spec/rubyspec/core/math/log10_spec.rb


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require File.expand_path('../../../spec_helper', __FILE__)
require File.expand_path('../fixtures/classes', __FILE__)

# The common logarithm, having base 10
describe "Math.log10" do
  it "returns a float" do
    Math.log10(1).should be_kind_of(Float)
  end

  it "returns the base-10 logarithm of the argument" do
    Math.log10(0.0001).should be_close(-4.0, TOLERANCE)
    Math.log10(0.000000000001e-15).should be_close(-27.0, TOLERANCE)
    Math.log10(1).should be_close(0.0, TOLERANCE)
    Math.log10(10).should be_close(1.0, TOLERANCE)
    Math.log10(10e15).should be_close(16.0, TOLERANCE)
  end

  conflicts_with :Complex do
    it "raises an Errno::EDOM if the argument is less than 0" do
      lambda { Math.log10(-1e-15) }.should raise_error( Errno::EDOM)
    end
  end

  it "raises a TypeError if the argument cannot be coerced with Float()" do
    lambda { Math.log10("test") }.should raise_error(TypeError)
  end

  it "returns NaN given NaN" do
    Math.log10(nan_value).nan?.should be_true
  end

  it "raises a TypeError if the argument is nil" do
    lambda { Math.log10(nil) }.should raise_error(TypeError)
  end

  it "accepts any argument that can be coerced with Float()" do
    Math.log10(MathSpecs::Float.new).should be_close(0.0, TOLERANCE)
  end
end

describe "Math#log10" do
  it "is accessible as a private instance method" do
    IncludesMath.new.send(:log10, 4.15).should be_close(0.618048096712093, TOLERANCE)
  end
end