Replace instanceof checks with other logic

src/ol/style/Fill.js

@@ -76,13 +76,15 @@ class Fill {
    */
   getChecksum() {
     if (this.checksum_ === undefined) {
-      if (
-        this.color_ instanceof CanvasPattern ||
-          this.color_ instanceof CanvasGradient
-      ) {
-        this.checksum_ = getUid(this.color_).toString();
+      const color = this.color_;
+      if (color) {
+        if (Array.isArray(color) || typeof color == 'string') {
+          this.checksum_ = 'f' + asString(/** @type {import("../Color.js").Color|string} */ (color));
+        } else {
+          this.checksum_ = getUid(this.color_).toString();
+        }
       } else {
-        this.checksum_ = 'f' + (this.color_ ? asString(this.color_) : '-');
+        this.checksum_ = 'f-';
       }
     }
 

src/ol/style/Icon.js

@@ -149,7 +149,7 @@ class Icon extends ImageStyle {
       5); // `imgSize` must be set when `image` is provided
 
     if ((src === undefined || src.length === 0) && image) {
-      src = image instanceof HTMLImageElement && image.src || getUid(image).toString();
+      src = /** @type {HTMLImageElement} */ (image).src || getUid(image).toString();
     }
     assert(src !== undefined && src.length > 0,
       6); // A defined and non-empty `src` or `image` must be provided

src/ol/style/IconImage.js

@@ -34,8 +34,8 @@ class IconImage extends EventTarget {
      */
     this.image_ = !image ? new Image() : image;
 
-    if (crossOrigin !== null && this.image_ instanceof HTMLImageElement) {
-      this.image_.crossOrigin = crossOrigin;
+    if (crossOrigin !== null) {
+      /** @type {HTMLImageElement} */ (this.image_).crossOrigin = crossOrigin;
     }
 
     /**

src/ol/style/Style.js

@@ -87,7 +87,6 @@
  * ```
  */
 import {assert} from '../asserts.js';
-import Geometry from '../geom/Geometry.js';
 import GeometryType from '../geom/GeometryType.js';
 import CircleStyle from '../style/Circle.js';
 import Fill from '../style/Fill.js';
@@ -103,6 +102,10 @@ import Stroke from '../style/Stroke.js';
  * @typedef {function(import("../Feature.js").FeatureLike, number):(Style|Array<Style>)} StyleFunction
  */
 
+/**
+ * A {@link Style}, an array of {@link Style}, or a {@link StyleFunction}.
+ * @typedef {Style|Array<Style>|StyleFunction} StyleLike
+ */
 
 /**
  * A function that takes an {@link module:ol/Feature} as argument and returns an
@@ -137,7 +140,6 @@ import Stroke from '../style/Stroke.js';
  * @property {number} [zIndex] Z index.
  */
 
-
 /**
  * @classdesc
  * Container for vector feature rendering styles. Any changes made to the style
@@ -214,8 +216,8 @@ class Style {
    */
   clone() {
     let geometry = this.getGeometry();
-    if (geometry instanceof Geometry) {
-      geometry = geometry.clone();
+    if (geometry && typeof geometry === 'object') {
+      geometry = /** @type {import("../geom/Geometry.js").default} */ (geometry).clone();
     }
     return new Style({
       geometry: geometry,
@@ -411,9 +413,10 @@ export function toFunction(obj) {
     if (Array.isArray(obj)) {
       styles = obj;
     } else {
-      assert(obj instanceof Style,
+      assert(typeof /** @type {?} */ (obj).getZIndex === 'function',
         41); // Expected an `Style` or an array of `Style`
-      styles = [obj];
+      const style = /** @type {Style} */ (obj);
+      styles = [style];
     }
     styleFunction = function() {
       return styles;