fix: REPL evaluates in strict mode (#5565)

Since everything that Deno loads is treated as an ES Module, 
it means that all code is treated as "use strict" except for 
when using the REPL. This PR changes that so code in the 
REPL is also always evaluated with "use strict". There are 
also a couple other places where we load code as scripts 
which should also use "use strict" just in case.

1 files changed, 18 insertions, 0 deletions

diff --git a/cli/tests/integration_tests.rs b/cli/tests/integration_tests.rs
index 606a40516..f892b9a87 100644
--- a/cli/tests/integration_tests.rs
+++ b/cli/tests/integration_tests.rs
@@ -693,6 +693,24 @@ fn repl_test_eof() {
   assert!(err.is_empty());
 }
 
+#[test]
+fn repl_test_strict() {
+  let (_, err) = util::run_and_collect_output(
+    true,
+    "repl",
+    Some(vec![
+      "let a = {};",
+      "Object.preventExtensions(a);",
+      "a.c = 1;",
+    ]),
+    None,
+    false,
+  );
+  assert!(err.contains(
+    "Uncaught TypeError: Cannot add property c, object is not extensible"
+  ));
+}
+
 const REPL_MSG: &str = "exit using ctrl+d or close()\n";
 
 #[test]