Enable the ESLint no-var rule in the examples/ folder

examples/.eslintrc

@@ -8,4 +8,9 @@
     "pdfjsLib": false,
     "pdfjsViewer": false,
   },
+
+  "rules": {
+    // ECMAScript 6
+    "no-var": "error",
+  },
 }

examples/browserify/gulpfile.js

@@ -1,12 +1,12 @@
-var gulp = require("gulp");
-var browserify = require("browserify");
-var streamify = require("gulp-streamify");
-var rename = require("gulp-rename");
-var uglify = require("gulp-uglify");
-var source = require("vinyl-source-stream");
+const gulp = require("gulp");
+const browserify = require("browserify");
+const streamify = require("gulp-streamify");
+const rename = require("gulp-rename");
+const uglify = require("gulp-uglify");
+const source = require("vinyl-source-stream");
 
-var OUTPUT_PATH = "../../build/browserify";
-var TMP_FILE_PREFIX = "../../build/browserify_";
+const OUTPUT_PATH = "../../build/browserify";
+const TMP_FILE_PREFIX = "../../build/browserify_";
 
 gulp.task("build-bundle", function () {
   return browserify("main.js", { output: TMP_FILE_PREFIX + "main.tmp" })
@@ -20,7 +20,7 @@ gulp.task("build-bundle", function () {
 
 gulp.task("build-worker", function () {
   // We can create our own viewer (see worker.js) or use already defined one.
-  var workerSrc = require.resolve("pdfjs-dist/build/pdf.worker.entry");
+  const workerSrc = require.resolve("pdfjs-dist/build/pdf.worker.entry");
   return browserify(workerSrc, { output: TMP_FILE_PREFIX + "worker.tmp" })
     .bundle()
     .pipe(source(TMP_FILE_PREFIX + "worker.tmp"))

examples/browserify/main.js

@@ -3,27 +3,27 @@
 
 // Hello world example for browserify.
 
-var pdfjsLib = require("pdfjs-dist");
+const pdfjsLib = require("pdfjs-dist");
 
-var pdfPath = "../learning/helloworld.pdf";
+const pdfPath = "../learning/helloworld.pdf";
 
 // Setting worker path to worker bundle.
 pdfjsLib.GlobalWorkerOptions.workerSrc =
   "../../build/browserify/pdf.worker.bundle.js";
 
 // Loading a document.
-var loadingTask = pdfjsLib.getDocument(pdfPath);
+const loadingTask = pdfjsLib.getDocument(pdfPath);
 loadingTask.promise
   .then(function (pdfDocument) {
     // Request a first page
     return pdfDocument.getPage(1).then(function (pdfPage) {
       // Display page on the existing canvas with 100% scale.
-      var viewport = pdfPage.getViewport({ scale: 1.0 });
-      var canvas = document.getElementById("theCanvas");
+      const viewport = pdfPage.getViewport({ scale: 1.0 });
+      const canvas = document.getElementById("theCanvas");
       canvas.width = viewport.width;
       canvas.height = viewport.height;
-      var ctx = canvas.getContext("2d");
-      var renderTask = pdfPage.render({
+      const ctx = canvas.getContext("2d");
+      const renderTask = pdfPage.render({
         canvasContext: ctx,
         viewport,
       });

examples/components/pageviewer.js

@@ -27,19 +27,19 @@ pdfjsLib.GlobalWorkerOptions.workerSrc =
 
 // Some PDFs need external cmaps.
 //
-var CMAP_URL = "../../node_modules/pdfjs-dist/cmaps/";
-var CMAP_PACKED = true;
+const CMAP_URL = "../../node_modules/pdfjs-dist/cmaps/";
+const CMAP_PACKED = true;
 
-var DEFAULT_URL = "../../web/compressed.tracemonkey-pldi-09.pdf";
-var PAGE_TO_VIEW = 1;
-var SCALE = 1.0;
+const DEFAULT_URL = "../../web/compressed.tracemonkey-pldi-09.pdf";
+const PAGE_TO_VIEW = 1;
+const SCALE = 1.0;
 
-var container = document.getElementById("pageContainer");
+const container = document.getElementById("pageContainer");
 
-var eventBus = new pdfjsViewer.EventBus();
+const eventBus = new pdfjsViewer.EventBus();
 
