Fix viewer/editor/linter bugs and add new features

cmd/lint.go

@@ -12,35 +12,58 @@ import (
 var lintCmd = &cobra.Command{
 	Use:   "lint [files...]",
 	Short: "Lint markdown files for structural issues",
-	Long:  "Checks markdown files for heading hierarchy, duplicate headings, empty links, and other structural issues.",
-	Args:  cobra.MinimumNArgs(1),
+	Long:  "Checks markdown files for heading hierarchy, duplicate headings, empty links, and other structural issues. Reads from stdin if no files are provided.",
+	Args:  cobra.ArbitraryArgs,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		errorStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("9"))
 		warnStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("11"))
 		fileStyle := lipgloss.NewStyle().Bold(true)
 
 		totalIssues := 0
 
-		for _, path := range args {
-			issues, err := linter.LintFile(path)
+		if len(args) == 0 || (len(args) == 1 && args[0] == "-") {
+			stat, _ := os.Stdin.Stat()
+			if (stat.Mode() & os.ModeCharDevice) != 0 {
+				return fmt.Errorf("no files provided and nothing on stdin")
+			}
+			issues, err := linter.LintReader(os.Stdin)
 			if err != nil {
-				fmt.Fprintf(os.Stderr, "error reading %s: %v\n", path, err)
-				continue
+				return fmt.Errorf("error reading stdin: %w", err)
 			}
-			if len(issues) == 0 {
-				continue
+			if len(issues) > 0 {
+				fmt.Println(fileStyle.Render("<stdin>"))
+				for _, issue := range issues {
+					prefix := warnStyle.Render("warning")
+					if issue.Severity == linter.SeverityError {
+						prefix = errorStyle.Render("error")
+					}
+					fmt.Printf("  line %d: %s %s (%s)\n", issue.Line, prefix, issue.Message, issue.Rule)
+				}
+				fmt.Println()
+				totalIssues += len(issues)
 			}
+		} else {
+			for _, path := range args {
+				issues, err := linter.LintFile(path)
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "error reading %s: %v\n", path, err)
+					continue
+				}
+				if len(issues) == 0 {
+					continue
+				}
 
-			fmt.Println(fileStyle.Render(path))
-			for _, issue := range issues {
-				prefix := warnStyle.Render("warning")
-				if issue.Severity == linter.SeverityError {
-					prefix = errorStyle.Render("error")
+				fmt.Println(fileStyle.Render(path))
+				for _, issue := range issues {
+					prefix := warnStyle.Render("warning")
+					if issue.Severity == linter.SeverityError {
+						prefix = errorStyle.Render("error")
+					}
+					fmt.Printf("  line %d: %s %s (%s)\n", issue.Line, prefix, issue.Message, issue.Rule)
 				}
-				fmt.Printf("  line %d: %s %s (%s)\n", issue.Line, prefix, issue.Message, issue.Rule)
+				fmt.Println()
+				totalIssues += len(issues)
 			}
-			fmt.Println()
-			totalIssues += len(issues)
 		}
 
 		if totalIssues > 0 {

cmd/stats.go

@@ -0,0 +1,46 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/charmbracelet/lipgloss"
+	"github.com/spf13/cobra"
+	"github.com/tirthpatell/mdr/internal/stats"
+)
+
+var statsCmd = &cobra.Command{
+	Use:   "stats [file]",
+	Short: "Show word count and document statistics for a markdown file",
+	Long:  "Displays word count, line count, heading count, link count, and estimated reading time. Reads from stdin if no file is provided.",
+	Args:  cobra.MaximumNArgs(1),
+	RunE: func(cmd *cobra.Command, args []string) error {
+		var s stats.Stats
+		var name string
+		var err error
+
+		if len(args) == 0 || args[0] == "-" {
+			stat, _ := os.Stdin.Stat()
+			if (stat.Mode() & os.ModeCharDevice) != 0 {
+				return fmt.Errorf("no file provided and nothing on stdin")
+			}
+			s, err = stats.FromReader(os.Stdin)
+			name = "<stdin>"
+		} else {
+			s, err = stats.FromFile(args[0])
+			name = args[0]
+		}
+		if err != nil {
+			return err
+		}
+
+		titleStyle := lipgloss.NewStyle().Bold(true)
+		fmt.Println(titleStyle.Render(name))
+		fmt.Println(s.String())
+		return nil
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(statsCmd)
+}

