Remove unnecessary parens

.eslintrc.json

@@ -39,6 +39,7 @@
     "jsdoc/require-returns-type": "error",
     "jsdoc/sort-tags": "error",
     "no-constant-condition": "off",
+    "no-extra-parens": "error",
     "no-multi-spaces": "error",
     "no-trailing-spaces": "error",
     "no-var": "error",

src/convert.js

@@ -89,9 +89,9 @@ function parseInt96Date(value) {
  */
 export function parseFloat16(bytes) {
   if (!bytes) return undefined
-  const int16 = (bytes[1] << 8) | bytes[0]
+  const int16 = bytes[1] << 8 | bytes[0]
   const sign = int16 >> 15 ? -1 : 1
-  const exp = (int16 >> 10) & 0x1f
+  const exp = int16 >> 10 & 0x1f
   const frac = int16 & 0x3ff
   if (exp === 0) return sign * Math.pow(2, -14) * (frac / 1024) // subnormals
   if (exp === 0x1f) return frac ? NaN : sign * Infinity

src/datapageV2.js

@@ -42,26 +42,25 @@ export function readDataPageV2(compressedBytes, ph, schemaPath, columnMetadata,
     page = decompressPage(page, uncompressedPageSize, columnMetadata.codec, compressors)
   }
   const pageView = new DataView(page.buffer, page.byteOffset, page.byteLength)
+  const pageReader = { view: pageView, offset: 0 }
 
   // read values based on encoding
   /** @type {import('./types.d.ts').DecodedArray} */
   let dataPage = []
   const nValues = daph2.num_values - daph2.num_nulls
   if (daph2.encoding === 'PLAIN') {
-    const pageReader = { view: pageView, offset: 0 }
     const { type_length } = schemaPath[schemaPath.length - 1].element
     dataPage = readPlain(pageReader, columnMetadata.type, nValues, type_length)
   } else if (daph2.encoding === 'RLE') {
-    const bitWidth = 1
-    const pageReader = { view: pageView, offset: 4 }
+    pageReader.offset = 4
     dataPage = new Array(nValues)
-    readRleBitPackedHybrid(pageReader, bitWidth, uncompressedPageSize, dataPage)
+    readRleBitPackedHybrid(pageReader, 1, uncompressedPageSize, dataPage)
   } else if (
     daph2.encoding === 'PLAIN_DICTIONARY' ||
     daph2.encoding === 'RLE_DICTIONARY'
   ) {
     const bitWidth = pageView.getUint8(0)
-    const pageReader = { view: pageView, offset: 1 }
+    pageReader.offset = 1
     dataPage = new Array(nValues)
     readRleBitPackedHybrid(pageReader, bitWidth, uncompressedPageSize, dataPage)
   } else if (daph2.encoding === 'DELTA_BINARY_PACKED') {
@@ -76,13 +75,11 @@ export function readDataPageV2(compressedBytes, ph, schemaPath, columnMetadata,
 }
 
 /**
- * Read the repetition levels from this page, if any.
- *
  * @typedef {import("./types.d.ts").DataReader} DataReader
- * @param {DataReader} reader data view for the page
- * @param {DataPageHeaderV2} daph2 data page header
+ * @param {DataReader} reader
+ * @param {DataPageHeaderV2} daph2 data page header v2
  * @param {SchemaTree[]} schemaPath
- * @returns {any[]} repetition levels and number of bytes read
+ * @returns {any[]} repetition levels
  */
 export function readRepetitionLevelsV2(reader, daph2, schemaPath) {
   const maxRepetitionLevel = getMaxRepetitionLevel(schemaPath)
@@ -98,12 +95,10 @@ export function readRepetitionLevelsV2(reader, daph2, schemaPath) {
 }
 
 /**
- * Read the definition levels from this page, if any.
- *
- * @param {DataReader} reader data view for the page
+ * @param {DataReader} reader
  * @param {DataPageHeaderV2} daph2 data page header v2
  * @param {number} maxDefinitionLevel
- * @returns {number[] | undefined} definition levels and number of bytes read
+ * @returns {number[] | undefined} definition levels
  */
 function readDefinitionLevelsV2(reader, daph2, maxDefinitionLevel) {
   if (maxDefinitionLevel) {
@@ -116,8 +111,6 @@ function readDefinitionLevelsV2(reader, daph2, maxDefinitionLevel) {
 }
 
