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Diffstat (limited to 'spec/arel/algebra/unit/primitives/expression_spec.rb')
-rw-r--r-- | spec/arel/algebra/unit/primitives/expression_spec.rb | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/spec/arel/algebra/unit/primitives/expression_spec.rb b/spec/arel/algebra/unit/primitives/expression_spec.rb new file mode 100644 index 0000000000..768bb492a7 --- /dev/null +++ b/spec/arel/algebra/unit/primitives/expression_spec.rb @@ -0,0 +1,45 @@ +require File.join(File.dirname(__FILE__), '..', '..', '..', '..', 'spec_helper') + +module Arel + describe Expression do + before do + @relation = Table.new(:users) + @attribute = @relation[:id] + end + + describe "#inspect" do + it "returns a simple, short inspect string" do + @attribute.count.inspect.should == "<Arel::Count <Attribute id>>" + end + end + + describe Expression::Transformations do + before do + @expression = Count.new(@attribute) + end + + describe '#bind' do + it "manufactures an attribute with a rebound relation and self as the ancestor" do + derived_relation = @relation.where(@relation[:id].eq(1)) + @expression.bind(derived_relation).should == Count.new(@attribute.bind(derived_relation), nil, @expression) + end + + it "returns self if the substituting to the same relation" do + @expression.bind(@relation).should == @expression + end + end + + describe '#as' do + it "manufactures an aliased expression" do + @expression.as(:alias).should == Expression.new(@attribute, :alias, @expression) + end + end + + describe '#to_attribute' do + it "manufactures an attribute with the expression as an ancestor" do + @expression.to_attribute(@relation).should == Attribute.new(@relation, @expression.alias, :ancestor => @expression) + end + end + end + end +end |