Merge pull request #13294 from timvandermeij/src-no-var

Enable the `no-var` linting rule in `src/core/{cmap,image,worker}.js`

src/core/cmap.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint-disable no-var */
 
 import {
   CMapCompressionType,
@@ -26,7 +25,7 @@ import { Lexer } from "./parser.js";
 import { MissingDataException } from "./core_utils.js";
 import { Stream } from "./stream.js";
 
-var BUILT_IN_CMAPS = [
+const BUILT_IN_CMAPS = [
   // << Start unicode maps.
   "Adobe-GB1-UCS2",
   "Adobe-CNS1-UCS2",
@@ -240,7 +239,7 @@ class CMap {
     if (high - low > MAX_MAP_RANGE) {
       throw new Error("mapBfRange - ignoring data above MAX_MAP_RANGE.");
     }
-    var lastByte = dstLow.length - 1;
+    const lastByte = dstLow.length - 1;
     while (low <= high) {
       this._map[low++] = dstLow;
       // Only the last byte has to be incremented.
@@ -437,10 +436,10 @@ class IdentityCMap extends CMap {
   }
 }
 
-var BinaryCMapReader = (function BinaryCMapReaderClosure() {
+const BinaryCMapReader = (function BinaryCMapReaderClosure() {
   function hexToInt(a, size) {
-    var n = 0;
+    let n = 0;
-    for (var i = 0; i <= size; i++) {
+    for (let i = 0; i <= size; i++) {
       n = (n << 8) | a[i];
     }
     return n >>> 0;
@@ -459,8 +458,8 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
   }
 
   function addHex(a, b, size) {
-    var c = 0;
+    let c = 0;
-    for (var i = size; i >= 0; i--) {
+    for (let i = size; i >= 0; i--) {
       c += a[i] + b[i];
       a[i] = c & 255;
       c >>= 8;
@@ -468,16 +467,16 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
   }
 
   function incHex(a, size) {
-    var c = 1;
+    let c = 1;
-    for (var i = size; i >= 0 && c > 0; i--) {
+    for (let i = size; i >= 0 && c > 0; i--) {
       c += a[i];
       a[i] = c & 255;
       c >>= 8;
     }
   }
 
-  var MAX_NUM_SIZE = 16;
+  const MAX_NUM_SIZE = 16;
-  var MAX_ENCODED_NUM_SIZE = 19; // ceil(MAX_NUM_SIZE * 7 / 8)
+  const MAX_ENCODED_NUM_SIZE = 19; // ceil(MAX_NUM_SIZE * 7 / 8)
 
   class BinaryCMapStream {
     constructor(data) {
@@ -495,10 +494,10 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
     }
 
     readNumber() {
-      var n = 0;
+      let n = 0;
-      var last;
+      let last;
       do {
-        var b = this.readByte();
+        const b = this.readByte();
         if (b < 0) {
           throw new FormatError("unexpected EOF in bcmap");
         }
@@ -509,7 +508,7 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
     }
 
     readSigned() {
-      var n = this.readNumber();
+      const n = this.readNumber();
       return n & 1 ? ~(n >>> 1) : n >>> 1;
     }
 
@@ -519,18 +518,18 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
     }
 
     readHexNumber(num, size) {
-      var last;
+      let last;
-      var stack = this.tmpBuf,
+      const stack = this.tmpBuf;
-        sp = 0;
+      let sp = 0;
       do {
-        var b = this.readByte();
+        const b = this.readByte();
         if (b < 0) {
           throw new FormatError("unexpected EOF in bcmap");
         }
         last = !(b & 0x80);
         stack[sp++] = b & 0x7f;
       } while (!last);
-      var i = size,
+      let i = size,
         buffer = 0,
         bufferSize = 0;
       while (i >= 0) {
@@ -547,18 +546,18 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
 
     readHexSigned(num, size) {
       this.readHexNumber(num, size);
-      var sign = num[size] & 1 ? 255 : 0;
+      const sign = num[size] & 1 ? 255 : 0;
-      var c = 0;
+      let c = 0;
-      for (var i = 0; i <= size; i++) {
+      for (let i = 0; i <= size; i++) {
         c = ((c & 1) << 8) | num[i];
         num[i] = (c >> 1) ^ sign;
       }
     }
 
     readString() {
-      var len = this.readNumber();
+      const len = this.readNumber();
-      var s = "";
+      let s = "";
-      for (var i = 0; i < len; i++) {
+      for (let i = 0; i < len; i++) {
         s += String.fromCharCode(this.readNumber());
       }
       return s;
@@ -568,21 +567,21 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
   // eslint-disable-next-line no-shadow
   class BinaryCMapReader {
     async process(data, cMap, extend) {
-      var stream = new BinaryCMapStream(data);
+      const stream = new BinaryCMapStream(data);
-      var header = stream.readByte();
+      const header = stream.readByte();
       cMap.vertical = !!(header & 1);
 
