fix(init): prevent data loss when reinitializing with existing content

internal/core/lnk_test.go

@@ -3,6 +3,7 @@ package core
 import (
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -1432,6 +1433,170 @@ func (suite *CoreTestSuite) TestPreviewAddValidation() {
 	suite.Contains(err.Error(), "already managed", "Error should mention already managed")
 }
 
+// Task 1.1: Tests for HasUserContent() method
+func (suite *CoreTestSuite) TestHasUserContent_WithCommonTracker_ReturnsTrue() {
+	// Initialize lnk repository
+	err := suite.lnk.Init()
+	suite.Require().NoError(err)
+
+	// Create .lnk file to simulate existing content
+	lnkFile := filepath.Join(suite.tempDir, "lnk", ".lnk")
+	err = os.WriteFile(lnkFile, []byte(".bashrc\n"), 0644)
+	suite.Require().NoError(err)
+
+	// Call HasUserContent()
+	hasContent := suite.lnk.HasUserContent()
+	suite.True(hasContent, "Should detect common tracker file")
+}
+
+func (suite *CoreTestSuite) TestHasUserContent_WithHostTracker_ReturnsTrue() {
+	// Initialize lnk repository
+	err := suite.lnk.Init()
+	suite.Require().NoError(err)
+
+	// Create host-specific lnk instance
+	hostLnk := NewLnk(WithHost("testhost"))
+
+	// Create .lnk.hostname file to simulate host-specific content
+	lnkFile := filepath.Join(suite.tempDir, "lnk", ".lnk.testhost")
+	err = os.WriteFile(lnkFile, []byte(".vimrc\n"), 0644)
+	suite.Require().NoError(err)
+
+	// Call HasUserContent()
+	hasContent := hostLnk.HasUserContent()
+	suite.True(hasContent, "Should detect host-specific tracker file")
+}
+
+func (suite *CoreTestSuite) TestHasUserContent_WithBothTrackers_ReturnsTrue() {
+	// Initialize lnk repository
+	err := suite.lnk.Init()
+	suite.Require().NoError(err)
+
+	// Create both common and host-specific tracker files
+	commonLnkFile := filepath.Join(suite.tempDir, "lnk", ".lnk")
+	err = os.WriteFile(commonLnkFile, []byte(".bashrc\n"), 0644)
+	suite.Require().NoError(err)
+
+	hostLnkFile := filepath.Join(suite.tempDir, "lnk", ".lnk.testhost")
+	err = os.WriteFile(hostLnkFile, []byte(".vimrc\n"), 0644)
+	suite.Require().NoError(err)
+
+	// Test with common instance
+	hasContent := suite.lnk.HasUserContent()
+	suite.True(hasContent, "Should detect common tracker file")
+
+	// Test with host-specific instance
+	hostLnk := NewLnk(WithHost("testhost"))
+	hasContent = hostLnk.HasUserContent()
+	suite.True(hasContent, "Should detect host-specific tracker file")
+}
+
+func (suite *CoreTestSuite) TestHasUserContent_EmptyDirectory_ReturnsFalse() {
+	// Initialize lnk repository
+	err := suite.lnk.Init()
+	suite.Require().NoError(err)
+
+	// Call HasUserContent() on empty repository
+	hasContent := suite.lnk.HasUserContent()
+	suite.False(hasContent, "Should return false for empty repository")
+}
+
+func (suite *CoreTestSuite) TestHasUserContent_NonTrackerFiles_ReturnsFalse() {
+	// Initialize lnk repository
+	err := suite.lnk.Init()
+	suite.Require().NoError(err)
+
+	// Create non-tracker files
+	randomFile := filepath.Join(suite.tempDir, "lnk", "random.txt")
+	err = os.WriteFile(randomFile, []byte("some content"), 0644)
+	suite.Require().NoError(err)
+
+	configFile := filepath.Join(suite.tempDir, "lnk", ".gitignore")
+	err = os.WriteFile(configFile, []byte("*.log"), 0644)
