Adding new tests & explanations of negative number behavior for round…

…ing and truncating

org.uqbar.project.wollok.lib/src/wollok/lang.wlk

@@ -1204,21 +1204,26 @@ class Double inherits Number {
 	/**
 	 * Answers the next integer greater than self
 	 * 13.224.roundUp() ==> 14
+	 * -13.224.roundUp() ==> -14
 	 * 15.942.roundUp() ==> 16
 	 */
 	method roundUp() = self.roundUp(0)
 
 	/**
-	 * Rounds up self up to a certain amount of decimals
+	 * Rounds up self up to a certain amount of decimals.
+	 * Amount of decimals must be positive
 	 * 1.223445.roundUp(3) ==> 1.224
+	 * -1.223445.roundUp(3) ==> -1.224
 	 * 14.6165.roundUp(3) ==> 14.617
 	 */
 	method roundUp(_decimals) native
 
 	/**
-	 * Truncates self up to a certain amount of decimals
+	 * Truncates self up to a certain amount of decimals.
+	 * Amount of decimals must be positive
 	 * 1.223445.truncate(3) ==> 1.223
 	 * 14.6165.truncate(3) ==> 14.616
+	 * -14.6165.truncate(3) ==> -14.616
 	 */
 	method truncate(_decimals) native
 }

org.uqbar.project.wollok.tests/src/org/uqbar/project/wollok/tests/interpreter/DecimalTestCase.xtend

@@ -12,15 +12,18 @@ class DecimalTestCase extends AbstractWollokInterpreterTestCase {
 	def void roundUp() {
 		'''
 		assert.equals(14, 13.224.roundUp())
+		assert.equals(-14, -13.224.roundUp())
 		assert.equals(16, 15.942.roundUp())
 		assert.equals(15, 15.0.roundUp())
+		assert.equals(-15, -15.0.roundUp())
 		'''.test
 	}
-	
+
 	@Test
 	def void roundUpDecimals() {
 		'''
 		assert.equals(1.224, 1.223445.roundUp(3))
+		assert.equals(-1.224, -1.223445.roundUp(3))
 		assert.equals(14.617, 14.6165.roundUp(3))
 		assert.equals(14.6165, 14.6165.roundUp(6))
 		'''.test
@@ -43,5 +46,13 @@ class DecimalTestCase extends AbstractWollokInterpreterTestCase {
 		assert.throwsExceptionWithMessage("Cannot set new scale with -3 decimals", { 1.223445.roundUp(-3) })
 		'''.test
 	}
+
+	@Test
+	def void roundUpAlphabeticDecimalsThrowsError() {
+		'''
+		assert.throwsException({ 1.223445.truncate("A") })
+		assert.throwsException({ 1.223445.roundUp("B") })
+		'''.test
+	}
 
 }