Do not always instantiate jsx signatures#21108
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weswigham merged 1 commit intoJan 10, 2018
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RyanCavanaugh
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mhegazy
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When I changed jsx to actually do inference, I hadn't realized that JSX had been instantiating signatures during its use in the
getContextualTypecode path. Since that path doesn't specify asourceAttributesType(because we're in the process of calculating it), signatures were being instantiated with{}(in the associated issue, this meant that props was set to{}and then{}was used to contextually type the attributes, rather thanP extends { x?: "a" | "b" }). Now, ifsourceAttributesTypeisundefined, we do not instantiate the signatures at all, which is what the contextual typing code actually expects.Fixes #21028