refactor: replace deprecated String.substr with String.slice

Fixes #6078

String.prototype.substr is deprecated and should be replaced with
String.prototype.slice or String.prototype.substring.

This commit replaces all occurrences of .substr() with .slice() across
the codebase. The slice method is preferred as it handles negative
indices more intuitively and matches the existing usage patterns.

Author: JBR-0100

src/components/calendars/index.js

@@ -143,7 +143,7 @@ function worldCalFmt(fmt, x, calendar) {
             // format the cDate according to the translated directive
             else replacementPart = cDate.formatDate(directiveObj[modifier]);
 
-            fmt = fmt.substr(0, i) + replacementPart + fmt.substr(i + directiveLen);
+            fmt = fmt.slice(0, i) + replacementPart + fmt.slice(i + directiveLen);
             i += replacementPart.length;
         }
     }

src/components/color/index.js

@@ -117,13 +117,13 @@ color.clean = function(container) {
         key = keys[i];
         val = container[key];
 
-        if(key.substr(key.length - 5) === 'color') {
+        if(key.slice(-5) === 'color') {
             // only sanitize keys that end in "color" or "colorscale"
 
             if(Array.isArray(val)) {
                 for(j = 0; j < val.length; j++) val[j] = cleanOne(val[j]);
             } else container[key] = cleanOne(val);
-        } else if(key.substr(key.length - 10) === 'colorscale' && Array.isArray(val)) {
+        } else if(key.slice(-10) === 'colorscale' && Array.isArray(val)) {
             // colorscales have the format [[0, color1], [frac, color2], ... [1, colorN]]
 
             for(j = 0; j < val.length; j++) {
@@ -144,7 +144,7 @@ function cleanOne(val) {
     if(isNumeric(val) || typeof val !== 'string') return val;
 
     var valTrim = val.trim();
-    if(valTrim.substr(0, 3) !== 'rgb') return val;
+    if(valTrim.slice(0, 3) !== 'rgb') return val;
 
     var match = valTrim.match(/^rgba?\s*\(([^()]*)\)$/);
     if(!match) return val;

src/components/colorbar/draw.js

@@ -338,7 +338,7 @@ function drawColorBar(g, opts, gd) {
         // wrong class (in case earlier the colorbar was drawn on
         // a different side, I think?)
         var otherClass = titleClass.charAt(0) === 'h' ?
-            titleClass.substr(1) :
+            titleClass.slice(1) :
             'h' + titleClass;
         g.selectAll('.' + otherClass + ',.' + otherClass + '-math-group').remove();
 

src/components/rangeslider/defaults.js

@@ -45,10 +45,10 @@ module.exports = function handleDefaults(layoutIn, layoutOut, axName) {
     if(subplots) {
         var yIds = subplots.cartesian
             .filter(function(subplotId) {
-                return subplotId.substr(0, subplotId.indexOf('y')) === axisIds.name2id(axName);
+                return subplotId.slice(0, subplotId.indexOf('y')) === axisIds.name2id(axName);
             })
             .map(function(subplotId) {
-                return subplotId.substr(subplotId.indexOf('y'), subplotId.length);
+                return subplotId.slice(subplotId.indexOf('y'), subplotId.length);
             });
         var yNames = Lib.simpleMap(yIds, axisIds.id2name);
         for(var i = 0; i < yNames.length; i++) {

src/components/shapes/calc_autorange.js

@@ -115,7 +115,7 @@ function shapeBounds(ax, shape, paramsToUse) {
         drawnParam = paramsToUse[segment.charAt(0)].drawn;
         if(drawnParam === undefined) continue;
 
-        params = segments[i].substr(1).match(constants.paramRE);
+        params = segments[i].slice(1).match(constants.paramRE);
         if(!params || params.length < drawnParam) continue;
 
         val = convertVal(params[drawnParam]);

src/components/shapes/draw.js

@@ -620,7 +620,7 @@ function movePath(pathIn, moveX, moveY) {
         var yParams = constants.paramIsY[segmentType];
         var nParams = constants.numParams[segmentType];
 
-        var paramString = segment.substr(1).replace(constants.paramRE, function(param) {
+        var paramString = segment.slice(1).replace(constants.paramRE, function(param) {
             if(paramNumber >= nParams) return param;
 
             if(xParams[paramNumber]) param = moveX(param);

src/components/shapes/helpers.js

@@ -41,7 +41,7 @@ exports.extractPathCoords = function(path, paramsToUse, isRaw) {
         var relevantParamIdx = paramsToUse[segment.charAt(0)].drawn;
         if(relevantParamIdx === undefined) return;
 
