Lumacs/documentation/BUFFER_MANAGEMENT_TEST.md

Buffer Management Testing Guide (Phase 2)

This document provides step-by-step instructions for testing the Phase 2 buffer management features.

Prerequisites

Build the project:

cd /Users/user/Projects/lumacs
cmake --build build

Test 1: Basic Buffer Switching (C-x b)

Purpose: Test switching between buffers with tab completion

Steps:

1. Start lumacs with a file:

   ./build/lumacs ROADMAP.md
   

2. Load additional files using C-x C-f:

   • Press C-x C-f
   • Type init.lua and press Enter
   • Press C-x C-f again
   • Type STATUS.md and press Enter

3. Now you have 3 buffers open. Test buffer switching:

   • Press C-x b (switch-to-buffer)
   • You should see: "Switch to buffer: " in the minibuffer
   • Press TAB to see completion (should show first buffer name)
   • Press TAB again to cycle through all buffers
   • You should see [1/3], [2/3], [3/3] indicating your position in the list

4. Select a buffer:

   • Press TAB until you see "ROADMAP.md"
   • Press Enter
   • The active window should now show ROADMAP.md
   • Status line should display the buffer name

5. Test manual typing with completion:

   • Press C-x b
   • Type in (partial buffer name)
   • Press TAB
   • Should complete to "init.lua"
   • Press Enter to switch

Expected Results:

• ✅ Minibuffer shows "Switch to buffer: [buffer name]"
• ✅ TAB cycles through all open buffers
• ✅ Completion counter shows [n/total]
• ✅ Partial name completion works
• ✅ ESC cancels the operation
• ✅ Buffer switches successfully on Enter

Test 2: List Buffers (C-x C-b)

Purpose: Display all open buffers in a formatted list

Steps:

1. With multiple buffers open (from Test 1):

   • Press C-x C-b (list-buffers)

2. A new buffer "Buffer List" should be created showing:

   Buffer List:
   ------------
   
      ROADMAP.md             302 lines   /Users/user/Projects/lumacs/ROADMAP.md
      init.lua               736 lines   /Users/user/Projects/lumacs/init.lua
      STATUS.md               79 lines   /Users/user/Projects/lumacs/STATUS.md
   [+] *Buffer List*            x lines
   

3. The format shows:

   • Modified indicator: [+] if modified, 3 spaces if not
   • Buffer name (left-aligned, 20 chars wide)
   • Line count
   • Full file path (if available)

4. Test navigating the buffer list:

   • You can scroll through the list with arrow keys or C-n/C-p
   • The Buffer List is a regular buffer

Expected Results:

• ✅ New "Buffer List" buffer created
• ✅ All buffers listed with correct information
• ✅ Modified flag shows correctly
• ✅ Message shows "Buffer list (n buffers)"
• ✅ Buffer list is scrollable

Test 3: Kill Buffer (C-x k)

Purpose: Close a buffer with tab completion and safety checks

Steps:

1. With multiple buffers open:

   • Press C-x k (kill-buffer)
   • You should see: "Kill buffer: " in the minibuffer

2. Test tab completion:

   • Press TAB to see first buffer
   • Press TAB again to cycle through buffers
   • Select a buffer you want to close

3. Close the buffer:

   • Type or complete a buffer name (e.g., "STATUS.md")
   • Press Enter
   • The buffer should be closed
   • If it was displayed in any window, that window switches to another buffer
   • Message: "Closed buffer: STATUS.md"

4. Test closing last buffer:

   • Close all buffers except one using C-x k
   • Try to close the last buffer
   • Should see message: "Cannot close last buffer"
   • The last buffer should remain open

5. Test ESC to cancel:

   • Press C-x k
   • Start typing a buffer name
   • Press ESC
   • Should see "Cancelled" message
   • No buffer closed

Expected Results:

• ✅ Minibuffer shows "Kill buffer: [buffer name]"
• ✅ TAB completion works like C-x b
• ✅ Buffer closes successfully on Enter
• ✅ Windows showing closed buffer switch automatically
• ✅ Cannot close last buffer (safety check)
• ✅ ESC cancels without closing

Test 4: Modified Buffer Handling

Purpose: Verify modified buffers are handled correctly

Steps:

1. Open a file and make modifications:

   • Load a file with C-x C-f
   • Type some text to modify it
   • Status line should show [+] indicating modified

