Merge pull request #43 from barrettruth/feat/test

more robust testing

README.md

@@ -5,13 +5,13 @@
 Enhance vim-fugitive and Neovim's built-in diff mode with language-aware syntax
 highlighting.
 
-![diffs.nvim preview](https://github.com/user-attachments/assets/fc849310-09c8-4282-8a92-a2edaf8fe2b4)
+![diffs.nvim preview](https://github.com/user-attachments/assets/d3d64c96-b824-4fcb-af7f-4aef3f7f498a)
 
 ## Features
 
 - Treesitter syntax highlighting in `:Git` diffs and commit views
 - `:Gdiffsplit` / `:Gvdiffsplit` syntax through diff backgrounds
-- Background-only diff colors for any `&diff` buffer
+- Background-only diff colors for any `&diff` buffer (`:diffthis`, `vimdiff`)
 - Vim syntax fallback for languages without a treesitter parser
 - Hunk header context highlighting (`@@ ... @@ function foo()`)
 - Configurable debouncing, max lines, and diff prefix concealment
@@ -19,7 +19,8 @@ highlighting.
 ## Requirements
 
 - Neovim 0.9.0+
-- [vim-fugitive](https://github.com/tpope/vim-fugitive)
+- [vim-fugitive](https://github.com/tpope/vim-fugitive) (optional, for unified
+  diff syntax highlighting)
 