+	suite.Require().NoError(err)
+
+	// Call HasUserContent()
+	hasContent := suite.lnk.HasUserContent()
+	suite.False(hasContent, "Should return false when only non-tracker files exist")
+}
+
+// Task 2.1: Tests for enhanced InitWithRemote() safety check
+func (suite *CoreTestSuite) TestInitWithRemote_HasUserContent_ReturnsError() {
+	// Initialize and add content first
+	err := suite.lnk.Init()
+	suite.Require().NoError(err)
+
+	// Create .lnk file to simulate existing content
+	lnkFile := filepath.Join(suite.tempDir, "lnk", ".lnk")
+	err = os.WriteFile(lnkFile, []byte(".bashrc\n"), 0644)
+	suite.Require().NoError(err)
+
+	// Try InitWithRemote - should fail
+	err = suite.lnk.InitWithRemote("https://github.com/test/dotfiles.git")
+	suite.Error(err, "Should fail when user content exists")
+	suite.Contains(err.Error(), "already contains managed files")
+	suite.Contains(err.Error(), "lnk pull")
+
+	// Verify .lnk file still exists (no deletion occurred)
+	suite.FileExists(lnkFile)
+}
+
+func (suite *CoreTestSuite) TestInitWithRemote_EmptyDirectory_Success() {
+	// Create a dummy remote directory for testing
+	remoteDir := filepath.Join(suite.tempDir, "remote")
+	err := os.MkdirAll(remoteDir, 0755)
+	suite.Require().NoError(err)
+
+	// Initialize a bare git repository as remote
+	cmd := exec.Command("git", "init", "--bare")
+	cmd.Dir = remoteDir
+	err = cmd.Run()
+	suite.Require().NoError(err)
+
+	// InitWithRemote should succeed on empty directory
+	err = suite.lnk.InitWithRemote(remoteDir)
+	suite.NoError(err, "Should succeed when no user content exists")
+
+	// Verify repository was cloned
+	lnkDir := filepath.Join(suite.tempDir, "lnk")
+	suite.DirExists(lnkDir)
+	gitDir := filepath.Join(lnkDir, ".git")
+	suite.DirExists(gitDir)
+}
+
+func (suite *CoreTestSuite) TestInitWithRemote_NoRemoteURL_BypassesSafetyCheck() {
+	// Initialize and add content first
+	err := suite.lnk.Init()
+	suite.Require().NoError(err)
+
+	// Create .lnk file to simulate existing content
+	lnkFile := filepath.Join(suite.tempDir, "lnk", ".lnk")
+	err = os.WriteFile(lnkFile, []byte(".bashrc\n"), 0644)
+	suite.Require().NoError(err)
+
+	// InitWithRemote with empty URL should bypass safety check (this is local init)
+	err = suite.lnk.InitWithRemote("")
+	suite.NoError(err, "Should bypass safety check when no remote URL provided")
+}
+
+func (suite *CoreTestSuite) TestInitWithRemote_ErrorMessage_ContainsSuggestedCommand() {
+	// Initialize and add content first
+	err := suite.lnk.Init()
+	suite.Require().NoError(err)
+
+	// Create host-specific content
+	hostLnk := NewLnk(WithHost("testhost"))
+	hostLnkFile := filepath.Join(suite.tempDir, "lnk", ".lnk.testhost")
+	err = os.WriteFile(hostLnkFile, []byte(".vimrc\n"), 0644)
+	suite.Require().NoError(err)
+
+	// Try InitWithRemote - should fail with helpful message
+	err = hostLnk.InitWithRemote("https://github.com/test/dotfiles.git")
+	suite.Error(err, "Should fail when user content exists")
+	suite.Contains(err.Error(), "lnk pull", "Should suggest pull command")
+	suite.Contains(err.Error(), "instead of", "Should explain alternative")
+}
+
 func TestCoreSuite(t *testing.T) {
 	suite.Run(t, new(CoreTestSuite))
 }