Bump Emacs version in GitHub action and install updated packages

Now using `use-package` to better install them, and setting
`load-prefer-newer` which was probably the bug.

Author: andyleejordan

.github/workflows/emacs-test.yml

@@ -25,9 +25,11 @@ jobs:
         run: tools/azurePipelinesBuild.ps1
 
       - name: Install Emacs
-        uses: purcell/setup-emacs@v4.0
+        uses: purcell/setup-emacs@master
         with:
-          version: '28.1'
+          version: '28.2'
 
       - name: Run ERT
-        run: emacs -batch -l ert -l test/emacs-test.el -f ert-run-tests-batch-and-exit
+        run: |
+          emacs -Q --batch -f package-refresh-contents --eval "(package-install 'eglot)"
+          emacs -Q --batch -l test/emacs-test.el -f ert-run-tests-batch-and-exit

.gitignore

@@ -11,6 +11,7 @@ App_Data
 *.sln.cache
 *.suo
 TestResults
+test/emacs-session.json
 [Tt]humbs.db
 buildd.*
 release/

test/emacs-test.el

@@ -8,7 +8,8 @@
 
 ;;; Code:
 
-(require 'ert)
+;; Avoid using old packages.
+(setq load-prefer-newer t)
 
 ;; Improved TLS Security.
 (with-eval-after-load 'gnutls
@@ -21,16 +22,17 @@
 (add-to-list 'package-archives
              '("melpa" . "https://melpa.org/packages/") t)
 (package-initialize)
+(package-refresh-contents)
+
+(require 'ert)
 
 (require 'flymake)
 
 (unless (package-installed-p 'powershell)
-  (package-refresh-contents)
   (package-install 'powershell))
 (require 'powershell)
 
 (unless (package-installed-p 'eglot)
-  (package-refresh-contents)
   (package-install 'eglot))
 (require 'eglot)