fix: float decimal (single-percision) detection

Author: usernmae0101

lib/BufferEncoder.js

@@ -92,11 +92,10 @@ BufferEncoder.prototype.encode = function(key, val, index) {
  * @param {Number} index
  */
 BufferEncoder.prototype._asFloat = function(val, index) {
-    // TODO: bad detection
-    var valLen = val.toString().split('.')[1].length;
+    var isFloat32 = (Math.fround(val) === val);
 
     // Float.
-    if (valLen <= 6) {
+    if (isFloat32) {
         this._setMark(marks.DEFAULT_MARK_FLOAT, index);
         this._toFloat32(val);
     }

test/BufferEncoder.test.js

@@ -114,8 +114,8 @@ describe("BufferEncoder", () => {
         expect(bufferEncoder._offset).toBe(16);
     });
 
-    it("encodes 1.234567 as 5 bytes (float with mark)", () => {
-        bufferEncoder.encode(undefined, 1.234567);
+    it("encodes 123.45600128173828 as 5 bytes (float with mark)", () => {
+        bufferEncoder.encode(undefined, 123.45600128173828);
         expect(bufferEncoder._offset).toBe(5);
     });