Font validate style, move defaults to weight (#8877)

src/helpers/helpers.options.js

@@ -3,6 +3,7 @@ import {isArray, isObject, toDimension, valueOrDefault} from './helpers.core';
 import {toFontString} from './helpers.canvas';
 
 const LINE_HEIGHT = new RegExp(/^(normal|(\d+(?:\.\d+)?)(px|em|%)?)$/);
+const FONT_STYLE = new RegExp(/^(normal|italic|initial|inherit|unset|(oblique( -?[0-9]?[0-9]deg)?))$/);
 
 /**
  * @alias Chart.helpers.options
@@ -95,6 +96,7 @@ export function toPadding(value) {
   return obj;
 }
 
+
 /**
  * Parses font options and returns the font object.
  * @param {object} options - A object that contains font options to be parsed.
@@ -111,12 +113,17 @@ export function toFont(options, fallback) {
   if (typeof size === 'string') {
     size = parseInt(size, 10);
   }
+  let style = valueOrDefault(options.style, fallback.style);
+  if (style && !('' + style).match(FONT_STYLE)) {
+    console.warn('Invalid font style specified: "' + style + '"');
+    style = '';
+  }
 
   const font = {
     family: valueOrDefault(options.family, fallback.family),
     lineHeight: toLineHeight(valueOrDefault(options.lineHeight, fallback.lineHeight), size),
     size,
-    style: valueOrDefault(options.style, fallback.style),
+    style,
     weight: valueOrDefault(options.weight, fallback.weight),
     string: ''
   };

src/plugins/plugin.title.js

@@ -148,7 +148,7 @@ export default {
     align: 'center',
     display: false,
     font: {
-      style: 'bold',
+      weight: 'bold',
     },
     fullSize: true,
     padding: 10,

src/plugins/plugin.tooltip.js

@@ -1143,7 +1143,7 @@ export default {
     backgroundColor: 'rgba(0,0,0,0.8)',
     titleColor: '#fff',
     titleFont: {
-      style: 'bold',
+      weight: 'bold',
     },
     titleSpacing: 2,
     titleMarginBottom: 6,
@@ -1157,7 +1157,7 @@ export default {
     footerSpacing: 2,
     footerMarginTop: 6,
     footerFont: {
-      style: 'bold',
+      weight: 'bold',
     },
     footerAlign: 'left',
     padding: 6,