Improved hasNativeStartsWith check

[apolakipso]

There are JS environments where String.startsWith exists but doesn't support the position parameter (e.g. in the taskpane of Outlook web add-ins). This commit adds a test for proper handling of position to the polyfill check.

Note: Turns out this broken polyfill comes with Microsoft's Office JS API in https://ajax.aspnetcdn.com/ajax/3.5/MicrosoftAjax.js 😱

Here's a regular Chrome dev console:

Here's the behavior in the dev console of an Outlook add-in:

This is how it breaks formatjs in an Outlook add-in taskpane:

A simple message with tags:

<FormattedMessage id="test" defaultMessage="<b>test</b>" />

The broken startsWith implementation breaks the parser. parseTag() throws INVALID_TAG because startsWith used in bumpIf() requires a proper handling of the position parameter (this.offset() in this case).

utils.js:20  Error: [@formatjs/intl Error FORMAT_ERROR] Error formatting default message for: "test", rendering default message verbatim
MessageID: test
Default Message: <b>test</b>
Description: undefined

Locale: en


INVALID_TAG
SyntaxError: INVALID_TAG (at error.js:58:1)
    at Function.parse [as __parse] (index.js:33:1)
    at new IntlMessageFormat (core.js:137:1)
    at utils.js:110:1
    at variadic (index.js:33:1)
    at formatMessage (message.js:69:1)
    at formatMessage (provider.js:46:18)
    at FormattedMessage (message.js:21:1)
    at renderWithHooks (react-dom.development.js:16305:1)
    at mountIndeterminateComponent (react-dom.development.js:20074:1)
    at beginWork (react-dom.development.js:21587:1)
    at MessageFormatError.IntlFormatError [as constructor] (error.js:58:1)
    at new MessageFormatError (error.js:68:1)
    at formatMessage (message.js:73:1)
    at formatMessage (provider.js:46:18)
    at FormattedMessage (message.js:21:1)
    at renderWithHooks (react-dom.development.js:16305:1)
    at mountIndeterminateComponent (react-dom.development.js:20074:1)
    at beginWork (react-dom.development.js:21587:1)
    at beginWork$1 (react-dom.development.js:27426:1)
    at performUnitOfWork (react-dom.development.js:26560:1)

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[longlho]

Thanks a lot for your contributions!