add some tests

Author: xi

test/functions/_cos.scss

@@ -1,6 +1,9 @@
 @include describe("Cos") {
   @include it("should calculate the cosine of a number") {
-    @include should(expect( cos(0.7854) ), to( be-close-to( 0.70711, 5 )));
-    @include should(expect( cos(45deg)  ), to( be-close-to( 0.70711, 5 )));
+    @include should(expect( cos(0.7854)   ), to( be-close-to( 0.70711, 5 )));
+    @include should(expect( cos(45deg)    ), to( be-close-to( 0.70711, 5 )));
+    @include should(expect( cos(315deg)   ), to( be-close-to( 0.70711, 5 )));
+    @include should(expect( cos(3645deg)  ), to( be-close-to( 0.70711, 5 )));
+    @include should(expect( cos(-3645deg) ), to( be-close-to( 0.70711, 5 )));
   }
 }

test/functions/_log.scss

@@ -4,4 +4,12 @@
     @include should(expect( log(10) ), to( be-close-to( 2.30259, 5 )));
     @include should(expect( log(2, 10) ), to( be-close-to( 0.30103, 5 )));
   }
+
+  @include it("should calculate the natural logarithm of a large fractional number") {
+    @include should(expect( log(12345.678)  ), to( be-close-to( 9.421061, 5 )));
+  }
+
+  @include it("should calculate the natural logarithm of a small fractional number") {
+    @include should(expect( log(0.0001)  ), to( be-close-to( -9.210340, 5 )));
+  }
 }

test/functions/_sqrt.scss

@@ -2,5 +2,6 @@
   @include it("should calculate square roots") {
     @include should(expect( sqrt(2) ), to( be-close-to( 1.41421, 5 )));
     @include should(expect( sqrt(5) ), to( be-close-to( 2.23607, 5 )));
+    @include should(expect( sqrt(12345.67) ), to( be-close-to( 111.11107, 5 )));
   }
 }