[DI] Sanitize instanceof class in probe conditions (#5520)

Author: watson

packages/dd-trace/src/debugger/devtools_client/condition.js

@@ -57,7 +57,7 @@ function compile (node) {
       }
     })()`
   } else if (type === 'instanceof') {
-    return `Function.prototype[Symbol.hasInstance].call(${value[1]}, ${compile(value[0])})`
+    return `Function.prototype[Symbol.hasInstance].call(${assertIdentifier(value[1])}, ${compile(value[0])})`
   } else if (type === 'ref') {
     if (value === '@it') {
       return '$dd_it'

packages/dd-trace/test/debugger/devtools_client/condition-test-cases.js

@@ -629,6 +629,11 @@ const typeAndDefinitionChecks = [
     { bar: new HasInstanceSideEffect(), HasInstanceSideEffect },
     true
   ],
+  {
+    ast: { instanceof: [{ ref: 'foo' }, 'foo.bar'] },
+    expected: new SyntaxError('Illegal identifier: foo.bar'),
+    execute: false
+  },
 
   [{ isDefined: { ref: 'foo' } }, { bar: 42 }, false],
   [{ isDefined: { ref: 'bar' } }, { bar: 42 }, true],