# VIM-GO
Plugin `https://github.com/fatih/vim-go`  
Tutorial `https://github.com/fatih/vim-go-tutorial`  
Vimrc `https://github.com/fatih/dotfiles/blob/master/vimrc`

## Run
### Commands
* File `:GoRun %`  
* Package `:GoRun`
* Debug `:GoDebugStart`

### vimrc
Shortkeys  

```
autocmd FileType go nmap <leader>r  <Plug>(go-run)
``` 

## Build
### Commands
* Package `:GoBuild` 

### vimrc
 
Auto save on make with 

```set autowrite```

Error navigation  

```
map <C-n> :cnext<CR>  
map <C-m> :cprevious<CR>  
nnoremap <leader>a :cclose<CR>  
```

## Test
### Commands
* File `:GoTest` from test or implementation
* Function `:GoTestFunc`
* Compile test `:GoTestCompile`

### vimrc
Shortkey to build go implementation or test 

```
" run :GoBuild or :GoTestCompile based on the go file
function! s:build_go_files()
  let l:file = expand('%')
  if l:file =~# '^\f\+_test\.go$'
    call go#test#Test(0, 1)
  elseif l:file =~# '^\f\+\.go$'
    call go#cmd#Build(0)
  endif
endfunction

autocmd FileType go nmap <leader>b :<C-u>call <SID>build_go_files()<CR>
```

## Coverage
### Commands
* `:GoCoverage`
* `:GoCoverageClear`
* `:GoCoverageToggle`
* `:GoCoverageBrowser`

### vimrc
Toggle coverage
```
autocmd FileType go nmap <Leader>c <Plug>(go-coverage-toggle)
```

## Edit
### Commands
* `:GoFmt`
* `:GoImports`
* Struct add tags `:GoAddTags`
* Struct remove tags `:GoRemoveTags`
* Manually import package `:GoImport <package>` - tab completion
* Manually remove package `:GoDrop <package>`
* Import with alias `:GoImportAs <alias> <package>`

### Text objects
* Inner function - `dif`, `yif`, `vif` etc
* Whole function - `daf`, `yaf`, `vaf` etc

### vimrc
Format on save  
`let g:go_fmt_autosave = 1`

Disable gofmt parse errors  
`let g:go_fmt_fail_silently = 1`

Goimports on save  
`let g:go_fmt_command = "goimports"`

Struct line split  
`Plug 'AndrewRadev/splitjoin.vim'`

* split `gS`
* join `gJ`

Snippets (Keyword + TAB)  
`Plug 'SirVer/ultisnips'` [reference](https://github.com/fatih/vim-go/blob/master/gosnippets/UltiSnips/go.snippets)


* `fn` fmt.Println()
* `ff` fmt.Printf()
* `ln` log.Println()
* `lf` log.Printf()

## Navigation
### Commands
* Between test and implementation `:GoAlternate`
* Go to definition `:GoDef` or `gd` or `ctrl-]`
* Back from definition `:GoDefPop` or `ctrl-t`
* Show navvigation stack `:GoDefStack`
* Clear navigation stack `:GoDefStackClear`
* File type and function declarations `:GoDecls`
* Directory tyle and function declarations `:GoDeclsDir`
* jump to next function `]]`
* jump to previous function `[[` 
* `3]]`, `d]]`, `v]]` 

### vimrc
Needed for `:GoDecls` and `:GoDeclsDir`
`Plug 'ctrlpvim/ctrlp.vim'`

Alternate commands