-      var useCMap = null;
+      let useCMap = null;
-      var start = new Uint8Array(MAX_NUM_SIZE);
+      const start = new Uint8Array(MAX_NUM_SIZE);
-      var end = new Uint8Array(MAX_NUM_SIZE);
+      const end = new Uint8Array(MAX_NUM_SIZE);
-      var char = new Uint8Array(MAX_NUM_SIZE);
+      const char = new Uint8Array(MAX_NUM_SIZE);
-      var charCode = new Uint8Array(MAX_NUM_SIZE);
+      const charCode = new Uint8Array(MAX_NUM_SIZE);
-      var tmp = new Uint8Array(MAX_NUM_SIZE);
+      const tmp = new Uint8Array(MAX_NUM_SIZE);
-      var code;
+      let code;
 
-      var b;
+      let b;
       while ((b = stream.readByte()) >= 0) {
-        var type = b >> 5;
+        const type = b >> 5;
         if (type === 7) {
           // metadata, e.g. comment or usecmap
           switch (b & 0x1f) {
@@ -595,16 +594,15 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
           }
           continue;
         }
-        var sequence = !!(b & 0x10);
+        const sequence = !!(b & 0x10);
-        var dataSize = b & 15;
+        const dataSize = b & 15;
 
         if (dataSize + 1 > MAX_NUM_SIZE) {
           throw new Error("BinaryCMapReader.process: Invalid dataSize.");
         }
 
-        var ucs2DataSize = 1;
+        const ucs2DataSize = 1;
-        var subitemsCount = stream.readNumber();
+        const subitemsCount = stream.readNumber();
-        var i;
         switch (type) {
           case 0: // codespacerange
             stream.readHex(start, dataSize);
@@ -615,7 +613,7 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
               hexToInt(start, dataSize),
               hexToInt(end, dataSize)
             );
-            for (i = 1; i < subitemsCount; i++) {
+            for (let i = 1; i < subitemsCount; i++) {
               incHex(end, dataSize);
               stream.readHexNumber(start, dataSize);
               addHex(start, end, dataSize);
@@ -634,7 +632,7 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
             addHex(end, start, dataSize);
             stream.readNumber(); // code
             // undefined range, skipping
-            for (i = 1; i < subitemsCount; i++) {
+            for (let i = 1; i < subitemsCount; i++) {
               incHex(end, dataSize);
               stream.readHexNumber(start, dataSize);
               addHex(start, end, dataSize);
@@ -648,7 +646,7 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
             stream.readHex(char, dataSize);
             code = stream.readNumber();
             cMap.mapOne(hexToInt(char, dataSize), code);
-            for (i = 1; i < subitemsCount; i++) {
+            for (let i = 1; i < subitemsCount; i++) {
               incHex(char, dataSize);
               if (!sequence) {
                 stream.readHexNumber(tmp, dataSize);
@@ -668,7 +666,7 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
               hexToInt(end, dataSize),
               code
             );
-            for (i = 1; i < subitemsCount; i++) {
+            for (let i = 1; i < subitemsCount; i++) {
               incHex(end, dataSize);
               if (!sequence) {
                 stream.readHexNumber(start, dataSize);
@@ -693,7 +691,7 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
               hexToInt(char, ucs2DataSize),
               hexToStr(charCode, dataSize)
             );
-            for (i = 1; i < subitemsCount; i++) {
+            for (let i = 1; i < subitemsCount; i++) {
               incHex(char, ucs2DataSize);
               if (!sequence) {
                 stream.readHexNumber(tmp, ucs2DataSize);
@@ -718,7 +716,7 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
               hexToInt(end, ucs2DataSize),
               hexToStr(charCode, dataSize)
             );
-            for (i = 1; i < subitemsCount; i++) {
+            for (let i = 1; i < subitemsCount; i++) {
               incHex(end, ucs2DataSize);
               if (!sequence) {
                 stream.readHexNumber(start, ucs2DataSize);
@@ -751,10 +749,10 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
   return BinaryCMapReader;
 })();
 
