knotserver/git: add tests for applyPatch

Signed-off-by: oppiliappan <[e-mail]>

knotserver/git/merge_test.go

···
+package git
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/config"
+	"github.com/go-git/go-git/v5/plumbing"
+	"github.com/go-git/go-git/v5/plumbing/object"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type Helper struct {
+	t       *testing.T
+	tempDir string
+	repo    *GitRepo
+}
+
+func helper(t *testing.T) *Helper {
+	tempDir, err := os.MkdirTemp("", "git-merge-test-*")
+	require.NoError(t, err)
+
+	return &Helper{
+		t:       t,
+		tempDir: tempDir,
+	}
+}
+
+func (h *Helper) cleanup() {
+	if h.tempDir != "" {
+		os.RemoveAll(h.tempDir)
+	}
+}
+
+// initRepo initializes a git repository with an initial commit
+func (h *Helper) initRepo() *GitRepo {
+	repoPath := filepath.Join(h.tempDir, "test-repo")
+
+	// initialize repository
+	r, err := git.PlainInit(repoPath, false)
+	require.NoError(h.t, err)
+
+	// configure git user
+	cfg, err := r.Config()
+	require.NoError(h.t, err)
+	cfg.User.Name = "Test User"
+	cfg.User.Email = "[e-mail]"
+	err = r.SetConfig(cfg)
+	require.NoError(h.t, err)
+
+	// create initial commit with a file
+	w, err := r.Worktree()
+	require.NoError(h.t, err)
+
+	// create initial file
+	initialFile := filepath.Join(repoPath, "README.md")
+	err = os.WriteFile(initialFile, []byte("# Test Repository\n\nInitial content.\n"), 0644)
+	require.NoError(h.t, err)
+
+	_, err = w.Add("README.md")
+	require.NoError(h.t, err)
+
+	_, err = w.Commit("Initial commit", &git.CommitOptions{
+		Author: &object.Signature{
+			Name:  "Test User",
+			Email: "[e-mail]",
+		},
+	})
+	require.NoError(h.t, err)
+
+	gitRepo, err := PlainOpen(repoPath)
+	require.NoError(h.t, err)
+
+	h.repo = gitRepo
+	return gitRepo
+}
+
+// addFile creates a file in the repository
+func (h *Helper) addFile(filename, content string) {
+	filePath := filepath.Join(h.repo.path, filename)
+	dir := filepath.Dir(filePath)
+
+	err := os.MkdirAll(dir, 0755)
+	require.NoError(h.t, err)
+
+	err = os.WriteFile(filePath, []byte(content), 0644)
+	require.NoError(h.t, err)
+}
+
+// commitFile adds and commits a file
+func (h *Helper) commitFile(filename, content, message string) plumbing.Hash {
+	h.addFile(filename, content)
+
+	w, err := h.repo.r.Worktree()
+	require.NoError(h.t, err)
+
+	_, err = w.Add(filename)
+	require.NoError(h.t, err)
+
+	hash, err := w.Commit(message, &git.CommitOptions{
+		Author: &object.Signature{
+			Name:  "Test User",
+			Email: "[e-mail]",
+		},
+	})
+	require.NoError(h.t, err)
+
+	return hash
+}
+
+// readFile reads a file from the repository
+func (h *Helper) readFile(filename string) string {
+	content, err := os.ReadFile(filepath.Join(h.repo.path, filename))
+	require.NoError(h.t, err)
+	return string(content)
+}
+
+// fileExists checks if a file exists in the repository
+func (h *Helper) fileExists(filename string) bool {
+	_, err := os.Stat(filepath.Join(h.repo.path, filename))
+	return err == nil
+}
+
+func TestApplyPatch_Success(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	// modify README.md
+	patch := `diff --git a/README.md b/README.md
+index 1234567..abcdefg 100644
+--- a/README.md
++++ b/README.md
+@@ -1,3 +1,3 @@
+ # Test Repository
+
+-Initial content.
