Use union type instead of enum for feature format

src/ol/format/Feature.js

@@ -51,6 +51,10 @@ import {
  * Default is no rounding.
  */
 
+/**
+ * @typedef {'arraybuffer' | 'json' | 'text' | 'xml'} Type
+ */
+
 /**
  * @classdesc
  * Abstract base class; normally only used for creating subclasses and not
@@ -134,7 +138,7 @@ class FeatureFormat {
 
   /**
    * @abstract
-   * @return {import("./FormatType.js").default} Format.
+   * @return {Type} The format type.
    */
   getType() {
     return abstract();

src/ol/format/FormatType.js

@@ -1,13 +0,0 @@
-/**
- * @module ol/format/FormatType
- */
-
-/**
- * @enum {string}
- */
-export default {
-  ARRAY_BUFFER: 'arraybuffer',
-  JSON: 'json',
-  TEXT: 'text',
-  XML: 'xml',
-};

src/ol/format/JSONFeature.js

@@ -2,7 +2,6 @@
  * @module ol/format/JSONFeature
  */
 import FeatureFormat from './Feature.js';
-import FormatType from './FormatType.js';
 import {abstract} from '../util.js';
 
 /**
@@ -19,10 +18,10 @@ class JSONFeature extends FeatureFormat {
   }
 
   /**
-   * @return {import("./FormatType.js").default} Format.
+   * @return {import("./Feature.js").Type} Format.
    */
   getType() {
-    return FormatType.JSON;
+    return 'json';
   }
 
   /**

src/ol/format/MVT.js

@@ -4,7 +4,6 @@
 //FIXME Implement projection handling
 
 import FeatureFormat, {transformGeometryWithOptions} from './Feature.js';
-import FormatType from './FormatType.js';
 import GeometryLayout from '../geom/GeometryLayout.js';
 import LineString from '../geom/LineString.js';
 import MultiLineString from '../geom/MultiLineString.js';
@@ -238,10 +237,10 @@ class MVT extends FeatureFormat {
   }
 
   /**
-   * @return {import("./FormatType.js").default} Format.
+   * @return {import("./Feature.js").Type} Format.
    */
   getType() {
-    return FormatType.ARRAY_BUFFER;
+    return 'arraybuffer';
   }
 
   /**

src/ol/format/TextFeature.js

@@ -2,7 +2,6 @@
  * @module ol/format/TextFeature
  */
 import FeatureFormat from '../format/Feature.js';
-import FormatType from '../format/FormatType.js';
 import {abstract} from '../util.js';
 
 /**
@@ -19,10 +18,10 @@ class TextFeature extends FeatureFormat {
   }
 
   /**
-   * @return {import("./FormatType.js").default} Format.
+   * @return {import("./Feature.js").Type} Format.
    */
   getType() {
-    return FormatType.TEXT;
+    return 'text';
   }
 
   /**

src/ol/format/WKB.js

@@ -3,7 +3,6 @@
  */
 import Feature from '../Feature.js';
 import FeatureFormat, {transformGeometryWithOptions} from './Feature.js';
-import FormatType from './FormatType.js';
 import GeometryCollection from '../geom/GeometryCollection.js';
 import GeometryLayout from '../geom/GeometryLayout.js';
 import LineString from '../geom/LineString.js';
@@ -691,10 +690,10 @@ class WKB extends FeatureFormat {
   }
 
   /**
-   * @return {import("./FormatType.js").default} Format.
+   * @return {import("./Feature.js").Type} Format.
    */
   getType() {
-    return this.hex_ ? FormatType.TEXT : FormatType.ARRAY_BUFFER;
+    return this.hex_ ? 'text' : 'arraybuffer';
   }
 
   /**

src/ol/format/XMLFeature.js

@@ -2,7 +2,6 @@
  * @module ol/format/XMLFeature
  */
 import FeatureFormat from '../format/Feature.js';
-import FormatType from '../format/FormatType.js';
 import {abstract} from '../util.js';
 import {extend} from '../array.js';
 import {getXMLSerializer, isDocument, parse} from '../xml.js';
@@ -27,10 +26,10 @@ class XMLFeature extends FeatureFormat {
   }
 
   /**
-   * @return {import("./FormatType.js").default} Format.
+   * @return {import("./Feature.js").Type} Format.
    */
   getType() {
-    return FormatType.XML;
+    return 'xml';
   }
 
   /**