internal/editor/editor.go

@@ -12,17 +12,19 @@ import (
 )
 
 type Model struct {
-	buffer    *Buffer
-	filePath  string
-	fileMode  fs.FileMode
-	cursorRow int
-	cursorCol int
-	offsetRow int
-	width     int
-	height    int
-	editWidth int
-	showHelp  bool
-	err       error
+	buffer      *Buffer
+	filePath    string
+	fileMode    fs.FileMode
+	cursorRow   int
+	cursorCol   int
+	offsetRow   int
+	width       int
+	height      int
+	editWidth   int
+	showHelp    bool
+	confirmQuit bool
+	err         error
+	saveMsg     string
 }
 
 func NewModel(content string, filePath string) Model {
@@ -60,12 +62,41 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		return m, nil
 
 	case tea.KeyMsg:
+		// Handle quit confirmation dialog
+		if m.confirmQuit {
+			switch msg.String() {
+			case "y", "Y":
+				return m, tea.Quit
+			case "n", "N", "esc":
+				m.confirmQuit = false
+				return m, nil
+			default:
+				return m, nil
+			}
+		}
+
+		// Clear transient messages on any non-save keypress
+		if msg.Type != tea.KeyCtrlS {
+			m.err = nil
+			m.saveMsg = ""
+		}
+
 		switch msg.Type {
 		case tea.KeyCtrlC:
+			if m.buffer.Modified() {
+				m.confirmQuit = true
+				return m, nil
+			}
 			return m, tea.Quit
 
 		case tea.KeyCtrlS:
 			m.err = m.save()
+			if m.err == nil {
+				m.buffer.ResetModified()
+				m.saveMsg = "Saved!"
+			} else {
+				m.saveMsg = ""
+			}
 			return m, nil
 
 		case tea.KeyCtrlH:
@@ -205,8 +236,16 @@ var (
 			BorderLeft(true).
 			BorderStyle(lipgloss.NormalBorder()).
 			BorderForeground(lipgloss.Color("241"))
-	helpStyle = lipgloss.NewStyle().
+	editorHelpStyle = lipgloss.NewStyle().
 			Foreground(lipgloss.Color("241"))
+	errStyle = lipgloss.NewStyle().
+			Foreground(lipgloss.Color("9")).
+			Bold(true)
+	savedStyle = lipgloss.NewStyle().
+			Foreground(lipgloss.Color("10"))
+	confirmStyle = lipgloss.NewStyle().
+			Foreground(lipgloss.Color("11")).
+			Bold(true)
 )
 
 func (m Model) View() string {
@@ -220,8 +259,13 @@ func (m Model) View() string {
 		editW = m.width / 2
 	}
 
+	if m.confirmQuit {
+		prompt := confirmStyle.Render("Unsaved changes. Quit without saving? (y/n)")
+		return lipgloss.Place(m.width, m.height, lipgloss.Center, lipgloss.Center, prompt)
+	}
+
 	if m.showHelp {
-		help := helpStyle.Render(strings.Join([]string{
+		help := editorHelpStyle.Render(strings.Join([]string{
 			"Editor Help",
 			"",
 			"  Arrow keys   Move cursor",
@@ -259,7 +303,10 @@ func (m Model) View() string {
 	editorPane := strings.Join(editorLines, "\n")
 
 	previewW := m.width - editW - 1
-	rendered, _ := markdown.Render(m.buffer.String())
+	rendered, renderErr := markdown.Render(m.buffer.String())
+	if renderErr != nil {
+		rendered = errStyle.Render("Preview error: " + renderErr.Error())
+	}
 	previewLines := strings.Split(rendered, "\n")
 	if len(previewLines) > editHeight {
 		previewLines = previewLines[:editHeight]
@@ -278,8 +325,15 @@ func (m Model) View() string {
 	if m.buffer.Modified() {
 		modIndicator = " [+]"
 	}
-	status := statusStyle.Render(fmt.Sprintf(" %s%s  Ln %d, Col %d  Ctrl+S: save  Ctrl+H: help  Ctrl+C: quit",
-		m.filePath, modIndicator, m.cursorRow+1, m.cursorCol+1))
+	statusText := fmt.Sprintf(" %s%s  Ln %d, Col %d  Ctrl+S: save  Ctrl+H: help  Ctrl+C: quit",
+		m.filePath, modIndicator, m.cursorRow+1, m.cursorCol+1)
+	if m.err != nil {
+		statusText += "  " + errStyle.Render("Error: "+m.err.Error())
+	}
+	if m.saveMsg != "" {
+		statusText += "  " + savedStyle.Render(m.saveMsg)
+	}
+	status := statusStyle.Render(statusText)
 
