Use String#startsWith instead of String#indexOf

src/ol/color.js

@@ -168,11 +168,11 @@ function fromStringInternal_(s) {
       }
     }
     color = [r, g, b, a / 255];
-  } else if (s.indexOf('rgba(') == 0) {
+  } else if (s.startsWith('rgba(')) {
     // rgba()
     color = s.slice(5, -1).split(',').map(Number);
     normalize(color);
-  } else if (s.indexOf('rgb(') == 0) {
+  } else if (s.startsWith('rgb(')) {
     // rgb()
     color = s.slice(4, -1).split(',').map(Number);
     color.push(1);
@@ -225,7 +225,5 @@ export function isStringColor(s) {
   if (NAMED_COLOR_RE_.test(s)) {
     s = fromNamed(s);
   }
-  return (
-    HEX_COLOR_RE_.test(s) || s.indexOf('rgba(') === 0 || s.indexOf('rgb(') === 0
-  );
+  return HEX_COLOR_RE_.test(s) || s.startsWith('rgba(') || s.startsWith('rgb(');
 }

src/ol/format/WFS.js

@@ -822,7 +822,7 @@ function getTypeName(featurePrefix, featureType) {
   featurePrefix = featurePrefix ? featurePrefix : FEATURE_PREFIX;
   const prefix = featurePrefix + ':';
   // The featureType already contains the prefix.
-  if (featureType.indexOf(prefix) === 0) {
+  if (featureType.startsWith(prefix)) {
     return featureType;
   } else {
     return prefix + featureType;

src/ol/format/WKB.js

@@ -864,7 +864,7 @@ class WKB extends FeatureFormat {
         options.dataProjection && getProjection(options.dataProjection);
       if (dataProjection) {
         const code = dataProjection.getCode();
-        if (code.indexOf('EPSG:') === 0) {
+        if (code.startsWith('EPSG:')) {
           srid = Number(code.substring(5));
         }
       }

src/ol/source/ogcTileUtil.js

@@ -114,7 +114,7 @@ export function getMapTileUrlTemplate(links, mediaType) {
       }
       if (knownMapMediaTypes[link.type]) {
         fallbackUrlTemplate = link.href;
-      } else if (!fallbackUrlTemplate && link.type.indexOf('image/') === 0) {
+      } else if (!fallbackUrlTemplate && link.type.startsWith('image/')) {
         fallbackUrlTemplate = link.href;
       }
     }