test: Add linting and byte-compile checks

run_tests.sh

@@ -2,4 +2,44 @@
 
 EMACS="${EMACS:=emacs}"
 
-${EMACS} --batch -l display-wttr.el -l display-wttr-test.el -f ert-run-tests-batch-and-exit
+NEEDED_PACKAGES="package-lint"
+
+INIT_PACKAGE_EL="(progn \
+  (require 'package) \
+  (push '(\"melpa\" . \"https://melpa.org/packages/\") package-archives) \
+  (package-initialize) \
+  (unless package-archive-contents \
+     (package-refresh-contents)) \
+  (dolist (pkg '(${NEEDED_PACKAGES})) \
+    (unless (package-installed-p pkg) \
+      (package-install pkg))))"
+
+# Refresh package archives, because the test suite needs to see at least
+# package-lint.
+"$EMACS" -Q -batch \
+         --eval "$INIT_PACKAGE_EL"
+
+# Byte-compile
+
+"$EMACS" -Q -batch \
+         --eval "$INIT_PACKAGE_EL" \
+         -l display-wttr.el \
+         -f batch-byte-compile \
+         display-wttr.el
+
+# Linting
+
+"$EMACS" -Q -batch \
+         --eval "$INIT_PACKAGE_EL" \
+         -L . \
+         --eval "(require 'package-lint)" \
+         -f package-lint-batch-and-exit \
+         display-wttr.el
+
+# Testing
+
+"$EMACS" -Q --batch \
+        --eval "$INIT_PACKAGE_EL" \
+         -l display-wttr.elc \
+         -l display-wttr-test.el \
+         -f ert-run-tests-batch-and-exit