From 23104bbfcc051e10c66cdb3c16096db7d52a7614 Mon Sep 17 00:00:00 2001
From: Tuure Piitulainen <tuure.piitulainen@gmail.com>
Date: Tue, 4 Nov 2025 23:35:25 +0200
Subject: [PATCH 1/4] Fix `cw` edge cases when cursor is on a space

Resolves https://github.com/chaoren/vim-wordmotion/issues/84
Resolves half of https://github.com/chaoren/vim-wordmotion/issues/69

Additionally, when cursor is at a "space-like", such as the underscore
in a snake case word:

    foo_bar
       ^

Fixes that it should only remove the underscore and not the word after.
---
 autoload/wordmotion.vim | 22 ++++++++++++----------
 tests/cw.vader          | 25 ++++++++++++++++++++-----
 2 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/autoload/wordmotion.vim b/autoload/wordmotion.vim
index 9db0333..249197c 100644
--- a/autoload/wordmotion.vim
+++ b/autoload/wordmotion.vim
@@ -87,10 +87,14 @@ function wordmotion#motion(count, mode, flags, uppercase, extra, ...)
 	set cpoptions+=c
 
 	let l:flags = a:flags
+	let l:s = a:uppercase ? s:us : s:s
 
+	" cw special case (see :help cw)
 	if a:mode == 'o' && v:operator == 'c' && l:flags == ''
-		" special case (see :help cw)
-		let l:flags = 'e'
+		let l:cursor_on_s = matchstr(getline('.'), '\%' . col('.') . 'c' . l:s) != ''
+		if !l:cursor_on_s
+			let l:flags = 'e'
+		endif
 		let l:cw = 1
 	else
 		let l:cw = 0
@@ -114,7 +118,7 @@ function wordmotion#motion(count, mode, flags, uppercase, extra, ...)
 	let l:pos = getpos('.')
 
 	let l:count = a:count
-	if l:cw
+	if l:cw && !l:cursor_on_s
 		" cw on the last character of a word will match the cursor position
 		call search('\m'.l:pattern, l:flags.'cW')
 		let l:count -= 1
@@ -124,19 +128,17 @@ function wordmotion#motion(count, mode, flags, uppercase, extra, ...)
 		let l:count -= 1
 	endwhile
 
-	" dw at the end of a line should not consume the newline or leading white
-	" space on the next line
-	let l:is_dw = a:mode == 'o' && v:operator == 'd' && l:flags == ''
+	" operator-pending w at the end of a line should not include the newline or leading
+	" white space on the next line
 	let l:next_line = l:pos[1] < getpos('.')[1]
-	if l:is_dw && l:next_line
-		let l:s = a:uppercase ? s:us : s:s
+	if a:mode == 'o' && l:flags == '' && l:next_line
 		" newline, leading whitespace, cursor
 		if search('\m\n\%('.l:s.'\)*\%#', 'bW') != 0
-			let l:dwpos = getpos('.')
+			let l:wpos = getpos('.')
 			" need to make range inclusive
 			call setpos('.', l:pos)
 			normal! v
-			call setpos('.', l:dwpos)
+			call setpos('.', l:wpos)
 		endif
 	endif
 
diff --git a/tests/cw.vader b/tests/cw.vader
index 06d4ec1..bb944b5 100644
--- a/tests/cw.vader
+++ b/tests/cw.vader
@@ -262,18 +262,33 @@ Then (Assert that cursor is at z):
 Expect ("b c\nd e" changed to z):
   a z f
 
+Given (Snake case word):
+  foo_bar
+
+Execute (cw on underscore):
+  normal lllcw
+  AssertEqual 3, col('.')
+
+Expect (Only underscore deleted):
+  foobar
+
 Given (Leading spaces):
       foo
+      bar
 
-Execute (FIXME: cw):
-  normal cw
+Execute (cw):
+  normal jcw
   AssertEqual 1, col('.')
 
 Expect (Leading spaces deleted):
-  foo
+      foo
+  bar
 
-Execute (reference cw):
-  normal! cw
+Given (Leading spaces with only 1 line):
+      foo
+
+Execute (cw at the first line and col of the file):
+  normal cw
   AssertEqual 1, col('.')
 
