Enable ESLint rules that no longer need to be disabled on a directory/file-basis

Given that browsers/environments without native support for both arrow functions and object shorthand properties are no longer supported in PDF.js, please refer to the compatibility information below, we can now enable a fair number of ESLint rules and also simplify/remove some `.eslintrc` files.

With the exception of the `no-alert` cases, all code changes were made automatically by using `gulp lint --fix`.

 - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions#browser_compatibility
 - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Object_initializer#browser_compatibility

Author: Snuffleupagus

examples/.eslintrc

@@ -3,23 +3,9 @@
     "../.eslintrc"
   ],
 
-  "parserOptions": {
-    "ecmaVersion": 6,
-  },
-
-  "env": {
-    "es6": false,
-  },
-
   "globals": {
     "pdfjsImageDecoders": false,
     "pdfjsLib": false,
     "pdfjsViewer": false,
-    "Uint8Array": false,
   },
-
-  "rules": {
-    "no-alert": "off",
-    "object-shorthand": ["error", "never"]
-  }
 }

examples/acroforms/acroforms.js

@@ -37,11 +37,11 @@ loadingTask.promise.then(function (doc) {
         return doc.getPage(pageNum).then(function (pdfPage) {
           // Create the page view.
           var pdfPageView = new pdfjsViewer.PDFPageView({
-            container: container,
+            container,
             id: pageNum,
             scale: DEFAULT_SCALE,
             defaultViewport: pdfPage.getViewport({ scale: DEFAULT_SCALE }),
-            eventBus: eventBus,
+            eventBus,
             annotationLayerFactory: new pdfjsViewer.DefaultAnnotationLayerFactory(),
             renderInteractiveForms: true,
           });

examples/browserify/main.js

@@ -25,7 +25,7 @@ loadingTask.promise
       var ctx = canvas.getContext("2d");
       var renderTask = pdfPage.render({
         canvasContext: ctx,
-        viewport: viewport,
+        viewport,
       });
       return renderTask.promise;
     });

examples/components/pageviewer.js

@@ -16,6 +16,7 @@
 "use strict";
 
 if (!pdfjsLib.getDocument || !pdfjsViewer.PDFPageView) {
+  // eslint-disable-next-line no-alert
   alert("Please build the pdfjs-dist library using\n  `gulp dist-install`");
 }
 
@@ -48,11 +49,11 @@ loadingTask.promise.then(function (pdfDocument) {
   return pdfDocument.getPage(PAGE_TO_VIEW).then(function (pdfPage) {
     // Creating the page view with default parameters.
     var pdfPageView = new pdfjsViewer.PDFPageView({
-      container: container,
+      container,
       id: PAGE_TO_VIEW,
       scale: SCALE,
       defaultViewport: pdfPage.getViewport({ scale: SCALE }),
-      eventBus: eventBus,
+      eventBus,
       // We can enable text/annotations layers, if needed
       textLayerFactory: new pdfjsViewer.DefaultTextLayerFactory(),
       annotationLayerFactory: new pdfjsViewer.DefaultAnnotationLayerFactory(),

examples/components/simpleviewer.js

@@ -16,6 +16,7 @@
 "use strict";
 
 if (!pdfjsLib.getDocument || !pdfjsViewer.PDFViewer) {
+  // eslint-disable-next-line no-alert
   alert("Please build the pdfjs-dist library using\n  `gulp dist-install`");
 }
 
@@ -38,18 +39,18 @@ var eventBus = new pdfjsViewer.EventBus();
 
 // (Optionally) enable hyperlinks within PDF files.
 var pdfLinkService = new pdfjsViewer.PDFLinkService({
-  eventBus: eventBus,
+  eventBus,
 });
 
 // (Optionally) enable find controller.
 var pdfFindController = new pdfjsViewer.PDFFindController({
-  eventBus: eventBus,
+  eventBus,
   linkService: pdfLinkService,
 });
 
 var pdfViewer = new pdfjsViewer.PDFViewer({
-  container: container,
-  eventBus: eventBus,
+  container,
+  eventBus,
   linkService: pdfLinkService,
   findController: pdfFindController,
 });

examples/components/singlepageviewer.js

@@ -16,6 +16,7 @@
 "use strict";
 
 if (!pdfjsLib.getDocument || !pdfjsViewer.PDFSinglePageViewer) {
+  // eslint-disable-next-line no-alert
   alert("Please build the pdfjs-dist library using\n  `gulp dist-install`");
 }
 
@@ -38,18 +39,18 @@ var eventBus = new pdfjsViewer.EventBus();
 
 // (Optionally) enable hyperlinks within PDF files.
 var pdfLinkService = new pdfjsViewer.PDFLinkService({
-  eventBus: eventBus,
+  eventBus,
 });
 
 // (Optionally) enable find controller.
 var pdfFindController = new pdfjsViewer.PDFFindController({
-  eventBus: eventBus,
+  eventBus,
   linkService: pdfLinkService,
 });
 
 var pdfSinglePageViewer = new pdfjsViewer.PDFSinglePageViewer({
-  container: container,
-  eventBus: eventBus,
+  container,
+  eventBus,
   linkService: pdfLinkService,
   findController: pdfFindController,
 });

examples/image_decoders/jpeg_viewer.js

@@ -16,6 +16,7 @@
 "use strict";
 
 if (!pdfjsImageDecoders.JpegImage) {
+  // eslint-disable-next-line no-alert
   alert("Please build the pdfjs-dist library using `gulp dist-install`");
 }
 