-var CMapFactory = (function CMapFactoryClosure() {
+const CMapFactory = (function CMapFactoryClosure() {
   function strToInt(str) {
-    var a = 0;
+    let a = 0;
-    for (var i = 0; i < str.length; i++) {
+    for (let i = 0; i < str.length; i++) {
       a = (a << 8) | str.charCodeAt(i);
     }
     return a >>> 0;
@@ -774,7 +772,7 @@ var CMapFactory = (function CMapFactoryClosure() {
 
   function parseBfChar(cMap, lexer) {
     while (true) {
-      var obj = lexer.getObj();
+      let obj = lexer.getObj();
       if (isEOF(obj)) {
         break;
       }
@@ -782,18 +780,18 @@ var CMapFactory = (function CMapFactoryClosure() {
         return;
       }
       expectString(obj);
-      var src = strToInt(obj);
+      const src = strToInt(obj);
       obj = lexer.getObj();
       // TODO are /dstName used?
       expectString(obj);
-      var dst = obj;
+      const dst = obj;
       cMap.mapOne(src, dst);
     }
   }
 
   function parseBfRange(cMap, lexer) {
     while (true) {
-      var obj = lexer.getObj();
+      let obj = lexer.getObj();
       if (isEOF(obj)) {
         break;
       }
@@ -801,17 +799,17 @@ var CMapFactory = (function CMapFactoryClosure() {
         return;
       }
       expectString(obj);
-      var low = strToInt(obj);
+      const low = strToInt(obj);
       obj = lexer.getObj();
       expectString(obj);
-      var high = strToInt(obj);
+      const high = strToInt(obj);
       obj = lexer.getObj();
       if (Number.isInteger(obj) || isString(obj)) {
-        var dstLow = Number.isInteger(obj) ? String.fromCharCode(obj) : obj;
+        const dstLow = Number.isInteger(obj) ? String.fromCharCode(obj) : obj;
         cMap.mapBfRange(low, high, dstLow);
       } else if (isCmd(obj, "[")) {
         obj = lexer.getObj();
-        var array = [];
+        const array = [];
         while (!isCmd(obj, "]") && !isEOF(obj)) {
           array.push(obj);
           obj = lexer.getObj();
@@ -826,7 +824,7 @@ var CMapFactory = (function CMapFactoryClosure() {
 
   function parseCidChar(cMap, lexer) {
     while (true) {
-      var obj = lexer.getObj();
+      let obj = lexer.getObj();
       if (isEOF(obj)) {
         break;
       }
@@ -834,17 +832,17 @@ var CMapFactory = (function CMapFactoryClosure() {
         return;
       }
       expectString(obj);
-      var src = strToInt(obj);
+      const src = strToInt(obj);
       obj = lexer.getObj();
       expectInt(obj);
-      var dst = obj;
+      const dst = obj;
       cMap.mapOne(src, dst);
     }
   }
 
   function parseCidRange(cMap, lexer) {
     while (true) {
-      var obj = lexer.getObj();
+      let obj = lexer.getObj();
       if (isEOF(obj)) {
         break;
       }
@@ -852,20 +850,20 @@ var CMapFactory = (function CMapFactoryClosure() {
         return;
       }
       expectString(obj);
-      var low = strToInt(obj);
+      const low = strToInt(obj);
       obj = lexer.getObj();
       expectString(obj);
-      var high = strToInt(obj);
+      const high = strToInt(obj);
       obj = lexer.getObj();
       expectInt(obj);
-      var dstLow = obj;
+      const dstLow = obj;
       cMap.mapCidRange(low, high, dstLow);
     }
   }
 
   function parseCodespaceRange(cMap, lexer) {
     while (true) {
-      var obj = lexer.getObj();
+      let obj = lexer.getObj();
       if (isEOF(obj)) {
         break;
       }
@@ -875,37 +873,36 @@ var CMapFactory = (function CMapFactoryClosure() {
       if (!isString(obj)) {
         break;
       }
-      var low = strToInt(obj);
+      const low = strToInt(obj);
       obj = lexer.getObj();
       if (!isString(obj)) {
         break;
       }
-      var high = strToInt(obj);
+      const high = strToInt(obj);
       cMap.addCodespaceRange(obj.length, low, high);
     }
     throw new FormatError("Invalid codespace range.");
   }
 
   function parseWMode(cMap, lexer) {
-    var obj = lexer.getObj();
+    const obj = lexer.getObj();
     if (Number.isInteger(obj)) {
       cMap.vertical = !!obj;
     }
   }
 
   function parseCMapName(cMap, lexer) {
-    var obj = lexer.getObj();
+    const obj = lexer.getObj();
     if (isName(obj) && isString(obj.name)) {
       cMap.name = obj.name;
     }
   }
 
