Rust analyzer postfix completion issue

[svcop3]

When expanding rust analyzer postfix completion, the trigger text is not replaced.

minimal.vim :

call minpac#init()
call minpac#add('k-takata/minpac', {'type': 'opt'})
call minpac#add('neovim/nvim-lspconfig')
call minpac#add('nvim-lua/completion-nvim')
call minpac#add('norcalli/snippets.nvim')

set completeopt=menuone,noinsert,noselect
set shortmess+=c
set signcolumn=yes

lua <<EOF

require'snippets'.use_suggested_mappings()
local nvim_lsp = require'lspconfig'

local on_attach = function(client)
	require'completion'.on_attach(client)
end

local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities.textDocument.completion.completionItem.snippetSupport = true

nvim_lsp.rust_analyzer.setup{ capabilities=capabilities; on_attach=on_attach }
EOF

let g:completion_enable_snippet = 'snippets.nvim'
inoremap <expr> <S-Tab> pumvisible() ? "\<C-p>" : "\<S-Tab>"
inoremap <expr> <Tab>   pumvisible() ? "\<C-n>" : "\<Tab>"	

How to reproduce

1. Type foo().
2. expand 'if' snippet
3. text displayed is
   foo().if foo() { |}

Expected behavior
if foo() { |}

edit: correct formatting

[matoous]

Hi! Just wanted to add: this applies to other LSPs (most likely) as well, for example for gopls the behaviour is same. I tried with the latest version 0.7.0 which has added support for postfix completions: https://github.com/golang/tools/releases/tag/gopls%2Fv0.7.0 and encountered same issues as you. I am not sure whether the issue is related to nvim-lua/completion-nvim though. This might be issue for neovim itself?