Proposal: Check outlying precision while running linter (#3750)

* Check outlying precision while running linter

* Prevent reduce error on empty array

* Rebase on branch develop

* Add svgpath dep

* Improve decimal precision verification

* Check outlying precision while running linter

* Prevent reduce error on empty array

* Fix ignored file

* Fix reverted dep version

* Check decimal according to review proposal

* Pin svgpath version

* Use te maximum precision only

* Run linter again

* Fix uglify-js version

* Add supported engines to package.json

* Improve message

* Revert engines and use version check in linter

* Move function

* Update node version to 12 in Travis

* Add skip ignored

.svglintrc.js

@@ -3,12 +3,14 @@ const fs = require('fs');
 const data = require("./_data/simple-icons.json");
 const { htmlFriendlyToTitle } = require("./scripts/utils.js");
 const getBounds = require("svg-path-bounding-box");
+const parsePath = require("svgpath/lib/path_parse");
 
 const titleRegexp = /(.+) icon$/;
 const svgRegexp = /^<svg( [^\s]*=".*"){3}><title>.*<\/title><path d=".*"\/><\/svg>\r?\n?$/;
 
 const iconSize = 24;
 const iconFloatPrecision = 3;
+const iconMaxFloatPrecision = 5;
 const iconTolerance = 0.001;
 
 // set env SI_UPDATE_IGNORE to recreate the ignore file
@@ -30,6 +32,11 @@ function sortObjectByValue(obj) {
     .reduce((r, k) => Object.assign(r, { [k]: obj[k] }), {});
 }
 
+if (Array.prototype.flat === undefined) {
+  console.error(`Minimum NodeJS v11.15.0 is required, but you are running ${process.version}.`);
+  process.exit(1);
+}
+
 if (updateIgnoreFile) {
   process.on('exit', () => {
     // ensure object output order is consistent due to async svglint processing
@@ -129,6 +136,38 @@ module.exports = {
               }
             }
           },
+          function(reporter, $, ast) {
+            reporter.name = "icon-precision";
+
+            const iconPath = $.find("path").attr("d");
+            if (!updateIgnoreFile && isIgnored(reporter.name, iconPath)) {
+              return;
+            }
+            
+            const { segments } = parsePath(iconPath);
+            const segmentParts = segments.flat().filter((num) => (typeof num === 'number'));
+
+            const countDecimals = (num) => {
+              if (num && num % 1) {
+                let [base, op, trail] = num.toExponential().split(/e([+-])/);
+                let elen = parseInt(trail, 10);
+                let idx = base.indexOf('.');
+                return idx == -1 ? elen : base.length - idx - 1 + (op === '+' ? -elen : elen);
+              }
+              return 0;
+            };
+            const precisionArray = segmentParts.map(countDecimals);
+            const precisionMax = precisionArray && precisionArray.length > 0 ?
+              Math.max(...precisionArray) :
+              0;
+
+            if (precisionMax > iconMaxFloatPrecision) {
+              reporter.error(`Maximum precision should not be greater than ${iconMaxFloatPrecision}; it is currently ${precisionMax}`);
+              if (updateIgnoreFile) {
+                ignoreIcon(reporter.name, iconPath, $);
+              }
+            }
+          },
           function(reporter, $, ast) {
             reporter.name = "extraneous";
 

.travis.yml

@@ -5,7 +5,7 @@ jobs:
     - stage: "Test"
       name: "Lint"
       language: node_js
-      node_js: 10
+      node_js: 12
       git:
         depth: 1
       script:
@@ -27,7 +27,7 @@ jobs:
         - jekyll build
     - name: "Test package"
       language: node_js
-      node_js: 10
+      node_js: 12
       git:
         depth: 1
       script:
@@ -51,7 +51,7 @@ jobs:
         cleanup: false
     - name: "NPM Package"
       language: node_js
-      node_js: 10
+      node_js: 12
       git:
         depth: 1
       if: branch = master

package-lock.json

@@ -7014,9 +7014,9 @@
       }
     },
     "svgpath": {
-      "version": "2.2.3",
+      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/svgpath/-/svgpath-2.2.3.tgz",
+      "resolved": "https://registry.npmjs.org/svgpath/-/svgpath-2.3.0.tgz",
-      "integrity": "sha512-xA0glXYpJ9SYT4JeMp3c0psbqdZsG1c0ywGvdJUPY2FKEgwJV7NgkeYuuQiOxMp+XsK9nCqjm3KDw0LkM1YLXw==",
+      "integrity": "sha512-N/4UDu3Y2ICik0daMmFW1tplw0XPs1nVIEVYkTiQfj9/JQZeEtAKaSYwheCwje1I4pQ5r22fGpoaNIvGgsyJyg==",
       "dev": true
     },
     "symbol-tree": {

package.json

@@ -25,6 +25,7 @@
     "svg-path-bounding-box": "1.0.4",
     "svglint": "1.0.6",
     "svgo": "1.3.2",
+    "svgpath": "2.3.0",
     "uglify-js": "3.11.6"
   },
   "scripts": {