Improve type checking in ol.ResolutionConstraint

src/ol/resolutionconstraint.js

@@ -20,14 +20,21 @@ ol.ResolutionConstraintType;
 ol.ResolutionConstraint.createContinuous =
     function(power, maxResolution, opt_minResolution) {
   var minResolution = opt_minResolution || 0;
-  return function(resolution, delta, direction) {
+  return (
+      /**
+       * @param {number|undefined} resolution Resolution.
+       * @param {number} delta Delta.
+       * @param {number} direction Direction.
+       * @return {number|undefined} Resolution.
+       */
+      function(resolution, delta, direction) {
         if (goog.isDef(resolution)) {
           resolution /= Math.pow(power, delta);
           return goog.math.clamp(resolution, minResolution, maxResolution);
         } else {
           return undefined;
         }
-  };
+      });
 };
 
 
@@ -37,15 +44,23 @@ ol.ResolutionConstraint.createContinuous =
  */
 ol.ResolutionConstraint.createSnapToResolutions =
     function(resolutions) {
-  return function(resolution, delta, direction) {
+  return (
+      /**
+       * @param {number|undefined} resolution Resolution.
+       * @param {number} delta Delta.
+       * @param {number} direction Direction.
+       * @return {number|undefined} Resolution.
+       */
+      function(resolution, delta, direction) {
         if (goog.isDef(resolution)) {
-      var z = ol.array.linearFindNearest(resolutions, resolution, direction);
+          var z =
+              ol.array.linearFindNearest(resolutions, resolution, direction);
           z = goog.math.clamp(z + delta, 0, resolutions.length - 1);
           return resolutions[z];
         } else {
           return undefined;
         }
-  };
+      });
 };
 
 
@@ -57,7 +72,14 @@ ol.ResolutionConstraint.createSnapToResolutions =
  */
 ol.ResolutionConstraint.createSnapToPower =
     function(power, maxResolution, opt_maxLevel) {
-  return function(resolution, delta, direction) {
+  return (
+      /**
+       * @param {number|undefined} resolution Resolution.
+       * @param {number} delta Delta.
+       * @param {number} direction Direction.
+       * @return {number|undefined} Resolution.
+       */
+      function(resolution, delta, direction) {
         if (goog.isDef(resolution)) {
           var offset;
           if (direction > 0) {
@@ -77,5 +99,5 @@ ol.ResolutionConstraint.createSnapToPower =
         } else {
           return undefined;
         }
-  };
+      });
 };