 // Loading document.
-var loadingTask = pdfjsLib.getDocument({
+const loadingTask = pdfjsLib.getDocument({
   url: DEFAULT_URL,
   cMapUrl: CMAP_URL,
   cMapPacked: CMAP_PACKED,
@@ -48,7 +48,7 @@ loadingTask.promise.then(function (pdfDocument) {
   // Document loaded, retrieving the page.
   return pdfDocument.getPage(PAGE_TO_VIEW).then(function (pdfPage) {
     // Creating the page view with default parameters.
-    var pdfPageView = new pdfjsViewer.PDFPageView({
+    const pdfPageView = new pdfjsViewer.PDFPageView({
       container,
       id: PAGE_TO_VIEW,
       scale: SCALE,

examples/components/simpleviewer.js

@@ -27,40 +27,40 @@ pdfjsLib.GlobalWorkerOptions.workerSrc =
 
 // Some PDFs need external cmaps.
 //
-var CMAP_URL = "../../node_modules/pdfjs-dist/cmaps/";
-var CMAP_PACKED = true;
+const CMAP_URL = "../../node_modules/pdfjs-dist/cmaps/";
+const CMAP_PACKED = true;
 
-var DEFAULT_URL = "../../web/compressed.tracemonkey-pldi-09.pdf";
+const DEFAULT_URL = "../../web/compressed.tracemonkey-pldi-09.pdf";
 // To test the AcroForm and/or scripting functionality, try e.g. this file:
 // var DEFAULT_URL = "../../test/pdfs/160F-2019.pdf";
 
-var SEARCH_FOR = ""; // try 'Mozilla';
+const SEARCH_FOR = ""; // try 'Mozilla';
 
 // For scripting support, note also `enableScripting` below.
-var SANDBOX_BUNDLE_SRC = "../../node_modules/pdfjs-dist/build/pdf.sandbox.js";
+const SANDBOX_BUNDLE_SRC = "../../node_modules/pdfjs-dist/build/pdf.sandbox.js";
 
-var container = document.getElementById("viewerContainer");
+const container = document.getElementById("viewerContainer");
 
-var eventBus = new pdfjsViewer.EventBus();
+const eventBus = new pdfjsViewer.EventBus();
 
 // (Optionally) enable hyperlinks within PDF files.
-var pdfLinkService = new pdfjsViewer.PDFLinkService({
+const pdfLinkService = new pdfjsViewer.PDFLinkService({
   eventBus,
 });
 
 // (Optionally) enable find controller.
-var pdfFindController = new pdfjsViewer.PDFFindController({
+const pdfFindController = new pdfjsViewer.PDFFindController({
   eventBus,
   linkService: pdfLinkService,
 });
 
 // (Optionally) enable scripting support.
-var pdfScriptingManager = new pdfjsViewer.PDFScriptingManager({
+const pdfScriptingManager = new pdfjsViewer.PDFScriptingManager({
   eventBus,
   sandboxBundleSrc: SANDBOX_BUNDLE_SRC,
 });
 
-var pdfViewer = new pdfjsViewer.PDFViewer({
+const pdfViewer = new pdfjsViewer.PDFViewer({
   container,
   eventBus,
   linkService: pdfLinkService,
@@ -82,7 +82,7 @@ eventBus.on("pagesinit", function () {
 });
 
 // Loading document.
-var loadingTask = pdfjsLib.getDocument({
+const loadingTask = pdfjsLib.getDocument({
   url: DEFAULT_URL,
   cMapUrl: CMAP_URL,
   cMapPacked: CMAP_PACKED,

examples/components/singlepageviewer.js

@@ -27,40 +27,40 @@ pdfjsLib.GlobalWorkerOptions.workerSrc =
 
 // Some PDFs need external cmaps.
 //
-var CMAP_URL = "../../node_modules/pdfjs-dist/cmaps/";
-var CMAP_PACKED = true;
+const CMAP_URL = "../../node_modules/pdfjs-dist/cmaps/";
+const CMAP_PACKED = true;
 
-var DEFAULT_URL = "../../web/compressed.tracemonkey-pldi-09.pdf";
+const DEFAULT_URL = "../../web/compressed.tracemonkey-pldi-09.pdf";
 // To test the AcroForm and/or scripting functionality, try e.g. this file:
 // var DEFAULT_URL = "../../test/pdfs/160F-2019.pdf";
 
-var SEARCH_FOR = ""; // try 'Mozilla';
+const SEARCH_FOR = ""; // try 'Mozilla';
 
