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ruby--ruby/spec/ruby/language/variables_spec.rb
2022-06-26 14:50:14 +02:00

870 lines
23 KiB
Ruby

require_relative '../spec_helper'
require_relative 'fixtures/variables'
describe "Multiple assignment" do
context "with a single RHS value" do
it "assigns a simple MLHS" do
(a, b, c = 1).should == 1
[a, b, c].should == [1, nil, nil]
end
it "calls #to_ary to convert an Object RHS when assigning a simple MLHS" do
x = mock("multi-assign single RHS")
x.should_receive(:to_ary).and_return([1, 2])
(a, b, c = x).should == x
[a, b, c].should == [1, 2, nil]
end
it "calls #to_ary if it is private" do
x = mock("multi-assign single RHS")
x.should_receive(:to_ary).and_return([1, 2])
class << x; private :to_ary; end
(a, b, c = x).should == x
[a, b, c].should == [1, 2, nil]
end
it "does not call #to_ary if #respond_to? returns false" do
x = mock("multi-assign single RHS")
x.should_receive(:respond_to?).with(:to_ary, true).and_return(false)
x.should_not_receive(:to_ary)
(a, b, c = x).should == x
[a, b, c].should == [x, nil, nil]
end
it "wraps the Object in an Array if #to_ary returns nil" do
x = mock("multi-assign single RHS")
x.should_receive(:to_ary).and_return(nil)
(a, b, c = x).should == x
[a, b, c].should == [x, nil, nil]
end
it "raises a TypeError of #to_ary does not return an Array" do
x = mock("multi-assign single RHS")
x.should_receive(:to_ary).and_return(1)
-> { a, b, c = x }.should raise_error(TypeError)
end
it "does not call #to_a to convert an Object RHS when assigning a simple MLHS" do
x = mock("multi-assign single RHS")
x.should_not_receive(:to_a)
(a, b, c = x).should == x
[a, b, c].should == [x, nil, nil]
end
it "does not call #to_ary on an Array instance" do
x = [1, 2]
x.should_not_receive(:to_ary)
(a, b = x).should == x
[a, b].should == [1, 2]
end
it "does not call #to_a on an Array instance" do
x = [1, 2]
x.should_not_receive(:to_a)
(a, b = x).should == x
[a, b].should == [1, 2]
end
it "returns the RHS when it is an Array" do
ary = [1, 2]
x = (a, b = ary)
x.should equal(ary)
end
it "returns the RHS when it is an Array subclass" do
cls = Class.new(Array)
ary = cls.new [1, 2]
x = (a, b = ary)
x.should equal(ary)
end
it "does not call #to_ary on an Array subclass instance" do
x = Class.new(Array).new [1, 2]
x.should_not_receive(:to_ary)
(a, b = x).should == x
[a, b].should == [1, 2]
end
it "does not call #to_a on an Array subclass instance" do
x = Class.new(Array).new [1, 2]
x.should_not_receive(:to_a)
(a, b = x).should == x
[a, b].should == [1, 2]
end
it "assigns a MLHS with a trailing comma" do
a, = 1
b, c, = []
[a, b, c].should == [1, nil, nil]
end
it "assigns a single LHS splat" do
(*a = 1).should == 1
a.should == [1]
end
it "calls #to_ary to convert an Object RHS" do
x = mock("multi-assign splat")
x.should_receive(:to_ary).and_return([1, 2])
(*a = x).should == x
a.should == [1, 2]
end
it "raises a TypeError if #to_ary does not return an Array" do
x = mock("multi-assign splat")
x.should_receive(:to_ary).and_return(1)
-> { *a = x }.should raise_error(TypeError)
end
it "does not call #to_ary on an Array subclass" do
cls = Class.new(Array)
ary = cls.new [1, 2]
ary.should_not_receive(:to_ary)
(*a = ary).should == [1, 2]
a.should == [1, 2]
end
it "assigns an Array when the RHS is an Array subclass" do
cls = Class.new(Array)
ary = cls.new [1, 2]
x = (*a = ary)
