shard-spectator/src/spectator/block.cr

34 lines
1.2 KiB
Crystal

require "./expression"
require "./label"
module Spectator
# Represents a block from a test.
# This is typically captured by an `expect` macro.
# It consists of a label and parameterless block.
# The label should be a string recognizable by the user,
# or nil if one isn't available.
class Block(T) < Expression(T)
# Creates the block expression from a proc.
# The *proc* will be called to evaluate the value of the expression.
# The *label* is usually the Crystal code for the *proc*.
# It can be nil if it isn't available.
def initialize(@block : -> T, label : Label = nil)
super(label)
end
# Creates the block expression by capturing a block as a proc.
# The block will be called to evaluate the value of the expression.
# The *label* is usually the Crystal code for the *block*.
# It can be nil if it isn't available.
def initialize(label : Label = nil, &@block : -> T)
super(label)
end
# Evaluates the block and returns the value from it.
# This method _does not_ cache the resulting value like `#value` does.
# Successive calls to this method may return different values.
def value : T
@block.call
end
end
end