Improve git_commits.go coverage (google#1760)

Author: gmlewis

github/git_commits_test.go

@@ -137,6 +137,20 @@ func TestGitService_GetCommit(t *testing.T) {
 	if !reflect.DeepEqual(commit, want) {
 		t.Errorf("Git.GetCommit returned %+v, want %+v", commit, want)
 	}
+
+	const methodName = "GetCommit"
+	testBadOptions(t, methodName, func() (err error) {
+		_, _, err = client.Git.GetCommit(ctx, "\n", "\n", "\n")
+		return err
+	})
+
+	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
+		got, resp, err := client.Git.GetCommit(ctx, "o", "r", "s")
+		if got != nil {
+			t.Errorf("testNewRequestAndDoFailure %v = %#v, want nil", methodName, got)
+		}
+		return resp, err
+	})
 }
 
 func TestGitService_GetCommit_invalidOwner(t *testing.T) {
@@ -185,6 +199,20 @@ func TestGitService_CreateCommit(t *testing.T) {
 	if !reflect.DeepEqual(commit, want) {
 		t.Errorf("Git.CreateCommit returned %+v, want %+v", commit, want)
 	}
+
+	const methodName = "CreateCommit"
+	testBadOptions(t, methodName, func() (err error) {
+		_, _, err = client.Git.CreateCommit(ctx, "\n", "\n", input)
+		return err
+	})
+
+	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
+		got, resp, err := client.Git.CreateCommit(ctx, "o", "r", input)
+		if got != nil {
+			t.Errorf("testNewRequestAndDoFailure %v = %#v, want nil", methodName, got)
+		}
+		return resp, err
+	})
 }
 
 func TestGitService_CreateSignedCommit(t *testing.T) {
@@ -230,7 +258,22 @@ func TestGitService_CreateSignedCommit(t *testing.T) {
 	if !reflect.DeepEqual(commit, want) {
 		t.Errorf("Git.CreateCommit returned %+v, want %+v", commit, want)
 	}
+
+	const methodName = "CreateCommit"
+	testBadOptions(t, methodName, func() (err error) {
+		_, _, err = client.Git.CreateCommit(ctx, "\n", "\n", input)
+		return err
+	})
+
+	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
+		got, resp, err := client.Git.CreateCommit(ctx, "o", "r", input)
+		if got != nil {
+			t.Errorf("testNewRequestAndDoFailure %v = %#v, want nil", methodName, got)
+		}
+		return resp, err
+	})
 }
+
 func TestGitService_CreateSignedCommitWithInvalidParams(t *testing.T) {
 	client, _, _, teardown := setup()
 	defer teardown()