Fix tree-shake issue

Author: giswqs

examples/basic/main.ts

@@ -1,8 +1,11 @@
 /// <reference path="../../src/types.d.ts" />
 
 import maplibregl from 'maplibre-gl';
-import '../../src/index'; // Import to extend Map.prototype
+import { extendMapPrototype } from '../../src/index';
 import 'maplibre-gl/dist/maplibre-gl.css';
+
+// Explicitly extend Map.prototype to ensure it's not tree-shaken in production builds
+extendMapPrototype();
 import { LayerControl } from 'maplibre-gl-layer-control';
 import 'maplibre-gl-layer-control/style.css';
 import type { BasemapName } from '../../src/lib/basemaps/types';

examples/cog-simple/main.ts

@@ -8,9 +8,12 @@
 /// <reference path="../../src/types.d.ts" />
 
 import maplibregl from 'maplibre-gl';
-import '../../src/index'; // Import to extend Map.prototype
+import { extendMapPrototype } from '../../src/index';
 import { COGLayerAdapter } from '../../src/lib/layers';
 import 'maplibre-gl/dist/maplibre-gl.css';
+
+// Explicitly extend Map.prototype to ensure it's not tree-shaken in production builds
+extendMapPrototype();
 import { LayerControl } from 'maplibre-gl-layer-control';
 import 'maplibre-gl-layer-control/style.css';
 

examples/cog/main.ts

@@ -1,9 +1,12 @@
 /// <reference path="../../src/types.d.ts" />
 
 import maplibregl from 'maplibre-gl';
-import '../../src/index'; // Import to extend Map.prototype
+import { extendMapPrototype } from '../../src/index';
 import { COGLayerAdapter } from '../../src/lib/layers';
 import 'maplibre-gl/dist/maplibre-gl.css';
+
+// Explicitly extend Map.prototype to ensure it's not tree-shaken in production builds
+extendMapPrototype();
 import { LayerControl } from 'maplibre-gl-layer-control';
 import 'maplibre-gl-layer-control/style.css';
 

examples/react/main.tsx

@@ -4,9 +4,12 @@ import React, { useState, useEffect, useRef } from 'react';
 import { createRoot } from 'react-dom/client';
 import maplibregl, { Map } from 'maplibre-gl';
 import 'maplibre-gl/dist/maplibre-gl.css';
-import { MapExtendProvider, useMapExtend } from '../../src/react';
+import { MapExtendProvider, useMapExtend, extendMapPrototype } from '../../src/react';
 import type { BasemapName } from '../../src/lib/basemaps/types';
 
+// Explicitly extend Map.prototype to ensure it's not tree-shaken in production builds
+extendMapPrototype();
+
 // Sample GeoJSON data
 const sampleGeojson = {
   type: 'FeatureCollection' as const,

examples/zarr-simple/main.ts

@@ -8,9 +8,12 @@
 /// <reference path="../../src/types.d.ts" />
 
 import maplibregl from 'maplibre-gl';
-import '../../src/index'; // Import to extend Map.prototype
+import { extendMapPrototype } from '../../src/index';
 import { ZarrLayerAdapter, getZarrLayersMap } from '../../src/lib/layers';
 import 'maplibre-gl/dist/maplibre-gl.css';
+
+// Explicitly extend Map.prototype to ensure it's not tree-shaken in production builds
+extendMapPrototype();
 import { LayerControl } from 'maplibre-gl-layer-control';
 import 'maplibre-gl-layer-control/style.css';
 import type { ZarrLayer } from '@carbonplan/zarr-layer';

examples/zarr/main.ts

@@ -1,9 +1,12 @@
 /// <reference path="../../src/types.d.ts" />
 
 import maplibregl from 'maplibre-gl';
-import '../../src/index'; // Import to extend Map.prototype
+import { extendMapPrototype } from '../../src/index';
 import { ZarrLayerAdapter, getZarrLayersMap } from '../../src/lib/layers';
 import 'maplibre-gl/dist/maplibre-gl.css';
+
+// Explicitly extend Map.prototype to ensure it's not tree-shaken in production builds
+extendMapPrototype();
 import { LayerControl } from 'maplibre-gl-layer-control';
 import 'maplibre-gl-layer-control/style.css';
 import type { ZarrLayer } from '@carbonplan/zarr-layer';

src/index.ts

@@ -40,11 +40,25 @@ import {
 
 // Note: Module augmentation for Map is in types.d.ts
 
+// Track if prototype has been extended to avoid duplicate extensions
+let prototypeExtended = false;
+
 /**
  * Extend the MapLibre GL Map prototype with convenience methods.
- * This function is called automatically when the module is imported.
+ * This function is called automatically when the module is imported,
+ * but can also be called explicitly to ensure reliable prototype extension
+ * in production builds where tree-shaking might occur.
+ * 
+ * It's safe to call this function multiple times - it will only extend
+ * the prototype once.
+ * 
+ * @returns true if the prototype was extended, false if already extended
  */
-function extendMapPrototype(): void {
+export function extendMapPrototype(): boolean {
+  if (prototypeExtended) {
+    return false;
+  }
+  prototypeExtended = true;
   // Basemap methods
   Map.prototype.addBasemap = function (name) {
     return addBasemap(this, name);
@@ -160,6 +174,8 @@ function extendMapPrototype(): void {
   Map.prototype.removeZarrLayer = function (layerId) {
     return removeZarrLayer(this, layerId);
   };
+
+  return true;
 }
 
 // Extend Map.prototype when module is imported