 ## Installation
 
@@ -39,6 +40,26 @@ Using [lazy.nvim](https://github.com/folke/lazy.nvim):
 :help diffs.nvim
 ```
 
+## Highlight Groups
+
+diffs.nvim defines the following highlight groups. All use `default = true`, so
+colorschemes can override them.
+
+| Group             | Purpose                                            |
+| ----------------- | -------------------------------------------------- |
+| `DiffsAdd`        | Background for `+` lines in fugitive unified diffs |
+| `DiffsDelete`     | Background for `-` lines in fugitive unified diffs |
+| `DiffsAddNr`      | Line number highlight for `+` lines                |
+| `DiffsDeleteNr`   | Line number highlight for `-` lines                |
+| `DiffsDiffAdd`    | Background-only `DiffAdd` for `&diff` windows      |
+| `DiffsDiffDelete` | Background-only `DiffDelete` for `&diff` windows   |
+| `DiffsDiffChange` | Background-only `DiffChange` for `&diff` windows   |
+| `DiffsDiffText`   | Background-only `DiffText` for `&diff` windows     |
+
+By default, these are computed from your colorscheme's `DiffAdd`, `DiffDelete`,
+`DiffChange`, `DiffText`, and `Normal` groups. To customize, define them in your
+colorscheme before diffs.nvim loads, or link them to existing groups.
+
 ## Known Limitations
 
 - Syntax "flashing": diffs.nvim hooks into the `FileType fugitive` event

doc/diffs.nvim.txt

@@ -23,9 +23,13 @@ Features: ~
 REQUIREMENTS                                              *diffs-requirements*
 
 - Neovim 0.9.0+
-- vim-fugitive (https://github.com/tpope/vim-fugitive) for unified diff views
+- vim-fugitive (https://github.com/tpope/vim-fugitive) (optional, for unified
+  diff syntax highlighting in |:Git| and commit views)
 - Treesitter parsers for languages you want highlighted
 
+Note: The diff mode feature (background-only colors for |:diffthis|, vimdiff,
+etc.) works without vim-fugitive.
+
 ==============================================================================
 SETUP                                                            *diffs-setup*
 
@@ -187,6 +191,50 @@ To minimize the flash, use a low debounce value: >lua
     })
 <
 
+==============================================================================
+HIGHLIGHT GROUPS                                          *diffs-highlights*
+
+diffs.nvim defines custom highlight groups. All are set with `default = true`,
+so colorschemes can override them by defining them first.
+
+Fugitive unified diff highlights: ~
+                                                                  *DiffsAdd*
+    DiffsAdd            Background for `+` lines. Derived by blending
+                        `DiffAdd` background with `Normal` at 40% alpha.
+
+                                                               *DiffsDelete*
+    DiffsDelete         Background for `-` lines. Derived by blending
+                        `DiffDelete` background with `Normal` at 40% alpha.
+
+                                                                *DiffsAddNr*
+    DiffsAddNr          Line number for `+` lines. Foreground from
+                        `diffAdded`, background from `DiffsAdd`.
+
+                                                             *DiffsDeleteNr*
+    DiffsDeleteNr       Line number for `-` lines. Foreground from
+                        `diffRemoved`, background from `DiffsDelete`.
+
+Diff mode window highlights: ~
+These are background-only variants used for |winhighlight| remapping in
+`&diff` windows, allowing treesitter syntax to show through.
+
+                                                             *DiffsDiffAdd*
+    DiffsDiffAdd        Background-only version of `DiffAdd`.
+
+                                                          *DiffsDiffDelete*
+    DiffsDiffDelete     Background-only version of `DiffDelete`.
+
+                                                          *DiffsDiffChange*
+    DiffsDiffChange     Background-only version of `DiffChange`.
+
+                                                            *DiffsDiffText*
+    DiffsDiffText       Background-only version of `DiffText`.
+
+To customize these in your colorscheme: >lua
+    vim.api.nvim_set_hl(0, 'DiffsAdd', { bg = '#2e4a3a' })
+    vim.api.nvim_set_hl(0, 'DiffsDiffDelete', { link = 'DiffDelete' })
+<
+
 ==============================================================================
 HEALTH CHECK                                                 *diffs-health*
 
@@ -194,7 +242,7 @@ Run |:checkhealth| diffs to verify your setup.
 
 Checks performed:
 - Neovim version >= 0.9.0
-- vim-fugitive is installed
+- vim-fugitive is installed (optional)
 
 ==============================================================================
  vim:tw=78:ts=8:ft=help:norl:

lua/diffs/init.lua

@@ -220,16 +220,16 @@ local function compute_highlight_groups()
   local blended_add = blend_color(add_bg, bg, 0.4)
   local blended_del = blend_color(del_bg, bg, 0.4)
 
-  vim.api.nvim_set_hl(0, 'DiffsAdd', { bg = blended_add })
-  vim.api.nvim_set_hl(0, 'DiffsDelete', { bg = blended_del })
-  vim.api.nvim_set_hl(0, 'DiffsAddNr', { fg = add_fg, bg = blended_add })
-  vim.api.nvim_set_hl(0, 'DiffsDeleteNr', { fg = del_fg, bg = blended_del })
+  vim.api.nvim_set_hl(0, 'DiffsAdd', { default = true, bg = blended_add })
+  vim.api.nvim_set_hl(0, 'DiffsDelete', { default = true, bg = blended_del })
+  vim.api.nvim_set_hl(0, 'DiffsAddNr', { default = true, fg = add_fg, bg = blended_add })
+  vim.api.nvim_set_hl(0, 'DiffsDeleteNr', { default = true, fg = del_fg, bg = blended_del })
 
   local diff_change = resolve_hl('DiffChange')
   local diff_text = resolve_hl('DiffText')
 
