[new layer][graphql] add graphql layer

It builds around graphql-mode
- Syntax highlight and graphql calls with graphql-mode
- Autocomplete with comapy-dabbrev
- Format buffer with prettier
- Go to definition with ahs

layers/+lang/graphql/README.org

@@ -0,0 +1,38 @@
+#+TITLE: graphql layer
+#+TAGS: layer|language
+
+[[file:img/graphql.png]]
+
+* Table of Contents                                       :TOC_4_gh:noexport:
+- [[#description][Description]]
+  - [[#features][Features:]]
+- [[#install][Install]]
+- [[#key-bindings][Key bindings]]
+
+* Description
+This layer adds support for graphql file. It builds around [[https://github.com/davazp/graphql-mode][graphql-mode]]. Please
+check its site for extra info.
+
+** Features:
+  - Syntax highlight and graphql calls with =graphql-mode= 
+  - Autocomplete with =comapy-dabbrev=
+  - Format buffer with =prettier=
+  - Go to definition with =ahs=
+
+* Install
+To use this configuration layer, add it to your =~/.spacemacs=. You will need to
+add =graphql= to the existing =dotspacemacs-configuration-layers= list in this
+file.
+
+If you want to format graphql buffers you need to enable =prettier= layer also.
+
+* Key bindings
+
+| Key Binding | Description                   |
+|-------------+-------------------------------|
+| ~SPC m = =~ | graphql-edit-headers          |
+| ~SPC m e~   | graphql-select-endpoint       |
+| ~SPC m g G~ | jump to definition new window |
+| ~SPC m g g~ | jump to definition            |
+| ~SPC m h~   | graphql-edit-headers          |
+| ~SPC m s~   | graphql-send-query            |

layers/+lang/graphql/config.el

@@ -0,0 +1,12 @@
+;;; config.el --- vue layer config file for Spacemacs. -*- lexical-binding: t -*-
+;;
+;; Copyright (c) 2012-2020 Sylvain Benner & Contributors
+;;
+;; Author: Thanh Vuong <thanhvg@gmail.com>
+;; URL: https://github.com/thanhvg
+;;
+;; This file is not part of GNU Emacs.
+;;
+;;; License: GPLv3
+
+(spacemacs|define-jump-handlers graphql-mode)

layers/+lang/graphql/packages.el

@@ -0,0 +1,56 @@
+;;; packages.el --- graphql layer packages file for Spacemacs.
+;;
+;; Copyright (c) 2012-2020 Sylvain Benner & Contributors
+;;
+;; Author: Thanh Vuong <thanh@gmail.com>
+;; URL: https://github.com/thanhvg
+;;
+;; This file is not part of GNU Emacs.
+;;
+;;; License: GPLv3
+
+;;; Commentary:
+
+;; See the Spacemacs documentation and FAQs for instructions on how to implement
+;; a new layer:
+;;
+;;   SPC h SPC layers RET
+;;
+;;
+;; Briefly, each package to be installed or configured by this layer should be
+;; added to `graphql-packages'. Then, for each package PACKAGE:
+;;
+;; - If PACKAGE is not referenced by any other Spacemacs layer, define a
+;;   function `graphql/init-PACKAGE' to load and initialize the package.
+
+;; - Otherwise, PACKAGE is already referenced by another Spacemacs layer, so
+;;   define the functions `graphql/pre-init-PACKAGE' and/or
+;;   `graphql/post-init-PACKAGE' to customize the package as it is loaded.
+
+;;; Code:
+
+(defconst graphql-packages
+  '(company
+    prettier-js
+    graphql-mode))
+
+(defun graphql/init-graphql-mode ()
+  (use-package graphql-mode
+    :defer t
+    :init
+    (add-to-list 'spacemacs-jump-handlers-graphql-mode 'ahs-backward-definition))
+    (when (configuration-layer/layer-used-p 'prettier)
+     (spacemacs/declare-prefix-for-mode 'graphql-mode "m=" "format"))
+    (spacemacs/declare-prefix-for-mode 'graphql-mode "mg" "goto")
+    (spacemacs/set-leader-keys-for-major-mode 'graphql-mode
+      "s" 'graphql-send-query
+      "e" 'graphql-select-endpoint
+      "h" 'graphql-edit-headers))
+
+(defun graphql/post-init-company ()
+  (spacemacs|add-company-backends
+    :backends company-dabbrev
+    :modes graphql-mode))
+
+(defun graphql/pre-init-prettier-js ()
+  (add-to-list 'spacemacs--prettier-modes 'graphql-mode))