added swaparound feature

Author: mlysle

lua/treewalker/init.lua

@@ -11,6 +11,7 @@ Treewalker.opts = {
   highlight_duration = 250,
   highlight_group = "CursorLine",
   jumplist = true,
+  swaparound = true
 }
 
 -- This does not need to be called for Treewalker to work. The defaults are preinitialized and aim to be sane.

lua/treewalker/nodes.lua

@@ -176,6 +176,22 @@ function M.next_sib(node)
   return node:next_named_sibling()
 end
 
+---@param node TSNode
+---@param fn function
+---@return TSNode | nil
+function M.farthest_sibling(node, fn)
+  if not node then return nil end
+
+  ---@type TSNode | nil
+  local iter = fn(node)
+
+  while iter do
+    node = iter
+    iter = fn(iter)
+  end
+  return node
+end
+
 -- Convenience for give me back prev sibling of a potentially nil node
 ---@param node TSNode | nil
 function M.prev_sib(node)

lua/treewalker/swap.lua

@@ -121,7 +121,7 @@ function M.swap_right()
   current = strategies.get_highest_string_node(current) or current
   current = nodes.get_highest_coincident(current)
 
-  local target = nodes.next_sib(current)
+  local target = nodes.next_sib(current) or nodes.farthest_sibling(current, nodes.prev_sib)
 
   if not current or not target then return end
 
@@ -158,7 +158,7 @@ function M.swap_left()
   current = strategies.get_highest_string_node(current) or current
   current = nodes.get_highest_coincident(current)
 
-  local target = nodes.prev_sib(current)
+  local target = nodes.prev_sib(current) or nodes.farthest_sibling(current, nodes.next_sib)
 
   if not current or not target then return end
 

tests/treewalker/c_sharp_spec.lua

@@ -41,4 +41,12 @@ describe("In a C Sharp file", function()
     assert.same(first_block, lines.get_lines(30, 48))
     h.assert_cursor_at(7, 5)
   end)
+
+  it("swaparound behavior works", function()
+    vim.fn.cursor(52, 31) -- (|node1, node2)
+    tw.swap_left()
+    assert.same("        public static int Add(int b, int a) => a + b;", lines.get_line(52))
+    tw.swap_right()
+    assert.same("        public static int Add(int a, int b) => a + b;", lines.get_line(52))
+  end)
 end)

tests/treewalker/c_spec.lua

@@ -5,51 +5,59 @@ local h = require 'tests.treewalker.helpers'
 local lines = require 'treewalker.lines'
 
