vm: mark global proxy as side-effect-free

Fixes: https://github.com/nodejs/node/issues/27518

PR-URL: https://github.com/nodejs/node/pull/27523
Reviewed-By: Aleksei Koziatinskii <ak239spb@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

2 files changed, 64 insertions, 0 deletions

diff --git a/test/parallel/test-inspector-vm-global-accessors-getter-sideeffect.js b/test/parallel/test-inspector-vm-global-accessors-getter-sideeffect.js
new file mode 100644
index 0000000000..5dc9c9bb2d
--- /dev/null
+++ b/test/parallel/test-inspector-vm-global-accessors-getter-sideeffect.js
@@ -0,0 +1,33 @@
+'use strict';
+const common = require('../common');
+common.skipIfInspectorDisabled();
+
+// Test that if there is a side effect in a getter invoked through the vm
+// global proxy, Runtime.evaluate recognizes that.
+
+const assert = require('assert');
+const inspector = require('inspector');
+const vm = require('vm');
+
+const session = new inspector.Session();
+session.connect();
+
+const context = vm.createContext({
+  get a() {
+    global.foo = '1';
+    return 100;
+  }
+});
+
+session.post('Runtime.evaluate', {
+  expression: 'a',
+  throwOnSideEffect: true,
+  contextId: 2 // context's id
+}, (error, res) => {
+  assert.ifError(error);
+  const { exception } = res.exceptionDetails;
+  assert.strictEqual(exception.className, 'EvalError');
+  assert(/Possible side-effect/.test(exception.description));
+
+  assert(context);  // Keep 'context' alive and make linter happy.
+});
diff --git a/test/parallel/test-inspector-vm-global-accessors-sideeffects.js b/test/parallel/test-inspector-vm-global-accessors-sideeffects.js
new file mode 100644
index 0000000000..31551a08cb
--- /dev/null
+++ b/test/parallel/test-inspector-vm-global-accessors-sideeffects.js
@@ -0,0 +1,31 @@
+'use strict';
+const common = require('../common');
+common.skipIfInspectorDisabled();
+
+// Regression test for https://github.com/nodejs/node/issues/27518.
+
+const assert = require('assert');
+const inspector = require('inspector');
+const vm = require('vm');
+
+const session = new inspector.Session();
+session.connect();
+
+const context = vm.createContext({
+  a: 100
+});
+
+session.post('Runtime.evaluate', {
+  expression: 'a',
+  throwOnSideEffect: true,
+  contextId: 2 // context's id
+}, (error, res) => {
+  assert.ifError(error),
+  assert.deepStrictEqual(res, {
+    result: {
+      type: 'number',
+      value: context.a,
+      description: '100'
+    }
+  });
+});