 // For scripting support, note also `enableScripting` below.
-var SANDBOX_BUNDLE_SRC = "../../node_modules/pdfjs-dist/build/pdf.sandbox.js";
+const SANDBOX_BUNDLE_SRC = "../../node_modules/pdfjs-dist/build/pdf.sandbox.js";
 
-var container = document.getElementById("viewerContainer");
+const container = document.getElementById("viewerContainer");
 
-var eventBus = new pdfjsViewer.EventBus();
+const eventBus = new pdfjsViewer.EventBus();
 
 // (Optionally) enable hyperlinks within PDF files.
-var pdfLinkService = new pdfjsViewer.PDFLinkService({
+const pdfLinkService = new pdfjsViewer.PDFLinkService({
   eventBus,
 });
 
 // (Optionally) enable find controller.
-var pdfFindController = new pdfjsViewer.PDFFindController({
+const pdfFindController = new pdfjsViewer.PDFFindController({
   eventBus,
   linkService: pdfLinkService,
 });
 
 // (Optionally) enable scripting support.
-var pdfScriptingManager = new pdfjsViewer.PDFScriptingManager({
+const pdfScriptingManager = new pdfjsViewer.PDFScriptingManager({
   eventBus,
   sandboxBundleSrc: SANDBOX_BUNDLE_SRC,
 });
 
-var pdfSinglePageViewer = new pdfjsViewer.PDFSinglePageViewer({
+const pdfSinglePageViewer = new pdfjsViewer.PDFSinglePageViewer({
   container,
   eventBus,
   linkService: pdfLinkService,
@@ -82,7 +82,7 @@ eventBus.on("pagesinit", function () {
 });
 
 // Loading document.
-var loadingTask = pdfjsLib.getDocument({
+const loadingTask = pdfjsLib.getDocument({
   url: DEFAULT_URL,
   cMapUrl: CMAP_URL,
   cMapPacked: CMAP_PACKED,

examples/image_decoders/jpeg_viewer.js

@@ -20,15 +20,15 @@ if (!pdfjsImageDecoders.JpegImage) {
   alert("Please build the pdfjs-dist library using `gulp dist-install`");
 }
 
-var JPEG_IMAGE = "fish.jpg";
+const JPEG_IMAGE = "fish.jpg";
 
-var jpegCanvas = document.getElementById("jpegCanvas");
-var jpegCtx = jpegCanvas.getContext("2d");
+const jpegCanvas = document.getElementById("jpegCanvas");
+const jpegCtx = jpegCanvas.getContext("2d");
 
 // Load the image data, and convert it to a Uint8Array.
 //
-var nonBinaryRequest = false;
-var request = new XMLHttpRequest();
+let nonBinaryRequest = false;
+const request = new XMLHttpRequest();
 request.open("GET", JPEG_IMAGE, false);
 try {
   request.responseType = "arraybuffer";
@@ -41,12 +41,12 @@ if (nonBinaryRequest && request.overrideMimeType) {
 }
 request.send(null);
 
-var typedArrayImage;
+let typedArrayImage;
 if (nonBinaryRequest) {
-  var str = request.responseText,
+  const str = request.responseText,
     length = str.length;
-  var bytes = new Uint8Array(length);
-  for (var i = 0; i < length; ++i) {
+  const bytes = new Uint8Array(length);
+  for (let i = 0; i < length; ++i) {
     bytes[i] = str.charCodeAt(i) & 0xff;
   }
   typedArrayImage = bytes;
@@ -56,22 +56,22 @@ if (nonBinaryRequest) {
 
 // Parse the image data using `JpegImage`.
 //
-var jpegImage = new pdfjsImageDecoders.JpegImage();
+const jpegImage = new pdfjsImageDecoders.JpegImage();
 jpegImage.parse(typedArrayImage);
 
-var width = jpegImage.width,
+const width = jpegImage.width,
   height = jpegImage.height;
-var jpegData = jpegImage.getData({
+const jpegData = jpegImage.getData({
   width,
   height,
   forceRGB: true,
 });
 
 // Render the JPEG image on a <canvas>.
 //
-var imageData = jpegCtx.createImageData(width, height);
-var imageBytes = imageData.data;
-for (var j = 0, k = 0, jj = width * height * 4; j < jj; ) {
+const imageData = jpegCtx.createImageData(width, height);
+const imageBytes = imageData.data;
+for (let j = 0, k = 0, jj = width * height * 4; j < jj; ) {
   imageBytes[j++] = jpegData[k++];
   imageBytes[j++] = jpegData[k++];
   imageBytes[j++] = jpegData[k++];