Add size support for svg

Solve #2

src/image.js

@@ -6,7 +6,7 @@ const Color = require('color')
 const svg = require('./svg')
 const helper = require('./helper')
 
-function generateGradient(username) {
+function generateGradient(username, size) {
   const hash = crypto.createHash('md5').update(username).digest('hex')
 
   let firstColor = helper.hashStringToColor(hash)
@@ -26,19 +26,25 @@ function generateGradient(username) {
   let avatar = svg.replace('$FIRST', firstColor.hex())
   avatar = avatar.replace('$SECOND', helper.getMatchingColor(firstColor).hex())
 
+  avatar = avatar.replace(/(\$SIZE)/g, size)
+
   return avatar
 }
 
-exports.generateSVG = function (username) {
-  return generateGradient(username)
+function parseSize(size) {
+  if (size && size.match(/^-?\d+$/)) {
+    return parseInt(size, 10)
+  }
+  return 120
+}
+
+exports.generateSVG = function (username, size) {
+  size = parseSize(size)
+  return generateGradient(username, size)
 }
 
 exports.generatePNG = function (username, size) {
-  size = size || '120'
-  const maxSize = 1000
-  if (size && size.match(/^-?\d+$/) && size <= maxSize) {
-    size = parseInt(size, 10)
-  }
-  const svg = generateGradient(username)
-  return sharp(new Buffer(svg)).resize(size, size).png()
+  size = parseSize(size)
+  const svg = generateGradient(username, size)
+  return sharp(new Buffer(svg)).png()
 }

src/index.js

@@ -5,7 +5,6 @@ const pngExt = /\.png$/;
 
 module.exports = (req, res) => {
   let {pathname, query} = url.parse(req.url, true)
-
   if (pathname === '/favicon.ico') {
     return ''
   }
@@ -16,7 +15,7 @@ module.exports = (req, res) => {
   }
   if (query.type === 'svg' || svgExt.test(pathname)) {
     res.setHeader('Content-Type', 'image/svg+xml')
-    return image.generateSVG(pathname.replace(svgExt, ''));
+    return image.generateSVG(pathname.replace(svgExt, ''), query.size);
   }
   res.setHeader('Content-Type', 'image/png')
   return image.generatePNG(pathname.replace(pngExt, ''), query.size)

src/svg.js

@@ -1,6 +1,6 @@
 module.exports = `<?xml version="1.0" standalone="no"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
-<svg width="120" height="120" viewBox="120 120 120 120" version="1.1" xmlns="http://www.w3.org/2000/svg">
+<svg width="$SIZE" height="$SIZE" viewBox="120 120 120 120" version="1.1" xmlns="http://www.w3.org/2000/svg">
   <g>
     <defs>
       <linearGradient id="avatar" x1="0" y1="0" x2="1" y2="1">