Improve some null types to prepare for strictNullChecks

src/ol/style/Fill.js

@@ -4,7 +4,7 @@
 
 /**
  * @typedef {Object} Options
- * @property {import("../color.js").Color|import("../colorlike.js").ColorLike} [color=null] A color, gradient or pattern.
+ * @property {import("../color.js").Color|import("../colorlike.js").ColorLike|null} [color=null] A color, gradient or pattern.
  * See {@link module:ol/color~Color} and {@link module:ol/colorlike~ColorLike} for possible formats.
  * Default null; if null, the Canvas/renderer default black will be used.
  */
@@ -23,7 +23,7 @@ class Fill {
 
     /**
      * @private
-     * @type {import("../color.js").Color|import("../colorlike.js").ColorLike}
+     * @type {import("../color.js").Color|import("../colorlike.js").ColorLike|null}
      */
     this.color_ = options.color !== undefined ? options.color : null;
   }
@@ -42,7 +42,7 @@ class Fill {
 
   /**
    * Get the fill color.
-   * @return {import("../color.js").Color|import("../colorlike.js").ColorLike} Color.
+   * @return {import("../color.js").Color|import("../colorlike.js").ColorLike|null} Color.
    * @api
    */
   getColor() {
@@ -52,7 +52,7 @@ class Fill {
   /**
    * Set the color.
    *
-   * @param {import("../color.js").Color|import("../colorlike.js").ColorLike} color Color.
+   * @param {import("../color.js").Color|import("../colorlike.js").ColorLike|null} color Color.
    * @api
    */
   setColor(color) {

src/ol/style/Style.js

@@ -455,7 +455,7 @@ export function toFunction(obj) {
 }
 
 /**
- * @type {Array<Style>}
+ * @type {Array<Style>|null}
  */
 let defaultStyles = null;
 

src/ol/style/Text.js

@@ -168,7 +168,7 @@ class Text {
 
     /**
      * @private
-     * @type {Array<number>}
+     * @type {Array<number>|null}
      */
     this.padding_ = options.padding === undefined ? null : options.padding;
   }
@@ -201,7 +201,7 @@ class Text {
       backgroundStroke: this.getBackgroundStroke()
         ? this.getBackgroundStroke().clone()
         : undefined,
-      padding: this.getPadding(),
+      padding: this.getPadding() || undefined,
     });
   }
 
@@ -359,7 +359,7 @@ class Text {
 
   /**
    * Get the padding for the text.
-   * @return {Array<number>} Padding.
+   * @return {Array<number>|null} Padding.
    * @api
    */
   getPadding() {
@@ -530,7 +530,7 @@ class Text {
   /**
    * Set the padding (`[top, right, bottom, left]`).
    *
-   * @param {!Array<number>} padding Padding.
+   * @param {Array<number>|null} padding Padding.
    * @api
    */
   setPadding(padding) {