Add lint rule to prohibit negative zeros within paths (#4350)

* Add lint to check negative zeros in paths

* Bump minimum NodeJS version to test locally to v12.4.0

* Simplify regular expression

* Add resolution tip to error message

* Convert iterator to array directly

* Improve comment

* Remove GodotEngine from lint ignores file

* Improve resolution tip message if previous character is a number

.svglintrc.js

@@ -8,6 +8,7 @@ const { svgPathBbox } = require("svg-path-bbox");
 
 const titleRegexp = /(.+) icon$/;
 const svgRegexp = /^<svg( [^\s]*=".*"){3}><title>.*<\/title><path d=".*"\/><\/svg>\r?\n?$/;
+const negativeZerosRegexp = /-0(?=[^\.]|[\s\d\w]|$)/g;
 
 const iconSize = 24;
 const iconFloatPrecision = 3;
@@ -308,6 +309,30 @@ module.exports = {
               reporter.error("Unexpected character(s), most likely extraneous whitespace, detected in SVG markup");
             }
           },
+          function(reporter, $, ast) {
+            reporter.name = "negative-zeros";
+
+            const iconPath = $.find("path").attr("d");
+            if (!updateIgnoreFile && isIgnored(reporter.name, iconPath)) {
+              return;
+            }
+
+            // Find negative zeros inside path
+            const negativeZeroMatches = Array.from(iconPath.matchAll(negativeZerosRegexp));
+            if (negativeZeroMatches.length) {
+              // Calculate the index for each match in the file
+              const pathDStart = '<path d="';
+              const svgFileHtml = $.html();
+              const pathDIndex = svgFileHtml.indexOf(pathDStart) + pathDStart.length;
+
+              negativeZeroMatches.forEach((match) => {
+                const negativeZeroFileIndex = match.index + pathDIndex;
+                const previousChar = svgFileHtml[negativeZeroFileIndex - 1];
+                const replacement = "0123456789".includes(previousChar) ? " 0" : "0";
+                reporter.error(`Found "-0" at index ${negativeZeroFileIndex} (should be "${replacement}")`);
+              })
+            }
+          },
           function(reporter, $, ast) {
             reporter.name = "icon-centered";
 

CONTRIBUTING.md

@@ -237,7 +237,7 @@ If you have an affiliation to the brand you contributing that allows you to spea
 
 ## Testing Package Locally
 
-* Make sure you have [NodeJS](https://nodejs.org/en/download/) installed. At least version 11.15.0 is required.
+* Make sure you have [NodeJS](https://nodejs.org/en/download/) installed. At least version 12.4.0 is required.
 * Install the dependencies using `$ npm install`.
 * Build and test the package using `$ npm test`.
 * Run the project linting process using `$ npm run lint`.