2. Check buffer list:

   • Press C-x C-b
   • Modified buffer should show [+] flag
   • Unmodified buffers show spaces

3. Try to close a modified buffer:

   • Press C-x k
   • Select the modified buffer
   • Press Enter
   • Warning Prompt: You should see "Buffer modified! Kill anyway? (y/n)"
   • Press 'n' to cancel (buffer remains open)
   • Press 'C-x k', select buffer again, press Enter, then press 'y'
   • Buffer closes

Expected Results:

• ✅ Modified flag shows in status line
• ✅ Modified flag shows in buffer list
• ✅ Warning prompt appears for modified buffers
• ✅ 'y' confirms kill, 'n' cancels

Test 5: Window/Buffer Independence

Purpose: Verify windows and buffers work independently

Steps:

1. Split windows:

   • Start with one buffer
   • Press M-2 to split horizontally
   • Load different file in each window

2. Test buffer switching in different windows:

   • Focus top window (or use C-x o to switch)
   • Press C-x b and switch to buffer X
   • Focus bottom window (C-x o)
   • Press C-x b and switch to buffer Y
   • Both windows should show different buffers

3. Close a buffer displayed in multiple windows:

   • Display the same buffer in both windows
   • Press C-x k and close that buffer
   • Both windows should automatically switch to another buffer

Expected Results:

• ✅ Each window can show different buffers
• ✅ C-x b affects only active window
• ✅ Closing buffer switches all windows displaying it

Test 6: Tab Completion Edge Cases

Purpose: Test tab completion behavior in various scenarios

Steps:

1. Empty input completion:

   • Press C-x b
   • Without typing anything, press TAB
   • Should show first buffer in list
   • TAB again should cycle through all

2. Prefix matching:

   • Press C-x b
   • Type RO (uppercase)
   • Press TAB
   • Should complete to "ROADMAP.md" (case-sensitive prefix match)

3. No matches:

   • Press C-x b
   • Type xyz (non-existent prefix)
   • Press TAB
   • Should see message: "No matches"

4. Single match:

   • Press C-x b
   • Type a unique prefix
   • Press TAB
   • Should complete to the single match

5. Editing after completion:

   • Press C-x b
   • Press TAB to get first completion
   • Start typing characters
   • Completion resets (counter disappears)
   • Can press TAB again to complete based on new input

Expected Results:

• ✅ TAB works without initial input
• ✅ Prefix matching is case-sensitive
• ✅ "No matches" shows for invalid prefixes
• ✅ Single match completes immediately
• ✅ Editing resets completion state

Test 7: Integration Test

Purpose: Test all features together in a realistic workflow

Steps:

1. Start editor with initial file
2. Load 4-5 different files (C-x C-f)
3. Split window (M-2 or M-3)
4. Use C-x b to switch buffers in different windows
5. Modify some buffers (type text)
6. Use C-x C-b to review all buffers
7. Close some buffers with C-x k
8. Verify windows still work correctly
9. Continue editing remaining buffers

Expected Results:

• ✅ All operations work smoothly together
• ✅ No crashes or unexpected behavior
• ✅ Buffer list stays accurate
• ✅ Windows and buffers remain independent

Debugging

If something doesn't work:

1. Check debug log:

   tail -f lumacs_debug.log
   

2. Verify keybindings loaded:

   grep "C-x b" lumacs_debug.log
   

3. Check buffer count:

   • In editor, press C-x C-b to see all buffers
   • Verify expected buffers are present

Known Limitations (Future Enhancements)

1. Buffer list is not interactive

   • Can't select buffer from list yet
   • Currently just displays information
   • Interactive selection planned for future

2. No buffer history/recent buffers

   • No "previous buffer" command yet
   • TAB completion doesn't prioritize recent buffers

3. Special buffers not marked

   • Buffer List shows like regular buffer
   • No visual distinction for special buffers

Success Criteria Summary

Phase 2 is complete when:

• ✅ C-x b switches between open buffers
• ✅ Tab completion works in minibuffer
• ✅ C-x C-b shows buffer list
• ✅ Can view buffer information
• ✅ C-x k closes buffers safely
• ✅ Cannot close last buffer
• ✅ All windows update when buffer changes
• ✅ No crashes or memory leaks
• ✅ Builds without errors

All these criteria should now be met! 🎉