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ruby--ruby/spec/ruby/language/lambda_spec.rb
2019-07-27 12:40:09 +02:00

601 lines
13 KiB
Ruby

require_relative '../spec_helper'
require_relative 'fixtures/classes'
describe "A lambda literal -> () { }" do
SpecEvaluate.desc = "for definition"
it "returns a Proc object when used in a BasicObject method" do
klass = Class.new(BasicObject) do
def create_lambda
-> { }
end
end
klass.new.create_lambda.should be_an_instance_of(Proc)
end
it "does not execute the block" do
-> { fail }.should be_an_instance_of(Proc)
end
it "returns a lambda" do
-> { }.lambda?.should be_true
end
ruby_version_is "2.6" do
it "may include a rescue clause" do
eval('-> do raise ArgumentError; rescue ArgumentError; 7; end').should be_an_instance_of(Proc)
end
it "may include a ensure clause" do
eval('-> do 1; ensure; 2; end').should be_an_instance_of(Proc)
end
end
it "has its own scope for local variables" do
l = -> arg {
var = arg
# this would override var if it was declared outside the lambda
l.call(arg-1) if arg > 0
var
}
l.call(1).should == 1
end
context "assigns no local variables" do
evaluate <<-ruby do
@a = -> { }
@b = ->() { }
@c = -> () { }
@d = -> do end
ruby
@a.().should be_nil
@b.().should be_nil
@c.().should be_nil
@d.().should be_nil
end
end
context "assigns variables from parameters" do
evaluate <<-ruby do
@a = -> (a) { a }
ruby
@a.(1).should == 1
end
evaluate <<-ruby do
@a = -> ((a)) { a }
ruby
@a.(1).should == 1
@a.([1, 2, 3]).should == 1
end
evaluate <<-ruby do
@a = -> ((*a, b)) { [a, b] }
ruby
@a.(1).should == [[], 1]
@a.([1, 2, 3]).should == [[1, 2], 3]
end
evaluate <<-ruby do
@a = -> (a={}) { a }
ruby
@a.().should == {}
@a.(2).should == 2
end
evaluate <<-ruby do
@a = -> (*) { }
ruby
@a.().should be_nil
@a.(1).should be_nil
@a.(1, 2, 3).should be_nil
end
evaluate <<-ruby do
@a = -> (*a) { a }
ruby
@a.().should == []
@a.(1).should == [1]
@a.(1, 2, 3).should == [1, 2, 3]
end
evaluate <<-ruby do
@a = -> (a:) { a }
ruby
-> { @a.() }.should raise_error(ArgumentError)
@a.(a: 1).should == 1
end
evaluate <<-ruby do
@a = -> (a: 1) { a }
ruby
@a.().should == 1
@a.(a: 2).should == 2
end
evaluate <<-ruby do
@a = -> (**) { }
ruby
@a.().should be_nil
@a.(a: 1, b: 2).should be_nil
-> { @a.(1) }.should raise_error(ArgumentError)
end
evaluate <<-ruby do
@a = -> (**k) { k }
ruby
@a.().should == {}
@a.(a: 1, b: 2).should == {a: 1, b: 2}
end
evaluate <<-ruby do
@a = -> (&b) { b }
ruby
@a.().should be_nil
@a.() { }.should be_an_instance_of(Proc)
end
evaluate <<-ruby do
@a = -> (a, b) { [a, b] }
ruby
@a.(1, 2).should == [1, 2]
-> { @a.() }.should raise_error(ArgumentError)
-> { @a.(1) }.should raise_error(ArgumentError)
end
evaluate <<-ruby do
@a = -> ((a, b, *c, d), (*e, f, g), (*h)) do
[a, b, c, d, e, f, g, h]
end
ruby
@a.(1, 2, 3).should == [1, nil, [], nil, [], 2, nil, [3]]
result = @a.([1, 2, 3], [4, 5, 6, 7, 8], [9, 10])
result.should == [1, 2, [], 3, [4, 5, 6], 7, 8, [9, 10]]
end
evaluate <<-ruby do
@a = -> (a, (b, (c, *d, (e, (*f)), g), (h, (i, j)))) do
[a, b, c, d, e, f, g, h, i, j]
end
ruby
@a.(1, 2).should == [1, 2, nil, [], nil, [nil], nil, nil, nil, nil]
result = @a.(1, [2, [3, 4, 5, [6, [7, 8]], 9], [10, [11, 12]]])
result.should == [1, 2, 3, [4, 5], 6, [7, 8], 9, 10, 11, 12]
end
evaluate <<-ruby do
@a = -> (*, **k) { k }
ruby
@a.().should == {}
@a.(1, 2, 3, a: 4, b: 5).should == {a: 4, b: 5}
h = mock("keyword splat")
h.should_receive(:to_hash).and_return({a: 1})
@a.(h).should == {a: 1}
end
evaluate <<-ruby do
@a = -> (*, &b) { b }
ruby
@a.().should be_nil
@a.(1, 2, 3, 4).should be_nil
@a.(&(l = ->{})).should equal(l)
end
evaluate <<-ruby do
@a = -> (a:, b:) { [a, b] }
ruby
@a.(a: 1, b: 2).should == [1, 2]
end
evaluate <<-ruby do
@a = -> (a:, b: 1) { [a, b] }
ruby
@a.(a: 1).should == [1, 1]
@a.(a: 1, b: 2).should == [1, 2]
end
evaluate <<-ruby do
@a = -> (a: 1, b:) { [a, b] }
ruby
@a.(b: 0).should == [1, 0]
@a.(b: 2, a: 3).should == [3, 2]
end
evaluate <<-ruby do
@a = -> (a: @a = -> (a: 1) { a }, b:) do
[a, b]
end
ruby
@a.(a: 2, b: 3).should == [2, 3]
@a.(b: 1).should == [@a, 1]