 /**
- * Unpack the delta binary packed encoding.
- *
  * @param {Uint8Array} page page data
  * @param {number} nValues number of values to read
  * @param {Int32Array | BigInt64Array} values array to write to
@@ -150,12 +143,12 @@ function deltaBinaryUnpack(page, nValues, values) {
           const mask = (1n << bitWidth) - 1n
           let bitpackPos = 0n
           while (count && miniblockCount) {
-            let bits = (BigInt(view.getUint8(reader.offset)) >> bitpackPos) & mask // TODO: don't re-read value every time
+            let bits = BigInt(view.getUint8(reader.offset)) >> bitpackPos & mask // TODO: don't re-read value every time
             bitpackPos += bitWidth
             while (bitpackPos >= 8) {
               bitpackPos -= 8n
               reader.offset++
-              bits |= (BigInt(view.getUint8(reader.offset)) << bitWidth - bitpackPos) & mask
+              bits |= BigInt(view.getUint8(reader.offset)) << bitWidth - bitpackPos & mask
             }
             const delta = minDelta + bits
             value += delta

src/encoding.js

@@ -57,7 +57,7 @@ export function readRleBitPackedHybrid(reader, width, length, values) {
  * @param {number} seen - number of values seen so far
  */
 function readRle(reader, count, bitWidth, values, seen) {
-  const width = (bitWidth + 7) >> 3
+  const width = bitWidth + 7 >> 3
   let value = 0
   if (width === 1) {
     value = reader.view.getUint8(reader.offset)
@@ -89,7 +89,7 @@ function readRle(reader, count, bitWidth, values, seen) {
  */
 function readBitPacked(reader, header, bitWidth, values, seen) {
   // extract number of values to read from header
-  let count = (header >> 1) << 3
+  let count = header >> 1 << 3
   // mask for bitWidth number of bits
   const mask = (1 << bitWidth) - 1
 
@@ -118,7 +118,7 @@ function readBitPacked(reader, header, bitWidth, values, seen) {
     } else {
       if (seen < values.length) {
         // emit value by shifting off to the right and masking
-        values[seen++] = (data >> right) & mask
+        values[seen++] = data >> right & mask
       }
       count--
       right += bitWidth

src/plain.js

@@ -47,7 +47,7 @@ function readPlainBoolean(reader, count) {
     const byteOffset = reader.offset + Math.floor(i / 8)
     const bitOffset = i % 8
     const byte = reader.view.getUint8(byteOffset)
-    values[i] = (byte & (1 << bitOffset)) !== 0
+    values[i] = (byte & 1 << bitOffset) !== 0
   }
   reader.offset += Math.ceil(count / 8)
   return values
@@ -95,7 +95,7 @@ function readPlainInt96(reader, count) {
   for (let i = 0; i < count; i++) {
     const low = reader.view.getBigInt64(reader.offset + i * 12, true)
     const high = reader.view.getInt32(reader.offset + i * 12 + 8, true)
-    values[i] = (BigInt(high) << 64n) | low
+    values[i] = BigInt(high) << 64n | low
   }
   reader.offset += count * 12
   return values

src/snappy.js

@@ -101,8 +101,8 @@ export function snappyUncompress(input, output) {
       switch (c & 0x3) {
       case 1:
         // Copy with 1-byte offset
-        len = ((c >>> 2) & 0x7) + 4
-        offset = input[pos] + ((c >>> 5) << 8)
+        len = (c >>> 2 & 0x7) + 4
+        offset = input[pos] + (c >>> 5 << 8)
         pos++
         break
       case 2:

src/thrift.js

@@ -165,7 +165,7 @@ function readVarBigInt(reader) {
 function readZigZag(reader) {
   const zigzag = readVarInt(reader)
   // convert zigzag to int
-  return (zigzag >>> 1) ^ -(zigzag & 1)
+  return zigzag >>> 1 ^ -(zigzag & 1)
 }
 
 /**
@@ -178,7 +178,7 @@ function readZigZag(reader) {
 export function readZigZagBigInt(reader) {
   const zigzag = readVarBigInt(reader)
   // convert zigzag to int
-  return (zigzag >> BigInt(1)) ^ -(zigzag & BigInt(1))
+  return zigzag >> BigInt(1) ^ -(zigzag & BigInt(1))
 }
 
 /**
@@ -247,7 +247,7 @@ export function toVarInt(n) {
       varInt[idx++] = n
       break
     } else {
-      varInt[idx++] = (n & 0x7f) | 0x80
+      varInt[idx++] = n & 0x7f | 0x80
       n >>>= 7
     }
   }

test/plain.test.js

@@ -66,7 +66,7 @@ describe('readPlain', () => {
     view.setInt32(8, high, true)
     const reader = { view, offset: 0 }
     const result = readPlain(reader, 'INT96', 1, undefined)
-    const expectedValue = (BigInt(high) << 64n) | low
+    const expectedValue = BigInt(high) << 64n | low
     expect(result).toEqual([expectedValue])
     expect(reader.offset).toBe(12)
   })