feat(test): misc tests for more robustness

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)