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