   async function parseCMap(cMap, lexer, fetchBuiltInCMap, useCMap) {
-    var previous;
+    let previous, embeddedUseCMap;
-    var embeddedUseCMap;
     objLoop: while (true) {
       try {
-        var obj = lexer.getObj();
+        const obj = lexer.getObj();
         if (isEOF(obj)) {
           break;
         } else if (isName(obj)) {
@@ -966,8 +963,8 @@ var CMapFactory = (function CMapFactoryClosure() {
     // If there aren't any code space ranges defined clone all the parent ones
     // into this cMap.
     if (cMap.numCodespaceRanges === 0) {
-      var useCodespaceRanges = cMap.useCMap.codespaceRanges;
+      const useCodespaceRanges = cMap.useCMap.codespaceRanges;
-      for (var i = 0; i < useCodespaceRanges.length; i++) {
+      for (let i = 0; i < useCodespaceRanges.length; i++) {
         cMap.codespaceRanges[i] = useCodespaceRanges[i].slice();
       }
       cMap.numCodespaceRanges = cMap.useCMap.numCodespaceRanges;
@@ -997,7 +994,7 @@ var CMapFactory = (function CMapFactoryClosure() {
     }
 
     const { cMapData, compressionType } = await fetchBuiltInCMap(name);
-    var cMap = new CMap(true);
+    const cMap = new CMap(true);
 
     if (compressionType === CMapCompressionType.BINARY) {
       return new BinaryCMapReader().process(cMapData, cMap, useCMap => {
@@ -1005,7 +1002,7 @@ var CMapFactory = (function CMapFactoryClosure() {
       });
     }
     if (compressionType === CMapCompressionType.NONE) {
-      var lexer = new Lexer(new Stream(cMapData));
+      const lexer = new Lexer(new Stream(cMapData));
       return parseCMap(cMap, lexer, fetchBuiltInCMap, null);
     }
     throw new Error(
@@ -1015,9 +1012,9 @@ var CMapFactory = (function CMapFactoryClosure() {
 
   return {
     async create(params) {
-      var encoding = params.encoding;
+      const encoding = params.encoding;
-      var fetchBuiltInCMap = params.fetchBuiltInCMap;
+      const fetchBuiltInCMap = params.fetchBuiltInCMap;
-      var useCMap = params.useCMap;
+      const useCMap = params.useCMap;
 
       if (isName(encoding)) {
         return createBuiltInCMap(encoding.name, fetchBuiltInCMap);

src/core/image.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint-disable no-var */
 
 import { assert, FormatError, ImageKind, info, warn } from "../shared/util.js";
 import { isName, isStream, Name } from "./primitives.js";
@@ -47,7 +46,7 @@ function decodeAndClamp(value, addend, coefficient, max) {
  * @returns {TypedArray} The resized image mask buffer.
  */
 function resizeImageMask(src, bpc, w1, h1, w2, h2) {
-  var length = w2 * h2;
+  const length = w2 * h2;
   let dest;
   if (bpc <= 8) {
     dest = new Uint8Array(length);
@@ -56,15 +55,15 @@ function resizeImageMask(src, bpc, w1, h1, w2, h2) {
   } else {
     dest = new Uint32Array(length);
   }
-  var xRatio = w1 / w2;
+  const xRatio = w1 / w2;
-  var yRatio = h1 / h2;
+  const yRatio = h1 / h2;
-  var i,
+  let i,
     j,
     py,
     newIndex = 0,
     oldIndex;
-  var xScaled = new Uint16Array(w2);
+  const xScaled = new Uint16Array(w2);
-  var w1Scanline = w1;
+  const w1Scanline = w1;
 
   for (i = 0; i < w2; i++) {
     xScaled[i] = Math.floor(i * xRatio);
@@ -92,13 +91,13 @@ class PDFImage {
     localColorSpaceCache,
   }) {
     this.image = image;
-    var dict = image.dict;
+    const dict = image.dict;
 
     const filter = dict.get("Filter");
     if (isName(filter)) {
       switch (filter.name) {
         case "JPXDecode":
-          var jpxImage = new JpxImage();
+          const jpxImage = new JpxImage();
           jpxImage.parseImageProperties(image.stream);
           image.stream.reset();
 
@@ -144,7 +143,7 @@ class PDFImage {
     this.imageMask = dict.get("ImageMask", "IM") || false;
     this.matte = dict.get("Matte") || false;
 
