shell layer: various improvements for eshell see below

- move the magit, helm and other dependencies to their own init
functions
- remove all nested use-package forms and enable correct lazy-loading
of eshell
- import interesting features from trishume like auto-completion and
automatic jump to prompt when switching to insert state
- new layer variable `shell-enable-smart-eshell` to conditionally enable
`em-smart` (default is not enabled)
- document all the last additions to the layer in README.org

contrib/shell/README.org

@@ -76,6 +76,48 @@ Default value is =/bin/bash=.
     '(shell :variables shell-default-term-shell "/bin/bash"))
 #+END_SRC
 
+** Enable em-smart in Eshell
+
+From the =em-smart= documentation:
+
+#+BEGIN_QUOTE
+The best way to get a sense of what this code is trying to do is by
+using it.  Basically, the philosophy represents a blend between the
+ease of use of modern day shells, and the review-before-you-proceed
+mentality of Plan 9's 9term.
+#+END_QUOTE
+
+In a nutshell, when =em-smart= is enabled the point won't jump at the
+end of the buffer when a command is executed, it will stay at the
+same command prompt used to executed the command. This allows to quickly
+edit the last command in the case of a mistake. If there is no mistake
+and you directly type a new command then the prompt will jump to the
+next prompt at the end of the buffer.
+
+To enable =em-smart= put the following layer variable to non-nil:
+
+#+BEGIN_SRC emacs-lisp
+  (setq-default dotspacemacs-configuration-layers
+    '(shell :variables shell-enable-smart-eshell t))
+#+END_SRC
+
+* Eshell
+
+Some advanced configuration is setup for =eshell= in this layer:
+- some elisp functions aliases for quick access
+  - =s= for =magit-status= in the current directory (when the =git= layer is
+    installed)
+  - =d= for =dired=
+  - =e= to find a file via a new buffer
+- optional configuration for =em-smart= (see =Install= section for more info)
+- support for visual commands via =em-term=
+- working directory sensitive prompt via [[https://github.com/hiddenlotus/eshell-prompt-extras][eshell-prompt-extras]]
+- advanced help support via =esh-help= (enable =el-doc= support in eshell)
+- add support for auto-completion via =company= (when the =auto-completion=
+  layer is installed)
+- pressing ~i~ in normal state will automatically jump to the prompt
+
+
 * Key bindings
 
 | Key Binding | Description                                                |
@@ -99,3 +141,9 @@ number of shell is indicated on the mode-line.
 | Key Binding | Description                  |
 |-------------+------------------------------|
 | ~SPC p $ t~ | run multi-term shell in root |
+
+** Eshell
+
+| Key Binding        | Description                                |
+|--------------------+--------------------------------------------|
+| ~SPC m H~ or ~M-l~ | shell commands history using a helm buffer |

contrib/shell/config.el

@@ -12,6 +12,8 @@
 
 ;; Variables
 
+(spacemacs|defvar-company-backends eshell-mode)
+
 (defvar shell-default-shell (if (eq window-system 'w32)
                                 'eshell
                               'ansi-term)
@@ -26,3 +28,7 @@
 
 (defvar shell-default-term-shell "/bin/bash"
   "Default shell to use in `term' and `ansi-term' shells.")
+
+(defvar shell-enable-smart-eshell nil
+  "If non-nil then `em-smart' is enabled. `em-smart' allows to quickly review
+commands, modify old commands or enter a new one.")

contrib/shell/packages.el

@@ -12,6 +12,7 @@
 
 (setq shell-packages
       '(
+        company
         helm
         multi-term
         shell
@@ -20,35 +21,48 @@
         eshell
         eshell-prompt-extras
         esh-help
+        magit
         ))
 