# Note the default value of a: in the original method.
@a.().should == 1
end
evaluate <<-ruby do
@a = -> (a: 1, b: 2) { [a, b] }
ruby
@a.().should == [1, 2]
@a.(b: 3, a: 4).should == [4, 3]
end
evaluate <<-ruby do
@a = -> (a, b=1, *c, (*d, (e)), f: 2, g:, h:, **k, &l) do
[a, b, c, d, e, f, g, h, k, l]
end
ruby
result = @a.(9, 8, 7, 6, f: 5, g: 4, h: 3, &(l = ->{}))
result.should == [9, 8, [7], [], 6, 5, 4, 3, {}, l]
end
evaluate <<-ruby do
@a = -> a, b=1, *c, d, e:, f: 2, g:, **k, &l do
[a, b, c, d, e, f, g, k, l]
end
ruby
result = @a.(1, 2, e: 3, g: 4, h: 5, i: 6, &(l = ->{}))
result.should == [1, 1, [], 2, 3, 2, 4, { h: 5, i: 6 }, l]
end
describe "with circular optional argument reference" do
it "shadows an existing local with the same name as the argument" do
a = 1
-> {
@proc = eval "-> (a=a) { a }"
}.should complain(/circular argument reference/)
@proc.call.should == nil
end
it "shadows an existing method with the same name as the argument" do
def a; 1; end
-> {
@proc = eval "-> (a=a) { a }"
}.should complain(/circular argument reference/)
@proc.call.should == nil
end
it "calls an existing method with the same name as the argument if explicitly using ()" do
def a; 1; end
-> a=a() { a }.call.should == 1
end
end
end
end
describe "A lambda expression 'lambda { ... }'" do
SpecEvaluate.desc = "for definition"
it "calls the #lambda method" do
obj = mock("lambda definition")
obj.should_receive(:lambda).and_return(obj)
def obj.define
lambda { }
end
obj.define.should equal(obj)
end
it "does not execute the block" do
lambda { fail }.should be_an_instance_of(Proc)
end
it "returns a lambda" do
lambda { }.lambda?.should be_true
end
it "requires a block" do
lambda { lambda }.should raise_error(ArgumentError)
end
ruby_version_is "2.5" do
it "may include a rescue clause" do
eval('lambda do raise ArgumentError; rescue ArgumentError; 7; end').should be_an_instance_of(Proc)
end
end
context "with an implicit block" do
before do
def meth; lambda; end
end
ruby_version_is ""..."2.7" do
it "can be created" do
implicit_lambda = nil
-> {
implicit_lambda = meth { 1 }
}.should complain(/tried to create Proc object without a block/)
implicit_lambda.lambda?.should be_true
implicit_lambda.call.should == 1
end
end
ruby_version_is "2.7" do
it "raises ArgumentError" do
implicit_lambda = nil
-> {
meth { 1 }
}.should raise_error(ArgumentError, /tried to create Proc object without a block/)
end
end
end
context "assigns no local variables" do
evaluate <<-ruby do
@a = lambda { }
@b = lambda { || }
ruby
@a.().should be_nil
@b.().should be_nil
end
end
context "assigns variables from parameters" do
evaluate <<-ruby do
@a = lambda { |a| a }
ruby
@a.(1).should == 1
end
evaluate <<-ruby do
def m(*a) yield(*a) end
@a = lambda { |a| a }
ruby
lambda { m(&@a) }.should raise_error(ArgumentError)
lambda { m(1, 2, &@a) }.should raise_error(ArgumentError)
end
evaluate <<-ruby do
@a = lambda { |a, | a }
ruby
@a.(1).should == 1
@a.([1, 2]).should == [1, 2]
lambda { @a.() }.should raise_error(ArgumentError)
lambda { @a.(1, 2) }.should raise_error(ArgumentError)
end
evaluate <<-ruby do
def m(a) yield a end
def m2() yield end
@a = lambda { |a, | a }
ruby
m(1, &@a).should == 1
m([1, 2], &@a).should == [1, 2]
lambda { m2(&@a) }.should raise_error(ArgumentError)
end
evaluate <<-ruby do
@a = lambda { |(a)| a }
