Make use of the prettier ignore file during our save script

package.json

@@ -107,6 +107,7 @@
     "eslint-plugin-jasmine": "^2.1.0",
     "eslint-plugin-promise": "^3.5.0",
     "eslint-plugin-vue": "^4.0.1",
+    "ignore": "^3.3.7",
     "istanbul": "^0.4.5",
     "jasmine-core": "^2.9.0",
     "jasmine-jquery": "^2.1.1",

scripts/frontend/prettier.js

 const glob = require('glob');
 const prettier = require('prettier');
 const fs = require('fs');
+const path = require('path');
+const prettierIgnore = require('ignore')();
 const getStagedFiles = require('./frontend_script_utils').getStagedFiles;
@@ -10,6 +12,10 @@ const allFiles = mode === 'check-all' || mode === 'save-all';
 const config = {
   patterns: ['**/*.js', '**/*.vue', '**/*.scss'],
+  /*
+   * The ignore patterns below are just to reduce search time with glob, as it includes the
+   * folders with the most ignored assets, the actual `.prettierignore` will be used later on
+   */
   ignore: ['**/node_modules/**', '**/vendor/**', '**/public/**'],
   parsers: {
     js: 'babylon',
@@ -17,6 +23,20 @@ const config = {
     scss: 'css',
   },
 };
+
+/*
+ * Unfortunately the prettier API does not expose support for `.prettierignore` files, they however
+ * use the ignore package, so we do the same. We simply cannot use the glob package, because
+ * gitignore style is not compatible with globs ignore style.
+ */
+prettierIgnore.add(
+  fs
+    .readFileSync(path.join(__dirname, '../../', '.prettierignore'))
+    .toString()
+    .trim()
+    .split(/\r?\n/)
+);
+
 const availableExtensions = Object.keys(config.parsers);
 console.log(`Loading ${allFiles ? 'All' : 'Staged'} Files ...`);
@@ -44,6 +64,8 @@ if (allFiles) {
   files = stagedFiles.filter(f => availableExtensions.includes(f.split('.').pop()));
 }
+files = prettierIgnore.filter(files);
+
 if (!files.length) {
   console.log('No Files found to process with Prettier');
   return;

yarn.lock

@@ -4232,7 +4232,7 @@ ignore@^3.2.0:
   version "3.3.3"
   resolved "https://registry.yarnpkg.com/ignore/-/ignore-3.3.3.tgz#432352e57accd87ab3110e82d3fea0e47812156d"
-ignore@^3.3.5:
+ignore@^3.3.5, ignore@^3.3.7:
   version "3.3.7"
   resolved "https://registry.yarnpkg.com/ignore/-/ignore-3.3.7.tgz#612289bfb3c220e186a58118618d5be8c1bab021"