 	return body + "\n" + status
 }

internal/editor/editor_test.go

@@ -1,6 +1,9 @@
 package editor
 
 import (
+	"os"
+	"path/filepath"
+	"strings"
 	"testing"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -70,3 +73,119 @@ func TestEditorModel_EnterKey(t *testing.T) {
 		t.Fatalf("expected cursor at col 0, got %d", model.cursorCol)
 	}
 }
+
+func TestEditorModel_SaveResetsModified(t *testing.T) {
+	tmp := t.TempDir()
+	path := filepath.Join(tmp, "test.md")
+	os.WriteFile(path, []byte("hello"), 0644)
+
+	m, err := NewModelFromFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	m.width = 80
+	m.height = 24
+
+	// Type a character to set modified
+	updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'!'}})
+	model := updated.(Model)
+	if !model.buffer.Modified() {
+		t.Fatal("buffer should be modified after typing")
+	}
+
+	// Save
+	updated, _ = model.Update(tea.KeyMsg{Type: tea.KeyCtrlS})
+	model = updated.(Model)
+	if model.buffer.Modified() {
+		t.Fatal("buffer should not be modified after save")
+	}
+	if model.saveMsg != "Saved!" {
+		t.Fatalf("expected save message 'Saved!', got %q", model.saveMsg)
+	}
+}
+
+func TestEditorModel_SaveError_DisplayedInView(t *testing.T) {
+	m := NewModel("hello", "/nonexistent/path/file.md")
+	m.width = 80
+	m.height = 24
+	m.editWidth = 40
+
+	// Trigger save
+	updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyCtrlS})
+	model := updated.(Model)
+	if model.err == nil {
+		t.Fatal("expected save error for invalid path")
+	}
+	view := model.View()
+	if !strings.Contains(view, "Error:") {
+		t.Fatal("expected error message in view output")
+	}
+}
+
+func TestEditorModel_QuitConfirmation_Modified(t *testing.T) {
+	m := NewModel("hello", "/tmp/test.md")
+	m.width = 80
+	m.height = 24
+
+	// Type to set modified
+	updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'!'}})
+	model := updated.(Model)
+
+	// Press Ctrl+C — should NOT quit, should show confirmation
+	updated, cmd := model.Update(tea.KeyMsg{Type: tea.KeyCtrlC})
+	model = updated.(Model)
+	if cmd != nil {
+		t.Fatal("should not quit immediately with unsaved changes")
+	}
+	if !model.confirmQuit {
+		t.Fatal("expected confirmQuit to be true")
+	}
+
+	// View should show the confirmation prompt
+	view := model.View()
+	if !strings.Contains(view, "Unsaved changes") {
+		t.Fatal("expected confirmation prompt in view")
+	}
+
+	// Press 'n' to cancel
+	updated, cmd = model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'n'}})
+	model = updated.(Model)
+	if cmd != nil {
+		t.Fatal("pressing 'n' should not quit")
+	}
+	if model.confirmQuit {
+		t.Fatal("confirmQuit should be false after 'n'")
+	}
+}
+
+func TestEditorModel_QuitConfirmation_Accept(t *testing.T) {
+	m := NewModel("hello", "/tmp/test.md")
+	m.width = 80
+	m.height = 24
+
+	// Type to set modified
+	updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'!'}})
+	model := updated.(Model)
+
+	// Press Ctrl+C
+	updated, _ = model.Update(tea.KeyMsg{Type: tea.KeyCtrlC})
+	model = updated.(Model)
+
+	// Press 'y' to confirm quit
+	_, cmd := model.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'y'}})
+	if cmd == nil {
+		t.Fatal("pressing 'y' should quit")
+	}
+}
+
+func TestEditorModel_QuitUnmodified(t *testing.T) {
+	m := NewModel("hello", "/tmp/test.md")
+	m.width = 80
+	m.height = 24
+
+	// Press Ctrl+C on unmodified buffer — should quit immediately
+	_, cmd := m.Update(tea.KeyMsg{Type: tea.KeyCtrlC})
+	if cmd == nil {
+		t.Fatal("should quit immediately when no unsaved changes")
+	}
+}