fix(cli/repl): interpret object literals as expressions (#7591)

cli/rt/40_repl.js

@@ -52,10 +52,21 @@
   // Evaluate code.
   // Returns true if code is consumed (no error/irrecoverable error).
   // Returns false if error is recoverable
-  function evaluate(code) {
+  function evaluate(code, preprocess = true) {
+    const rawCode = code;
+    if (preprocess) {
+      // It is a bit unexpected that { "foo": "bar" } is interpreted as a block
+      // statement rather than an object literal so we interpret it as an expression statement
+      // to match the behavior found in a typical prompt including browser developer tools.
+      if (code.trimLeft().startsWith("{") && !code.trimRight().endsWith(";")) {
+        code = `(${code})`;
+      }
+    }
+
     // each evalContext is a separate function body, and we want strict mode to
     // work, so we should ensure that the code starts with "use strict"
     const [result, errInfo] = core.evalContext(`"use strict";\n\n${code}`);
+
     if (!errInfo) {
       // when a function is eval'ed with just "use strict" sometimes the result
       // is "use strict" which should be discarded
@@ -65,6 +76,8 @@
       if (!isCloseCalled()) {
         replLog("%o", lastEvalResult);
       }
+    } else if (errInfo.isCompileError && code.length != rawCode.length) {
+      return evaluate(rawCode, false);
     } else if (errInfo.isCompileError && isRecoverableError(errInfo.thrown)) {
       // Recoverable compiler error
       return false; // don't consume code.

cli/tests/integration_tests.rs

@@ -1058,6 +1058,32 @@ fn repl_test_console_log() {
   assert!(err.is_empty());
 }
 
+#[test]
+fn repl_test_object_literal() {
+  let (out, err) = util::run_and_collect_output(
+    true,
+    "repl",
+    Some(vec!["{}", "{ foo: 'bar' }"]),
+    Some(vec![("NO_COLOR".to_owned(), "1".to_owned())]),
+    false,
+  );
+  assert!(out.ends_with("{}\n{ foo: \"bar\" }\n"));
+  assert!(err.is_empty());
+}
+
+#[test]
+fn repl_test_block_expression() {
+  let (out, err) = util::run_and_collect_output(
+    true,
+    "repl",
+    Some(vec!["{};", "{\"\"}"]),
+    Some(vec![("NO_COLOR".to_owned(), "1".to_owned())]),
+    false,
+  );
+  assert!(out.ends_with("undefined\n\"\"\n"));
+  assert!(err.is_empty());
+}
+
 #[test]
 fn repl_cwd() {
   let (_out, err) = util::run_and_collect_output(