Until we know what we want to return, return undefined

src/objectliterals.jsdoc

@@ -20,9 +20,9 @@
  *     information for each layer, with array indices being the same as in the
  *     passed `layers` array or in the layer collection as returned from
  *     `ol.Map#getLayers()` if no `layers` were provided.
- * @property {function(Object)|undefined} error Callback for unsuccessful
+ * @property {function()|undefined} error Callback for unsuccessful queries.
- *     queries. Note that queries with no matching features trigger the success
+ *     Note that queries with no matching features trigger the success callback,
- *     callback, not the error callback.
+ *     not the error callback.
  */
 
 /**
@@ -35,9 +35,9 @@
  *     each layer, with array indices being the same as in the passed `layers`
  *     array or in the layer collection as returned from `ol.Map#getLayers()` if
  *     no layers were provided.
- * @property {function(Object)|undefined} error Callback for unsuccessful
+ * @property {function()|undefined} error Callback for unsuccessful queries.
- *     queries. Note that queries with no matching features trigger the success
+ *     Note that queries with no matching features trigger the success callback,
- *     callback, not the error callback.
+ *     not the error callback.
  */
 
 /**
@@ -441,6 +441,8 @@
  * @property {null|string|undefined} crossOrigin crossOrigin setting for image
  *     requests.
  * @property {ol.Extent|undefined} extent Extent.
+ * @property {ol.source.WMSGetFeatureInfoOptions|undefined}
+ *     getFeatureInfoOptions Options for GetFeatureInfo.
  * @property {Object.<string,*>} params WMS request parameters. At least a
  *     `LAYERS` param is required. `STYLES` is '' by default. `VERSION` is
  *     '1.3.0' by default. `WIDTH`, `HEIGHT`, `BBOX` and `CRS` (`SRS` for WMS
@@ -500,6 +502,8 @@
  * @property {null|string|undefined} crossOrigin crossOrigin setting for image
  *     requests.
  * @property {ol.Extent|undefined} extent Extent.
+ * @property {ol.source.WMSGetFeatureInfoOptions|undefined}
+ *     getFeatureInfoOptions Options for GetFeatureInfo.
  * @property {ol.tilegrid.TileGrid|undefined} tileGrid Tile grid.
  * @property {number|undefined} maxZoom Maximum zoom.
  * @property {ol.ProjectionLike} projection Projection.
@@ -533,6 +537,16 @@
  * @property {ol.ProjectionLike} projection Projection.
  */
 
+
+/**
+ * @typedef {Object} ol.source.WMSGetFeatureInfoOptions
+ * @property {ol.source.WMSGetFeatureInfoMethod} method Method for requesting
+ *     GetFeatureInfo. Default is `ol.source.WMSGetFeatureInfoMethod.IFRAME`.
+ * @property {Object} params Params for the GetFeatureInfo request. Default is
+ *     `{'INFO_FORMAT': 'text/html'}`.
+ */
+
+
 /**
  * @typedef {Object} ol.source.WMTSOptions
  * @property {Array.<ol.Attribution>|undefined} attributions Attributions.

src/ol/renderer/maprenderer.js

@@ -106,7 +106,7 @@ ol.renderer.Map.prototype.getCanvas = goog.functions.NULL;
  *     information.  Layers that are able to provide attribute data will put
  *     ol.Feature instances, other layers will put a string which can either
  *     be plain text or markup.
- * @param {function(Object)=} opt_error Callback for unsuccessful
+ * @param {function()=} opt_error Callback for unsuccessful
  *     queries.
  */
 ol.renderer.Map.prototype.getFeatureInfoForPixel =
@@ -142,7 +142,7 @@ ol.renderer.Map.prototype.getFeatureInfoForPixel =
  *     information.  Layers that are able to provide attribute data will put
  *     ol.Feature instances, other layers will put a string which can either
  *     be plain text or markup.
- * @param {function(Object)=} opt_error Callback for unsuccessful
+ * @param {function()=} opt_error Callback for unsuccessful
  *     queries.
  */
 ol.renderer.Map.prototype.getFeaturesForPixel =