-    var bitsPerComponent = image.bitsPerComponent;
+    let bitsPerComponent = image.bitsPerComponent;
     if (!bitsPerComponent) {
       bitsPerComponent = dict.get("BitsPerComponent", "BPC");
       if (!bitsPerComponent) {
@@ -201,13 +200,13 @@ class PDFImage {
     ) {
       this.needsDecode = true;
       // Do some preprocessing to avoid more math.
-      var max = (1 << bitsPerComponent) - 1;
+      const max = (1 << bitsPerComponent) - 1;
       this.decodeCoefficients = [];
       this.decodeAddends = [];
       const isIndexed = this.colorSpace && this.colorSpace.name === "Indexed";
-      for (var i = 0, j = 0; i < this.decode.length; i += 2, ++j) {
+      for (let i = 0, j = 0; i < this.decode.length; i += 2, ++j) {
-        var dmin = this.decode[i];
+        const dmin = this.decode[i];
-        var dmax = this.decode[i + 1];
+        const dmax = this.decode[i + 1];
         this.decodeCoefficients[j] = isIndexed
           ? (dmax - dmin) / max
           : dmax - dmin;
@@ -226,7 +225,7 @@ class PDFImage {
       });
     } else if (mask) {
       if (isStream(mask)) {
-        var maskDict = mask.dict,
+        const maskDict = mask.dict,
           imageMask = maskDict.get("ImageMask", "IM");
         if (!imageMask) {
           warn("Ignoring /Mask in image without /ImageMask.");
@@ -310,10 +309,10 @@ class PDFImage {
     // In particular, if inverseDecode is true, then the array we return must
     // have a length of |computedLength|.
 
-    var computedLength = ((width + 7) >> 3) * height;
+    const computedLength = ((width + 7) >> 3) * height;
-    var actualLength = imgArray.byteLength;
+    const actualLength = imgArray.byteLength;
-    var haveFullData = computedLength === actualLength;
+    const haveFullData = computedLength === actualLength;
-    var data, i;
+    let data, i;
 
     if (imageIsFromDecodeStream && (!inverseDecode || haveFullData)) {
       // imgArray came from a DecodeStream and its data is in an appropriate
@@ -360,13 +359,13 @@ class PDFImage {
   }
 
   decodeBuffer(buffer) {
-    var bpc = this.bpc;
+    const bpc = this.bpc;
-    var numComps = this.numComps;
+    const numComps = this.numComps;
 
-    var decodeAddends = this.decodeAddends;
+    const decodeAddends = this.decodeAddends;
-    var decodeCoefficients = this.decodeCoefficients;
+    const decodeCoefficients = this.decodeCoefficients;
-    var max = (1 << bpc) - 1;
+    const max = (1 << bpc) - 1;
-    var i, ii;
+    let i, ii;
 
     if (bpc === 1) {
       // If the buffer needed decode that means it just needs to be inverted.
@@ -375,9 +374,9 @@ class PDFImage {
       }
       return;
     }
-    var index = 0;
+    let index = 0;
     for (i = 0, ii = this.width * this.height; i < ii; i++) {
-      for (var j = 0; j < numComps; j++) {
+      for (let j = 0; j < numComps; j++) {
         buffer[index] = decodeAndClamp(
           buffer[index],
           decodeAddends[j],
@@ -390,19 +389,19 @@ class PDFImage {
   }
 
   getComponents(buffer) {
-    var bpc = this.bpc;
+    const bpc = this.bpc;
 
     // This image doesn't require any extra work.
     if (bpc === 8) {
       return buffer;
     }
 
-    var width = this.width;
+    const width = this.width;
-    var height = this.height;
+    const height = this.height;
-    var numComps = this.numComps;
+    const numComps = this.numComps;
 
-    var length = width * height * numComps;
+    const length = width * height * numComps;
-    var bufferPos = 0;
+    let bufferPos = 0;
     let output;
     if (bpc <= 8) {
       output = new Uint8Array(length);
@@ -411,17 +410,17 @@ class PDFImage {
     } else {
       output = new Uint32Array(length);
     }
-    var rowComps = width * numComps;
+    const rowComps = width * numComps;
 
-    var max = (1 << bpc) - 1;
+    const max = (1 << bpc) - 1;
-    var i = 0,
+    let i = 0,
       ii,
       buf;
 
     if (bpc === 1) {
       // Optimization for reading 1 bpc images.
-      var mask, loop1End, loop2End;
+      let mask, loop1End, loop2End;
-      for (var j = 0; j < height; j++) {
+      for (let j = 0; j < height; j++) {
         loop1End = i + (rowComps & ~7);
         loop2End = i + rowComps;
 
@@ -451,7 +450,7 @@ class PDFImage {
       }
     } else {
       // The general case that handles all other bpc values.
-      var bits = 0;
+      let bits = 0;
       buf = 0;
       for (i = 0, ii = length; i < ii; ++i) {
         if (i % rowComps === 0) {
@@ -464,7 +463,7 @@ class PDFImage {
           bits += 8;
         }
 
