add function declaration to arrow action

README.md

@@ -44,6 +44,7 @@ _you can provide custom key bindings by passing your own keys to the `keys` fiel
 | ------------------- | ----------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | **`<leader>jer`**   | `lua require("shrub").statement_block_surround` | When the cursor in the body of a function or conditional that doesnt have a wrapping `{}` will add a surrounding statement block                                                                                                                                                                                  |
 | **`<leader>jir`**   | `lua require("shrub").statement_block_remove`   | If the cursor is in the body of an arrow function, will remove surrounding `{}` and will move everything following the `return` statement to an implicit return (e.g `const myFn => "result"`). If the cursor is in a conditional everything will produce a one line early return e.g `if (true) return "result"` |
+| **`<leader>jfa`**   | `lua require("shrub").fun_declaration_to_arrow` | converts a named function declaraton to an arrow function assigning the function name to a `const` declaration                                                                                                                                                                                                    |
 
 **shrub.nvim** only provides a few key bindings to perform common text manipulations. It does not format or lint your code. It is recommended to have prettier and eslint set up in your Javascript/Typescript to format and lint your code
 

lua/shrub/actions/fun_declaration_to_arrow.lua

@@ -7,10 +7,29 @@ local M = {
             name: (_) @name
             parameters: (_) @params
             body: (_) @body
-            )
+            ) @function
         ]],
     root_node_type = { "function_declaration" },
-    handle_captures = function(captures, bufnr) end,
+    handle_captures = function(captures, bufnr)
+        utils.replace_ts_node_text(bufnr, captures["function"], function()
+            -- TODO: write multiple statement blocks or add formatting
+            return string.format(
+                "const %s = %s => %s",
+                table.concat(
+                    utils.get_ts_node_text(bufnr, captures["name"]),
+                    " "
+                ),
+                table.concat(
+                    utils.get_ts_node_text(bufnr, captures["params"]),
+                    " "
+                ),
+                table.concat(
+                    utils.get_ts_node_text(bufnr, captures["body"]),
+                    " "
+                )
+            )
+        end)
+    end,
 }
 
 return M

lua/shrub/config.lua

@@ -23,6 +23,16 @@ M.keys = {
             desc = "intelligent remove surrounding statement block",
         },
     },
+    {
+        "n",
+        "<leader>jfa",
+        '<cmd>lua require"shrub".fun_declaration_to_arrow()<cr>',
+        {
+            noremap = true,
+            silent = true,
+            desc = "convert a function declaration to an arrow function",
+        },
+    },
 }
 
 return M

lua/shrub/init.lua

@@ -2,6 +2,7 @@ local actions = require("shrub.actions")
 local default_config = require("shrub.config")
 local M = {}
 
+---@param action ShrubAction
 M._run_action = function(action)
     actions.run(
         action,
@@ -18,6 +19,14 @@ M.statement_block_remove = function()
     M._run_action("statement_block_remove")
 end
 
+M.fun_declaration_to_arrow = function()
+    M._run_action("fun_declaration_to_arrow")
+end
+
+M.arrow_fun_to_declaration = function()
+    M._run_action("arrow_fun_to_declaration")
+end
+
 --- accepts a config table with a keys field to override default keybindings
 --- @param config table | nil
 M.setup = function(config)

lua/shrub/utils.lua

@@ -19,6 +19,18 @@ M.find_nearest_parent_ts_node = function(node, types)
     return nil
 end
 
+M.get_ts_node_text = function(bufnr, node)
+    local start_row, start_col, end_row, end_col = node:range()
+    return vim.api.nvim_buf_get_text(
+        bufnr,
+        start_row,
+        start_col,
+        end_row,
+        end_col,
+        {}
+    )
+end
+
 ---@param bufnr integer
 ---@param node TSNode
 ---@param callback function accepts a string[] and returns a string to replace the node text with

tests/actions_spec.lua

@@ -31,6 +31,13 @@ describe("Actions:", function()
             after = [[if (true) return "something";]],
             pos = { 0, 20 },
         },
+        {
+            action = "fun_declaration_to_arrow",
+            description = "chould convert a function declaration to an arrow function",
+            before = [[function myFn() { return "success"; }]],
+            after = [[const myFn = () => { return "success"; }]],
+            pos = { 0, 20 },
+        },
     }
 
     for _, test in ipairs(test_table) do