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Diffstat (limited to 'spec/ruby/language/yield_spec.rb')
| -rw-r--r-- | spec/ruby/language/yield_spec.rb | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/spec/ruby/language/yield_spec.rb b/spec/ruby/language/yield_spec.rb new file mode 100644 index 0000000000..3173f41b0c --- /dev/null +++ b/spec/ruby/language/yield_spec.rb @@ -0,0 +1,226 @@ +require_relative '../spec_helper' +require_relative 'fixtures/yield' + +# Note that these specs use blocks defined as { |*a| ... } to capture the +# arguments with which the block is invoked. This is slightly confusing +# because the outer Array is a consequence of |*a| but it is necessary to +# clearly distinguish some behaviors. + +describe "The yield call" do + before :each do + @y = YieldSpecs::Yielder.new + end + + describe "taking no arguments" do + it "raises a LocalJumpError when the method is not passed a block" do + -> { @y.z }.should.raise(LocalJumpError) + end + + it "ignores assignment to the explicit block argument and calls the passed block" do + @y.ze { 42 }.should == 42 + end + + it "does not pass a named block to the block being yielded to" do + @y.z() { |&block| block == nil }.should == true + end + end + + describe "taking a single argument" do + describe "when no block is given" do + it "raises a LocalJumpError" do + -> { @y.s(1) }.should.raise(LocalJumpError) + end + end + + describe "yielding to a literal block" do + it "passes an empty Array when the argument is an empty Array" do + @y.s([]) { |*a| a }.should == [[]] + end + + it "passes nil as a value" do + @y.s(nil) { |*a| a }.should == [nil] + end + + it "passes a single value" do + @y.s(1) { |*a| a }.should == [1] + end + + it "passes a single, multi-value Array" do + @y.s([1, 2, 3]) { |*a| a }.should == [[1, 2, 3]] + end + + describe "with optional argument" do + it "does not destructure a single array argument" do + @y.s([1, 2, 3]) { |a = 99| a }.should == [1, 2, 3] + end + end + end + + describe "yielding to a lambda" do + it "passes an empty Array when the argument is an empty Array" do + @y.s([], &-> *a { a }).should == [[]] + end + + it "passes nil as a value" do + @y.s(nil, &-> *a { a }).should == [nil] + end + + it "passes a single value" do + @y.s(1, &-> *a { a }).should == [1] + end + + it "passes a single, multi-value Array" do + @y.s([1, 2, 3], &-> *a { a }).should == [[1, 2, 3]] + end + + it "raises an ArgumentError if too few arguments are passed" do + -> { + @y.s(1, &-> a, b { [a,b] }) + }.should.raise(ArgumentError) + end + + it "should not destructure an Array into multiple arguments" do + -> { + @y.s([1, 2], &-> a, b { [a,b] }) + }.should.raise(ArgumentError) + end + end + end + + describe "taking multiple arguments" do + it "raises a LocalJumpError when the method is not passed a block" do + -> { @y.m(1, 2, 3) }.should.raise(LocalJumpError) + end + + it "passes the arguments to the block" do + @y.m(1, 2, 3) { |*a| a }.should == [1, 2, 3] + end + + it "passes only the first argument if the block takes one parameter" do + @y.m(1, 2, 3) { |a| a }.should == 1 + end + + it "raises an ArgumentError if too many arguments are passed to a lambda" do + -> { + @y.m(1, 2, 3, &-> a { }) + }.should.raise(ArgumentError) + end + + it "raises an ArgumentError if too few arguments are passed to a lambda" do + -> { + @y.m(1, 2, 3, &-> a, b, c, d { }) + }.should.raise(ArgumentError) + end + end + + describe "taking a single splatted argument" do + it "raises a LocalJumpError when the method is not passed a block" do + -> { @y.r(0) }.should.raise(LocalJumpError) + end + + it "passes a single value" do + @y.r(1) { |*a| a }.should == [1] + end + + it "passes no arguments when the argument is an empty Array" do + @y.r([]) { |*a| a }.should == [] + end + + it "passes the value when the argument is an Array containing a single value" do + @y.r([1]) { |*a| a }.should == [1] + end + + it "passes the values of the Array as individual arguments" do + @y.r([1, 2, 3]) { |*a| a }.should == [1, 2, 3] + end + + it "passes the element of a single element Array" do + @y.r([[1, 2]]) { |*a| a }.should == [[1, 2]] + @y.r([nil]) { |*a| a }.should == [nil] + @y.r([[]]) { |*a| a }.should == [[]] + end + + it "passes no values when give nil as an argument" do + @y.r(nil) { |*a| a }.should == [] + end + end + + describe "taking multiple arguments with a splat" do + it "raises a LocalJumpError when the method is not passed a block" do + -> { @y.rs(1, 2, [3, 4]) }.should.raise(LocalJumpError) + end + + it "passes the arguments to the block" do + @y.rs(1, 2, 3) { |*a| a }.should == [1, 2, 3] + end + + it "does not pass an argument value if the splatted argument is an empty Array" do + @y.rs(1, 2, []) { |*a| a }.should == [1, 2] + end + + it "passes the Array elements as arguments if the splatted argument is a non-empty Array" do + @y.rs(1, 2, [3]) { |*a| a }.should == [1, 2, 3] + @y.rs(1, 2, [nil]) { |*a| a }.should == [1, 2, nil] + @y.rs(1, 2, [[]]) { |*a| a }.should == [1, 2, []] + @y.rs(1, 2, [3, 4, 5]) { |*a| a }.should == [1, 2, 3, 4, 5] + end + + it "does not pass an argument value if the splatted argument is nil" do + @y.rs(1, 2, nil) { |*a| a }.should == [1, 2] + end + end + + describe "taking matching arguments with splats and post args" do + it "raises a LocalJumpError when the method is not passed a block" do + -> { @y.rs(1, 2, [3, 4]) }.should.raise(LocalJumpError) + end + + it "passes the arguments to the block" do + @y.rs([1, 2], 3, 4) { |(*a, b), c, d| [a, b, c, d] }.should == [[1], 2, 3, 4] + end + end + + describe "taking a splat and a keyword argument" do + it "passes it as an array of the values and a hash" do + @y.k([1, 2]) { |*a| a }.should == [1, 2, {:b=>true}] + end + end + + it "uses captured block of a block used in define_method" do + @y.deep(2).should == 4 + end +end + +describe "Using yield in a singleton class literal" do + it 'raises a SyntaxError' do + code = <<~RUBY + class << Object.new + yield + end + RUBY + + -> { eval(code) }.should.raise(SyntaxError, /Invalid yield/) + end +end + +describe "Using yield in non-lambda block" do + it 'raises a SyntaxError' do + code = <<~RUBY + 1.times { yield } + RUBY + + -> { eval(code) }.should.raise(SyntaxError, /Invalid yield/) + end +end + +describe "Using yield in a module literal" do + it 'raises a SyntaxError' do + code = <<~RUBY + module YieldSpecs::ModuleWithYield + yield + end + RUBY + + -> { eval(code) }.should.raise(SyntaxError, /Invalid yield/) + end +end |