-        var remainingBits = bits - bpc;
+        const remainingBits = bits - bpc;
         let value = buf >> remainingBits;
         if (value < 0) {
           value = 0;
@@ -489,9 +488,9 @@ class PDFImage {
         'PDFImage.fillOpacity: Unsupported "rgbaBuf" type.'
       );
     }
-    var smask = this.smask;
+    const smask = this.smask;
-    var mask = this.mask;
+    const mask = this.mask;
-    var alphaBuf, sw, sh, i, ii, j;
+    let alphaBuf, sw, sh, i, ii, j;
 
     if (smask) {
       sw = smask.width;
@@ -521,13 +520,13 @@ class PDFImage {
         // Color key mask: if any of the components are outside the range
         // then they should be painted.
         alphaBuf = new Uint8ClampedArray(width * height);
-        var numComps = this.numComps;
+        const numComps = this.numComps;
         for (i = 0, ii = width * height; i < ii; ++i) {
-          var opacity = 0;
+          let opacity = 0;
-          var imageOffset = i * numComps;
+          const imageOffset = i * numComps;
           for (j = 0; j < numComps; ++j) {
-            var color = image[imageOffset + j];
+            const color = image[imageOffset + j];
-            var maskOffset = j * 2;
+            const maskOffset = j * 2;
             if (color < mask[maskOffset] || color > mask[maskOffset + 1]) {
               opacity = 255;
               break;
@@ -562,17 +561,17 @@ class PDFImage {
         'PDFImage.undoPreblend: Unsupported "buffer" type.'
       );
     }
-    var matte = this.smask && this.smask.matte;
+    const matte = this.smask && this.smask.matte;
     if (!matte) {
       return;
     }
-    var matteRgb = this.colorSpace.getRgb(matte, 0);
+    const matteRgb = this.colorSpace.getRgb(matte, 0);
-    var matteR = matteRgb[0];
+    const matteR = matteRgb[0];
-    var matteG = matteRgb[1];
+    const matteG = matteRgb[1];
-    var matteB = matteRgb[2];
+    const matteB = matteRgb[2];
-    var length = width * height * 4;
+    const length = width * height * 4;
-    for (var i = 0; i < length; i += 4) {
+    for (let i = 0; i < length; i += 4) {
-      var alpha = buffer[i + 3];
+      const alpha = buffer[i + 3];
       if (alpha === 0) {
         // according formula we have to get Infinity in all components
         // making it white (typical paper color) should be okay
@@ -581,7 +580,7 @@ class PDFImage {
         buffer[i + 2] = 255;
         continue;
       }
-      var k = 255 / alpha;
+      const k = 255 / alpha;
       buffer[i] = (buffer[i] - matteR) * k + matteR;
       buffer[i + 1] = (buffer[i + 1] - matteG) * k + matteG;
       buffer[i + 2] = (buffer[i + 2] - matteB) * k + matteB;
@@ -589,9 +588,9 @@ class PDFImage {
   }
 
   createImageData(forceRGBA = false) {
-    var drawWidth = this.drawWidth;
+    const drawWidth = this.drawWidth;
-    var drawHeight = this.drawHeight;
+    const drawHeight = this.drawHeight;
-    var imgData = {
+    const imgData = {
       width: drawWidth,
       height: drawHeight,
       kind: 0,
@@ -599,14 +598,14 @@ class PDFImage {
       // Other fields are filled in below.
     };
 
-    var numComps = this.numComps;
+    const numComps = this.numComps;
-    var originalWidth = this.width;
+    const originalWidth = this.width;
-    var originalHeight = this.height;
+    const originalHeight = this.height;
-    var bpc = this.bpc;
+    const bpc = this.bpc;
 
     // Rows start at byte boundary.
-    var rowBytes = (originalWidth * numComps * bpc + 7) >> 3;
+    const rowBytes = (originalWidth * numComps * bpc + 7) >> 3;
-    var imgArray;
+    let imgArray;
 
     if (!forceRGBA) {
       // If it is a 1-bit-per-pixel grayscale (i.e. black-and-white) image
@@ -616,7 +615,7 @@ class PDFImage {
       //
       // Similarly, if it is a 24-bit-per pixel RGB image without any
       // complications, we avoid expanding by 1.333x to RGBA form.
-      var kind;
+      let kind;
       if (this.colorSpace.name === "DeviceGray" && bpc === 1) {
         kind = ImageKind.GRAYSCALE_1BPP;
       } else if (
@@ -644,7 +643,7 @@ class PDFImage {
         if (this.image instanceof DecodeStream) {
           imgData.data = imgArray;
         } else {
-          var newArray = new Uint8ClampedArray(imgArray.length);
+          const newArray = new Uint8ClampedArray(imgArray.length);
           newArray.set(imgArray);
           imgData.data = newArray;
         }
@@ -654,8 +653,8 @@ class PDFImage {
             kind === ImageKind.GRAYSCALE_1BPP,
             "PDFImage.createImageData: The image must be grayscale."
           );
-          var buffer = imgData.data;
+          const buffer = imgData.data;
-          for (var i = 0, ii = buffer.length; i < ii; i++) {
+          for (let i = 0, ii = buffer.length; i < ii; i++) {
             buffer[i] ^= 0xff;
           }
         }
@@ -685,14 +684,14 @@ class PDFImage {
 
