test: add tests for new language features

PR-URL: #27400
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

Author: BridgeAR

test/parallel/test-assert.js

@@ -631,13 +631,13 @@ common.expectsError(
 }
 );
 common.expectsError(
-()=>assert(typeof123==='string'),
+()=>assert(typeof123n==='string'),
 {
 code: 'ERR_ASSERTION',
 type: assert.AssertionError,
 generatedMessage: true,
 message: 'The expression evaluated to a falsy value:\n\n '+
-"assert(typeof 123 === 'string')\n"
+"assert(typeof 123n === 'string')\n"
 }
 );
 

test/parallel/test-repl.js

@@ -328,6 +328,21 @@ const errorTests = [
 send: '1 }',
 expect: '{ a: 1 }'
 },
+// Multiline class with private member.
+{
+send: 'class Foo { #private = true ',
+expect: '... '
+},
+// Class field with bigint.
+{
+send: 'num = 123456789n',
+expect: '... '
+},
+// Static class features.
+{
+send: 'static foo = "bar" }',
+expect: 'undefined'
+},
 // Multiline anonymous function with comment
 {
 send: '(function() {',
@@ -338,12 +353,12 @@ const errorTests = [
 expect: '... '
 },
 {
-send: 'return 1;',
+send: 'return 1n;',
 expect: '... '
 },
 {
 send: '})()',
-expect: '1'
+expect: '1n'
 },
 // Multiline function call
 {