x.should equal(ary)
a.should be_an_instance_of(Array)
end
it "calls #to_ary to convert an Object RHS with MLHS" do
x = mock("multi-assign splat")
x.should_receive(:to_ary).and_return([1, 2])
(a, *b, c = x).should == x
[a, b, c].should == [1, [], 2]
end
it "raises a TypeError if #to_ary does not return an Array with MLHS" do
x = mock("multi-assign splat")
x.should_receive(:to_ary).and_return(1)
-> { a, *b, c = x }.should raise_error(TypeError)
end
it "does not call #to_a to convert an Object RHS with a MLHS" do
x = mock("multi-assign splat")
x.should_not_receive(:to_a)
(a, *b = x).should == x
[a, b].should == [x, []]
end
it "assigns a MLHS with leading splat" do
(*a, b, c = 1).should == 1
[a, b, c].should == [[], 1, nil]
end
it "assigns a MLHS with a middle splat" do
a, b, *c, d, e = 1
[a, b, c, d, e].should == [1, nil, [], nil, nil]
end
it "assigns a MLHS with a trailing splat" do
a, b, *c = 1
[a, b, c].should == [1, nil, []]
end
it "assigns a grouped LHS without splat" do
((a, b), c), (d, (e,), (f, (g, h))) = 1
[a, b, c, d, e, f, g, h].should == [1, nil, nil, nil, nil, nil, nil, nil]
end
it "assigns a single grouped LHS splat" do
(*a) = nil
a.should == [nil]
end
it "assigns a grouped LHS with splats" do
(a, *b), c, (*d, (e, *f, g)) = 1
[a, b, c, d, e, f, g].should == [1, [], nil, [], nil, [], nil]
end
it "consumes values for an anonymous splat" do
(* = 1).should == 1
end
it "consumes values for a grouped anonymous splat" do
((*) = 1).should == 1
end
it "does not mutate a RHS Array" do
x = [1, 2, 3, 4]
a, *b, c, d = x
[a, b, c, d].should == [1, [2], 3, 4]
x.should == [1, 2, 3, 4]
end
it "assigns values from a RHS method call" do
def x() 1 end
(a, b = x).should == 1
[a, b].should == [1, nil]
end
it "assigns values from a RHS method call with arguments" do
def x(a) a end
(a, b = x []).should == []
[a, b].should == [nil, nil]
end
it "assigns values from a RHS method call with receiver" do
x = mock("multi-assign attributes")
x.should_receive(:m).and_return([1, 2, 3])
a, b = x.m
[a, b].should == [1, 2]
end
it "calls #to_ary on the value returned by the method call" do
y = mock("multi-assign method return value")
y.should_receive(:to_ary).and_return([1, 2])
x = mock("multi-assign attributes")
x.should_receive(:m).and_return(y)
(a, b = x.m).should == y
[a, b].should == [1, 2]
end
it "raises a TypeError if #to_ary does not return an Array on a single RHS" do
y = mock("multi-assign method return value")
y.should_receive(:to_ary).and_return(1)
x = mock("multi-assign attributes")
x.should_receive(:m).and_return(y)
-> { a, b = x.m }.should raise_error(TypeError)
end
it "assigns values from a RHS method call with receiver and arguments" do
x = mock("multi-assign attributes")
x.should_receive(:m).with(1, 2).and_return([1, 2, 3])
a, b = x.m 1, 2
[a, b].should == [1, 2]
end
it "assigns global variables" do
$spec_a, $spec_b = 1
[$spec_a, $spec_b].should == [1, nil]
end
it "assigns instance variables" do
@a, @b = 1
[@a, @b].should == [1, nil]
end
it "assigns attributes" do
a = mock("multi-assign attributes")
a.should_receive(:x=).with(1)
a.should_receive(:y=).with(nil)
a.x, a.y = 1
end
it "assigns indexed elements" do
a = []
a[1], a[2] = 1
a.should == [nil, 1, nil]
end
it "assigns constants" do
module VariableSpecs
SINGLE_RHS_1, SINGLE_RHS_2 = 1
[SINGLE_RHS_1, SINGLE_RHS_2].should == [1, nil]
end
end
end
context "with a single splatted RHS value" do