     imgArray = this.getImageBytes(originalHeight * rowBytes);
     // imgArray can be incomplete (e.g. after CCITT fax encoding).
-    var actualHeight =
+    const actualHeight =
       0 | (((imgArray.length / rowBytes) * drawHeight) / originalHeight);
 
-    var comps = this.getComponents(imgArray);
+    const comps = this.getComponents(imgArray);
 
     // If opacity data is present, use RGBA_32BPP form. Otherwise, use the
     // more compact RGB_24BPP form if allowable.
-    var alpha01, maybeUndoPreblend;
+    let alpha01, maybeUndoPreblend;
     if (!forceRGBA && !this.smask && !this.mask) {
       imgData.kind = ImageKind.RGB_24BPP;
       imgData.data = new Uint8ClampedArray(drawWidth * drawHeight * 3);
@@ -745,23 +744,23 @@ class PDFImage {
         'PDFImage.fillGrayBuffer: Unsupported "buffer" type.'
       );
     }
-    var numComps = this.numComps;
+    const numComps = this.numComps;
     if (numComps !== 1) {
       throw new FormatError(
         `Reading gray scale from a color image: ${numComps}`
       );
     }
 
-    var width = this.width;
+    const width = this.width;
-    var height = this.height;
+    const height = this.height;
-    var bpc = this.bpc;
+    const bpc = this.bpc;
 
     // rows start at byte boundary
-    var rowBytes = (width * numComps * bpc + 7) >> 3;
+    const rowBytes = (width * numComps * bpc + 7) >> 3;
-    var imgArray = this.getImageBytes(height * rowBytes);
+    const imgArray = this.getImageBytes(height * rowBytes);
 
-    var comps = this.getComponents(imgArray);
+    const comps = this.getComponents(imgArray);
-    var i, length;
+    let i, length;
 
     if (bpc === 1) {
       // inline decoding (= inversion) for 1 bpc images
@@ -785,7 +784,7 @@ class PDFImage {
     }
     length = width * height;
     // we aren't using a colorspace so we need to scale the value
-    var scale = 255 / ((1 << bpc) - 1);
+    const scale = 255 / ((1 << bpc) - 1);
     for (i = 0; i < length; ++i) {
       buffer[i] = scale * comps[i];
     }

src/core/worker.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint-disable no-var */
 
 import {
   AbortException,
@@ -69,7 +68,7 @@ class WorkerTask {
 
 class WorkerMessageHandler {
   static setup(handler, port) {
-    var testMessageProcessed = false;
+    let testMessageProcessed = false;
     handler.on("test", function wphSetupTest(data) {
       if (testMessageProcessed) {
         return; // we already processed 'test' message once
@@ -100,10 +99,10 @@ class WorkerMessageHandler {
   static createDocumentHandler(docParams, port) {
     // This context is actually holds references on pdfManager and handler,
     // until the latter is destroyed.
-    var pdfManager;
+    let pdfManager;
-    var terminated = false;
+    let terminated = false;
-    var cancelXHRs = null;
+    let cancelXHRs = null;
-    var WorkerTasks = [];
+    const WorkerTasks = [];
     const verbosity = getVerbosityLevel();
 
     const apiVersion = docParams.apiVersion;
@@ -152,10 +151,10 @@ class WorkerMessageHandler {
       }
     }
 
-    var docId = docParams.docId;
+    const docId = docParams.docId;
-    var docBaseUrl = docParams.docBaseUrl;
+    const docBaseUrl = docParams.docBaseUrl;
-    var workerHandlerName = docParams.docId + "_worker";
+    const workerHandlerName = docParams.docId + "_worker";
-    var handler = new MessageHandler(workerHandlerName, docId, port);
+    let handler = new MessageHandler(workerHandlerName, docId, port);
 
     // Ensure that postMessage transfers are always correctly enabled/disabled,
     // to prevent "DataCloneError" in browsers without transfers support.
@@ -173,7 +172,7 @@ class WorkerMessageHandler {
 
     function finishWorkerTask(task) {
       task.finish();
-      var i = WorkerTasks.indexOf(task);
+      const i = WorkerTasks.indexOf(task);
       WorkerTasks.splice(i, 1);
     }
 
