From 9da3710a32fbee80665b9c3e662327e5381fe720 Mon Sep 17 00:00:00 2001
From: jwasilgeo <jwasilkowski@esri.com>
Date: Tue, 3 Aug 2021 10:13:11 -0500
Subject: [PATCH 1/4] chore: added exported function comment documentation and
 slight reorganization

---
 src/Util.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/Util.js b/src/Util.js
index d8e2e4a..987bae3 100644
--- a/src/Util.js
+++ b/src/Util.js
@@ -1,8 +1,6 @@
 import { latLng, latLngBounds } from 'leaflet';
 import { request, Support, Util } from 'esri-leaflet';
 
-const WEB_MERCATOR_WKIDS = [3857, 102100, 102113];
-
 /*
   utility to establish a URL for the basemap styles API
   used primarily by VectorBasemapLayer.js
@@ -223,6 +221,12 @@ export function getAttributionData (url, map) {
   }
 }
 
+/*
+  utility to check if a service's tileInfo spatial reference is in Web Mercator
+  used primarily by VectorTileLayer.js
+*/
+const WEB_MERCATOR_WKIDS = [3857, 102100, 102113];
+
 export function isWebMercator (wkid) {
   return WEB_MERCATOR_WKIDS.indexOf(wkid) >= 0;
 }

From 9177081fcef1717a514b81924b1e2d23d38fdfde Mon Sep 17 00:00:00 2001
From: jwasilgeo <jwasilkowski@esri.com>
Date: Tue, 3 Aug 2021 10:17:45 -0500
Subject: [PATCH 2/4] `formatStyle`: changed to be more forgiving if the
 optional `style.sprite` or `style.glyphs` properties do not exist

---
 src/Util.js | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/src/Util.js b/src/Util.js
index 987bae3..9128500 100644
--- a/src/Util.js
+++ b/src/Util.js
@@ -160,24 +160,27 @@ export function formatStyle (style, styleUrl, metadata, token) {
     }
   }
 
-  // resolve absolute URLs for style.sprite and style.glyphs
-  if (style.sprite.indexOf('http') === -1) {
+  if (style.sprite && style.sprite.indexOf('http') === -1) {
+    // resolve absolute URL for style.sprite
     style.sprite = styleUrl.replace(
       'styles/root.json',
       style.sprite.replace('../', '')
     );
+
+    // add the token to the style.sprite property as a query param
+    style.sprite += token ? '?token=' + token : '';
   }
 
-  if (style.glyphs.indexOf('http') === -1) {
+  if (style.glyphs && style.glyphs.indexOf('http') === -1) {
+    // resolve absolute URL for style.glyphs
     style.glyphs = styleUrl.replace(
       'styles/root.json',
       style.glyphs.replace('../', '')
     );
-  }
 
-  // add the token to the style.sprite and style.glyphs properties as a query param
-  style.sprite += token ? '?token=' + token : '';
-  style.glyphs += token ? '?token=' + token : '';
+    // add the token to the style.glyphs property as a query param
+    style.glyphs += token ? '?token=' + token : '';
+  }
 
   return style;
 }

From e2ad67fd3f9c02cf4acd5458d1cd047a48ea3186 Mon Sep 17 00:00:00 2001
From: jwasilgeo <jwasilkowski@esri.com>
Date: Fri, 6 Aug 2021 15:29:12 -0500
Subject: [PATCH 3/4] `loadStyleFromService` and `formatStyle`: cleaned up
 known areas where and extra "/" might be present and lead to invalid paths

---
 src/Util.js | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/Util.js b/src/Util.js
index 9128500..0d10ed8 100644
--- a/src/Util.js
+++ b/src/Util.js
@@ -80,15 +80,20 @@ function loadStyleFromService (serviceUrl, options, callback) {
       console.error(error);
     }
 
+    var sanitizedServiceUrl = serviceUrl;
+    // a trailing "/" may create invalid paths
+    if (serviceUrl.charAt(serviceUrl.length - 1) === '/') {
+      sanitizedServiceUrl = serviceUrl.slice(0, serviceUrl.length - 1);
+    }
+
     var defaultStylesUrl;
-    if (
-      serviceUrl.charAt(0) !== '/' &&
-      service.defaultStyles.charAt(service.defaultStyles.length - 1) !== '/'
-    ) {
+    // inadvertently inserting more than 1 adjacent "/" may create invalid paths
+    if (service.defaultStyles.charAt(0) === '/') {
       defaultStylesUrl =
-        serviceUrl + '/' + service.defaultStyles + '/root.json';
+        sanitizedServiceUrl + service.defaultStyles + '/root.json';
     } else {
-      defaultStylesUrl = serviceUrl + service.defaultStyles + '/root.json';
+      defaultStylesUrl =
+        sanitizedServiceUrl + '/' + service.defaultStyles + '/root.json';
     }
 
     loadStyleFromUrl(defaultStylesUrl, options, function (error, style) {
@@ -118,6 +123,11 @@ export function formatStyle (style, styleUrl, metadata, token) {
       source.url = styleUrl.replace('/resources/styles/root.json', '');
     }
 
+    // a trailing "/" may create invalid paths
+    if (source.url.charAt(source.url.length - 1) === '/') {
+      source.url = source.url.slice(0, source.url.length - 1);
+    }
+
     // add tiles property if missing
     if (!source.tiles) {
       // right now ArcGIS Pro published vector services have a slightly different signature

From 62e4ae18fc07433cc5c9e0063b2e29dbac1441ff Mon Sep 17 00:00:00 2001
From: jwasilgeo <jwasilkowski@esri.com>
Date: Fri, 6 Aug 2021 15:43:38 -0500
Subject: [PATCH 4/4] updated CHANGELOG

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 692df41..9a9920b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 * Updated peerDependencies to be more flexible for using v3 of `esri-leaflet`. [#99](https://github.com/Esri/esri-leaflet-vector/pull/99)
 
+### Fixed
+
+* Utility functions used by `L.esri.Vector.vectorTileLayer` have been improved to be more friendly with URL structures and style reformatting assumptions. [#100](https://github.com/Esri/esri-leaflet-vector/pull/100)
+
 ## [3.0.1] - 2021-06-03
 
 ### Fixed