Issues generating fakes on demand when using go 1.13.1

[jfmyers9]

As a design decision, we have decided to not check in our counterfeiter fakes and choose to generate them on demand in CI when necessary.

As of go 1.13.1, counterfeiter is no longer able to generate fakes when the following is true:

• the <package>fakes directory does not exist
• there is a file that imports the <pacakge>fakes directory

It will fail with the following output:

± |master ✓ | → go generate ./...
Writing `FakeThingDoer` to `counterfeiterreprofakes/fake_thing_doer.go`...
-: go: finding github.com/jfmyers9/counterfeiterrepro/counterfeiterreprofakes latest
go build github.com/jfmyers9/counterfeiterrepro/counterfeiterreprofakes: no Go files in
exit status 1
stuff.go:3: running "go": exit status 1

As an example, we built the following repository: https://github.com/jfmyers9/counterfeiterrepro

In our exploration, we oddly found that if you added packages.NeedTypesInfo to

counterfeiter/generator/loader.go

Line 33 in 4b91f4b

Mode: packages.NeedName | packages.NeedFiles | packages.NeedImports | packages.NeedDeps | packages.NeedTypes,

it will fix the issue. But we weren't confident in the reasoning behind this change and wanted to discuss it further.

Let us know if you have any other questions,

@jfmyers9 && @christarazi