++Modified content.
+`
+
+	patchFile, err := createTempFileWithPatch(patch)
+	require.NoError(t, err)
+	defer os.Remove(patchFile)
+
+	opts := MergeOptions{
+		CommitMessage:  "Apply test patch",
+		CommitterName:  "Test Committer",
+		CommitterEmail: "[e-mail]",
+		FormatPatch:    false,
+	}
+
+	err = repo.applyPatch(patch, patchFile, opts)
+	assert.NoError(t, err)
+
+	// verify the file was modified
+	content := h.readFile("README.md")
+	assert.Contains(t, content, "Modified content.")
+}
+
+func TestApplyPatch_AddNewFile(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	// add a new file
+	patch := `diff --git a/newfile.txt b/newfile.txt
+new file mode 100644
+index 0000000..ce01362
+--- /dev/null
++++ b/newfile.txt
+@@ -0,0 +1 @@
++hello
+`
+
+	patchFile, err := createTempFileWithPatch(patch)
+	require.NoError(t, err)
+	defer os.Remove(patchFile)
+
+	opts := MergeOptions{
+		CommitMessage:  "Add new file",
+		CommitterName:  "Test Committer",
+		CommitterEmail: "[e-mail]",
+		FormatPatch:    false,
+	}
+
+	err = repo.applyPatch(patch, patchFile, opts)
+	assert.NoError(t, err)
+
+	assert.True(t, h.fileExists("newfile.txt"))
+	content := h.readFile("newfile.txt")
+	assert.Equal(t, "hello\n", content)
+}
+
+func TestApplyPatch_DeleteFile(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	// add a file
+	h.commitFile("deleteme.txt", "content to delete\n", "Add file to delete")
+
+	// delete the file
+	patch := `diff --git a/deleteme.txt b/deleteme.txt
+deleted file mode 100644
+index 1234567..0000000
+--- a/deleteme.txt
++++ /dev/null
+@@ -1 +0,0 @@
+-content to delete
+`
+
+	patchFile, err := createTempFileWithPatch(patch)
+	require.NoError(t, err)
+	defer os.Remove(patchFile)
+
+	opts := MergeOptions{
+		CommitMessage:  "Delete file",
+		CommitterName:  "Test Committer",
+		CommitterEmail: "[e-mail]",
+		FormatPatch:    false,
+	}
+
+	err = repo.applyPatch(patch, patchFile, opts)
+	assert.NoError(t, err)
+
+	assert.False(t, h.fileExists("deleteme.txt"))
+}
+
+func TestApplyPatch_WithAuthor(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	patch := `diff --git a/README.md b/README.md
+index 1234567..abcdefg 100644
+--- a/README.md
++++ b/README.md
+@@ -1,3 +1,4 @@
+ # Test Repository
+
+ Initial content.
++New line.
+`
+
+	patchFile, err := createTempFileWithPatch(patch)
+	require.NoError(t, err)
+	defer os.Remove(patchFile)
+
+	opts := MergeOptions{
+		CommitMessage:  "Patch with author",
+		AuthorName:     "Patch Author",
+		AuthorEmail:    "[e-mail]",
+		CommitterName:  "Test Committer",
+		CommitterEmail: "[e-mail]",
+		FormatPatch:    false,
+	}
+
+	err = repo.applyPatch(patch, patchFile, opts)
+	assert.NoError(t, err)
+
+	head, err := repo.r.Head()
+	require.NoError(t, err)
+
+	commit, err := repo.r.CommitObject(head.Hash())
+	require.NoError(t, err)
+
+	assert.Equal(t, "Patch Author", commit.Author.Name)
+	assert.Equal(t, "[e-mail]", commit.Author.Email)
+}
+
+func TestApplyPatch_MissingFile(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	// patch that modifies a non-existent file
+	patch := `diff --git a/nonexistent.txt b/nonexistent.txt
+index 1234567..abcdefg 100644
+--- a/nonexistent.txt
++++ b/nonexistent.txt
+@@ -1 +1 @@
+-old content
++new content
+`
+
+	patchFile, err := createTempFileWithPatch(patch)
+	require.NoError(t, err)
+	defer os.Remove(patchFile)
+
+	opts := MergeOptions{
+		CommitMessage:  "Should fail",
+		CommitterName:  "Test Committer",
+		CommitterEmail: "[e-mail]",
+		FormatPatch:    false,
+	}
+
+	err = repo.applyPatch(patch, patchFile, opts)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "patch application failed")
+}
+
+func TestApplyPatch_Conflict(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	// modify the file to create a conflict
+	h.commitFile("README.md", "# Test Repository\n\nDifferent content.\n", "Modify README")
+
+	// patch that expects different content
+	patch := `diff --git a/README.md b/README.md
+index 1234567..abcdefg 100644
+--- a/README.md
++++ b/README.md
+@@ -1,3 +1,3 @@
+ # Test Repository
+
+-Initial content.