-        var params = segment.substr(1).match(constants.paramRE);
+        var params = segment.slice(1).match(constants.paramRE);
         if(!params || params.length < relevantParamIdx) return;
 
         var str = params[relevantParamIdx];
@@ -261,7 +261,7 @@ function convertPath(options, x2p, y2p) {
         var yParams = constants.paramIsY[segmentType];
         var nParams = constants.numParams[segmentType];
 
-        var paramString = segment.substr(1).replace(constants.paramRE, function(param) {
+        var paramString = segment.slice(1).replace(constants.paramRE, function(param) {
             if(xParams[paramNumber]) {
                 if(xSizemode === 'pixel') param = x2p(xAnchor) + Number(param);
                 else param = x2p(param);

src/lib/coerce.js

@@ -76,7 +76,7 @@ exports.valObjectMeta = {
                 var k = String(values[i]);
 
                 if((k.charAt(0) === '/' && k.charAt(k.length - 1) === '/')) {
-                    var regex = new RegExp(k.substr(1, k.length - 2));
+                    var regex = new RegExp(k.slice(1, -1));
                     if(regex.test(v)) return true;
                 } else if(v === values[i]) return true;
             }

src/lib/dates.js

@@ -166,11 +166,11 @@ exports.dateTime2ms = function(s, calendar) {
     // 'G' as a prefix to force the built-in gregorian calendar.
     var s0 = s.charAt(0);
     if(isWorld && (s0 === 'G' || s0 === 'g')) {
-        s = s.substr(1);
+        s = s.slice(1);
         calendar = '';
     }
 
-    var isChinese = isWorld && calendar.substr(0, 7) === 'chinese';
+    var isChinese = isWorld && calendar.slice(0, 7) === 'chinese';
 
     var match = s.match(isChinese ? DATETIME_REGEXP_CN : DATETIME_REGEXP);
     if(!match) return BADNUM;
@@ -234,7 +234,7 @@ exports.isDateTime = function(s, calendar) {
 
 // pad a number with zeroes, to given # of digits before the decimal point
 function lpad(val, digits) {
-    return String(val + Math.pow(10, digits)).substr(1);
+    return String(val + Math.pow(10, digits)).slice(1);
 }
 
 /**
@@ -272,7 +272,7 @@ exports.ms2DateTime = function(ms, r, calendar) {
         // other things for a few calendars, so we can't trust it. Just pad
         // it manually (after the '-' if there is one)
         if(dateStr.charAt(0) === '-') {
-            while(dateStr.length < 11) dateStr = '-0' + dateStr.substr(1);
+            while(dateStr.length < 11) dateStr = '-0' + dateStr.slice(1);
         } else {
             while(dateStr.length < 10) dateStr = '0' + dateStr;
         }
@@ -388,7 +388,7 @@ function modDateFormat(fmt, x, formatter, calendar) {
         var digits = Math.min(+(match.charAt(1)) || 6, 6);
         var fracSecs = ((x / 1000 % 1) + 2)
             .toFixed(digits)
-            .substr(2).replace(/0+$/, '') || '0';
+            .slice(2).replace(/0+$/, '') || '0';
         return fracSecs;
     });
 
@@ -441,7 +441,7 @@ function formatTime(x, tr) {
          */
         var sec = Math.min(mod(x / ONESEC, 60), MAXSECONDS[tr]);
 
-        var secStr = (100 + sec).toFixed(tr).substr(1);
+        var secStr = (100 + sec).toFixed(tr).slice(1);
         if(tr > 0) {
             secStr = secStr.replace(/0+$/, '').replace(/[\.]$/, '');
         }

src/lib/index.js

@@ -462,7 +462,7 @@ lib.syncOrAsync = function (sequence, arg, finalStep) {
  * http://stackoverflow.com/questions/6680825/return-string-without-trailing-slash
  */
 lib.stripTrailingSlash = function (str) {
-    if (str.substr(-1) === '/') return str.substr(0, str.length - 1);
+    if (str.slice(-1) === '/') return str.slice(0, -1);
     return str;
 };
 
@@ -737,7 +737,7 @@ function minExtend(obj1, obj2, opt) {
 lib.minExtend = minExtend;
 
 lib.titleCase = function (s) {
-    return s.charAt(0).toUpperCase() + s.substr(1);
+    return s.charAt(0).toUpperCase() + s.slice(1);
 };
 
 lib.containsAny = function (s, fragments) {