-(defun shell/post-init-helm ()
-  (spacemacs|use-package-add-hook helm
+(defun shell/post-init-company ()
+  ;; support in eshell
+  (spacemacs|use-package-add-hook eshell
     :post-config
     (progn
-      (defun spacemacs//shell-helm-post-:config ()
-        "Configuration to append to helm package `:config' block."
-        ;; eshell
-        (defun spacemacs/helm-eshell-history ()
-          "Correctly revert to insert state after selection."
-          (interactive)
-          (helm-eshell-history)
-          (evil-insert-state))
-        (defun spacemacs/helm-shell-history ()
-          "Correctly revert to insert state after selection."
-          (interactive)
-          (helm-comint-input-ring)
-          (evil-insert-state))
-        (defun spacemacs/init-helm-eshell ()
-          "Initialize helm-eshell."
-          ;; this is buggy for now
-          ;; (define-key eshell-mode-map (kbd "<tab>") 'helm-esh-pcomplete)
-          (evil-leader/set-key-for-mode 'eshell-mode
-            "mH" 'spacemacs/helm-eshell-history))
-        (add-hook 'eshell-mode-hook 'spacemacs/init-helm-eshell)
-        ;;shell
-        (evil-leader/set-key-for-mode 'shell-mode
-          "mH" 'spacemacs/helm-shell-history)))))
+      (setq-local company-idle-delay 0.2)
+      ;; The default frontend screws everything up in short windows like
+      ;; terminal often are
+      (setq-local company-frontends '(company-preview-frontend))
+      (push 'company-capf company-backends-eshell-mode)
+      (spacemacs|add-company-hook eshell-mode))))
+
+(defun shell/pre-init-helm ()
+  (spacemacs|use-package-add-hook helm
+    :post-init
+    (progn
+      ;; eshell
+      (defun spacemacs/helm-eshell-history ()
+        "Correctly revert to insert state after selection."
+        (interactive)
+        (helm-eshell-history)
+        (evil-insert-state))
+      (defun spacemacs/helm-shell-history ()
+        "Correctly revert to insert state after selection."
+        (interactive)
+        (helm-comint-input-ring)
+        (evil-insert-state))
+      (defun spacemacs/init-helm-eshell ()
+        "Initialize helm-eshell."
+        ;; this is buggy for now
+        ;; (define-key eshell-mode-map (kbd "<tab>") 'helm-esh-pcomplete)
+        (evil-leader/set-key-for-mode 'eshell-mode
+          "mH" 'spacemacs/helm-eshell-history)
+        (define-key eshell-mode-map
+          (kbd "M-l") 'spacemacs/helm-eshell-history))
+      (add-hook 'eshell-mode-hook 'spacemacs/init-helm-eshell)
+      ;;shell
+      (evil-leader/set-key-for-mode 'shell-mode
+        "mH" 'spacemacs/helm-shell-history))))
 
 (defun shell/init-multi-term ()
   (use-package multi-term
@@ -94,14 +108,7 @@
               (funcall 'man command))
              ;; Send other commands to the default handler.
              (t (comint-simple-send proc command))))))
-  (defun eshell/clear ()
-    "Clear contents in eshell."
-    (interactive)
-    (let ((inhibit-read-only t))
-      (erase-buffer)))
-  (add-hook 'shell-mode-hook 'shell-comint-input-sender-hook)
-  (add-hook 'eshell-mode-hook (lambda ()
-                                (setq pcomplete-cycle-completions nil))))
+  (add-hook 'shell-mode-hook 'shell-comint-input-sender-hook))
 
 (defun shell/init-shell-pop ()
   (use-package shell-pop
@@ -174,72 +181,82 @@
 
 (defun shell/init-eshell ()
   (use-package eshell
+    :defer t
+    :init
+    (progn
+      (setq eshell-cmpl-cycle-completions nil
+            ;; auto truncate after 20k lines
+            eshell-buffer-maximum-lines 20000
+            ;; history size
+            eshell-history-size 350
+            ;; buffer shorthand -> echo foo > #'buffer
+            eshell-buffer-shorthand t
+            ;; my prompt is easy enough to see
+            eshell-highlight-prompt nil
+            ;; treat 'echo' like shell echo
+            eshell-plain-echo-behavior t)
+
+      (defun spacemacs//eshell-auto-end ()
+        "Move point to end of current prompt when switching to insert state."
+        (when (and (eq major-mode 'eshell-mode)
+                   ;; Not on last line, we might want to edit within it.
+                   (not (eq (line-end-position) (point-max))))
+          (end-of-buffer)))
+
+      (defun spacemacs//init-eshell ()
+        "Stuff to do when enabling eshell."
+        (setq pcomplete-cycle-completions nil)
+        (add-hook 'evil-insert-state-entry-hook
+                  'spacemacs//eshell-auto-end nil t)
+        (when (configuration-layer/package-usedp 'semantic)
+          (semantic-mode -1)))
+      (add-hook 'eshell-mode-hook 'spacemacs//init-eshell))
     :config
     (progn
+      (require 'esh-opt)
+
+      ;; quick commands
       (defalias 'e 'find-file-other-window)
-      (defalias 's 'eshell/magit)
       (defalias 'd 'dired)
       (setenv "PAGER" "cat")
 
