CosmosDB mocking support for IDocumentClient is extremely poor
I found it is borderline impossible to mock IDocumentClient (CosmosDB) due to the inconsistent implementation of interfaces.
Simple example: IDocumentClient is defined. This is good. IFeedResponse, IResourceResponse are defined. This is good. IDocumentClient returns FeedResponse and ResourceResponse instead of IFeedResponse and IResourceResponse. This is bad. The properties from the concrete implementations that I need to mock are all read-only, so this stymied all my efforts to write any unit tests whatsoever for my storage layer code in my latest project.