New error: This spread always overwrites this property

I believe the error is both correct and valuable, but filing it for completeness, since it wasn’t produced by 3.8.

https://github.com/apollographql/apollo-server/blob/c177acd7959aaf516f8ac814f1a6bb2e6d3ed2e6/packages/apollo-server-core/src/ApolloServer.ts#L775

packages/apollo-server-core/src/ApolloServer.ts:775:7 - error TS2783: 'context' is specified more than once, so this usage will be overwritten.

775       context,
          ~~~~~~~

  packages/apollo-server-core/src/ApolloServer.ts:787:7
    787       ...this.requestOptions,
              ~~~~~~~~~~~~~~~~~~~~~~
    This spread always overwrites this property.

To repro:

1. npm ci
2. tsc -b -f tsconfig.build.json

[sethlowie]

I’m not sure this error is correct. I have the use case of wanting to overwrite the properties. I have to use Object.assign which compiles fine, even though it’s the same behavior. This change is forcing users to choose a specific syntax for the same behavior.

[amcasey]

So maybe the issue here is that using Object.assign instead of spreading doesn’t throw an error.

It does seem like they should be consistent.

In your example, it looks like MockFlags should be optional? Otherwise, the || {} will never do anything, will it? As written, it seems to guarantee that both featureA and featureB will be present on window.MockFlags and will override your explicit values.