```
autocmd Filetype go command! -bang A call go#alternate#Switch(<bang>0, 'edit')
autocmd Filetype go command! -bang AV call go#alternate#Switch(<bang>0, 'vsplit')
autocmd Filetype go command! -bang AS call go#alternate#Switch(<bang>0, 'split')
autocmd Filetype go command! -bang AT call go#alternate#Switch(<bang>0, 'tabe')
```

## Documentation
### Commands
* `:GoDoc` or `K`
* `:GoDocBrowser`
* `:GoInfo` function signature
* Highlight identifiers `:GoSameIds`
* Clear highlight identifiers `:GoSameIdsClear`
* List files in a package `:GoFiles`
* List file dependencies `:GoDeps`
* Find references to identifier `:GoReferrers`
* Info for identifier `:GoDescribe`
* Interfaces a type implements `:GoImplements`
* Possible error types `:GoWhicherrs`
* Channel info `:GoChannelPeers`
* Show possible call targets of cunction call `:GoCallees`
* Show function call locations `::GoCallers`
* `:GoCallstack`
* Guru scope whole GOPATH `:GoGuruScope ...`

### vimrc
Get info  
`autocmd FileType go nmap <Leader>i <Plug>(go-info)`

Automatically show function info  
`let g:go_auto_type_info = 1`

Function info update delay (ms)  
`set updatetime=100`

Automatically highlight identifiers  
`let g:go_auto_sameids = 1`


## Refactor
### Commands
* Rename identifier `:GoRename <newname>`
* Show free variables `visual select + :GoFreevars`

## Codegen
### Commands
* Implement interface for type `:GoImpl <interface>`

## Checks
### Commands
* `:GoLint`
* `:GoVet`
* `:GoMetaLinter`

### vimrc
Meta linter checks for `:GoMetaLinter`
`let g:go_metalinter_enabled = ['vet', 'golint', 'errcheck', 'deadcode']`

Meta linter on save
`let g:go_metalinter_autosave = 1`

Meta linter checks for autosave
`let g:go_metalinter_autosave_enabled = ['vet', 'golint']`

## Syntax highlighting
### vimrc
* `let g:go_highlight_types = 1`
* `let g:go_highlight_fields = 1`
* `let g:go_highlight_functions = 1`
* `let g:go_highlight_function_calls = 1`
* `let g:go_highlight_operators = 1`
* `let g:go_highlight_extra_types = 1`
* `let g:go_highlight_build_constraints = 1`
* tab size `autocmd BufNewFile,BufRead *.go setlocal noexpandtab tabstop=4 shiftwidth=4 `


## Shortkey suggestion


### " Leader keys
#### " Q
"`q` Show how function is reached `:GoCallstack`  
`autocmd FileType go nmap <leader>q  <Plug>(go-callstack)`

#### " W
"`w` Alternwate window splits  
`nnoremap <leader>w <C-w>w`  
"`W` Only one active window
`nnoremap <Leader>W :only<CR>`
#### " E
"`e` Generate error handling `:GoIfErr`  
`autocmd FileType go nmap <leader>e <Plug>(go-iferr)`
#### " R
"`r` Rename `:GoRename[!] [to]`  
`autocmd FileType go nmap <leader>r  <Plug>(go-rename)`
#### " T
"`t` Test function `:GoTestFunc[!] [expand]`  
`autocmd FileType go nmap <leader>t  <Plug>(go-test-func)`  
"`T` Test file `:GoTest[!] [expand]`
`autocmd FileType go nmap <leader>T  <Plug>(go-test)`
#### " Y
"`y` Keyify struct literals `:GoKeyify`  
`nnoremap <Leader>y :GoKeyify<CR>`
#### " U
"`u` Fill struct with defaults `:GoFillStruct`  
`nnoremap <Leader>u :GoFillStruct<CR>`
#### " I
"`i` List interfaces implemented `:GoImplements`  
`autocmd FileType go nmap <leader>i  <Plug>(go-implements)`  
"`I` Stub interface methods `:GoImpl [receiver] [interface]`  
`nnoremap <Leader>I :GoImpl<CR>`
#### " O
#### " P
"`p c` Possible callers of a function `:GoCallers`  
`autocmd FileType go nmap <leader>pc  <Plug>(go-callers)`  
"`p t` Possible call targets for a type `:GoCallees`
`autocmd FileType go nmap <leader>pt  <Plug>(go-callees)`  
"`p v` Possible vars of a pointer `:GoPointsTo`
`autocmd FileType go nmap <leader>pv  <Plug>(go-pointsto)`  
"`p e` Possible error types of an error `:GoWhicherrs`  
`nnoremap <Leader>pe :GoWhicherrs<CR>`  
"`p c` Channel peers `:GoChannelPeers`
`autocmd FileType go nmap <leader>pp  <Plug>(go-channelpeers)`
#### " A
"`a` Alternate test/implementation `:GoAlternate[!]`  
`autocmd FileType go nmap <leader>a  <Plug>(go-alternate-edit)`
#### " S
"`s` Describe type or identifier `:GoDescribe`  
`autocmd FileType go nmap <leader>s  <Plug>(go-describe)`
#### " D
"`d` Show doc `:GoDoc [word]`  
`autocmd FileType go nmap <leader>d  <Plug>(go-doc)`  
"`D` Browse doc `:GoDocBrowser [word]`  
`autocmd FileType go nmap <leader>D  <Plug>(go-doc-browser)`
#### " F
"`f` Show all functions and types in file `:GoDecls [file]`  
`nnoremap <Leader>f :GoDecls<CR>`  
"`F` Show all functions and types in directory `:GoDeclsDir [dir]`  
`nnoremap <Leader>F :GoDeclsDir<CR>`
#### " G
"`g` Show definition jump stack `:GoDefStack [number]`  
`autocmd FileType go nmap <leader>g  <Plug>(go-def-stack)`  
"`G` Clear definition jump stack `:GoDefStackClear`  
`autocmd FileType go nmap <leader>G  <Plug>(go-def-stack-clear)`
#### " H
"`h` Show all identifiers referring to the object `:GoReferrers`  
`autocmd FileType go nmap <leader>h  <Plug>(go-referrers)`  
"`H` Toggle highlight same identifiers `:GoSameIdsToggle`  
`nnoremap <Leader>H :GoSameIdsToggle<CR>`
#### " J
#### " K
#### " L
"`l` List buffers  
`nnoremap <leader>l :ls<CR>:b<space>`  
"`L` List files  
`nnoremap <Leader>L :Explore<CR>`
#### " Z
#### " X
"`w` Close window split  
`nnoremap <leader>x <C-w>c`  
#### " C
"`c` Toggle coverage `:GoCoverageToggle[!] [options]`  
`autocmd FileType go nmap <Leader>c <Plug>(go-coverage-toggle)`  
"`C` Browse coverage `:GoCoverageBrowser[!] [options]`  
`nnoremap <Leader>C :GoCoverageBrowser<CR>`
#### " V
"`v` Show free variables in selection `:GoFreevars`  
`autocmd FileType go nmap <leader>v  <Plug>(go-freevars)`
#### " B
"`b` Build `:GoBuild[!] [expand]` `:GoTestCompile[!] [expand]`  
`autocmd FileType go nmap <leader>b :<C-u>call <SID>build_go_files()<CR>`  
"`B` Run `:GoRun[!] [expand]`  
`autocmd FileType go nmap <leader>B  <Plug>(go-run)`
#### " N
#### " M
"`m` Meta linter `:GoMetaLinter [path]`  
`autocmd FileType go nmap <leader>M <Plug>(go-metalinter)`
#### " Extra
"`gd` Go to definition `:GoDef`  
"`<C-t>` Back from definition `:GoDefPop [count]`  
`nnoremap <leader><TAB> :b#<CR>`  
`nnoremap <CR> :nohlsearch<CR><CR>`