refactor: replace indexOf with equivalent includes and startsWith

packages/vega-event-selector/src/event-selector.js

@@ -48,8 +48,8 @@ function find(s, i, endChar, pushChar, popChar) {
   for (; i < n; ++i) {
     c = s[i];
     if (!count && c === endChar) return i;
-    else if (popChar && popChar.indexOf(c) >= 0) --count;
-    else if (pushChar && pushChar.indexOf(c) >= 0) ++count;
+    else if (popChar && popChar.includes(c)) --count;
+    else if (pushChar && pushChar.includes(c)) ++count;
   }
   return i;
 }

packages/vega-expression/src/parser.js

@@ -111,18 +111,18 @@ function isDecimalDigit(ch) {
 }
 
 function isHexDigit(ch) {
-  return '0123456789abcdefABCDEF'.indexOf(ch) >= 0;
+  return '0123456789abcdefABCDEF'.includes(ch);
 }
 
 function isOctalDigit(ch) {
-  return '01234567'.indexOf(ch) >= 0;
+  return '01234567'.includes(ch);
 }
 
 // 7.2 White Space
 
 function isWhiteSpace(ch) {
   return (ch === 0x20) || (ch === 0x09) || (ch === 0x0B) || (ch === 0x0C) || (ch === 0xA0) ||
-    (ch >= 0x1680 && [0x1680, 0x180E, 0x2000, 0x2001, 0x2002, 0x2003, 0x2004, 0x2005, 0x2006, 0x2007, 0x2008, 0x2009, 0x200A, 0x202F, 0x205F, 0x3000, 0xFEFF].indexOf(ch) >= 0);
+    (ch >= 0x1680 && [0x1680, 0x180E, 0x2000, 0x2001, 0x2002, 0x2003, 0x2004, 0x2005, 0x2006, 0x2007, 0x2008, 0x2009, 0x200A, 0x202F, 0x205F, 0x3000, 0xFEFF].includes(ch));
 }
 
 // 7.3 Line Terminators
@@ -426,7 +426,7 @@ function scanPunctuator() {
   // Other 2-character punctuators: ++ -- << >> && ||
   ch2 = ch3.substr(0, 2);
 
-  if ((ch1 === ch2[1] && ('+-<>&|'.indexOf(ch1) >= 0)) || ch2 === '=>') {
+  if ((ch1 === ch2[1] && ('+-<>&|'.includes(ch1))) || ch2 === '=>') {
     index += 2;
     return {
       type: TokenPunctuator,
@@ -442,7 +442,7 @@ function scanPunctuator() {
 
   // 1-character punctuators: < > = ! + - * % & | ^ /
 
-  if ('<>=!+-*%&|^/'.indexOf(ch1) >= 0) {
+  if ('<>=!+-*%&|^/'.includes(ch1)) {
     ++index;
     return {
       type: TokenPunctuator,
@@ -643,7 +643,7 @@ function scanStringLiteral() {
 
                 // 3 digits are only allowed when string starts
                 // with 0, 1, 2, 3
-                if ('0123'.indexOf(ch) >= 0 &&
+                if ('0123'.includes(ch) &&
                   index < length &&
                   isOctalDigit(source[index])) {
                   code = code * 8 + '01234567'.indexOf(source[index++]);
@@ -683,7 +683,7 @@ function scanStringLiteral() {
 function testRegExp(pattern, flags) {
   let tmp = pattern;
 
-  if (flags.indexOf('u') >= 0) {
+  if (flags.includes('u')) {
     // Replace each astral symbol and every Unicode code point
     // escape sequence with a single ASCII symbol to avoid throwing on
     // regular expressions that are only valid in combination with the

packages/vega-parser/src/parsers/marks/role.js

@@ -3,7 +3,7 @@ import {MarkRole, ScopeRole} from './roles';
 
 export default function(spec) {
   const role = spec.role || '';
-  return (!role.indexOf('axis') || !role.indexOf('legend') || !role.indexOf('title'))
+  return (role.startsWith('axis') || role.startsWith('legend') || role.startsWith('title'))
     ? role
     : spec.type === GroupMark ? ScopeRole : (role || MarkRole);
 }

packages/vega-selections/src/selectionResolve.js

@@ -94,13 +94,13 @@ var ops = {
     if (!base.length) return value;
 
     var i = 0, n = value.length;
-    for (; i<n; ++i) if (base.indexOf(value[i]) < 0) base.push(value[i]);
+    for (; i<n; ++i) if (!base.includes(value[i])) base.push(value[i]);
     return base;
   },
 
   E_intersect: function(base, value) {
     return !base.length ? value :
-      base.filter(v => value.indexOf(v) >= 0);
+      base.filter(v => value.includes(v));
   },
 
   R_union: function(base, value) {

packages/vega-selections/src/selectionTest.js

@@ -27,7 +27,7 @@ function testPoint(datum, entry) {
     if (f.type === TYPE_ENUM) {
       // Enumerated fields can either specify individual values (single/multi selections)
       // or an array of values (interval selections).
-      if(isArray(values[i]) ? values[i].indexOf(dval) < 0 : dval !== values[i]) {
+      if(isArray(values[i]) ? !values[i].includes(dval) : dval !== values[i]) {
         return false;
       }
     } else {

packages/vega-view/src/View.js

@@ -305,7 +305,7 @@ inherits(View, Dataflow, {
 
   addResizeListener(handler) {
     const l = this._resizeListeners;
-    if (l.indexOf(handler) < 0) {
+    if (!l.includes(handler)) {
       // add handler if it isn't already registered
       // note: error trapping handled elsewhere, so
       // no need to wrap handlers here

packages/vega-view/src/state.js

@@ -28,7 +28,7 @@ export function getState(options) {
 function dataTest(name, data) {
   return data.modified
       && isArray(data.input.value)
-      && name.indexOf('_:vega:_');
+      && !name.startsWith('_:vega:_');
 }
 
 function signalTest(name, op) {

rollup.config.mjs

@@ -116,7 +116,7 @@ export default function(commandLineArgs) {
 
   const outputs = [{
     input: './index.js',
-    external: dependencies.filter(dep => esmDeps.indexOf(dep) < 0),
+    external: dependencies.filter(dep => !esmDeps.includes(dep)),
     onwarn,
     output: {
       file: pkg.main,