it "assigns a single grouped LHS splat" do
(*a) = *1
a.should == [1]
end
it "assigns an empty Array to a single LHS value when passed nil" do
(a = *nil).should == []
a.should == []
end
it "calls #to_a to convert nil to an empty Array" do
nil.should_receive(:to_a).and_return([])
(*a = *nil).should == []
a.should == []
end
it "does not call #to_a on an Array" do
ary = [1, 2]
ary.should_not_receive(:to_a)
(a = *ary).should == [1, 2]
a.should == [1, 2]
end
it "returns a copy of a splatted Array" do
ary = [1, 2]
(a = *ary).should == [1, 2]
a.should_not equal(ary)
end
it "does not call #to_a on an Array subclass" do
cls = Class.new(Array)
ary = cls.new [1, 2]
ary.should_not_receive(:to_a)
(a = *ary).should == [1, 2]
a.should == [1, 2]
end
it "returns an Array when the splatted object is an Array subclass" do
cls = Class.new(Array)
ary = cls.new [1, 2]
x = (a = *ary)
x.should == [1, 2]
x.should be_an_instance_of(Array)
a.should == [1, 2]
a.should be_an_instance_of(Array)
end
it "unfreezes the array returned from calling 'to_a' on the splatted value" do
obj = Object.new
def obj.to_a
[1,2].freeze
end
res = *obj
res.should == [1,2]
res.should_not.frozen?
end
it "consumes values for an anonymous splat" do
a = 1
(* = *a).should == [1]
end
it "consumes values for a grouped anonymous splat" do
((*) = *1).should == [1]
end
it "assigns a single LHS splat" do
x = 1
(*a = *x).should == [1]
a.should == [1]
end
it "calls #to_a to convert an Object RHS with a single splat LHS" do
x = mock("multi-assign RHS splat")
x.should_receive(:to_a).and_return([1, 2])
(*a = *x).should == [1, 2]
a.should == [1, 2]
end
it "calls #to_a if it is private" do
x = mock("multi-assign RHS splat")
x.should_receive(:to_a).and_return([1, 2])
class << x; private :to_a; end
(*a = *x).should == [1, 2]
a.should == [1, 2]
end
it "does not call #to_a if #respond_to? returns false" do
x = mock("multi-assign RHS splat")
x.should_receive(:respond_to?).with(:to_a, true).and_return(false)
x.should_not_receive(:to_a)
(*a = *x).should == [x]
a.should == [x]
end
it "wraps the Object in an Array if #to_a returns nil" do
x = mock("multi-assign RHS splat")
x.should_receive(:to_a).and_return(nil)
(*a = *x).should == [x]
a.should == [x]
end
it "raises a TypeError if #to_a does not return an Array" do
x = mock("multi-assign RHS splat")
x.should_receive(:to_a).and_return(1)
-> { *a = *x }.should raise_error(TypeError)
end
it "does not call #to_ary to convert an Object RHS with a single splat LHS" do
x = mock("multi-assign RHS splat")
x.should_not_receive(:to_ary)
(*a = *x).should == [x]
a.should == [x]
end
it "assigns a MLHS with leading splat" do
(*a, b, c = *1).should == [1]
[a, b, c].should == [[], 1, nil]
end
it "assigns a MLHS with a middle splat" do
a, b, *c, d, e = *1
[a, b, c, d, e].should == [1, nil, [], nil, nil]
end
it "assigns a MLHS with a trailing splat" do
a, b, *c = *nil
[a, b, c].should == [nil, nil, []]
end
it "calls #to_a to convert an Object RHS with a single LHS" do
x = mock("multi-assign RHS splat")
x.should_receive(:to_a).and_return([1, 2])
(a = *x).should == [1, 2]
a.should == [1, 2]
end
it "does not call #to_ary to convert an Object RHS with a single LHS" do
x = mock("multi-assign RHS splat")
x.should_not_receive(:to_ary)
(a = *x).should == [x]
a.should == [x]
end
it "raises a TypeError if #to_a does not return an Array with a single LHS" do
