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Diffstat (limited to 'spec/ruby/language/optional_assignments_spec.rb')
-rw-r--r-- | spec/ruby/language/optional_assignments_spec.rb | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/spec/ruby/language/optional_assignments_spec.rb b/spec/ruby/language/optional_assignments_spec.rb new file mode 100644 index 0000000000..c104d08253 --- /dev/null +++ b/spec/ruby/language/optional_assignments_spec.rb @@ -0,0 +1,226 @@ +require File.expand_path('../../spec_helper', __FILE__) + +describe 'Optional variable assignments' do + describe 'using ||=' do + describe 'using a single variable' do + it 'assigns a new variable' do + a ||= 10 + + a.should == 10 + end + + it 're-assigns an existing variable set to false' do + a = false + a ||= 10 + + a.should == 10 + end + + it 're-assigns an existing variable set to nil' do + a = nil + a ||= 10 + + a.should == 10 + end + + it 'does not re-assign a variable with a truthy value' do + a = 10 + a ||= 20 + + a.should == 10 + end + + it 'does not evaluate the right side when not needed' do + a = 10 + a ||= raise('should not be executed') + a.should == 10 + end + + it 'does not re-assign a variable with a truthy value when using an inline rescue' do + a = 10 + a ||= 20 rescue 30 + + a.should == 10 + end + end + + describe 'using a accessor' do + before do + klass = Class.new { attr_accessor :b } + @a = klass.new + end + + it 'assigns a new variable' do + @a.b ||= 10 + + @a.b.should == 10 + end + + it 're-assigns an existing variable set to false' do + @a.b = false + @a.b ||= 10 + + @a.b.should == 10 + end + + it 're-assigns an existing variable set to nil' do + @a.b = nil + @a.b ||= 10 + + @a.b.should == 10 + end + + it 'does not re-assign a variable with a truthy value' do + @a.b = 10 + @a.b ||= 20 + + @a.b.should == 10 + end + + it 'does not evaluate the right side when not needed' do + @a.b = 10 + @a.b ||= raise('should not be executed') + @a.b.should == 10 + end + + it 'does not re-assign a variable with a truthy value when using an inline rescue' do + @a.b = 10 + @a.b ||= 20 rescue 30 + + @a.b.should == 10 + end + end + end + + describe 'using &&=' do + describe 'using a single variable' do + it 'leaves new variable unassigned' do + a &&= 10 + + a.should == nil + end + + it 'leaves false' do + a = false + a &&= 10 + + a.should == false + end + + it 'leaves nil' do + a = nil + a &&= 10 + + a.should == nil + end + + it 'does not evaluate the right side when not needed' do + a = nil + a &&= raise('should not be executed') + a.should == nil + end + + it 'does re-assign a variable with a truthy value' do + a = 10 + a &&= 20 + + a.should == 20 + end + + it 'does re-assign a variable with a truthy value when using an inline rescue' do + a = 10 + a &&= 20 rescue 30 + + a.should == 20 + end + end + + describe 'using a single variable' do + before do + klass = Class.new { attr_accessor :b } + @a = klass.new + end + + it 'leaves new variable unassigned' do + @a.b &&= 10 + + @a.b.should == nil + end + + it 'leaves false' do + @a.b = false + @a.b &&= 10 + + @a.b.should == false + end + + it 'leaves nil' do + @a.b = nil + @a.b &&= 10 + + @a.b.should == nil + end + + it 'does not evaluate the right side when not needed' do + @a.b = nil + @a.b &&= raise('should not be executed') + @a.b.should == nil + end + + it 'does re-assign a variable with a truthy value' do + @a.b = 10 + @a.b &&= 20 + + @a.b.should == 20 + end + + it 'does re-assign a variable with a truthy value when using an inline rescue' do + @a.b = 10 + @a.b &&= 20 rescue 30 + + @a.b.should == 20 + end + end + end + + describe 'using compunded constants' do + before do + Object.send(:remove_const, :A) if defined? Object::A + end + + it 'with ||= assignments' do + Object::A ||= 10 + Object::A.should == 10 + end + + it 'with ||= do not reassign' do + Object::A = 20 + Object::A ||= 10 + Object::A.should == 20 + end + + it 'with &&= assignments' do + Object::A = 20 + -> { + Object::A &&= 10 + }.should complain(/already initialized constant/) + Object::A.should == 10 + end + + it 'with &&= assignments will fail with non-existant constants' do + lambda { Object::A &&= 10 }.should raise_error(NameError) + end + + it 'with operator assignments' do + Object::A = 20 + -> { + Object::A += 10 + }.should complain(/already initialized constant/) + Object::A.should == 30 + end + + it 'with operator assignments will fail with non-existant constants' do + lambda { Object::A += 10 }.should raise_error(NameError) + end + end +end |