 Expect (Leading spaces deleted):

From 40dc6a2249c35c061b71d76d8c1482f0ba40e6fb Mon Sep 17 00:00:00 2001
From: Tuure Piitulainen <tuure.piitulainen@gmail.com>
Date: Wed, 5 Nov 2025 00:28:13 +0200
Subject: [PATCH 2/4] Honor `cpoptions_z` for `cw`

Resolves the rest of https://github.com/chaoren/vim-wordmotion/issues/69

To have `cw` work similarly to `dw` and delete the spaces after a word,
set this option:

    set cpoptions-=z (Vim)
    set cpoptions-=_ (Neovim)
---
 autoload/wordmotion.vim |  4 +++-
 tests/cpoptions.vader   | 11 +++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/autoload/wordmotion.vim b/autoload/wordmotion.vim
index 249197c..8910672 100644
--- a/autoload/wordmotion.vim
+++ b/autoload/wordmotion.vim
@@ -90,7 +90,9 @@ function wordmotion#motion(count, mode, flags, uppercase, extra, ...)
 	let l:s = a:uppercase ? s:us : s:s
 
 	" cw special case (see :help cw)
-	if a:mode == 'o' && v:operator == 'c' && l:flags == ''
+	let l:cpo_z = has('nvim') ? stridx(l:cpo, '_') : stridx(l:cpo, 'z')
+
+	if l:cpo_z != -1 && a:mode == 'o' && v:operator == 'c' && l:flags == ''
 		let l:cursor_on_s = matchstr(getline('.'), '\%' . col('.') . 'c' . l:s) != ''
 		if !l:cursor_on_s
 			let l:flags = 'e'
diff --git a/tests/cpoptions.vader b/tests/cpoptions.vader
index 4bc3683..ce491bc 100644
--- a/tests/cpoptions.vader
+++ b/tests/cpoptions.vader
@@ -28,6 +28,17 @@ Execute (w with cpo-<):
   normal w
   AssertEqual 5, col('.')
 
+Execute (cw without cpo-z):
+  if has('nvim')
+    set cpoptions-=_
+  else
+    set cpoptions-=z
+  endif
+  normal cw
+
+Expect (Delete the space):
+  bar
+
 Given (Leading spaces):
       foo
 

From a82ad9a28c1669225d2aa65438ba16afd67c6b6b Mon Sep 17 00:00:00 2001
From: Tuure Piitulainen <tuure.piitulainen@gmail.com>
Date: Wed, 5 Nov 2025 20:48:08 +0200
Subject: [PATCH 3/4] Refactor to make special `cw` case easier to understand

When cpo-z was not supported, we called it l:cw and did it
unconditionally on cw command. Now we call it l:cw_special_case to
differentiate, and only have to check if cursor is on whitespace in one
place.
---
 autoload/wordmotion.vim | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/autoload/wordmotion.vim b/autoload/wordmotion.vim
index 8910672..7798ec3 100644
--- a/autoload/wordmotion.vim
+++ b/autoload/wordmotion.vim
@@ -89,17 +89,17 @@ function wordmotion#motion(count, mode, flags, uppercase, extra, ...)
 	let l:flags = a:flags
 	let l:s = a:uppercase ? s:us : s:s
 
-	" cw special case (see :help cw)
+	" cw special case
+	" see :help cw, :help cpo-z (vim), :help cpo-_ (neovim)
 	let l:cpo_z = has('nvim') ? stridx(l:cpo, '_') : stridx(l:cpo, 'z')
+	let l:cw_special_case = 0
 
 	if l:cpo_z != -1 && a:mode == 'o' && v:operator == 'c' && l:flags == ''
 		let l:cursor_on_s = matchstr(getline('.'), '\%' . col('.') . 'c' . l:s) != ''
 		if !l:cursor_on_s
 			let l:flags = 'e'
+			let l:cw_special_case = 1
 		endif
-		let l:cw = 1
-	else
-		let l:cw = 0
 	endif
 
 	if a:mode == 'x'
@@ -120,7 +120,7 @@ function wordmotion#motion(count, mode, flags, uppercase, extra, ...)
 	let l:pos = getpos('.')
 
 	let l:count = a:count
-	if l:cw && !l:cursor_on_s
+	if l:cw_special_case
 		" cw on the last character of a word will match the cursor position
 		call search('\m'.l:pattern, l:flags.'cW')
 		let l:count -= 1

From d81a78b8fc3863a30235f928428cb3d6c440b898 Mon Sep 17 00:00:00 2001
From: Tuure Piitulainen <tuure.piitulainen@gmail.com>
Date: Sat, 8 Nov 2025 10:11:45 +0200
Subject: [PATCH 4/4] Simplify check for if cursor is on a space

---
 autoload/wordmotion.vim | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/autoload/wordmotion.vim b/autoload/wordmotion.vim
index 7798ec3..3de792b 100644
--- a/autoload/wordmotion.vim
+++ b/autoload/wordmotion.vim
@@ -95,7 +95,7 @@ function wordmotion#motion(count, mode, flags, uppercase, extra, ...)
 	let l:cw_special_case = 0
 
 	if l:cpo_z != -1 && a:mode == 'o' && v:operator == 'c' && l:flags == ''
-		let l:cursor_on_s = matchstr(getline('.'), '\%' . col('.') . 'c' . l:s) != ''
+		let l:cursor_on_s = getline('.') =~# '\%.c' . l:s
 		if !l:cursor_on_s
 			let l:flags = 'e'
 			let l:cw_special_case = 1