x = mock("multi-assign splat")
x.should_receive(:to_a).and_return(1)
-> { a = *x }.should raise_error(TypeError)
end
it "calls #to_a to convert an Object splat RHS when assigned to a simple MLHS" do
x = mock("multi-assign splat")
x.should_receive(:to_a).and_return([1, 2])
(a, b, c = *x).should == [1, 2]
[a, b, c].should == [1, 2, nil]
end
it "raises a TypeError if #to_a does not return an Array with a simple MLHS" do
x = mock("multi-assign splat")
x.should_receive(:to_a).and_return(1)
-> { a, b, c = *x }.should raise_error(TypeError)
end
it "does not call #to_ary to convert an Object splat RHS when assigned to a simple MLHS" do
x = mock("multi-assign splat")
x.should_not_receive(:to_ary)
(a, b, c = *x).should == [x]
[a, b, c].should == [x, nil, nil]
end
it "calls #to_a to convert an Object RHS with MLHS" do
x = mock("multi-assign splat")
x.should_receive(:to_a).and_return([1, 2])
a, *b, c = *x
[a, b, c].should == [1, [], 2]
end
it "raises a TypeError if #to_a does not return an Array with MLHS" do
x = mock("multi-assign splat")
x.should_receive(:to_a).and_return(1)
-> { a, *b, c = *x }.should raise_error(TypeError)
end
it "does not call #to_ary to convert an Object RHS with a MLHS" do
x = mock("multi-assign splat")
x.should_not_receive(:to_ary)
a, *b = *x
[a, b].should == [x, []]
end
it "assigns a grouped LHS without splats" do
((a, b), c), (d, (e,), (f, (g, h))) = *1
[a, b, c, d, e, f, g, h].should == [1, nil, nil, nil, nil, nil, nil, nil]
end
it "assigns a grouped LHS with splats" do
(a, *b), c, (*d, (e, *f, g)) = *1
[a, b, c, d, e, f, g].should == [1, [], nil, [], nil, [], nil]
end
it "does not mutate a RHS Array" do
x = [1, 2, 3, 4]
a, *b, c, d = *x
[a, b, c, d].should == [1, [2], 3, 4]
x.should == [1, 2, 3, 4]
end
it "assigns constants" do
module VariableSpecs
(*SINGLE_SPLATTED_RHS) = *1
SINGLE_SPLATTED_RHS.should == [1]
end
end
end
context "with a MRHS value" do
it "consumes values for an anonymous splat" do
(* = 1, 2, 3).should == [1, 2, 3]
end
it "consumes values for a grouped anonymous splat" do
((*) = 1, 2, 3).should == [1, 2, 3]
end
it "consumes values for multiple '_' variables" do
a, _, b, _, c = 1, 2, 3, 4, 5
[a, b, c].should == [1, 3, 5]
end
it "does not call #to_a to convert an Object in a MRHS" do
x = mock("multi-assign MRHS")
x.should_not_receive(:to_a)
(a, b = 1, x).should == [1, x]
[a, b].should == [1, x]
end
it "does not call #to_ary to convert an Object in a MRHS" do
x = mock("multi-assign MRHS")
x.should_not_receive(:to_ary)
(a, b = 1, x).should == [1, x]
[a, b].should == [1, x]
end
it "calls #to_a to convert a splatted Object as part of a MRHS with a splat MLHS" do
x = mock("multi-assign splat MRHS")
x.should_receive(:to_a).and_return([3, 4])
(a, *b = 1, *x).should == [1, 3, 4]
[a, b].should == [1, [3, 4]]
end
it "raises a TypeError if #to_a does not return an Array with a splat MLHS" do
x = mock("multi-assign splat MRHS")
x.should_receive(:to_a).and_return(1)
-> { a, *b = 1, *x }.should raise_error(TypeError)
end
it "does not call #to_ary to convert a splatted Object as part of a MRHS with a splat MRHS" do
x = mock("multi-assign splat MRHS")
x.should_not_receive(:to_ary)
(a, *b = 1, *x).should == [1, x]
[a, b].should == [1, [x]]
end
it "calls #to_a to convert a splatted Object as part of a MRHS" do
x = mock("multi-assign splat MRHS")
x.should_receive(:to_a).and_return([3, 4])
