Revert "support emacs 27"

This reverts commit 1d2c27d.

Author: Chen Bin

.github/workflows/actions.yml

@@ -4,7 +4,7 @@ jobs:
   test-emacs-versions:
     strategy:
       matrix:
-        emacs-version: [27, 28, 29]
+        emacs-version: [28, 29]
     runs-on: ubuntu-latest
     container: silex/emacs:${{matrix.emacs-version}}-ci-eask
     steps:

Eask

@@ -12,7 +12,7 @@
 (source "gnu")
 (source "melpa")
 
-(depends-on "emacs" "27.1")
+(depends-on "emacs" "28.1")
 
 (development
  (depends-on "el-mock")

js-comint.el

@@ -9,7 +9,7 @@
 ;;; Created: 15 Feb 2014
 ;;; Version: 1.2.0
 ;;; URL: https://github.com/redguardtoo/js-comint
-;;; Package-Requires: ((emacs "27.1"))
+;;; Package-Requires: ((emacs "28.1"))
 ;;; Keywords: javascript, node, inferior-mode, convenience
 
 ;; This file is NOT part of GNU Emacs.

test/unit-tests.el

@@ -82,13 +82,9 @@ reduce((prev, curr) => prev + curr, 0);"
 
 (ert-deftest js-comint/test-strict-mode ()
   "When NODE_REPL_MODE=strict should use strict mode."
-  (let ((old (getenv "NODE_REPL_MODE")))
-    (unwind-protect
-        (progn
-          (setenv "NODE_REPL_MODE" "strict")
-          ;; global variables are not allowed in strict mode
-          (js-comint-test-output-matches "foo = 5;" "Uncaught ReferenceError.*"))
-      (setenv "NODE_REPL_MODE" old))))
+  (with-environment-variables (("NODE_REPL_MODE" "strict"))
+    ;; global variables are not allowed in strict mode
+    (js-comint-test-output-matches "foo = 5;" "Uncaught ReferenceError.*")))
 
 (ert-deftest js-comint-select-node-version/test-no-nvm ()
   "Should error if nvm is missing."