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A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.
val square : Int => Int = x => x * x
| # Model | |
| expect(@user).to have(1).error_on(:username) # checks whether there is an error in username | |
| expect(@user.errors[:username]).to include("can't be blank") # check for the error message | |
| # Rendering | |
| expect(response).to render_template(:index) | |
| # Redirecting |
Magic words:
psql -U postgresSome interesting flags (to see all, use -h or --help depending on your psql version):
-E: will describe the underlaying queries of the \ commands (cool for learning!)-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)