Support Next.js Edge Runtime

[angeloashmore]

Is your feature request related to a problem? Please describe.

Next.js supports a runtime called Edge Runtime built upon Web APIs, unlike the default Node.js-based runtime.

Some @prismicio/next APIs are incompatible with Edge Runtime, such as setPreviewData(). setPreviewData() reads an API Route request and sets a Prismic-specific Preview Data property, but the function does not currently support reading a Web API Request object as used in Edge Runtime.

Describe the solution you'd like

The existing @prismicio/next APIs could be made universal to run in both the default non-Edge Runtime and Edge Runtime environments. This can probably be done using duck typing to test the received data.

Describe alternatives you've considered

• 🚫 Provide a different set of helpers specific to a runtime.
• 🚫 Only support one runtime.

Additional context

None.