shard-ameba/spec/ameba/rule/lint/rand_zero_spec.cr

require "../../../spec_helper"

module Ameba::Rule::Lint
  describe RandZero do
    subject = RandZero.new

    it "passes if it is not rand(1) or rand(0)" do
      expect_no_issues subject, <<-CRYSTAL
        rand(1.0)
        rand(0.11)
        rand(2)
        CRYSTAL
    end

    it "fails if it is rand(0)" do
      expect_issue subject, <<-CRYSTAL
        rand(0)
        # ^^^^^ error: rand(0) always returns 0
        CRYSTAL
    end

    it "fails if it is rand(1)" do
      expect_issue subject, <<-CRYSTAL
        rand(1)
        # ^^^^^ error: rand(1) always returns 0
        CRYSTAL
    end

    it "reports rule, location and a message" do
      s = Source.new "rand(1)", "source.cr"
      subject.catch(s).should_not be_valid
      issue = s.issues.first

      issue.rule.should_not be_nil
      issue.location.to_s.should eq "source.cr:1:1"
      issue.end_location.to_s.should eq "source.cr:1:7"
      issue.message.should eq "rand(1) always returns 0"
    end
  end
end