-      (require 'em-smart)
-      (setq eshell-where-to-jump 'begin
-            eshell-review-quick-commands nil
-            eshell-smart-space-goes-to-end t)
-      (add-hook 'eshell-mode-hook 'eshell-smart-initialize)
+      ;; support `em-smart'
+      (when shell-enable-smart-eshell
+        (require 'em-smart)
+        (setq eshell-where-to-jump 'begin
+              eshell-review-quick-commands nil
+              eshell-smart-space-goes-to-end t)
+        (add-hook 'eshell-mode-hook 'eshell-smart-initialize))
 
-      (use-package esh-opt
-        :config
-        (progn
-          (use-package em-term)
+      ;; Visual commands
+      (require 'em-term)
+      (mapc (lambda (x) (push x eshell-visual-commands))
+            '("el" "elinks" "htop" "less" "ssh" "tmux" "top"))
 
-          (setq eshell-cmpl-cycle-completions nil
-                ;; auto truncate after 20k lines
-                eshell-buffer-maximum-lines 20000
-                ;; history size
-                eshell-history-size 350
-                ;; buffer shorthand -> echo foo > #'buffer
-                eshell-buffer-shorthand t
-                ;; my prompt is easy enough to see
-                eshell-highlight-prompt nil
-                ;; treat 'echo' like shell echo
-                eshell-plain-echo-behavior t)
-
-          ;; Visual commands
-          (setq eshell-visual-commands
-                (append '("ssh" "less" "top" "htop" "el" "elinks" "tmux")
-                        eshell-visual-commands))
-
-          ;; automatically truncate buffer after output
-          (add-to-list 'eshell-output-filter-functions 'eshell-truncate-buffer)))
-
-      (add-hook 'eshell-mode-hook
-                (lambda ()
-                  ;; turn off semantic-mode in eshell buffers
-                  (semantic-mode -1)
-                  (define-key eshell-mode-map (kbd "M-l")
-                    'helm-eshell-history)))
-
-      (defun eshell/magit ()
-        "Function to open magit-status for the current directory"
-        (interactive)
-        (magit-status default-directory)
-        nil))))
+      ;; automatically truncate buffer after output
+      (when (boundp 'eshell-output-filter-functions)
+        (push 'eshell-truncate-buffer eshell-output-filter-functions)))))
 
 (defun shell/init-eshell-prompt-extras ()
-  (use-package eshell
-    :config
-    (use-package esh-opt
-      :config
-      (use-package eshell-prompt-extras
-        :init
-        (setq eshell-highlight-prompt nil
-              eshell-prompt-function 'epe-theme-lambda)))))
+  (use-package eshell-prompt-extras
+    :commands epe-theme-lambda
+    :init
+    (setq eshell-highlight-prompt nil
+          eshell-prompt-function 'epe-theme-lambda)))
 
 (defun shell/init-esh-help ()
-  (use-package eshell
-    :config
-    (use-package esh-help
-      :init
-      (progn
-        (setup-esh-help-eldoc)
-        (add-hook 'eshell-mode-hook 'eldoc-mode)))))
+  (use-package esh-help
+    :defer t
+    :init (add-hook 'eshell-mode-hook 'eldoc-mode)
+    :config (setup-esh-help-eldoc)))
+
+(defun shell/pre-init-magit ()
+  (spacemacs|use-package-add-hook magit
+    :post-init
+    (progn
+      ;; add a quick alias to open magit-status in current directory
+      (defun spacemacs/eshell-magit-status ()
+        "Function to open magit-status for the current directory"
+        (interactive)
+        (magit-status default-directory))
+      (defalias 's 'spacemacs/eshell-magit-status))))