twirp-transport: Guard access of response.type to support Cloudflare Workers

[mikeylemmon]

Fetch responses in Cloudflare Workers currently throw an error on access of the "type" property¹². This PR guards access of the property with a try/catch so that twirp clients can be used inside of Cloudflare Workers.

Footnotes

1. https://developers.cloudflare.com/workers/runtime-apis/response/#properties ↩

2. https://github.com/cloudflare/miniflare/blob/72f046e/packages/core/src/standards/http.ts#L646 ↩

[mikeylemmon]

It's unclear to me why the CI run failed, but it doesn't appear to be related to the code I changed — the twirp-transport tests all pass, error is in @protobuf-ts/test-generated (which doesn't fail for me when I run it locally):

@protobuf-ts/test-generated: Jasmine started
@protobuf-ts/test-generated:   generated client style call
@protobuf-ts/test-generated:     server-streaming
@protobuf-ts/test-generated:       ✗ should reject results on abort
@protobuf-ts/test-generated:         - Expected a promise to be rejected but it was resolved.
@protobuf-ts/test-generated:         /home/circleci/project/packages/test-generated/spec/generated-client-style-call.spec.ts:194:45
@protobuf-ts/test-generated:                     }, 5)
@protobuf-ts/test-generated:                     const call = client.serverStream({value: "abc"}, {abort: abort.signal});
@protobuf-ts/test-generated:                     await expectAsync(call.headers).toBeRejectedWithError("user cancel")
@protobuf-ts/test-generated:                                                     ~
@protobuf-ts/test-generated:                     await expectAsync(call.status).toBeRejectedWithError("user cancel")
@protobuf-ts/test-generated:                     await expectAsync(call.trailers).toBeRejectedWithError("user cancel")
@protobuf-ts/test-generated:         /home/circleci/project/packages/test-generated/spec/generated-client-style-call.spec.ts:4:12
@protobuf-ts/test-generated:         import {AbortController} from "abort-controller";
@protobuf-ts/test-generated:         import {Int32Value, StringValue} from "../ts-out/google/protobuf/wrappers";
@protobuf-ts/test-generated:         import {AllStyleServiceClient} from "../ts-out/service-style-all.client";
@protobuf-ts/test-generated:                    ~
@protobuf-ts/test-generated:         globalThis.AbortController = AbortController; // AbortController polyfill via https://github.com/mysticatea/abort-controller
@protobuf-ts/test-generated:         /home/circleci/project/packages/test-generated/spec/generated-client-style-call.spec.ts:238:20
@protobuf-ts/test-generated: **************************************************
@protobuf-ts/test-generated: *                    Failures                    *
@protobuf-ts/test-generated: **************************************************
@protobuf-ts/test-generated: 1) generated client style call server-streaming should reject results on abort
@protobuf-ts/test-generated:   - Expected a promise to be rejected but it was resolved.
@protobuf-ts/test-generated: Executed 196 of 196 specs (1 FAILED) in 1 sec.
@protobuf-ts/test-generated: Randomized with seed 73784.
@protobuf-ts/test-generated: Makefile:45: recipe for target 'test-spec' failed
@protobuf-ts/test-generated: make[2]: Leaving directory '/home/circleci/project/packages/test-generated'
@protobuf-ts/test-generated: make[2]: *** [test-spec] Error 1
@protobuf-ts/test-generated: make[1]: *** [default] Error 2
@protobuf-ts/test-generated: Makefile:10: recipe for target 'default' failed
@protobuf-ts/test-generated: make[1]: Leaving directory '/home/circleci/project/packages/test-generated'

https://app.circleci.com/pipelines/github/timostamm/protobuf-ts/684/workflows/4c523394-5990-474c-a143-55f67ed04cbc/jobs/621

[timostamm]

Hey @mikeylemmon, I tried it locally and don't see the test failure either. CI must have been a timing-related fluke 🤔

The code looks solid, thank you for this!

[timostamm]

Applied the same workaround to the grpcweb-transport in #329

[timostamm]

Released in v2.7.0.