 describe("In a c file:", function()
-  before_each(function()
-    load_fixture("/c.c")
-  end)
-
-  h.ensure_has_parser("c")
-
-  it("Moves around", function()
-    vim.fn.cursor(46, 1)
-    tw.move_down()
-    h.assert_cursor_at(50, 1, "int main")
-    tw.move_down()
-    h.assert_cursor_at(64, 1)
-    tw.move_down()
-    h.assert_cursor_at(69, 1)
-  end)
-
-  it("swaps right, when cursor is inside a string, the whole string", function()
-    vim.fn.cursor(14, 17) -- the o in one
-    assert.same('        printf("one\\n", "two\\n");', lines.get_line(14))
-    tw.swap_right()
-    assert.same('        printf("two\\n", "one\\n");', lines.get_line(14))
-  end)
-
-  it("swaps left, when cursor is inside a string, the whole string", function()
-    vim.fn.cursor(17, 28) -- the t in two
-    assert.same('        printf("one\\n", "\\ntwo\\n");', lines.get_line(17))
-    tw.swap_left()
-    assert.same('        printf("\\ntwo\\n", "one\\n");', lines.get_line(17))
-  end)
-
-  it("swaps down on next line bracket structured functions", function()
-    local first_block = lines.get_lines(63, 67)
-    local second_block = lines.get_lines(69, 72)
-    vim.fn.cursor(64, 1)
-    tw.swap_down()
-    assert.same(first_block, lines.get_lines(68, 72))
-    assert.same(second_block, lines.get_lines(63, 66))
-  end)
-
-  it("swaps up on next line bracket structured functions", function()
-    local first_block = lines.get_lines(63, 67)
-    local second_block = lines.get_lines(69, 72)
-    vim.fn.cursor(69, 1)
-    tw.swap_up()
-    assert.same(first_block, lines.get_lines(68, 72))
-    assert.same(second_block, lines.get_lines(63, 66))
-  end)
+	before_each(function()
+		load_fixture("/c.c")
+	end)
+
+	h.ensure_has_parser("c")
+
+	it("Moves around", function()
+		vim.fn.cursor(46, 1)
+		tw.move_down()
+		h.assert_cursor_at(50, 1, "int main")
+		tw.move_down()
+		h.assert_cursor_at(64, 1)
+		tw.move_down()
+		h.assert_cursor_at(69, 1)
+	end)
+
+	it("swaps right, when cursor is inside a string, the whole string", function()
+		vim.fn.cursor(14, 17) -- the o in one
+		assert.same('        printf("one\\n", "two\\n");', lines.get_line(14))
+		tw.swap_right()
+		assert.same('        printf("two\\n", "one\\n");', lines.get_line(14))
+	end)
+
+	it("swaps left, when cursor is inside a string, the whole string", function()
+		vim.fn.cursor(17, 28) -- the t in two
+		assert.same('        printf("one\\n", "\\ntwo\\n");', lines.get_line(17))
+		tw.swap_left()
+		assert.same('        printf("\\ntwo\\n", "one\\n");', lines.get_line(17))
+	end)
+
+	it("swaps down on next line bracket structured functions", function()
+		local first_block = lines.get_lines(63, 67)
+		local second_block = lines.get_lines(69, 72)
+		vim.fn.cursor(64, 1)
+		tw.swap_down()
+		assert.same(first_block, lines.get_lines(68, 72))
+		assert.same(second_block, lines.get_lines(63, 66))
+	end)
+
+	it("swaps up on next line bracket structured functions", function()
+		local first_block = lines.get_lines(63, 67)
+		local second_block = lines.get_lines(69, 72)
+		vim.fn.cursor(69, 1)
+		tw.swap_up()
+		assert.same(first_block, lines.get_lines(68, 72))
+		assert.same(second_block, lines.get_lines(63, 66))
+	end)
+
+	it("swaparound behavior works", function()
+		vim.fn.cursor(11, 24) -- (|node1, node2)
+		tw.swap_left()
+		assert.same("Account* createAccount(float initialBalance, int accountNumber) {", lines.get_line(11))
+		tw.swap_right()
+		assert.same("Account* createAccount(int accountNumber, float initialBalance) {", lines.get_line(11))
+	end)
 end)

tests/treewalker/haskell_spec.lua

@@ -7,10 +7,8 @@ describe("In a haskell file: ", function()
     load_fixture("/haskell.hs")
   end)
 
-  h.ensure_has_parser("haskell")
-
-  -- Oh dang when did this break?
-  pending("moves around in a haskell file", function ()
+  h.ensure_has_parser("haskell") -- Oh dang when did this break?
+  pending("moves around in a haskell file", function()
     vim.fn.cursor(1, 1)
     tw.move_down()
     h.assert_cursor_at(2, 1)
@@ -27,6 +25,12 @@ describe("In a haskell file: ", function()
     tw.move_out()
     h.assert_cursor_at(19, 1)
   end)
-end)
-
 
+  it("swaparound behavior works", function()
+    vim.fn.cursor(40, 15) -- (|node1, node2)
+    tw.swap_left()
+    assert.same("  printEvens [9, 3, 5, 7, 1]\", lines.get_line(40)")
+    tw.swap_right()
+    assert.same("  printEvens [1, 3, 5, 7, 9]\", lines.get_line(40)")
+  end)
+end)

tests/treewalker/lua_spec.lua

@@ -321,6 +321,15 @@ describe("Swapping in a regular lua file:", function()
     apply_text_edits_stub:revert()
   end)
 
+	it("swaparound behavior works", function()
+    vim.fn.cursor(38, 32) -- (|node1, node2)
+    tw.swap_left()
+		assert.same("local function have_same_range(node2, node1)", lines.get_line(38))
+    tw.swap_right()
+		assert.same("local function have_same_range(node1, node2)", lines.get_line(38))
+	end)
+
+
   -- Actually I don't think this is supposed to work. It's ambiguous what
   -- node we're on. We'd need to do the lowest coincident that is the highest string
   -- or something.