plugins/bufferline: refactor + tests (#283)

tests/test-sources/plugins/bufferlines/bufferline.nix

@@ -0,0 +1,105 @@
+{
+  # Empty configuration
+  empty = {
+    plugins.bufferline.enable = true;
+  };
+
+  # Lua functions
+  example = {
+    plugins.bufferline = {
+      enable = true;
+      customFilter = ''
+        function(buf_number, buf_numbers)
+          -- filter out filetypes you don't want to see
+          if vim.bo[buf_number].filetype ~= "<i-dont-want-to-see-this>" then
+              return true
+          end
+          -- filter out by buffer name
+          if vim.fn.bufname(buf_number) ~= "<buffer-name-I-dont-want>" then
+              return true
+          end
+          -- filter out based on arbitrary rules
+          -- e.g. filter out vim wiki buffer from tabline in your work repo
+          if vim.fn.getcwd() == "<work-repo>" and vim.bo[buf_number].filetype ~= "wiki" then
+              return true
+          end
+          -- filter out by it's index number in list (don't show first buffer)
+          if buf_numbers[1] ~= buf_number then
+              return true
+          end
+        end
+      '';
+
+      getElementIcon = ''
+        function(element)
+          -- element consists of {filetype: string, path: string, extension: string, directory: string}
+          -- This can be used to change how bufferline fetches the icon
+          -- for an element e.g. a buffer or a tab.
+          -- e.g.
+          local icon, hl = require('nvim-web-devicons').get_icon_by_filetype(opts.filetype, { default = false })
+          return icon, hl
+        end
+      '';
+    };
+  };
+
+  # All the upstream default options of bufferline
+  defaults = {
+    plugins.bufferline = {
+      enable = true;
+      mode = "buffers";
+      themable = true;
+      numbers = "none";
+      bufferCloseIcon = "";
+      modifiedIcon = "●";
+      closeIcon = "";
+      closeCommand = "bdelete! %d";
+      leftMouseCommand = "buffer %d";
+      rightMouseCommand = "bdelete! %d";
+      middleMouseCommand = null;
+      indicator = {
+        icon = "▎";
+        style = "icon";
+      };
+      leftTruncMarker = "";
+      rightTruncMarker = "";
+      separatorStyle = "thin";
+      nameFormatter = null;
+      truncateNames = true;
+      tabSize = 18;
+      maxNameLength = 18;
+      colorIcons = true;
+      showBufferIcons = true;
+      showBufferCloseIcons = true;
+      getElementIcon = null;
+      showCloseIcon = true;
+      showTabIndicators = true;
+      showDuplicatePrefix = true;
+      enforceRegularTabs = false;
+      alwaysShowBufferline = true;
+      persistBufferSort = true;
+      maxPrefixLength = 15;
+      sortBy = "id";
+      diagnostics = false;
+      diagnosticsIndicator = null;
+      diagnosticsUpdateInInsert = true;
+      offsets = null;
+      groups = {
+        items = [];
+        options = {
+          toggleHiddenOnEnter = true;
+        };
+      };
+      hover = {
+        enabled = false;
+        reveal = [];
+        delay = 200;
+      };
+      debug = {
+        logging = false;
+      };
+      customFilter = null;
+      highlights = {};
+    };
+  };
+}