File: srand_spec.rb

package info (click to toggle)
ruby2.7 2.7.4-1%2Bdeb11u1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 112,576 kB
  • sloc: ruby: 849,454; ansic: 697,834; yacc: 45,100; xml: 25,367; pascal: 10,051; javascript: 6,575; sh: 3,848; makefile: 759; cpp: 713; asm: 333; python: 295; lisp: 97; sed: 94; perl: 62; awk: 36
file content (39 lines) | stat: -rw-r--r-- 1,307 bytes parent folder | download | duplicates (7)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
require_relative '../../spec_helper'

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