Support minisnip (#1589)

Supprt minisnip

Needs joereynolds/vim-minisnip#5

I've also changed the default for `g:go_snippet_engine` to `automatic`,
which is a new value that will use the first snippet engine that's
loaded. I think that's more user-friendly than expecting the user to set
it.

I also changed the detection method to use the variables, instead of
scanning `runtimepath`. This is more efficient.

CHANGELOG.md

@@ -59,6 +59,12 @@ IMPROVEMENTS:
   [[GH-1582]](https://github.com/fatih/vim-go/pull/1582).
 * `:GoDescribe` doesn't require a scope anymore
   [[GH-1596]](https://github.com/fatih/vim-go/pull/1596).
+* Add some standard snippets for
+  [vim-minisnip](https://github.com/joereynolds/vim-minisnip)
+  [[GH-1589]](https://github.com/fatih/vim-go/pull/1589).
+* `g:go_snippet_engine` now defaults to `automatic` to use the first installed
+  snippet engine it can find.
+  [[GH-1589]](https://github.com/fatih/vim-go/pull/1589).
 
 ## 1.15 - (October 3, 2017)
 

doc/vim-go.txt

@@ -57,7 +57,8 @@ tools developed by the Go community to provide a seamless Vim experience.
   * Advanced source analysis tools utilizing `guru`, such as |:GoImplements|,
     |:GoCallees|, and |:GoReferrers|.
   * Precise type-safe renaming of identifiers with |:GoRename|.
-  * Integrated and improved snippets, supporting `ultisnips` or `neosnippet`.
+  * Integrated and improved snippets, supporting `ultisnips`, `neosnippet`,
+    and `vim-minisnip`.
   * Share your current code to play.golang.org with |:GoPlay|.
   * On-the-fly information about the word under the cursor. Plug it into your
     custom Vim function.
@@ -136,7 +137,8 @@ The following plugins are supported for use with vim-go:
 
 * Snippets:
   https://github.com/Shougo/neosnippet.vim or
-  https://github.com/SirVer/ultisnips
+  https://github.com/SirVer/ultisnips or
+  https://github.com/joereynolds/vim-minisnip
 
 * For a better documentation viewer check out:
   https://github.com/garyburd/go-explorer
@@ -1278,10 +1280,16 @@ Use this option to change default path for vim-go tools when using
 <
                                                        *'g:go_snippet_engine'*
 
-Use this option to define the default snippet engine.  By default "ultisnips"
-is used. Use "neosnippet" for neosnippet.vim: >
+Define the snippet engine to use. The default is to auto-detect one. Valid
+values are:
 
-  let g:go_snippet_engine = "ultisnips"
+  automatic      Automatically detect a snippet engine.
+  ultisnips      https://github.com/SirVer/ultisnips
+  neosnippet     https://github.com/Shougo/neosnippet.vim
+  minisnip       https://github.com/joereynolds/vim-minisnip
+                 Note: the original at KeyboardFire/vim-minisnip won't work.
+>
+  let g:go_snippet_engine = "automatic"
 <
                                                            *'g:go_get_update'*
 

ftplugin/go/snippets.vim

@@ -3,13 +3,8 @@ if exists("g:go_loaded_gosnippets")
 endif
 let g:go_loaded_gosnippets = 1
 
-" by default UltiSnips
-if !exists("g:go_snippet_engine")
-  let g:go_snippet_engine = "ultisnips"
-endif
-
-function! s:GoUltiSnips()
-  if globpath(&rtp, 'plugin/UltiSnips.vim') == ""
+function! s:GoUltiSnips() abort
+  if get(g:, 'did_plugin_ultisnips') isnot 1
     return
   endif
 