@@ -61,8 +62,8 @@ jpegImage.parse(typedArrayImage);
 var width = jpegImage.width,
   height = jpegImage.height;
 var jpegData = jpegImage.getData({
-  width: width,
-  height: height,
+  width,
+  height,
   forceRGB: true,
 });
 

examples/mobile-viewer/viewer.js

@@ -16,6 +16,7 @@
 "use strict";
 
 if (!pdfjsLib.getDocument || !pdfjsViewer.PDFViewer) {
+  // eslint-disable-next-line no-alert
   alert("Please build the pdfjs-dist library using\n `gulp dist-install`");
 }
 
@@ -47,7 +48,7 @@ var PDFViewerApplication = {
    * @returns {Promise} - Returns the promise, which is resolved when document
    *                      is opened.
    */
-  open: function (params) {
+  open(params) {
     if (this.pdfLoadingTask) {
       // We need to destroy already opened document
       return this.close().then(
@@ -64,7 +65,7 @@ var PDFViewerApplication = {
 
     // Loading document.
     var loadingTask = pdfjsLib.getDocument({
-      url: url,
+      url,
       maxImageSize: MAX_IMAGE_SIZE,
       cMapUrl: CMAP_URL,
       cMapPacked: CMAP_PACKED,
@@ -120,7 +121,7 @@ var PDFViewerApplication = {
         }
 
         loadingErrorMessage.then(function (msg) {
-          self.error(msg, { message: message });
+          self.error(msg, { message });
         });
         self.loadingBar.hide();
       }
@@ -132,7 +133,7 @@ var PDFViewerApplication = {
    * @returns {Promise} - Returns the promise, which is resolved when all
    *                      destruction is completed.
    */
-  close: function () {
+  close() {
     var errorWrapper = document.getElementById("errorWrapper");
     errorWrapper.setAttribute("hidden", "true");
 
@@ -175,7 +176,7 @@ var PDFViewerApplication = {
     this.setTitle(title);
   },
 
-  setTitleUsingMetadata: function (pdfDocument) {
+  setTitleUsingMetadata(pdfDocument) {
     var self = this;
     pdfDocument.getMetadata().then(function (data) {
       var info = data.info,
@@ -345,17 +346,17 @@ var PDFViewerApplication = {
     this.eventBus = eventBus;
 
     var linkService = new pdfjsViewer.PDFLinkService({
-      eventBus: eventBus,
+      eventBus,
     });
     this.pdfLinkService = linkService;
 
     this.l10n = pdfjsViewer.NullL10n;
 
     var container = document.getElementById("viewerContainer");
     var pdfViewer = new pdfjsViewer.PDFViewer({
-      container: container,
-      eventBus: eventBus,
-      linkService: linkService,
+      container,
+      eventBus,
+      linkService,
       l10n: this.l10n,
       useOnlyCssZoom: USE_ONLY_CSS_ZOOM,
       textLayerMode: TEXT_LAYER_MODE,
@@ -364,8 +365,8 @@ var PDFViewerApplication = {
     linkService.setViewer(pdfViewer);
 
     this.pdfHistory = new pdfjsViewer.PDFHistory({
-      eventBus: eventBus,
-      linkService: linkService,
+      eventBus,
+      linkService,
     });
     linkService.setHistory(this.pdfHistory);
 

examples/node/domstubs.js

@@ -58,7 +58,7 @@ function DOMElement(name) {
   if (name === "style") {
     this.sheet = {
       cssRules: [],
-      insertRule: function (rule) {
+      insertRule(rule) {
         this.cssRules.push(rule);
       },
     };
@@ -226,16 +226,16 @@ const document = {
     return this;
   },
 
-  createElementNS: function (NS, element) {
+  createElementNS(NS, element) {
     var elObject = new DOMElement(element);
     return elObject;
   },
 
-  createElement: function (element) {
+  createElement(element) {
     return this.createElementNS("", element);
   },
 
-  getElementsByTagName: function (element) {
+  getElementsByTagName(element) {
     if (element === "head") {
       return [this.head || (this.head = new DOMElement("head"))];
     }

examples/node/pdf2png/pdf2png.js

@@ -24,8 +24,8 @@ NodeCanvasFactory.prototype = {
     var canvas = Canvas.createCanvas(width, height);
     var context = canvas.getContext("2d");
     return {
-      canvas: canvas,
-      context: context,
+      canvas,
+      context,
     };
   },
 
@@ -61,7 +61,7 @@ var data = new Uint8Array(fs.readFileSync(pdfPath));
 
 // Load the PDF file.
 var loadingTask = pdfjsLib.getDocument({
-  data: data,
+  data,
   cMapUrl: CMAP_URL,
   cMapPacked: CMAP_PACKED,
 });
@@ -80,8 +80,8 @@ loadingTask.promise
       );
       var renderContext = {
         canvasContext: canvasAndContext.context,
-        viewport: viewport,
-        canvasFactory: canvasFactory,
+        viewport,
+        canvasFactory,
       };
 
       var renderTask = page.render(renderContext);