Remove Unknown Type From Interfaces

[grant]

Describe the Bug

The TS interfaces are pretty great.

I found a bug where the TS unknown type is used for some of the properties in src/event/interfaces.ts.

This is a problem because this TS type causes some issues:

Type 'unknown' is not assignable to type '{}'.ts(2322)

---

We should simply remove the unknown type as a possibility for these interfaces.

---

Test code:

const TEST_CLOUD_EVENT: CloudEventV1 = {
  specversion: '1.0',
  type: 'com.google.cloud.storage',
  source: 'https://github.com/GoogleCloudPlatform/functions-framework-nodejs',
  subject: 'test-subject',
  id: 'test-1234-1234',
  time: '2020-05-13T01:23:45Z',
  datacontenttype: 'application/json',
  data: {
    some: 'payload',
  },
};

describe('CloudEvents request to event function', () => {
  interface TestData {
    name: string;
    headers: { [key: string]: string | Date | undefined };
    body: {};
  }

  const testData: TestData[] = [
    {
      name: 'CloudEvents v1.0 structured content mode',
      headers: { 'Content-Type': 'application/cloudevents+json' },
      body: TEST_CLOUD_EVENT,
    },
    {
      name: 'CloudEvents v1.0 binary content mode',
      headers: {
        'Content-Type': 'application/cloudevents+json',
        'ce-specversion': TEST_CLOUD_EVENT.specversion,
        'ce-type': TEST_CLOUD_EVENT.type,
        'ce-source': TEST_CLOUD_EVENT.source,
        'ce-subject': TEST_CLOUD_EVENT.subject,
        'ce-id': TEST_CLOUD_EVENT.id,
        'ce-time': TEST_CLOUD_EVENT.time,
        'ce-datacontenttype': TEST_CLOUD_EVENT.datacontenttype,
      },
      body: TEST_CLOUD_EVENT.data,
    },
  ];

[lance]

Hmm. I don't think it's that simple. As the specification states.

Description: The event payload. This specification does not place any restriction on the type of this information. It is encoded into a media format which is specified by the datacontenttype attribute (e.g. application/json), and adheres to the dataschema format when those respective attributes are present.

In your sample data, the TestData interface declares data to be {}. But there's no way to know for sure if that's actually the case. Even removing unknown, null and undefined from the CloudEvent#data type declaration, it still could be any of Record<string, unknown | string | number | boolean> | string | number | boolean; which would continue to be a problem for this example.

Type 'string | number | boolean | Record<string, string | number | boolean> | undefined' is not assignable to type '{}'.
  Type 'undefined' is not assignable to type '{}'.

313     body: TEST_CLOUD_EVENT.data,```

You can fix your example, by coercing the value

const testData: TestData[] = [
  {
    name: 'CloudEvents v1.0 structured content mode',
    headers: { 'Content-Type': 'application/cloudevents+json' },
    body: TEST_CLOUD_EVENT,
  },
  {
    name: 'CloudEvents v1.0 binary content mode',
    headers: {
      'Content-Type': 'application/cloudevents+json',
      'ce-specversion': TEST_CLOUD_EVENT.specversion,
      'ce-type': TEST_CLOUD_EVENT.type,
      'ce-source': TEST_CLOUD_EVENT.source,
      'ce-subject': TEST_CLOUD_EVENT.subject,
      'ce-id': TEST_CLOUD_EVENT.id,
      'ce-time': TEST_CLOUD_EVENT.time,
      'ce-datacontenttype': TEST_CLOUD_EVENT.datacontenttype,
    },
    body: TEST_CLOUD_EVENT.data as {},
  },
];

[lance]

Going ahead and closing this, as I don't believe it is an issue with the module