++Modified content.
+`
+
+	patchFile, err := createTempFileWithPatch(patch)
+	require.NoError(t, err)
+	defer os.Remove(patchFile)
+
+	opts := MergeOptions{
+		CommitMessage:  "Should conflict",
+		CommitterName:  "Test Committer",
+		CommitterEmail: "[e-mail]",
+		FormatPatch:    false,
+	}
+
+	err = repo.applyPatch(patch, patchFile, opts)
+	assert.Error(t, err)
+}
+
+func TestApplyPatch_MissingDirectory(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	// patch that adds a file in a non-existent directory
+	patch := `diff --git a/subdir/newfile.txt b/subdir/newfile.txt
+new file mode 100644
+index 0000000..ce01362
+--- /dev/null
++++ b/subdir/newfile.txt
+@@ -0,0 +1 @@
++content
+`
+
+	patchFile, err := createTempFileWithPatch(patch)
+	require.NoError(t, err)
+	defer os.Remove(patchFile)
+
+	opts := MergeOptions{
+		CommitMessage:  "Add file in subdir",
+		CommitterName:  "Test Committer",
+		CommitterEmail: "[e-mail]",
+		FormatPatch:    false,
+	}
+
+	// git apply should create the directory automatically
+	err = repo.applyPatch(patch, patchFile, opts)
+	assert.NoError(t, err)
+
+	// Verify the file and directory were created
+	assert.True(t, h.fileExists("subdir/newfile.txt"))
+}
+
+func TestApplyMailbox_Single(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	// format-patch mailbox format
+	patch := `From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Patch Author <[e-mail]>
+Date: Mon, 1 Jan 2024 12:00:00 +0000
+Subject: [PATCH] Add new feature
+
+This is a test patch.
+---
+ newfile.txt | 1 +
+ 1 file changed, 1 insertion(+)
+ create mode 100644 newfile.txt
+
+diff --git a/newfile.txt b/newfile.txt
+new file mode 100644
+index 0000000..ce01362
+--- /dev/null
++++ b/newfile.txt
+@@ -0,0 +1 @@
++hello
+--
+2.40.0
+`
+
+	err := repo.applyMailbox(patch)
+	assert.NoError(t, err)
+
+	assert.True(t, h.fileExists("newfile.txt"))
+	content := h.readFile("newfile.txt")
+	assert.Equal(t, "hello\n", content)
+}
+
+func TestApplyMailbox_Multiple(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	// multiple patches in mailbox format
+	patch := `From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Patch Author <[e-mail]>
+Date: Mon, 1 Jan 2024 12:00:00 +0000
+Subject: [PATCH 1/2] Add first file
+
+---
+ file1.txt | 1 +
+ 1 file changed, 1 insertion(+)
+ create mode 100644 file1.txt
+
+diff --git a/file1.txt b/file1.txt
+new file mode 100644
+index 0000000..ce01362
+--- /dev/null
++++ b/file1.txt
+@@ -0,0 +1 @@
++first
+--
+2.40.0
+
+From 1111111111111111111111111111111111111111 Mon Sep 17 00:00:00 2001
+From: Patch Author <[e-mail]>
+Date: Mon, 1 Jan 2024 12:01:00 +0000
+Subject: [PATCH 2/2] Add second file
+
+---
+ file2.txt | 1 +
+ 1 file changed, 1 insertion(+)
+ create mode 100644 file2.txt
+
+diff --git a/file2.txt b/file2.txt
+new file mode 100644
+index 0000000..ce01362
+--- /dev/null
++++ b/file2.txt
+@@ -0,0 +1 @@
++second
+--
+2.40.0
+`
+
+	err := repo.applyMailbox(patch)
+	assert.NoError(t, err)
+
