🐛 handle gitlab repos with no commits (#3731)

* fix: handle gitlab repos with no commits

Signed-off-by: Allen Shearin <allen.p.shearin@gmail.com>

* fix: gitlab listcommits tests, remove else in commit array length check

Signed-off-by: Allen Shearin <allen.p.shearin@gmail.com>

* rename test file, remove unneeded test

Signed-off-by: Allen Shearin <allen.p.shearin@gmail.com>

---------

Signed-off-by: Allen Shearin <allen.p.shearin@gmail.com>

clients/gitlabrepo/checkruns_test.go

@@ -48,7 +48,7 @@ func Test_CheckRuns(t *testing.T) {
 		},
 		{
 			name:         "valid checkruns with zero results",
-			responsePath: "./testdata/valid-checkruns-1",
+			responsePath: "./testdata/empty-response",
 			ref:          "eb94b618fb5865b26e80fdd8ae531b7a63ad851a",
 			wantErr:      false,
 		},

clients/gitlabrepo/client.go

@@ -184,6 +184,10 @@ func (client *Client) ListCommits() ([]clients.Commit, error) {
 		return []clients.Commit{}, err
 	}
 
+	if len(commitsRaw) < 1 {
+		return []clients.Commit{}, nil
+	}
+
 	before := commitsRaw[0].CommittedDate
 	// Get merge request details from GraphQL
 	// GitLab REST API doesn't provide a way to link Merge Requests and Commits that

clients/gitlabrepo/client_test.go

@@ -15,10 +15,15 @@
 package gitlabrepo
 
 import (
+	"context"
 	"errors"
+	"net/http"
 	"testing"
 
+	"github.com/google/go-cmp/cmp"
 	"github.com/xanzy/go-gitlab"
+
+	"github.com/ossf/scorecard/v4/clients"
 )
 
 func TestCheckRepoInaccessible(t *testing.T) {
@@ -69,3 +74,71 @@ func TestCheckRepoInaccessible(t *testing.T) {
 		})
 	}
 }
+
+func TestListCommits(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name         string
+		responsePath string
+		commits      []clients.Commit
+		wantErr      bool
+	}{
+		{
+			name:         "Error in ListRawCommits",
+			responsePath: "./testdata/invalid-commits",
+			commits:      []clients.Commit{},
+			wantErr:      true,
+		},
+		{
+			name:         "No commits in repo",
+			responsePath: "./testdata/empty-response",
+			commits:      []clients.Commit{},
+			wantErr:      false,
+		},
+	}
+	for _, tt := range tests {
+		tt := tt
+
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			httpClient := &http.Client{
+				Transport: suffixStubTripper{
+					responsePaths: map[string]string{
+						"commits": tt.responsePath, // corresponds to projects/<id>/repository/commits
+					},
+				},
+			}
+			glclient, err := gitlab.NewClient("", gitlab.WithHTTPClient(httpClient))
+			if err != nil {
+				t.Fatalf("gitlab.NewClient error: %v", err)
+			}
+			commitshandler := &commitsHandler{
+				glClient: glclient,
+			}
+
+			repoURL := repoURL{
+				owner:     "ossf-tests",
+				commitSHA: clients.HeadSHA,
+			}
+
+			commitshandler.init(&repoURL, 30)
+
+			gqlhandler := graphqlHandler{
+				client: httpClient,
+			}
+			gqlhandler.init(context.Background(), &repoURL)
+
+			client := &Client{glClient: glclient, commits: commitshandler, graphql: &gqlhandler}
+
+			got, Err := client.ListCommits()
+
+			if (Err != nil) != tt.wantErr {
+				t.Fatalf("ListCommits, wanted Error: %v, got Error: %v", tt.wantErr, Err)
+			}
+			if !cmp.Equal(got, tt.commits) {
+				t.Errorf("ListCommits() got %v, want %v", got, tt.commits)
+			}
+		})
+	}
+}