Add and improve tests

src/ol/render/canvas.js

@@ -121,6 +121,7 @@ ol.render.canvas.textHeights_ = {};
  * @param {string} fontSpec CSS font spec.
  */
 ol.render.canvas.checkFont = (function() {
+  var retries = 60;
   var checked = ol.render.canvas.checkedFonts_;
   var labelCache = ol.render.canvas.labelCache;
   var font = '32px monospace';
@@ -146,13 +147,13 @@ ol.render.canvas.checkFont = (function() {
   function check() {
     var done = true;
     for (var font in checked) {
-      if (checked[font] < 60) {
+      if (checked[font] < retries) {
         if (isAvailable(font)) {
-          checked[font] = 60;
+          checked[font] = retries;
-          labelCache.clear();
           ol.obj.clear(ol.render.canvas.textHeights_);
           // Make sure that loaded fonts are picked up by Safari
           ol.render.canvas.measureContext_ = null;
+          labelCache.clear();
         } else {
           ++checked[font];
           done = false;
@@ -173,7 +174,7 @@ ol.render.canvas.checkFont = (function() {
     for (var i = 0, ii = fontFamilies.length; i < ii; ++i) {
       var fontFamily = fontFamilies[i];
       if (!(fontFamily in checked)) {
-        checked[fontFamily] = 60;
+        checked[fontFamily] = retries;
         if (!isAvailable(fontFamily)) {
           checked[fontFamily] = 0;
           if (interval === undefined) {

test/spec/ol/render/canvas/index.test.js

@@ -12,56 +12,72 @@ describe('ol.render.canvas', function() {
 
   describe('ol.render.canvas.checkFont()', function() {
 
+    beforeEach(function() {
+      ol.obj.clear(ol.render.canvas.checkedFonts_);
+      ol.render.canvas.getMeasureContext();
+      ol.render.canvas.measureTextHeight('12px sans-serif');
+    });
+
     var checkFont = ol.render.canvas.checkFont;
+    var retries = 60;
 
-    it('does not clear the label cache for unavailable fonts', function(done) {
+    it('does not clear label cache and measurements for unavailable fonts', function(done) {
-      ol.obj.clear(ol.render.canvas.checkedFonts_);
+      this.timeout(3000);
       var spy = sinon.spy();
       ol.events.listen(ol.render.canvas.labelCache, 'clear', spy);
+      var interval = setInterval(function() {
+        if (ol.render.canvas.checkedFonts_['foo'] == retries && ol.render.canvas.checkedFonts_['sans-serif'] == retries) {
+          clearInterval(interval);
+          ol.events.unlisten(ol.render.canvas.labelCache, 'clear', spy);
+          expect(spy.callCount).to.be(0);
+          expect(ol.render.canvas.measureContext_).to.not.be(null);
+          expect(ol.render.canvas.textHeights_).to.not.eql({});
+          done();
+        }
+      }, 32);
       checkFont('12px foo,sans-serif');
-      setTimeout(function() {
-        ol.events.unlisten(ol.render.canvas.labelCache, 'clear', spy);
-        expect(spy.callCount).to.be(0);
-        done();
-      }, 1600);
     });
 
-    it('does not clear the label cache for available fonts', function(done) {
+    it('does not clear label cache and measurements for available fonts', function(done) {
-      ol.obj.clear(ol.render.canvas.checkedFonts_);
       var spy = sinon.spy();
       ol.events.listen(ol.render.canvas.labelCache, 'clear', spy);
+      var interval = setInterval(function() {
+        if (ol.render.canvas.checkedFonts_['sans-serif'] == retries) {
+          clearInterval(interval);
+          ol.events.unlisten(ol.render.canvas.labelCache, 'clear', spy);
+          expect(spy.callCount).to.be(0);
+          expect(ol.render.canvas.measureContext_).to.not.be(null);
+          expect(ol.render.canvas.textHeights_).to.not.eql({});
+          done();
+        }
+      }, 32);
       checkFont('12px sans-serif');
-      setTimeout(function() {
-        ol.events.unlisten(ol.render.canvas.labelCache, 'clear', spy);
-        expect(spy.callCount).to.be(0);
-        done();
-      }, 800);
     });
 
-    it('does not clear the label cache for the \'monospace\' font', function(done) {
+    it('does not clear label cache and measurements for the \'monospace\' font', function(done) {
-      ol.obj.clear(ol.render.canvas.checkedFonts_);
       var spy = sinon.spy();
       ol.events.listen(ol.render.canvas.labelCache, 'clear', spy);
+      var interval = setInterval(function() {
+        if (ol.render.canvas.checkedFonts_['monospace'] == retries) {
+          clearInterval(interval);
+          ol.events.unlisten(ol.render.canvas.labelCache, 'clear', spy);
+          expect(spy.callCount).to.be(0);
+          expect(ol.render.canvas.measureContext_).to.not.be(null);
+          expect(ol.render.canvas.textHeights_).to.not.eql({});
+          done();
+        }
+      }, 32);
       checkFont('12px monospace');
-      setTimeout(function() {
-        ol.events.unlisten(ol.render.canvas.labelCache, 'clear', spy);
-        expect(spy.callCount).to.be(0);
-        done();
-      }, 800);
     });
 
-    it('clears the label cache for fonts that become available', function(done) {
+    it('clears label cache and measurements for fonts that become available', function(done) {
-      ol.obj.clear(ol.render.canvas.checkedFonts_);
       head.appendChild(font);
-      var spy = sinon.spy();
+      ol.events.listen(ol.render.canvas.labelCache, 'clear', function() {
-      ol.events.listen(ol.render.canvas.labelCache, 'clear', spy);
+        expect(ol.render.canvas.measureContext_).to.be(null);
-      checkFont('12px Abel');
+        expect(ol.render.canvas.textHeights_).to.eql({});
-      setTimeout(function() {
-        ol.events.unlisten(ol.render.canvas.labelCache, 'clear', spy);
-        head.removeChild(font);
-        expect(spy.callCount).to.be(1);
         done();
-      }, 1600);
+      });
+      checkFont('12px Abel');
     });
 
   });