1 files changed, 40 insertions, 0 deletions
diff --git a/devtools/server/tests/xpcshell/test_console_eval-private.js b/devtools/server/tests/xpcshell/test_console_eval-private.js
new file mode 100644
index 0000000000..14afbbfcc8
--- /dev/null
+++ b/devtools/server/tests/xpcshell/test_console_eval-private.js
@@ -0,0 +1,40 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/*
+ * Check that private field initialization is marked as effectful.
+ */
+
+add_task(
+  threadFrontTest(async ({ threadFront, targetFront, debuggee }) => {
+    const consoleFront = await targetFront.getFront("console");
+    const initial_response = await consoleFront.evaluateJSAsync(`
+      // This is a silly trick that allows stamping a field into
+      // arbitrary objects.
+      class Base { constructor(o) { return o; }};
+      class A extends Base {
+        #x = 10;
+      };
+      var obj = {};
+    `);
+    // If an exception occurred, private fields are not yet enabled. Abort
+    // the rest of this test.
+    if (initial_response.hasException) {
+      return;
+    }
+
+    const eagerResult = await consoleFront.evaluateJSAsync("new A(obj)", {
+      eager: true,
+    });
+    Assert.equal(
+      eagerResult.result.type,
+      "undefined",
+      "shouldn't have actually produced a result"
+    );
+
+    const timeoutResult = await consoleFront.evaluateJSAsync("new A(obj); 1;");
+    Assert.equal(timeoutResult.result, 1, "normal eval, no throw.");
+  })
+);