Package vdltestutil provides testing utilities for v.io/x/ref/lib/vdl/...
ExpectFail makes sure errs has an error that matches all the re regexps.
ExpectPass makes sure errs has no errors.
ExpectResult ensures errs has an error that matches all the re regexps, or that errs has no errors if no regexps were provided, or only one was provided with the empty string.
FakeBuildPackage constructs a fake build package for testing, with files mapping from file names to file contents.
FakeOpenFiles returns a function that obeys the build.Package.OpenFilesFunc signature, that simply uses the files map to return readers.