ConfigureServices IServiceCollection exception message is confusing.

[JesperTreetop]

The code calling ConfigureServices generates the following exception message:

ConfigureServices can take at most a single IServiceCollection parameter.

When I got this, I read this as "ConfigureServices can take various parameters, but just one of the type IServiceCollection, so you're trying to use two or more IServiceCollection parameters"! I had to go find the code where the exception was thrown to realize that it meant that it can't take any other parameters, which was my problem (trying to have IHostingEnvironment injected to set up services differently based on environment; I solved that by having the constructor, which can take it, squirrel away the IHostingEnvironment instance).

How about:

ConfigureServices can not take any parameters besides at most one IServiceCollection parameter.

..?

[davidfowl]

besides at most one IServiceCollection parameter

Is confusing as well. I'm all for changing it to be clearer though.

/cc @Eilon

[Eilon]

I'll come up with something.

[davidfowl]

@Eilon last chance 😄

[JunTaoLuo]

"ConfigureServices must be parameterless or take only one IServiceCollection parameter."?

[Eilon]

Slight modification @JunTaoLuo 's text:

The ConfigureServices method must either be parameterless or take only one parameter of type IServiceCollection.

[Eilon]

Unassigning from me. @muratg can find a new owner to implement this complex feature 😄

[JesperTreetop]

Thanks for listening and caring about things like this. I know it would have been very easy to swat it away and say "nah, you just weren't thinking". I think the message you settled on was great and better than my proposal.

[Eilon]

@JesperTreetop of course, and thanks for bringing it to our attention!