Fix the division bug in uploaded size, #173

src/flow.js

@@ -1435,7 +1435,7 @@
       } else if (s === 'pending') {
         return 0;
       } else {
-        return this.total > 0 ? this.loaded / this.total : 0;
+        return getSuccessProgress(this.loaded, this.total);
       }
     },
 
@@ -1448,7 +1448,9 @@
       var size = this.endByte - this.startByte;
       // can't return only chunk.loaded value, because it is bigger than chunk size
       if (this.status() !== 'success') {
-        size = this.progress() * size;
+        // Multiply integers before computing progress to prevent floating point issue
+        // https://github.com/flowjs/flow.js/issues/173
+        return getSuccessProgress(this.loaded * size, this.total);
       }
       return size;
     },
@@ -1534,6 +1536,16 @@
     setTimeout(fn.bind(context), 0);
   }
 
+  /**
+   * Get the progress from loaded and total sizes
+   * @function
+   * @param {number} loaded Number of uploaded bytes
+   * @param {number} total Number of total bytes to be uploaded
+   */
+  function getSuccessProgress(loaded, total) {
+    return total > 0 ? loaded / total : 0;
+  }
+
   /**
    * Extends the destination object `dst` by copying all of the properties from
    * the `src` object(s) to `dst`. You can specify multiple `src` objects.

test/uploadSpec.js

@@ -552,6 +552,37 @@ describe('upload file', function() {
     expect(flow.timeRemaining()).toBe(0);
   });
 
+  // Related issue: https://github.com/flowjs/flow.js/issues/173
+  it('should provide the sizeUploaded() number in integer format', function () {
+
+    flow.opts.testChunks = false;
+
+    // The size 49 was chosen because it's the smallest number causing the division precision bug on my system:
+    // var foo = 1 / 49; => 0.02040816326530612
+    // var bar = 49 * foo; => 0.9999999999999999
+    var fileSize = 49;
+
+    var str = '';
+
+    for (var i = 0; i < fileSize; i++) {
+      str += 'X';
+    }
+
+    flow.addFile(new Blob([str]));
+
+    var fileFirst = flow.files[0];
+
+    expect(fileFirst.sizeUploaded()).toBe(0);
+    expect(flow.sizeUploaded()).toBe(0);
+
+    flow.upload();
+
+    requests[0].progress(1, fileSize, true);
+    expect(fileFirst.sizeUploaded()).toBe(1);
+
+    flow.cancel();
+  });
+
   it('should allow to hook initFileFn and readFileFn', function () {
     var error = jasmine.createSpy('error');
     var success = jasmine.createSpy('success');