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require File.expand_path('../../../spec_helper', __FILE__)
ruby_version_is "1.9" do
describe "Random.srand" do
it "returns an arbitrary seed if .srand wasn't called previously with an argument and no argument is supplied this time" do
Random.srand # Reset to random seed in case .srand was called previously
Random.srand.should_not == Random.srand
end
it "returns the previous argument to .srand if one was given and no argument is supplied" do
Random.srand 34
Random.srand.should == 34
end
it "returns an arbitrary seed if .srand wasn't called previously with an argument and 0 is supplied this time" do
Random.srand # Reset to random seed in case .srand was called previously
Random.srand(0).should_not == Random.srand(0)
end
it "returns the previous argument to .srand if one was given and 0 is supplied" do
Random.srand 34
Random.srand(0).should == 34
end
it "seeds Random.rand such that its return value is deterministic" do
Random.srand 176542
a = 20.times.map { Random.rand }
Random.srand 176542
b = 20.times.map { Random.rand }
a.should == b
end
it "seeds Kernel.rand such that its return value is deterministic" do
Random.srand 176542
a = 20.times.map { Kernel.rand }
Random.srand 176542
b = 20.times.map { Kernel.rand }
a.should == b
end
end
end
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