What is the expected shape of request.body when POSTing multipart/form-data?

[samtsai]

With this recent fix #14235 for #9359 the request body is an ArrayBuffer vs previously a string.

My question is if this will change for any reason in the future? If not, maybe we should add details of intercepting multipart/form-data. In my case, we have a single API endpoint like GraphQL but instead of POSTing JSON we have for legacy reasons to POST as multipart/form-data. I mimic the example https://docs.cypress.io/api/commands/intercept.html#Aliasing-individual-requests:

cy.intercept('POST', '/graphql', (req) => {
  if (req.body.indexOf(SOME_FUNCTION_NAME) > -1) {
    req.alias = SOME_FUNCTION_NAME
  }
})

// assert that a matching request has been made
cy.wait('@SOME_FUNCTION_NAME')

My workaround when upgrading to 6.2.1 is to decode the buffer to a String:

String.fromCharCode.apply(null, new Uint8Array(body))

OR

new TextDecoder().decode(body)

Related issue #14527

[samtsai]

Just discovered this form spec example, maybe a brief explanation and link to the example: https://github.com/cypress-io/cypress-example-recipes/blob/master/examples/stubbing-spying__intercept/cypress/integration/form-spec.js