Add support for calling loadPackage for "User" package

[d-torrance]

Previously, we got an error because User.m2 doesn't exist.

The use case I was interested in is creating and running tests outside of a package:

i1 : TEST "assert(1 + 1 == 2)"

i2 : tests User

o2 = HashTable{0 => TestInput[stdio:1:1-2:1]}

o2 : HashTable

i3 : code 0

o3 =  -- stdio:2:1: location of test code
     assert(1 + 1 == 2)

So far, so good! But now:

i4 : check User
 -- capturing check(0, "User")                  -- 0.057196 seconds elapsed
stdio:4:5:(3): error: file not found on path: "User.m2"

The problem is due to loadPackage, which always tries to load a file. If we just immediately return the User package when loadPackage "User" is called, then everything works:

i2 : check User
 -- capturing check(0, "User")                   -- 0.0576815 seconds elapsed

i3 : 

[mahrud]

Unrelated, but can we have tests return a numbered vertical list?

i2 : tests User

o2 = HashTable{0 => TestInput[stdio:1:1-2:1]}

o2 : HashTable

i3 : code 0

[mahrud]

Side note: it's a little alarming that User.PackageIsLoaded is false.

[d-torrance]

PackageIsLoaded is usually set by endPackage, but that never gets called for User. And it probably shouldn't -- but calling endPackage "User" doesn't raise any errors.

[mahrud]

I don't see why someone would call endPackage on User, but I also don't see why it should be an error (for the same reasons as loadPackage).

I should say that if you set PackageIsLoaded to true then your change in loadPackage is actually unnecessary to get check working.

[d-torrance]

Good points!

I've changed this so that it's just the PackageIsLoaded commit. check "User" and needsPackage "User" now work nicely. loadPackage "User" still raises the "file not found" error, but I think that kind of makes sense since we can't really "load" it.

[mahrud]

Oh yes, that makes sense!