Split out SVG serialization+quirks-mode conversion

I may be going a bit overboard with the exports here.

src/index.js

@@ -2,7 +2,9 @@ const SVGRenderer = require('./svg-renderer');
 const BitmapAdapter = require('./bitmap-adapter');
 const inlineSvgFonts = require('./font-inliner');
 const loadSvgString = require('./load-svg-string');
+const serializeSvgToString = require('./serialize-svg-to-string');
 const SvgElement = require('./svg-element');
+const V2SVGAdapter = require('./v2-svg-adapter');
 const convertFonts = require('./font-converter');
 // /**
 //  * Export for NPM & Node.js
@@ -13,6 +15,8 @@ module.exports = {
     convertFonts: convertFonts,
     inlineSvgFonts: inlineSvgFonts,
     loadSvgString: loadSvgString,
+    serializeSvgToString: serializeSvgToString,
     SvgElement: SvgElement,
-    SVGRenderer: SVGRenderer
+    SVGRenderer: SVGRenderer,
+    V2SVGAdapter: V2SVGAdapter
 };

src/serialize-svg-to-string.js

@@ -0,0 +1,19 @@
+const inlineSvgFonts = require('./font-inliner');
+
+/**
+ * Serialize a given SVG DOM to a string.
+ * @param {SVGSVGElement} svgTag The SVG element to serialize.
+ * @param {?boolean} shouldInjectFonts True if fonts should be included in the SVG as
+ *     base64 data.
+ * @returns {string} String representing current SVG data.
+ */
+const serializeSvgToString = (svgTag, shouldInjectFonts) => {
+    const serializer = new XMLSerializer();
+    let string = serializer.serializeToString(svgTag);
+    if (shouldInjectFonts) {
+        string = inlineSvgFonts(string);
+    }
+    return string;
+};
+
+module.exports = serializeSvgToString;

src/svg-renderer.js

@@ -1,5 +1,5 @@
-const inlineSvgFonts = require('./font-inliner');
 const loadSvgString = require('./load-svg-string');
+const serializeSvgToString = require('./serialize-svg-to-string');
 
 /**
  * Main quirks-mode SVG rendering code.
@@ -124,14 +124,10 @@ class SvgRenderer {
      * @param {?boolean} shouldInjectFonts True if fonts should be included in the SVG as
      *     base64 data.
      * @returns {string} String representing current SVG data.
+     * @deprecated Use the standalone `serializeSvgToString` export instead.
      */
     toString (shouldInjectFonts) {
-        const serializer = new XMLSerializer();
-        let string = serializer.serializeToString(this._svgTag);
-        if (shouldInjectFonts) {
-            string = inlineSvgFonts(string);
-        }
-        return string;
+        return serializeSvgToString(this._svgTag, shouldInjectFonts);
     }
 
     /**

src/v2-svg-adapter.js

@@ -0,0 +1,9 @@
+const loadSvgString = require('./load-svg-string');
+const serializeSvgToString = require('./serialize-svg-to-string');
+
+/**
+ * Convert a version 2 SVG (Scratch 2.0 "quirks mode") to a version 3 svg (complies with normal SVG standards).
+ * @param {string} svgString the SVG string to convert from version 2 SVG.
+ * @returns {string} the converted SVG string.
+ */
+module.exports = svgString => serializeSvgToString(loadSvgString(svgString, true /* fromVersion2 */));