Check if startsWith is configurable #702
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This will throw an exception if the property is not configurable
| : that.slice(index, index + search.length) === search; | ||
| } | ||
| }); | ||
| if(Object.getOwnPropertyDescriptor(String.prototype, "startsWith").configurable) { |
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If the property is not configurable, do nothing since it is going to fail anyway with an exception
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When would it not be configurable?
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It could be non-configurable only with incorrect polyfill, like a polyfill from MDN. It would be better just to remove incorrect polyfill. |
I agree 100%. Here is my scenario (IE11)
In this case the cloud service is Microsoft 365 SharePoint (using the SharePoint Framework) and "dependency x" is the botframework-webchat es5 bundle https://github.com/microsoft/BotFramework-WebChat/tree/master/samples/01.b.getting-started-es5-bundle |
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Maybe it would be better to start from fixing this bug on MDN and related sources? |
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I'm not a fan of adding workarounds for other polyfills bugs - that means incorrect usage of polyfills. However, it's not the first mention of this issue and if it would be fixed in the source of the problem, I'll think about adding a workaround. |
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Still not fixed on MDN side: |
String.startsWith polyfill will throw an exception if the existing property is not configurable. Other polyfills will likely throw an exception under the same scenario. Perhaps an update like this belongs farther up the chain.
This still needs to be tested. Wanted to start the PR process to open the discussion