069fb35ff9" {
+		t.Errorf("Exepected Hash %s, got %s", "5f32ec7b08dfe3a097c1a5316de5b5069fb35ff9", commit.Hash)
+	}
+
+	if commit.Status != "Success" {
+		t.Errorf("Exepected Status %s, got %s", "Success", commit.Status)
+	}
+}
+
 func TestGetCommitHash(t *testing.T) {
 	Setup()
 	defer Teardown()

pkg/database/testing/testing.go

@@ -191,12 +191,22 @@ func Setup() {
 		Gravatar: user1.Gravatar,
 		Message:  "commit message",
 	}
+	commit5 := Commit{
+		RepoID:   repo2.ID,
+		Status:   "Success",
+		Hash:     "5f32ec7b08dfe3a097c1a5316de5b5069fb35ff9",
+		Branch:   "develop",
+		Author:   user1.Email,
+		Gravatar: user1.Gravatar,
+		Message:  "commit message",
+	}
 
 	// create dummy commit data
 	database.SaveCommit(&commit1)
 	database.SaveCommit(&commit2)
 	database.SaveCommit(&commit3)
 	database.SaveCommit(&commit4)
+	database.SaveCommit(&commit5)
 
 	// create dummy build data
 	database.SaveBuild(&Build{CommitID: commit1.ID, Slug: "node_0.10", Status: "Success", Duration: 60})