add eslint config and missing semicolons

.eslintrc.json

@@ -0,0 +1,40 @@
+{
+    "env": {
+        "browser": true,
+        "es2022": true
+    },
+    "extends": "eslint:recommended",
+    "parserOptions": {
+        "ecmaVersion": 2022,
+        "sourceType": "module"
+    },
+    "rules": {
+        "indent": [
+            "error",
+            4
+        ],
+        "linebreak-style": [
+            "error",
+            "unix"
+        ],
+        "quotes": [
+            "error",
+            "double"
+        ],
+        "semi": [
+            "error",
+            "always"
+        ],
+        "no-var": [
+            "error"
+        ]
+    },
+    "globals": {
+        "pdfjsLib": "readonly",
+        "channel": "readonly"
+    },
+    "ignorePatterns": [
+        "pdf.js",
+        "pdf.worker.js"
+    ]
+}

app/src/main/assets/viewer.js

@@ -181,7 +181,7 @@ function renderPage(pageNumber, zoom, prerender, prerenderTrigger=0) {
                 }
 
                 if (cache.length === maxCached) {
-                    cache.shift()
+                    cache.shift();
                 }
                 cache.push({
                     pageNumber: pageNumber,
@@ -244,7 +244,7 @@ function loadDocument() {
         } else if (error === pdfjsLib.PasswordResponses.INCORRECT_PASSWORD) {
             channel.invalidPassword();
         }
-    }
+    };
 
     loadingTask.promise.then(function (newDoc) {
         channel.onLoaded();
@@ -263,4 +263,4 @@ function loadDocument() {
 
 window.onresize = () => {
     setLayerTransform(canvas.clientWidth, canvas.clientHeight, textLayerDiv);
-}
+};

package.json

@@ -1,5 +1,8 @@
 {
   "dependencies": {
     "pdfjs-dist": "3.7.107"
+  },
+  "devDependencies": {
+    "eslint": "^8.42.0"
   }
 }