🌱 Unit tests for git client (#3328)

- Add test functions to the Git client for testing repository initialization, commit listing, and search functionality

[clients/git/client_test.go]
- Add `createTestRepo` function to set up a test repository
- Add `TestInitRepo` to test the initialization of a repository
- Add `TestListCommits` to test the listing of commits
- Add `TestSearch` to test the search functionality

Signed-off-by: naveensrinivasan <172697+naveensrinivasan@users.noreply.github.com>

clients/git/client_test.go

@@ -0,0 +1,235 @@
+// Copyright 2023 OpenSSF Scorecard Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package git
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	gitV5 "github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/plumbing/object"
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+
+	"github.com/ossf/scorecard/v4/clients"
+)
+
+func createTestRepo(t *testing.T) (path string) {
+	t.Helper()
+	dir, err := os.MkdirTemp("", "testrepo")
+	if err != nil {
+		t.Fatalf("Failed to create temporary directory: %v", err)
+	}
+	t.Cleanup(func() {
+		os.RemoveAll(dir) // nolint:errcheck
+	})
+	r, err := gitV5.PlainInit(dir, false)
+	if err != nil {
+		t.Fatalf("Failed to initialize git repo: %v", err)
+	}
+
+	w, err := r.Worktree()
+	if err != nil {
+		t.Fatalf("Failed to get worktree: %v", err)
+	}
+
+	// Create a new file
+	filePath := filepath.Join(dir, "file")
+	err = os.WriteFile(filePath, []byte("Hello, World!"), 0o644) //nolint:gosec
+	if err != nil {
+		t.Fatalf("Failed to write a file: %v", err)
+	}
+
+	// Add it to the staging area
+	_, err = w.Add("file")
+	if err != nil {
+		t.Fatalf("Failed to add a file to staging area: %v", err)
+	}
+
+	// Commit
+	_, err = w.Commit("Initial commit", &gitV5.CommitOptions{
+		Author: &object.Signature{
+			Name:  "Test Author",
+			Email: "author@example.com",
+			When:  time.Now(),
+		},
+	})
+
+	if err != nil {
+		t.Fatalf("Failed to make initial commit: %v", err)
+	}
+
+	return dir
+}
+
+//nolint:testparallel
+func TestInitRepo(t *testing.T) {
+	tests := []struct { //nolint:govet
+		name        string
+		uri         string
+		commitSHA   string
+		commitDepth int
+		expectedErr string
+	}{
+		{
+			name:        "Success",
+			uri:         "file://%s",
+			commitSHA:   "HEAD",
+			commitDepth: 1,
+		},
+		{
+			name:        "InvalidUri",
+			uri:         ":",
+			commitSHA:   "",
+			commitDepth: 1,
+			expectedErr: "repository does not exist",
+		},
+		{
+			name:        "NegativeCommitDepth",
+			uri:         "file://%s",
+			commitSHA:   "HEAD",
+			commitDepth: -1,
+		},
+	}
+
+	repoPath := createTestRepo(t)
+
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			uri := fmt.Sprintf(test.uri, repoPath)
+
+			client := &Client{}
+			err := client.InitRepo(uri, test.commitSHA, test.commitDepth)
+			if (test.expectedErr != "") != (err != nil) {
+				t.Errorf("Unexpected error during InitRepo: %v", err)
+			}
+		})
+	}
+}
+
+func TestListCommits(t *testing.T) {
+	repoPath := createTestRepo(t)
+
+	client := &Client{}
+	commitDepth := 1
+	expectedLen := 1
+	commitSHA := "HEAD"
+	uri := fmt.Sprintf("file://%s", repoPath)
+	if err := client.InitRepo(uri, commitSHA, commitDepth); err != nil {
+		t.Fatalf("InitRepo(%s) failed: %v", uri, err)
+	}
+
+	// Act
+	commits, err := client.ListCommits()
+	if err != nil {
+		t.Fatalf("ListCommits() failed: %v", err)
+	}
+
+	// Assert
+	if len(commits) != expectedLen {
+		t.Errorf("ListCommits() returned %d commits, want %d", len(commits), expectedLen)
+	}
+}
+
+//nolint:testparallel
+func TestSearch(t *testing.T) {
+	testCases := []struct {
+		name     string
+		request  clients.SearchRequest
+		expected clients.SearchResponse
+	}{
+		{
+			name: "Search with valid query",
+			request: clients.SearchRequest{
+				Query: "Hello",
+			},
+			expected: clients.SearchResponse{
+				Results: []clients.SearchResult{
+					{
+						Path: "file",
+					},
+					{
+						Path: "test.txt",
+					},
+				},
+				Hits: 2,
+			},
+		},
+		{
+			name: "Search with zero results",
+			request: clients.SearchRequest{
+				Query: "Invalid",
+			},
+			expected: clients.SearchResponse{
+				Hits: 0,
+			},
+		},
+	}
+
+	// Use the same test repo for all test cases.
+	repoPath := createTestRepo(t)
+	filePath := filepath.Join(repoPath, "test.txt")
+	err := os.WriteFile(filePath, []byte("Hello, World!"), 0o644) //nolint:gosec
+	if err != nil {
+		t.Fatalf("WriteFile() failed: %v", err)
+	}
+
+	// Make a commit that adds the file.
+	r, err := gitV5.PlainOpen(repoPath)
+	if err != nil {
+		t.Fatalf("PlainOpen() failed: %v", err)
+	}
+	w, err := r.Worktree()
+	if err != nil {
+		t.Fatalf("Worktree() failed: %v", err)
+	}
+	_, err = w.Add("test.txt")
+	if err != nil {
+		t.Fatalf("Add() failed: %v", err)
+	}
+	_, err = w.Commit("Add test.txt", &gitV5.CommitOptions{
+		Author: &object.Signature{
+			Name:  "Test Author",
+			Email: "author@example.com",
+			When:  time.Now(),
+		},
+	})
+	if err != nil {
+		t.Fatalf("Commit() failed: %v", err)
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			client := &Client{}
+			uri := fmt.Sprintf("file://%s", repoPath)
+			if err := client.InitRepo(uri, "HEAD", 1); err != nil {
+				t.Fatalf("InitRepo(%s) failed: %v", uri, err)
+			}
+
+			response, err := client.Search(tc.request)
+			if err != nil {
+				t.Fatalf("Search() failed: %v", err)
+			}
+
+			if diff := cmp.Diff(tc.expected, response, cmpopts.IgnoreUnexported(clients.SearchResult{})); diff != "" {
+				t.Errorf("Search() returned diff (-want +got):\n%s", diff)
+			}
+		})
+	}
+}