(a, *b = *x, 1).should == [3, 4, 1]
[a, b].should == [3, [4, 1]]
end
it "raises a TypeError if #to_a does not return an Array with a splat MRHS" do
x = mock("multi-assign splat MRHS")
x.should_receive(:to_a).and_return(1)
-> { a, *b = *x, 1 }.should raise_error(TypeError)
end
it "does not call #to_ary to convert a splatted Object with a splat MRHS" do
x = mock("multi-assign splat MRHS")
x.should_not_receive(:to_ary)
(a, *b = *x, 1).should == [x, 1]
[a, b].should == [x, [1]]
end
it "assigns a grouped LHS without splat from a simple Array" do
((a, b), c), (d, (e,), (f, (g, h))) = 1, 2, 3, 4, 5
[a, b, c, d, e, f, g, h].should == [1, nil, nil, 2, nil, nil, nil, nil]
end
it "assigns a grouped LHS without splat from nested Arrays" do
ary = [[1, 2, 3], 4], [[5], [6, 7], [8, [9, 10]]]
((a, b), c), (d, (e,), (f, (g, h))) = ary
[a, b, c, d, e, f, g, h].should == [1, 2, 4, [5], 6, 8, 9, 10]
end
it "assigns a single grouped LHS splat" do
(*a) = 1, 2, 3
a.should == [1, 2, 3]
end
it "assigns a grouped LHS with splats from nested Arrays for simple values" do
(a, *b), c, (*d, (e, *f, g)) = 1, 2, 3, 4
[a, b, c, d, e, f, g].should == [1, [], 2, [], 3, [], nil]
end
it "assigns a grouped LHS with splats from nested Arrays for nested arrays" do
(a, *b), c, (*d, (e, *f, g)) = [1, [2, 3]], [4, 5], [6, 7, 8]
[a, b, c, d, e, f, g].should == [1, [[2, 3]], [4, 5], [6, 7], 8, [], nil]
end
it "calls #to_ary to convert an Object when the position receiving the value is a multiple assignment" do
x = mock("multi-assign mixed RHS")
x.should_receive(:to_ary).and_return([1, 2])
(a, (b, c), d, e = 1, x, 3, 4).should == [1, x, 3, 4]
[a, b, c, d, e].should == [1, 1, 2, 3, 4]
end
it "raises a TypeError if #to_ary does not return an Array" do
x = mock("multi-assign mixed RHS")
x.should_receive(:to_ary).and_return(x)
-> { a, (b, c), d = 1, x, 3, 4 }.should raise_error(TypeError)
end
it "calls #to_a to convert a splatted Object value in a MRHS" do
x = mock("multi-assign mixed splatted RHS")
x.should_receive(:to_a).and_return([4, 5])
(a, *b, (c, d) = 1, 2, 3, *x).should == [1, 2, 3, 4, 5]
[a, b, c, d].should == [1, [2, 3, 4], 5, nil]
end
it "calls #to_ary to convert a splatted Object when the position receiving the value is a multiple assignment" do
x = mock("multi-assign mixed splatted RHS")
x.should_receive(:to_ary).and_return([4, 5])
(a, *b, (c, d) = 1, 2, 3, *x).should == [1, 2, 3, x]
[a, b, c, d].should == [1, [2, 3], 4, 5]
end
it "raises a TypeError if #to_ary does not return an Array in a MRHS" do
x = mock("multi-assign mixed splatted RHS")
x.should_receive(:to_ary).and_return(x)
-> { a, *b, (c, d) = 1, 2, 3, *x }.should raise_error(TypeError)
end
it "does not call #to_ary to convert an Object when the position receiving the value is a simple variable" do
x = mock("multi-assign mixed RHS")
x.should_not_receive(:to_ary)
a, b, c, d = 1, x, 3, 4
[a, b, c, d].should == [1, x, 3, 4]
end
it "does not call #to_ary to convert an Object when the position receiving the value is a rest variable" do
x = mock("multi-assign mixed RHS")
x.should_not_receive(:to_ary)
a, *b, c, d = 1, x, 3, 4
[a, b, c, d].should == [1, [x], 3, 4]
end
it "does not call #to_ary to convert a splatted Object when the position receiving the value is a simple variable" do
x = mock("multi-assign mixed splatted RHS")
x.should_not_receive(:to_ary)
a, *b, c = 1, 2, *x
[a, b, c].should == [1, [2], x]
