Mapping a key to escape moves to the next line

Question

I have recently started using neovim and am having a problem.

I have mapped <leader>m to <esc>. It seems to be working fine but has a small problem. It moves to the next line after getting back to normal mode and I don't want this behavior. I have also tried to map jj instead, but I have the same problem.

" My sorry-state noevim conf script
"  ---------- 
" | Settings |
"  ----------
set number " display line-no
set ignorecase " Ignore case's while searching strings
set tabstop=4 " set tab to 4 spaces
set shiftwidth=4 " To set an indentation to single TAB
set mouse=a " Use mouse globally on all modes
set incsearch " Use incremental search,i.e jump to first occurrences while search is going
set autoread " Automatically reload the file,if it is changed by external source
set expandtab " Expand Tabs to spaces
set background=dark "Set background for theme
 
" powerline fonts don't work out of the box,we gotta install the patch fonts
" as described here(https://github.com/vim-airline/vim-airline#user-content-integrating-with-powerline-fonts) and then set following var to 1.if that doesn't work this(https://vi.stackexchange.com/a/3363) might help.
let g:airline_powerline_fonts = 1
let mapleader = "," " settin <leader> to ','

"Disable code completion since we use coc for that 
let g:jedi#completions_enabled = 0

" open the go-to function" in split, not another buffer
let g:jedi#use_splits_not_buffers = "right"

"  ---------------------------
" | Custom defined functions |
"  ---------------------------

" function Yank_to_sys_clipboard()
"     y:call system("xclip -selection clipboard", @")<CR>   
"     echon ''
" endfunction

" function Is_previous_line_empty()
"     return strchars(getbufline(bufnr('%'),line('.')-1)[0]) > 0
" endfunction 



"  ---------- 
" | Mappings |
"  ---------- 
 
inoremap <expr><tab> pumvisible() ? "\<c-n>" : "\<tab>" " completion on pressing tab
inoremap <leader>m  <esc> 
map <leader>l ggVG " Select all text
" Copy to system clipboard using external binary:https://stackoverflow.com/a/51682050
" Requires xclip to be installed
map <c-c> y:call system("xclip -selection clipboard", @")<CR>:echon ''<CR>

" Colorscheme
autocmd vimenter * ++nested colorscheme gruvbox

"  ---------- 
" | Plugins  |
"  ----------

call plug#begin('~/.local/share/nvim/plugged')
" to temp disable a plugin: Plug 'foo/bar', { 'on': [] }

Plug 'neoclide/coc.nvim', {'branch': 'release'}
Plug 'vim-airline/vim-airline' 
Plug 'vim-airline/vim-airline-themes'
Plug 'scrooloose/nerdcommenter'
Plug 'sbdchd/neoformat'
Plug 'jiangmiao/auto-pairs'
Plug 'davidhalter/jedi-vim' " Only for code jump,definition
Plug 'scrooloose/nerdtree'
Plug 'mg979/vim-visual-multi', {'branch': 'master'}
Plug 'tmhedberg/SimpylFold'
Plug 'morhetz/gruvbox'

call plug#end()

Answer 1

You mapping:

inoremap <leader>m  <esc> 

contains a trailing space. Since Space causes the cursor to move to the next line, because Space is allowed to move the cursor to the next line. This is caused by the default value of the 'whichwrap' which is b,s in Vim default mode.

Note, when using :imap command, Vim even shows you that in your mapping, by outputing:

i  \m          * <Esc><Space>

So you can see, that you are always executing ESCSpace when hitting Leader, followed by m in insert mode.

Long story short: Please remove the trailing Space from your mapping, since it is significant for the mapping.