997075 - NFC: a is undefined in nfc_util.js line 208

Status: RESOLVED FIXED

(Firefox OS Graveyard :: NFC, defect)

Description

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

This is found out by QA, but without debug enabled, so only error log is captured.

E/GeckoConsole(  177): [JavaScript Error: "a is undefined" {file: "app://system.gaiamobile.org/shared/js/nfc_utils.js" line: 208}]
E/GeckoConsole(  177): [JavaScript Error: "NS_ERROR_XPC_JAVASCRIPT_ERROR_WITH_DETAILS: [JavaScript Error: "a is undefined" {file: "app://system.gaiamobile.org/shared/js/nfc_utils.js" line: 208}]'[JavaScript Error: "a is undefined" {file: "app://system.gaiamobile.org/shared/js/nfc_utils.js" line: 208}]' when calling method: [nsIDOMSystemMessageCallback::handleMessage]" {file: "null" line: 0}]

Comment 1

[Garner Lee]

Reproduction steps/scenario would be useful, even if no debug. It was probably actually passed a undefined value as stated...

Comment 2

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

But even without the log we should ask ourself:
What should the function return when the argument is undefined or null?

Comment 3

[Garner Lee]

Sure, return null, or a throw to the caller. Why an undefined is an argument to a utility function is a good question to answer too.

Comment 4

[Ken Chang[:kenkai]]

We can not expect the caller would be careful to use utility functions, I wonder if we could have some methods to tell caller there are something wrong. Or this error is already enough.

Alison, do you have reproduction steps or scenarios? Thanks.

Comment 5

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

It's easy to add 
if (!a) {
  return null;
}
to that function,

and it's fairly easy to find out the many callers to use NfcUtils.toUTF8(record.type);
in which type could be null from NDEF spec.

Comment 6

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

Attachment: Pull Request

Comment 7

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi]]

https://github.com/mozilla-b2g/gaia/commit/09cf174bb73386d98a1f7024958ba7e02447f3de