feat(windows): substitute unix-style vars for cmd.exe (#1056)

lua/fzf-lua/defaults.lua

@@ -17,10 +17,7 @@ function M._default_previewer_fn()
 end
 
 function M._preview_pager_fn()
-  if vim.fn.executable("delta") ~= 1 then
-    return nil
-  end
-  return "delta --width=" .. utils._if_win("%COLUMNS%", "$COLUMNS")
+  return vim.fn.executable("delta") == 1 and "delta --width=$COLUMNS" or nil
 end
 
 M.defaults = {

lua/fzf-lua/previewer/codeaction.lua

@@ -248,7 +248,7 @@ function M.native:cmdline(o)
     return table.concat(lines, "\r\n")
   end, "{}", self.opts.debug)
   if self.pager and #self.pager > 0 and vim.fn.executable(self.pager:match("[^%s]+")) == 1 then
-    act = act .. " | " .. self.pager
+    act = act .. " | " .. utils._if_win_normalize_vars(self.pager)
   end
   return act
 end

lua/fzf-lua/previewer/fzf.lua

@@ -340,13 +340,9 @@ function Previewer.git_diff:cmdline(o)
     local pager = ""
     if self.pager and #self.pager > 0 and
         vim.fn.executable(self.pager:match("[^%s]+")) == 1 then
-      pager = "| " .. self.pager
-      if utils.__IS_WINDOWS then
-        -- we are unable to use variables within a "cmd /c" without "!var!" variable expansion
-        -- https://superuser.com/questions/223104/setting-and-using-variable-within-same-command-line-in-windows-cmd-ex
-        pager = pager:gsub("%$[%a%d]+", function(x) return "!" .. x:sub(2) .. "!" end)
-        pager = pager:gsub("%%[%a%d]+%%", function(x) return "!" .. x:sub(2, #x - 1) .. "!" end)
-      end
+      -- style 2: as we are unable to use %var% within a "cmd /c" without !var! expansion
+      -- https://superuser.com/questions/223104/setting-and-using-variable-within-same-command-line-in-windows-cmd-ex
+      pager = "| " .. utils._if_win_normalize_vars(self.pager, 2)
     end
     -- with default commands we add the filepath at the end.
     -- If the user configured a more complex command, e.g.:

lua/fzf-lua/providers/git.lua

@@ -104,7 +104,8 @@ M.commits = function(opts)
       opts.preview_pager = opts.preview_pager()
     end
     if opts.preview_pager then
-      opts.preview = string.format("%s | %s", opts.preview, opts.preview_pager)
+      opts.preview = string.format("%s | %s", opts.preview,
+        utils._if_win_normalize_vars(opts.preview_pager))
     end
     if vim.o.shell and vim.o.shell:match("fish$") then
       -- TODO: why does fish shell refuse to pass along $COLUMNS
@@ -152,7 +153,8 @@ M.bcommits = function(opts)
       opts.preview_pager = opts.preview_pager()
     end
     if opts.preview_pager then
-      opts.preview = string.format("%s | %s", opts.preview, opts.preview_pager)
+      opts.preview = string.format("%s | %s", opts.preview,
+        utils._if_win_normalize_vars(opts.preview_pager))
     end
   end
   opts = core.set_header(opts, opts.headers or { "actions", "cwd" })

lua/fzf-lua/utils.lua

@@ -94,6 +94,21 @@ M._if_win = function(a, b)
   end
 end
 
+
+-- Substitute unix style $VAR with
+--   Style 1: %VAR%
+--   Style 2: !VAR!
+M._if_win_normalize_vars = function(cmd, style)
+  if not M.__IS_WINDOWS then return cmd end
+  local expander = style == 2 and "!" or "%"
+  cmd = cmd:gsub("%$[^%s]+", function(x) return expander .. x:sub(2) .. expander end)
+  if style == 2 then
+    -- also sub %VAR% for !VAR!
+    cmd = cmd:gsub("%%[^%s]+%%", function(x) return "!" .. x:sub(2, #x - 1) .. "!" end)
+  end
+  return cmd
+end
+
 M.shell_nop = function()
   return M._if_win("break", "true")
 end

tests/utils_spec.lua

@@ -0,0 +1,17 @@
+local fzf = require("fzf-lua")
+local utils = fzf.utils
+
+describe("Testing utils module", function()
+  it("separator", function()
+    utils.__IS_WINDOWS = false
+    assert.are.same(utils._if_win_normalize_vars("--w=$COLUMNS"), "--w=$COLUMNS")
+
+    utils.__IS_WINDOWS = true
+    assert.are.same(utils._if_win_normalize_vars("--w=$COLUMNS", 1), "--w=%COLUMNS%")
+    assert.are.same(utils._if_win_normalize_vars("--w=%COLUMNS%", 1), "--w=%COLUMNS%")
+    assert.are.same(utils._if_win_normalize_vars("-w=$C -l=$L", 1), "-w=%C% -l=%L%")
+    assert.are.same(utils._if_win_normalize_vars("--w=$COLUMNS", 2), "--w=!COLUMNS!")
+    assert.are.same(utils._if_win_normalize_vars("--w=%COLUMNS%", 2), "--w=!COLUMNS!")
+    assert.are.same(utils._if_win_normalize_vars("-w=$C -l=$L", 2), "-w=!C! -l=!L!")
+  end)
+end)