@@ -20,29 +15,53 @@ function! s:GoUltiSnips()
   endif
 endfunction
 
-function! s:GoNeosnippet()
-  if globpath(&rtp, 'plugin/neosnippet.vim') == ""
+function! s:GoNeosnippet() abort
+  if get(g:, 'loaded_neosnippet') isnot 1
     return
   endif
 
   let g:neosnippet#enable_snipmate_compatibility = 1
 
-  let gosnippets_dir = globpath(&rtp, 'gosnippets/snippets')
+  let l:gosnippets_dir = globpath(&rtp, 'gosnippets/snippets')
   if type(g:neosnippet#snippets_directory) == type([])
-    let g:neosnippet#snippets_directory += [gosnippets_dir]
+    let g:neosnippet#snippets_directory += [l:gosnippets_dir]
   elseif type(g:neosnippet#snippets_directory) == type("")
     if strlen(g:neosnippet#snippets_directory) > 0
-      let g:neosnippet#snippets_directory = g:neosnippet#snippets_directory . "," . gosnippets_dir
+      let g:neosnippet#snippets_directory = g:neosnippet#snippets_directory . "," . l:gosnippets_dir
     else
-      let g:neosnippet#snippets_directory = gosnippets_dir
+      let g:neosnippet#snippets_directory = l:gosnippets_dir
     endif
   endif
 endfunction
 
-if g:go_snippet_engine == "ultisnips"
+function! s:GoMinisnip() abort
+  if get(g:, 'loaded_minisnip') isnot 1
+    return
+  endif
+
+  if exists('g:minisnip_dir')
+    let g:minisnip_dir .= ':' . globpath(&rtp, 'gosnippets/minisnip')
+  else
+    let g:minisnip_dir = globpath(&rtp, 'gosnippets/minisnip')
+  endif
+endfunction
+
+
+let s:engine = get(g:, 'go_snippet_engine', 'automatic')
+if s:engine is? "automatic"
+  if get(g:, 'did_plugin_ultisnips') is 1
+    call s:GoUltiSnips()
+  elseif get(g:, 'loaded_neosnippet') is 1
+    call s:GoNeosnippet()
+  elseif get(g:, 'loaded_minisnip') is 1
+    call s:GoMinisnip()
+  endif
+elseif s:engine is? "ultisnips"
   call s:GoUltiSnips()
-elseif g:go_snippet_engine == "neosnippet"
+elseif s:engine is? "neosnippet"
   call s:GoNeosnippet()
+elseif s:engine is? "minisnip"
+  call s:GoMinisnip()
 endif
 
 " vim: sw=2 ts=2 et

gosnippets/minisnip/_go_eq

@@ -0,0 +1,3 @@
+if !reflect.DeepEqual({{+got+}}, {{+want+}}) {
+	t.Errorf("\ngot:  %#v\nwant: %#v\n", {{+~\~2+}}, {{+~\~2+}})	
+}

gosnippets/minisnip/_go_err

@@ -0,0 +1,3 @@
+if err != nil {
+	return {{+err+}}
+}

gosnippets/minisnip/_go_errt

@@ -0,0 +1,4 @@
+if err != nil {
+	t.Fatal(err)
+}
+{{++}}

gosnippets/minisnip/_go_errw

@@ -0,0 +1,3 @@
+if err != nil {
+	return errors.Wrap(err, "{{++}}")
+}

gosnippets/minisnip/_go_f

@@ -0,0 +1,3 @@
+// {{++}}
+func {{+~\~1+}}() {
+}

gosnippets/minisnip/_go_ff

@@ -0,0 +1 @@
+fmt.Printf("%#v\n", {{++}})

gosnippets/minisnip/_go_fori

@@ -0,0 +1,3 @@
+for i := 0; i < {{++}}; i++ {
+	{{++}}
+}

gosnippets/minisnip/_go_pkg

@@ -0,0 +1,2 @@
+// Package {{+~expand('%:p:h:t')+}} {{++}}
+package {{+~\~2+}}

gosnippets/minisnip/_go_sp

@@ -0,0 +1,2 @@
+fmt.Sprintf("{{++}}", {{++}})
+