Add argument coerce assertion for all BigMath methods

Author: tompng

test/bigdecimal/test_bigmath.rb

@@ -30,6 +30,33 @@ def test_e
     assert_converge_in_precision {|n| E(n) }
   end
 
+  def test_coerce_argument
+    f = 0.8
+    bd = BigDecimal(f)
+    assert_equal(BigMath.exp(bd, N), BigMath.exp(f, N))
+    assert_equal(BigMath.log(bd, N), BigMath.log(f, N))
+    assert_equal(sqrt(bd, N), sqrt(f, N))
+    assert_equal(cbrt(bd, N), cbrt(f, N))
+    assert_equal(hypot(bd, bd, N), hypot(f, f, N))
+    assert_equal(sin(bd, N), sin(f, N))
+    assert_equal(cos(bd, N), cos(f, N))
+    assert_equal(tan(bd, N), tan(f, N))
+    assert_equal(asin(bd, N), asin(f, N))
+    assert_equal(acos(bd, N), acos(f, N))
+    assert_equal(atan(bd, N), atan(f, N))
+    assert_equal(atan2(bd, bd, N), atan2(f, f, N))
+    assert_equal(sinh(bd, N), sinh(f, N))
+    assert_equal(cosh(bd, N), cosh(f, N))
+    assert_equal(tanh(bd, N), tanh(f, N))
+    assert_equal(asinh(bd, N), asinh(f, N))
+    assert_equal(acosh(bd * 2, N), acosh(f * 2, N))
+    assert_equal(atanh(bd, N), atanh(f, N))
+    assert_equal(log2(bd, N), log2(f, N))
+    assert_equal(log10(bd, N), log10(f, N))
+    assert_equal(log1p(bd, N), log1p(f, N))
+    assert_equal(expm1(bd, N), expm1(f, N))
+  end
+
   def test_sqrt
     assert_in_delta(2**0.5, sqrt(BigDecimal("2"), N))
     assert_equal(10, sqrt(BigDecimal("100"), N))