Fix add method

Wildhoney · jonathantneal · commit 09ebc15a9f95 · 2018-05-11T00:53:48.000-04:00
diff --git a/lib/CSSNumericValue.js b/lib/CSSNumericValue.js
@@ -16,7 +16,7 @@ export default class CSSNumericValue {
 				if (values.length || result.unit !== arg.unit) {
 					values.push(arg)
 				} else {
-					result.value -= arg.value
+					result.value += arg.value
 				}
 			} else if (
 				arg instanceof CSSMathProduct ||

Original file line number	Diff line number	Diff line change
`@@ -16,7 +16,7 @@ export default class CSSNumericValue {`
`16`	`16`	`if (values.length \|\| result.unit !== arg.unit) {`
`17`	`17`	`values.push(arg)`
`18`	`18`	`} else {`
`19`		`- result.value -= arg.value`
	`19`	`+ result.value += arg.value`
`20`	`20`	`}`
`21`	`21`	`} else if (`
`22`	`22`	`arg instanceof CSSMathProduct \|\|`