@@ -208,10 +207,10 @@ class WorkerMessageHandler {
     }
 
     function getPdfManager(data, evaluatorOptions, enableXfa) {
-      var pdfManagerCapability = createPromiseCapability();
+      const pdfManagerCapability = createPromiseCapability();
       let newPdfManager;
 
-      var source = data.source;
+      const source = data.source;
       if (source.data) {
         try {
           newPdfManager = new LocalPdfManager(
@@ -229,7 +228,7 @@ class WorkerMessageHandler {
         return pdfManagerCapability.promise;
       }
 
-      var pdfStream,
+      let pdfStream,
         cachedChunks = [];
       try {
         pdfStream = new PDFWorkerStream(handler);
@@ -238,7 +237,7 @@ class WorkerMessageHandler {
         return pdfManagerCapability.promise;
       }
 
-      var fullRequest = pdfStream.getFullReader();
+      const fullRequest = pdfStream.getFullReader();
       fullRequest.headersReady
         .then(function () {
           if (!fullRequest.isRangeSupported) {
@@ -246,7 +245,7 @@ class WorkerMessageHandler {
           }
 
           // We don't need auto-fetch when streaming is enabled.
-          var disableAutoFetch =
+          const disableAutoFetch =
             source.disableAutoFetch || fullRequest.isStreamingSupported;
           newPdfManager = new NetworkPdfManager(
             docId,
@@ -278,9 +277,9 @@ class WorkerMessageHandler {
           cancelXHRs = null;
         });
 
-      var loaded = 0;
+      let loaded = 0;
-      var flushChunks = function () {
+      const flushChunks = function () {
-        var pdfFile = arraysToBytes(cachedChunks);
+        const pdfFile = arraysToBytes(cachedChunks);
         if (source.length && pdfFile.length !== source.length) {
           warn("reported HTTP length is different from actual");
         }
@@ -300,8 +299,8 @@ class WorkerMessageHandler {
         }
         cachedChunks = [];
       };
-      var readPromise = new Promise(function (resolve, reject) {
+      const readPromise = new Promise(function (resolve, reject) {
-        var readChunk = function ({ value, done }) {
+        const readChunk = function ({ value, done }) {
           try {
             ensureNotTerminated();
             if (done) {
@@ -355,7 +354,7 @@ class WorkerMessageHandler {
         ensureNotTerminated();
 
         if (ex instanceof PasswordException) {
-          var task = new WorkerTask(`PasswordException: response ${ex.code}`);
+          const task = new WorkerTask(`PasswordException: response ${ex.code}`);
           startWorkerTask(task);
 
           handler
@@ -406,7 +405,7 @@ class WorkerMessageHandler {
 
       ensureNotTerminated();
 
-      var evaluatorOptions = {
+      const evaluatorOptions = {
         maxImageSize: data.maxImageSize,
         disableFontFace: data.disableFontFace,
         ignoreErrors: data.ignoreErrors,
@@ -656,9 +655,9 @@ class WorkerMessageHandler {
     );
 
     handler.on("GetOperatorList", function wphSetupRenderPage(data, sink) {
-      var pageIndex = data.pageIndex;
+      const pageIndex = data.pageIndex;
       pdfManager.getPage(pageIndex).then(function (page) {
-        var task = new WorkerTask(`GetOperatorList: page ${pageIndex}`);
+        const task = new WorkerTask(`GetOperatorList: page ${pageIndex}`);
         startWorkerTask(task);
 
         // NOTE: Keep this condition in sync with the `info` helper function.
@@ -707,12 +706,12 @@ class WorkerMessageHandler {
     });
 
     handler.on("GetTextContent", function wphExtractText(data, sink) {
-      var pageIndex = data.pageIndex;
+      const pageIndex = data.pageIndex;
       sink.onPull = function (desiredSize) {};
       sink.onCancel = function (reason) {};
 
       pdfManager.getPage(pageIndex).then(function (page) {
-        var task = new WorkerTask("GetTextContent: page " + pageIndex);
+        const task = new WorkerTask("GetTextContent: page " + pageIndex);
         startWorkerTask(task);
 
         // NOTE: Keep this condition in sync with the `info` helper function.
@@ -806,7 +805,7 @@ class WorkerMessageHandler {
   }
 
   static initializeFromPort(port) {
-    var handler = new MessageHandler("worker", "main", port);
+    const handler = new MessageHandler("worker", "main", port);
     WorkerMessageHandler.setup(handler, port);
     handler.send("ready", null);
   }