   vim.api.nvim_set_hl(0, 'DiffsDiffAdd', { bg = diff_add.bg })
-  vim.api.nvim_set_hl(0, 'DiffsDiffDelete', { bg = diff_delete.bg })
+  vim.api.nvim_set_hl(0, 'DiffsDiffDelete', { fg = diff_delete.fg, bg = diff_delete.bg })
   vim.api.nvim_set_hl(0, 'DiffsDiffChange', { bg = diff_change.bg })
   vim.api.nvim_set_hl(0, 'DiffsDiffText', { bg = diff_text.bg })
 end

spec/init_spec.lua

@@ -150,4 +150,159 @@ describe('diffs', function()
       vim.api.nvim_buf_delete(bufnr, { force = true })
     end)
   end)
+
+  describe('is_fugitive_buffer', function()
+    it('returns true for fugitive:// URLs', function()
+      local bufnr = vim.api.nvim_create_buf(false, true)
+      vim.api.nvim_buf_set_name(bufnr, 'fugitive:///path/to/repo/.git//abc123:file.lua')
+      assert.is_true(diffs.is_fugitive_buffer(bufnr))
+      vim.api.nvim_buf_delete(bufnr, { force = true })
+    end)
+
+    it('returns false for normal paths', function()
+      local bufnr = vim.api.nvim_create_buf(false, true)
+      vim.api.nvim_buf_set_name(bufnr, '/home/user/project/file.lua')
+      assert.is_false(diffs.is_fugitive_buffer(bufnr))
+      vim.api.nvim_buf_delete(bufnr, { force = true })
+    end)
+
+    it('returns false for empty buffer names', function()
+      local bufnr = vim.api.nvim_create_buf(false, true)
+      assert.is_false(diffs.is_fugitive_buffer(bufnr))
+      vim.api.nvim_buf_delete(bufnr, { force = true })
+    end)
+  end)
+
+  describe('diff mode', function()
+    local function create_diff_window()
+      vim.cmd('new')
+      local win = vim.api.nvim_get_current_win()
+      local buf = vim.api.nvim_get_current_buf()
+      vim.wo[win].diff = true
+      return win, buf
+    end
+
+    local function close_window(win)
+      if vim.api.nvim_win_is_valid(win) then
+        vim.api.nvim_win_close(win, true)
+      end
+    end
+
+    before_each(function()
+      diffs.setup({ enabled = true })
+    end)
+
+    describe('attach_diff', function()
+      it('applies winhighlight to diff windows', function()
+        local win, _ = create_diff_window()
+        diffs.attach_diff()
+
+        local whl = vim.api.nvim_get_option_value('winhighlight', { win = win })
+        assert.is_not_nil(whl:match('DiffAdd:DiffsDiffAdd'))
+        assert.is_not_nil(whl:match('DiffDelete:DiffsDiffDelete'))
+
+        close_window(win)
+      end)
+
+      it('does nothing when enabled=false', function()
+        diffs.setup({ enabled = false })
+        local win, _ = create_diff_window()
+        diffs.attach_diff()
+
+        local whl = vim.api.nvim_get_option_value('winhighlight', { win = win })
+        assert.are.equal('', whl)
+
+        close_window(win)
+      end)
+
+      it('is idempotent', function()
+        local win, _ = create_diff_window()
+        assert.has_no.errors(function()
+          diffs.attach_diff()
+          diffs.attach_diff()
+          diffs.attach_diff()
+        end)
+
+        local whl = vim.api.nvim_get_option_value('winhighlight', { win = win })
+        assert.is_not_nil(whl:match('DiffAdd:DiffsDiffAdd'))
+
+        close_window(win)
+      end)
+
+      it('applies to multiple diff windows', function()
+        local win1, _ = create_diff_window()
+        local win2, _ = create_diff_window()
+        diffs.attach_diff()
+
+        local whl1 = vim.api.nvim_get_option_value('winhighlight', { win = win1 })
+        local whl2 = vim.api.nvim_get_option_value('winhighlight', { win = win2 })
+        assert.is_not_nil(whl1:match('DiffAdd:DiffsDiffAdd'))
+        assert.is_not_nil(whl2:match('DiffAdd:DiffsDiffAdd'))
+
+        close_window(win1)
+        close_window(win2)
+      end)
+
+      it('ignores non-diff windows', function()
+        vim.cmd('new')
+        local non_diff_win = vim.api.nvim_get_current_win()
+
+        local diff_win, _ = create_diff_window()
+        diffs.attach_diff()
+
+        local non_diff_whl = vim.api.nvim_get_option_value('winhighlight', { win = non_diff_win })
+        local diff_whl = vim.api.nvim_get_option_value('winhighlight', { win = diff_win })
+
+        assert.are.equal('', non_diff_whl)
+        assert.is_not_nil(diff_whl:match('DiffAdd:DiffsDiffAdd'))
+
+        close_window(non_diff_win)
+        close_window(diff_win)
+      end)
+    end)
+
+    describe('detach_diff', function()
+      it('clears winhighlight from tracked windows', function()
+        local win, _ = create_diff_window()
+        diffs.attach_diff()
+        diffs.detach_diff()
+
+        local whl = vim.api.nvim_get_option_value('winhighlight', { win = win })
+        assert.are.equal('', whl)
+
+        close_window(win)
+      end)
+
+      it('does not error when no windows are tracked', function()
+        assert.has_no.errors(function()
+          diffs.detach_diff()
+        end)
+      end)
+
+      it('handles already-closed windows gracefully', function()
+        local win, _ = create_diff_window()
+        diffs.attach_diff()
+        close_window(win)
+
+        assert.has_no.errors(function()
+          diffs.detach_diff()
+        end)
+      end)
+
+      it('clears all tracked windows', function()
+        local win1, _ = create_diff_window()
+        local win2, _ = create_diff_window()
+        diffs.attach_diff()
+        diffs.detach_diff()
+
+        local whl1 = vim.api.nvim_get_option_value('winhighlight', { win = win1 })
+        local whl2 = vim.api.nvim_get_option_value('winhighlight', { win = win2 })
+        assert.are.equal('', whl1)
+        assert.are.equal('', whl2)
+
+        close_window(win1)
+        close_window(win2)
+      end)
+    end)
+  end)
 end)