Add tests for svgToImg

lib/svg-to-img.js

@@ -11,6 +11,7 @@ module.exports = function (svg, format, out, cb) {
   if (imgCache.has(cacheIndex)) {
     // We own a cache for this svg conversion.
     (new DataStream(imgCache.get(cacheIndex))).pipe(out);
+    cb && cb();
     return;
   }
 
@@ -28,6 +29,9 @@ module.exports = function (svg, format, out, cb) {
   });
 };
 
+// To simplify testing.
+module.exports._imgCache = imgCache;
+
 // Fake stream from the cache.
 var Readable = require('stream').Readable;
 var util = require('util');

package.json

@@ -58,6 +58,8 @@
     "eslint": "^3.18.0",
     "is-png": "^1.0.0",
     "is-svg": "^2.1.0",
-    "mocha": "^3.2.0"
+    "memory-streams": "^0.1.2",
+    "mocha": "^3.2.0",
+    "sinon": "^2.1.0"
   }
 }

test/svg-to-img.spec.js

@@ -0,0 +1,43 @@
+const assert = require('assert');
+const sinon = require('sinon');
+const WritableStream = require('memory-streams').WritableStream;
+const isPng = require('is-png');
+
+const badge = require('../lib/badge');
+const svg2img = require('../lib/svg-to-img.js');
+
+describe('The rasterizer', function () {
+  let cacheGet;
+  beforeEach(function () { cacheGet = sinon.spy(svg2img._imgCache, 'get'); });
+  afterEach(function () { cacheGet.restore(); });
+
+  it('should produce PNG', function(done) {
+    badge({ text: ['cactus', 'grown'], format: 'svg' }, svg => {
+      const out = new WritableStream();
+
+      svg2img(svg, 'png', out, () => {
+        assert.ok(isPng(out.toBuffer()));
+        done();
+      });
+    });
+  });
+
+  it('should cache its results', function(done) {
+    badge({ text: ['will-this', 'be-cached?'], format: 'svg' }, svg => {
+      const out1 = new WritableStream();
+      const out2 = new WritableStream();
+
+      svg2img(svg, 'png', out1, () => {
+        assert.ok(isPng(out1.toBuffer()));
+        assert.equal(cacheGet.called, false);
+
+        svg2img(svg, 'png', out2, () => {
+          assert.ok(isPng(out2.toBuffer()));
+          assert.ok(cacheGet.calledOnce);
+
+          done();
+        });
+      });
+    });
+  });
+});