spacemacs/layers/+lang/go/README.org

GO layer

• Description
  • Features:
• Install
  • Pre-requisites
  • Layer
• Configuration
  • Indentation
  • Tests
• Working with Go
  • Go commands (start with m):
  • Go Oracle

Description

This layer adds extensive support for go.

Features:

• gofmt/goimports on file save
• Auto-completion using go-autocomplete (with the auto-completion layer)
• Source analysis using go-oracle
• Linting with flycheck's built-in checkers or flycheck-gometalinter
• Coverage profile visualization

Install

Pre-requisites

You will need gocode and godef:

  go get -u -v github.com/nsf/gocode
  go get -u -v github.com/rogpeppe/godef
  go get -u -v golang.org/x/tools/cmd/oracle
  go get -u -v golang.org/x/tools/cmd/gorename
  go get -u -v golang.org/x/tools/cmd/goimports

If you wish to use gometalinter set the value of go-use-gometalinter to t:

  (go :variables go-use-gometalinter t)

and install the tool:

  go get -u -v github.com/alecthomas/gometalinter
  gometalinter --install --update

For more information read gometalinter README.md and flycheck-gometalinter README.md

Make sure that gocode executable is in your PATH. For information about setting up $PATH, check out the corresponding section in the FAQ (SPC h SPC $PATH RET).

For best results, make sure that the auto-completion and syntax-checking layers are enabled as well.

Layer

To use this configuration layer, add it to your ~/.spacemacs. You will need to add go to the existing dotspacemacs-configuration-layers list in this file.

Configuration

By default, go buffers are run through gofmt on save. To use a different formatter, set the value of gofmt-command, e.g.

  (setq gofmt-command "goimports")

or

  (go :variables gofmt-command "goimports")

Indentation

By default, the tab width in Go mode is 8 spaces. To use a different value set the layer variable go-tab-width, e.g.

  (go :variables go-tab-width 4)

Tests

If you're using gocheck in your project you can use the go-use-gocheck-for-testing variable to enable suite testing and to get single function testing to work.

go-coverage-display-buffer-func controls how go-coverage should display the coverage buffer. See display-buffer for a list of possible functions. The default value is display-buffer-reuse-window.

Working with Go

Go commands (start with m):

Key Binding	Description
SPC m h h	godoc at point
SPC m i g	goto imports
SPC m i a	add import
SPC m i r	remove unused import
SPC m e b	go-play buffer
SPC m e r	go-play region
SPC m e d	download go-play snippet
SPC m x x	run "go run" for the current 'main' package
SPC m g a	jump to matching test file or back from test to code file
SPC m g c	open a clone of the current buffer with a coverage info (go tool cover -h for help)
SPC m g g	go jump to definition
SPC m r n	go rename
SPC m t p	run "go test" for the current package
SPC m t P	run "go test" for the current package and all packages under it
SPC m t t	run "go test" for the function you're currently in (while you're in a _.test.go file)
SPC m t s	run "go test" for the suite you're currently in (requires gocheck)

Go Oracle

Key Binding	Description
SPC m r o	go-oracle set analysis scope
SPC m r <	go-oracle show possible callers
SPC m r >	go-oracle show call targets
SPC m r c	go-oracle show channel sends/receives
SPC m r d	go-oracle show definition
SPC m r f	go-oracle show free variables
SPC m r g	go-oracle show callgraph
SPC m r i	go-oracle show implements relation
SPC m r p	go-oracle show what the select expression points to
SPC m r r	go-oracle show all references to object
SPC m r s	go-oracle show callstack
SPC m r t	go-oracle describe selected syntax, kind, type and methods