Add script to check for duplicates

check-dups.js

@@ -0,0 +1,39 @@
+const items = require('./src/items.json');
+
+function main() {
+    const { fileExtensions, fileNames } = items;
+
+    const duplicates = [
+        ...getDuplicates(fileExtensions),
+        ...getDuplicates(fileNames),
+    ];
+
+    if (duplicates.length > 0) {
+        for (const [ext, type] of duplicates) {
+            console.log(`Duplicate "${ext}" in "${type}" section`);
+        }
+    } else {
+        console.log('No duplicates are found');
+    }
+}
+
+function getDuplicates(props) {
+    const checkedItems = [];
+    const duplicates = [];
+
+    for (const type in props) {
+        const extensions = props[type];
+
+        for (const ext of extensions) {
+            if (checkedItems.includes(ext)) {
+                duplicates.push([ext, type]);
+            } else {
+                checkedItems.push(ext);
+            }
+        }
+    }
+
+    return duplicates;
+}
+
+main();

package.json

@@ -40,7 +40,7 @@
         "build": "node generate-icons.js",
         "dist": "npm run build && vsce package",
         "test": "npm run build && ava",
-        "lint": "eslint ."
+        "lint": "eslint . && node check-dups.js"
     },
     "devDependencies": {
         "ava": "^2.4.0",