end
it "does not call #to_ary to convert a splatted Object when the position receiving the value is a rest variable" do
x = mock("multi-assign mixed splatted RHS")
x.should_not_receive(:to_ary)
a, b, *c = 1, 2, *x
[a, b, c].should == [1, 2, [x]]
end
it "does not mutate the assigned Array" do
x = ((a, *b, c, d) = 1, 2, 3, 4, 5)
x.should == [1, 2, 3, 4, 5]
end
it "can be used to swap array elements" do
a = [1, 2]
a[0], a[1] = a[1], a[0]
a.should == [2, 1]
end
it "can be used to swap range of array elements" do
a = [1, 2, 3, 4]
a[0, 2], a[2, 2] = a[2, 2], a[0, 2]
a.should == [3, 4, 1, 2]
end
it "assigns RHS values to LHS constants" do
module VariableSpecs
MRHS_VALUES_1, MRHS_VALUES_2 = 1, 2
MRHS_VALUES_1.should == 1
MRHS_VALUES_2.should == 2
end
end
it "assigns all RHS values as an array to a single LHS constant" do
module VariableSpecs
MRHS_VALUES = 1, 2, 3
MRHS_VALUES.should == [1, 2, 3]
end
end
end
context "with a RHS assignment value" do
it "consumes values for an anonymous splat" do
(* = (a = 1)).should == 1
a.should == 1
end
it "does not mutate a RHS Array" do
a, *b, c, d = (e = [1, 2, 3, 4])
[a, b, c, d].should == [1, [2], 3, 4]
e.should == [1, 2, 3, 4]
end
end
end
describe "A local variable assigned only within a conditional block" do
context "accessed from a later closure" do
it "is defined?" do
if VariablesSpecs.false
a = 1
end
1.times do
defined?(a).should == "local-variable"
end
end
it "is nil" do
if VariablesSpecs.false
a = 1
end
1.times do
a.inspect.should == "nil"
end
end
end
end
describe 'Local variable shadowing' do
it "does not warn in verbose mode" do
result = nil
-> do
eval <<-CODE
a = [1, 2, 3]
result = a.map { |a| a = 3 }
CODE
end.should_not complain(verbose: true)
result.should == [3, 3, 3]
end
end
describe 'Allowed characters' do
it 'allows non-ASCII lowercased characters at the beginning' do
result = nil
eval <<-CODE
def test
μ = 1
end
result = test
CODE
result.should == 1
end
it 'parses a non-ASCII upcased character as a constant identifier' do
-> do
eval <<-CODE
def test
BB = 1
end
CODE
end.should raise_error(SyntaxError, /dynamic constant assignment/)
end
end
describe "Instance variables" do
context "when instance variable is uninitialized" do
ruby_version_is ""..."3.0" do
it "warns about accessing uninitialized instance variable" do
obj = Object.new
def obj.foobar; a = @a; end
-> { obj.foobar }.should complain(/warning: instance variable @a not initialized/, verbose: true)
end
end
ruby_version_is "3.0" do
it "doesn't warn about accessing uninitialized instance variable" do
obj = Object.new
def obj.foobar; a = @a; end
-> { obj.foobar }.should_not complain(verbose: true)
end
end
it "doesn't warn at lazy initialization" do
obj = Object.new
def obj.foobar; @a ||= 42; end
-> { obj.foobar }.should_not complain(verbose: true)
end
end
describe "global variable" do
context "when global variable is uninitialized" do
it "warns about accessing uninitialized global variable in verbose mode" do
obj = Object.new
def obj.foobar; a = $specs_uninitialized_global_variable; end
-> { obj.foobar }.should complain(/warning: global variable `\$specs_uninitialized_global_variable' not initialized/, verbose: true)
end
it "doesn't warn at lazy initialization" do
obj = Object.new
def obj.foobar; $specs_uninitialized_global_variable_lazy ||= 42; end
-> { obj.foobar }.should_not complain(verbose: true)
end
end
end
end