+	assert.True(t, h.fileExists("file1.txt"))
+	assert.True(t, h.fileExists("file2.txt"))
+
+	content1 := h.readFile("file1.txt")
+	assert.Equal(t, "first\n", content1)
+
+	content2 := h.readFile("file2.txt")
+	assert.Equal(t, "second\n", content2)
+}
+
+func TestApplyMailbox_Conflict(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	repo := h.initRepo()
+
+	h.commitFile("README.md", "# Test Repository\n\nConflicting content.\n", "Create conflict")
+
+	patch := `From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Patch Author <[e-mail]>
+Date: Mon, 1 Jan 2024 12:00:00 +0000
+Subject: [PATCH] Modify README
+
+---
+ README.md | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/README.md b/README.md
+index 1234567..abcdefg 100644
+--- a/README.md
++++ b/README.md
+@@ -1,3 +1,3 @@
+ # Test Repository
+
+-Initial content.
++Different content.
+--
+2.40.0
+`
+
+	err := repo.applyMailbox(patch)
+	assert.Error(t, err)
+
+	var mergeErr *ErrMerge
+	assert.ErrorAs(t, err, &mergeErr)
+}
+
+func TestParseGitApplyErrors(t *testing.T) {
+	tests := []struct {
+		name           string
+		errorOutput    string
+		expectedCount  int
+		expectedReason string
+	}{
+		{
+			name:           "file already exists",
+			errorOutput:    `error: path/to/file.txt: already exists in working directory`,
+			expectedCount:  1,
+			expectedReason: "file already exists",
+		},
+		{
+			name:           "file does not exist",
+			errorOutput:    `error: path/to/file.txt: does not exist in working tree`,
+			expectedCount:  1,
+			expectedReason: "file does not exist",
+		},
+		{
+			name: "patch does not apply",
+			errorOutput: `error: patch failed: file.txt:10
+error: file.txt: patch does not apply`,
+			expectedCount:  1,
+			expectedReason: "patch does not apply",
+		},
+		{
+			name: "multiple conflicts",
+			errorOutput: `error: patch failed: file1.txt:5
+error: file1.txt:5: some error
+error: patch failed: file2.txt:10
+error: file2.txt:10: another error`,
+			expectedCount: 2,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			conflicts := parseGitApplyErrors(tt.errorOutput)
+			assert.Len(t, conflicts, tt.expectedCount)
+
+			if tt.expectedReason != "" && len(conflicts) > 0 {
+				assert.Equal(t, tt.expectedReason, conflicts[0].Reason)
+			}
+		})
+	}
+}
+
+func TestErrMerge_Error(t *testing.T) {
+	tests := []struct {
+		name        string
+		err         ErrMerge
+		expectedMsg string
+	}{
+		{
+			name: "with conflicts",
+			err: ErrMerge{
+				Message:     "test merge failed",
+				HasConflict: true,
+				Conflicts: []ConflictInfo{
+					{Filename: "file1.txt", Reason: "conflict 1"},
+					{Filename: "file2.txt", Reason: "conflict 2"},
+				},
+			},
+			expectedMsg: "merge failed due to conflicts: test merge failed (2 conflicts)",
+		},
+		{
+			name: "with other error",
+			err: ErrMerge{
+				Message:    "command failed",
+				OtherError: assert.AnError,
+			},
+			expectedMsg: "merge failed: command failed:",
+		},
+		{
+			name: "message only",