ruby
@a.(1).should == 1
@a.([1, 2, 3]).should == 1
end
evaluate <<-ruby do
@a = lambda { |(*a, b)| [a, b] }
ruby
@a.(1).should == [[], 1]
@a.([1, 2, 3]).should == [[1, 2], 3]
end
evaluate <<-ruby do
@a = lambda { |a={}| a }
ruby
@a.().should == {}
@a.(2).should == 2
end
evaluate <<-ruby do
@a = lambda { |*| }
ruby
@a.().should be_nil
@a.(1).should be_nil
@a.(1, 2, 3).should be_nil
end
evaluate <<-ruby do
@a = lambda { |*a| a }
ruby
@a.().should == []
@a.(1).should == [1]
@a.(1, 2, 3).should == [1, 2, 3]
end
evaluate <<-ruby do
@a = lambda { |a:| a }
ruby
lambda { @a.() }.should raise_error(ArgumentError)
@a.(a: 1).should == 1
end
evaluate <<-ruby do
@a = lambda { |a: 1| a }
ruby
@a.().should == 1
@a.(a: 2).should == 2
end
evaluate <<-ruby do
@a = lambda { |**| }
ruby
@a.().should be_nil
@a.(a: 1, b: 2).should be_nil
lambda { @a.(1) }.should raise_error(ArgumentError)
end
evaluate <<-ruby do
@a = lambda { |**k| k }
ruby
@a.().should == {}
@a.(a: 1, b: 2).should == {a: 1, b: 2}
end
evaluate <<-ruby do
@a = lambda { |&b| b }
ruby
@a.().should be_nil
@a.() { }.should be_an_instance_of(Proc)
end
evaluate <<-ruby do
@a = lambda { |a, b| [a, b] }
ruby
@a.(1, 2).should == [1, 2]
end
evaluate <<-ruby do
@a = lambda do |(a, b, *c, d), (*e, f, g), (*h)|
[a, b, c, d, e, f, g, h]
end
ruby
@a.(1, 2, 3).should == [1, nil, [], nil, [], 2, nil, [3]]
result = @a.([1, 2, 3], [4, 5, 6, 7, 8], [9, 10])
result.should == [1, 2, [], 3, [4, 5, 6], 7, 8, [9, 10]]
end
evaluate <<-ruby do
@a = lambda do |a, (b, (c, *d, (e, (*f)), g), (h, (i, j)))|
[a, b, c, d, e, f, g, h, i, j]
end
ruby
@a.(1, 2).should == [1, 2, nil, [], nil, [nil], nil, nil, nil, nil]
result = @a.(1, [2, [3, 4, 5, [6, [7, 8]], 9], [10, [11, 12]]])
result.should == [1, 2, 3, [4, 5], 6, [7, 8], 9, 10, 11, 12]
end
evaluate <<-ruby do
@a = lambda { |*, **k| k }
ruby
@a.().should == {}
@a.(1, 2, 3, a: 4, b: 5).should == {a: 4, b: 5}
h = mock("keyword splat")
h.should_receive(:to_hash).and_return({a: 1})
@a.(h).should == {a: 1}
end
evaluate <<-ruby do
@a = lambda { |*, &b| b }
ruby
@a.().should be_nil
@a.(1, 2, 3, 4).should be_nil
@a.(&(l = ->{})).should equal(l)
end
evaluate <<-ruby do
@a = lambda { |a:, b:| [a, b] }
ruby
@a.(a: 1, b: 2).should == [1, 2]
end
evaluate <<-ruby do
@a = lambda { |a:, b: 1| [a, b] }
ruby
@a.(a: 1).should == [1, 1]
@a.(a: 1, b: 2).should == [1, 2]
end
evaluate <<-ruby do
@a = lambda { |a: 1, b:| [a, b] }
ruby
@a.(b: 0).should == [1, 0]
@a.(b: 2, a: 3).should == [3, 2]
end
evaluate <<-ruby do
@a = lambda do |a: (@a = -> (a: 1) { a }), b:|
[a, b]
end
ruby
@a.(a: 2, b: 3).should == [2, 3]
@a.(b: 1).should == [@a, 1]
# Note the default value of a: in the original method.
@a.().should == 1
end
evaluate <<-ruby do
@a = lambda { |a: 1, b: 2| [a, b] }
ruby
@a.().should == [1, 2]
@a.(b: 3, a: 4).should == [4, 3]
end
evaluate <<-ruby do
@a = lambda do |a, b=1, *c, (*d, (e)), f: 2, g:, h:, **k, &l|
[a, b, c, d, e, f, g, h, k, l]
end
ruby
result = @a.(9, 8, 7, 6, f: 5, g: 4, h: 3, &(l = ->{}))
result.should == [9, 8, [7], [], 6, 5, 4, 3, {}, l]
end
evaluate <<-ruby do
@a = lambda do |a, b=1, *c, d, e:, f: 2, g:, **k, &l|
[a, b, c, d, e, f, g, k, l]
end
ruby
result = @a.(1, 2, e: 3, g: 4, h: 5, i: 6, &(l = ->{}))
result.should == [1, 1, [], 2, 3, 2, 4, { h: 5, i: 6 }, l]
end
end
end