feat(wpcarro/emacs): Test that my Emacs can initialize

...without warnings, errors.

This was previously a step in my buildkite instance, but I'm no longer
supporting that (in favor of the TVL one).

Change-Id: Ifed39aef248b21a1eb5a6c9d8427ebe6996abc3a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5103
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>

users/wpcarro/emacs/ci.el

@@ -0,0 +1,44 @@
+;; This script initializes Emacs and exits with either a zero or non-zero status
+;; depending on whether or not Emacs initialized without logging warnings or
+;; encountering errors.
+;;
+;; This script reads the location of init.el as the last argument in `argv'.
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Dependencies
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(require 'prelude)
+(require 'f)
+(require 'dash)
+(require 'buffer)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Script
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defvar init-el-path (-last-item argv)
+  "Path to the init.el file that this script attempts to load.")
+
+(prelude-assert (f-exists? init-el-path))
+
+(condition-case err
+    (load init-el-path)
+  (error
+   (message "Encountered an error while attempting to load init.el: %s" err)
+   (kill-emacs 1)))
+
+(when (buffer-exists? "*Errors*")
+  (progn
+    (with-current-buffer "*Errors*"
+      (message "Encountered errors in *Errors* buffer: %s" (buffer-string)))
+    (kill-emacs 1)))
+
+(when (buffer-exists? "*Warnings*")
+  (progn
+    (with-current-buffer "*Warnings*"
+      (message "Encountered warnings in *Warnings* buffer: %s" (buffer-string)))
+    (kill-emacs 1)))
+
+(message "Successfully init'd Emacs without encountering errors or warnings!")
+(kill-emacs 0)