Test that the second argument of window.postMessage is ignored or triggers an error if it is not a message port. You should see PASS message '1' through '7', followed by 'done', with messages 4-7 received below.

PASS: Posting message ('1', 1): threw exception TypeError: Value is not a sequence
PASS: Posting message ('2', c): threw exception TypeError: Value is not a sequence
PASS: Posting message ('3', [object Object]): threw exception TypeError: Type error
PASS: Posting message ('4', [object Window]): threw exception TypeError: Type error
PASS: Posting message ('4a', *): threw exception TypeError: Value is not a sequence
PASS: Posting message ('5', null) did not throw an exception
PASS: Posting message ('6', undefined) did not throw an exception
PASS: Posting message ('7', [object MessagePort],[object MessagePort]) did not throw an exception
PASS: Posting message ('7a', *): threw exception TypeError: Value is not a sequence
PASS: Posting message ('7', [object MessagePort],[object MessagePort]) did not throw an exception
PASS: Posting message ('2147483648', null) did not throw an exception
PASS: Posting message ('[object MessagePort]', [object MessagePort],[object MessagePort]) did not throw an exception
PASS: Posting message ('[object MessagePort]', [object MessagePort],[object MessagePort]) did not throw an exception
PASS: Posting message ('[object MessagePort],[object MessagePort]', [object MessagePort],[object MessagePort]) did not throw an exception
PASS: Posting message ('[object ArrayBuffer]', [object ArrayBuffer]) did not throw an exception
PASS: arrayBuffer neutered
PASS: view neutered
PASS: Posting message ('done', undefined) did not throw an exception
Received message '5' with 0 ports.
Received message '6' with 0 ports.
Received message '7' with 2 ports.
Received message '7' with 2 ports.
Received message '2147483648' with 0 ports.
Received message '[object MessagePort]' with 2 ports.
Received message '[object MessagePort]' with 2 ports.
Received message '[object MessagePort],[object MessagePort]' with 2 ports.
Received message '[object ArrayBuffer]' with 0 ports.
Received message 'done' with 0 ports.