+			err: ErrMerge{
+				Message: "simple failure",
+			},
+			expectedMsg: "merge failed: simple failure",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			errMsg := tt.err.Error()
+			assert.Contains(t, errMsg, tt.expectedMsg)
+		})
+	}
+}
+
+func TestMergeWithOptions_Integration(t *testing.T) {
+	h := helper(t)
+	defer h.cleanup()
+
+	// create a repository first with initial content
+	workRepoPath := filepath.Join(h.tempDir, "work-repo")
+	workRepo, err := git.PlainInit(workRepoPath, false)
+	require.NoError(t, err)
+
+	// configure git user
+	cfg, err := workRepo.Config()
+	require.NoError(t, err)
+	cfg.User.Name = "Test User"
+	cfg.User.Email = "[e-mail]"
+	err = workRepo.SetConfig(cfg)
+	require.NoError(t, err)
+
+	// Create initial commit
+	w, err := workRepo.Worktree()
+	require.NoError(t, err)
+
+	err = os.WriteFile(filepath.Join(workRepoPath, "README.md"), []byte("# Initial\n"), 0644)
+	require.NoError(t, err)
+
+	_, err = w.Add("README.md")
+	require.NoError(t, err)
+
+	_, err = w.Commit("Initial commit", &git.CommitOptions{
+		Author: &object.Signature{
+			Name:  "Test User",
+			Email: "[e-mail]",
+		},
+	})
+	require.NoError(t, err)
+
+	// create a bare repository (like production)
+	bareRepoPath := filepath.Join(h.tempDir, "bare-repo")
+	err = InitBare(bareRepoPath, "main")
+	require.NoError(t, err)
+
+	// add bare repo as remote and push to it
+	_, err = workRepo.CreateRemote(&config.RemoteConfig{
+		Name: "origin",
+		URLs: []string{"file://" + bareRepoPath},
+	})
+	require.NoError(t, err)
+
+	err = workRepo.Push(&git.PushOptions{
+		RemoteName: "origin",
+		RefSpecs:   []config.RefSpec{"refs/heads/master:refs/heads/main"},
+	})
+	require.NoError(t, err)
+
+	// now merge a patch into the bare repo
+	gitRepo, err := PlainOpen(bareRepoPath)
+	require.NoError(t, err)
+
+	patch := `diff --git a/feature.txt b/feature.txt
+new file mode 100644
+index 0000000..5e1c309
+--- /dev/null
++++ b/feature.txt
+@@ -0,0 +1 @@
++Hello World
+`
+
+	opts := MergeOptions{
+		CommitMessage:  "Add feature",
+		CommitterName:  "Test Committer",
+		CommitterEmail: "[e-mail]",
+		FormatPatch:    false,
+	}
+
+	err = gitRepo.MergeWithOptions(patch, "main", opts)
+	assert.NoError(t, err)
+
+	// Clone again and verify the changes were merged
+	verifyRepoPath := filepath.Join(h.tempDir, "verify-repo")
+	verifyRepo, err := git.PlainClone(verifyRepoPath, false, &git.CloneOptions{
+		URL: "file://" + bareRepoPath,
+	})
+	require.NoError(t, err)
+
+	// check that feature.txt exists
+	featureFile := filepath.Join(verifyRepoPath, "feature.txt")
+	assert.FileExists(t, featureFile)
+
+	content, err := os.ReadFile(featureFile)
+	require.NoError(t, err)
+	assert.Equal(t, "Hello World\n", string(content))
+
+	// verify commit message
+	head, err := verifyRepo.Head()
+	require.NoError(t, err)
+
+	commit, err := verifyRepo.CommitObject(head.Hash())
+	require.NoError(t, err)
+	assert.Equal(t, "Add feature", strings.TrimSpace(commit.Message))
+}