buffer: add includes() for parity with TypedArray

Add Buffer#includes() by wrapping an indexOf and performing a strict
equals check to -1.

The includes method takes the search value, byteOffset, and encoding as
arguments.

The test is a modified version of the indexOf test.

Fixes: #3552
PR-URL: #3567
Reviewed-By: Trevor Norris <[email protected]>
Reviewed-By: Evan Lucas <[email protected]>
Reviewed-By: Jeremiah Senkpiel <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Author: umamialex

doc/api/buffer.markdown

@@ -291,6 +291,19 @@ Strings are interpreted as UTF8. Buffers will use the entire buffer. So in order
 to compare a partial Buffer use [`Buffer#slice()`][]. Numbers can range from 0 to
 255.
 
+### buf.includes(value[, byteOffset][, encoding])
+
+* `value` String, Buffer or Number
+* `byteOffset` Number, Optional, Default: 0
+* `encoding` String, Optional, Default: 'utf8'
+
+Operates similar to
+[Array#includes()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes).
+Accepts a String, Buffer or Number. Strings are interpreted as UTF8 unless
+overridden with the `encoding` argument. Buffers will use the entire buffer.
+So in order to compare a partial Buffer use `Buffer#slice()`. Numbers can range
+from 0 to 255.
+
 ### buf.length
 
 * Number

lib/buffer.js

@@ -488,6 +488,11 @@ Buffer.prototype.indexOf = function indexOf(val, byteOffset, encoding) {
 };
 
 
+Buffer.prototype.includes = function includes(val, byteOffset, encoding) {
+  return this.indexOf(val, byteOffset, encoding) !== -1;
+};
+
+
 Buffer.prototype.fill = function fill(val, start, end) {
   start = start >> 0;
   end = (end === undefined) ? this.length : end >> 0;

test/parallel/test-buffer-includes.js

@@ -0,0 +1,256 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const Buffer = require('buffer').Buffer;
+
+const b = new Buffer('abcdef');
+const buf_a = new Buffer('a');
+const buf_bc = new Buffer('bc');
+const buf_f = new Buffer('f');
+const buf_z = new Buffer('z');
+const buf_empty = new Buffer('');
+
+assert(b.includes('a'));
+assert(!b.includes('a', 1));
+assert(!b.includes('a', -1));
+assert(!b.includes('a', -4));
+assert(b.includes('a', -b.length));
+assert(b.includes('a', NaN));
+assert(b.includes('a', -Infinity));
+assert(!b.includes('a', Infinity));
+assert(b.includes('bc'));
+assert(!b.includes('bc', 2));
+assert(!b.includes('bc', -1));
+assert(!b.includes('bc', -3));
+assert(b.includes('bc', -5));
+assert(b.includes('bc', NaN));
+assert(b.includes('bc', -Infinity));
+assert(!b.includes('bc', Infinity));
+assert(b.includes('f'), b.length - 1);
+assert(!b.includes('z'));
+assert(!b.includes(''));
+assert(!b.includes('', 1));
+assert(!b.includes('', b.length + 1));
+assert(!b.includes('', Infinity));
+assert(b.includes(buf_a));
+assert(!b.includes(buf_a, 1));
+assert(!b.includes(buf_a, -1));
+assert(!b.includes(buf_a, -4));
+assert(b.includes(buf_a, -b.length));
+assert(b.includes(buf_a, NaN));
+assert(b.includes(buf_a, -Infinity));
+assert(!b.includes(buf_a, Infinity));
+assert(b.includes(buf_bc));
+assert(!b.includes(buf_bc, 2));
+assert(!b.includes(buf_bc, -1));
+assert(!b.includes(buf_bc, -3));
+assert(b.includes(buf_bc, -5));
+assert(b.includes(buf_bc, NaN));
+assert(b.includes(buf_bc, -Infinity));
+assert(!b.includes(buf_bc, Infinity));
+assert(b.includes(buf_f), b.length - 1);
+assert(!b.includes(buf_z));
+assert(!b.includes(buf_empty));
+assert(!b.includes(buf_empty, 1));
+assert(!b.includes(buf_empty, b.length + 1));
+assert(!b.includes(buf_empty, Infinity));
+assert(b.includes(0x61));
+assert(!b.includes(0x61, 1));
+assert(!b.includes(0x61, -1));
+assert(!b.includes(0x61, -4));
+assert(b.includes(0x61, -b.length));
+assert(b.includes(0x61, NaN));
+assert(b.includes(0x61, -Infinity));
+assert(!b.includes(0x61, Infinity));
+assert(!b.includes(0x0));
+
+// test offsets
+assert(b.includes('d', 2));
+assert(b.includes('f', 5));
+assert(b.includes('f', -1));
+assert(!b.includes('f', 6));
+
+assert(b.includes(Buffer('d'), 2));
+assert(b.includes(Buffer('f'), 5));
+assert(b.includes(Buffer('f'), -1));
+assert(!b.includes(Buffer('f'), 6));
+
+assert(!Buffer('ff').includes(Buffer('f'), 1, 'ucs2'));
+
+// test hex encoding
+assert(
+    Buffer(b.toString('hex'), 'hex')
+    .includes('64', 0, 'hex'));
+assert(
+    Buffer(b.toString('hex'), 'hex')
+    .includes(Buffer('64', 'hex'), 0, 'hex'));
+
+// test base64 encoding
+assert(
+    Buffer(b.toString('base64'), 'base64')
+    .includes('ZA==', 0, 'base64'));
+assert(
+    Buffer(b.toString('base64'), 'base64')
+    .includes(Buffer('ZA==', 'base64'), 0, 'base64'));
+
+// test ascii encoding
+assert(
+    Buffer(b.toString('ascii'), 'ascii')
+    .includes('d', 0, 'ascii'));
+assert(
+    Buffer(b.toString('ascii'), 'ascii')
+    .includes(Buffer('d', 'ascii'), 0, 'ascii'));
+
+// test binary encoding
+assert(
+    Buffer(b.toString('binary'), 'binary')
+    .includes('d', 0, 'binary'));
+assert(
+    Buffer(b.toString('binary'), 'binary')
+    .includes(Buffer('d', 'binary'), 0, 'binary'));
+
+
+// test usc2 encoding
+var twoByteString = new Buffer('\u039a\u0391\u03a3\u03a3\u0395', 'ucs2');
+
+assert(twoByteString.includes('\u0395', 4, 'ucs2'));
+assert(twoByteString.includes('\u03a3', -4, 'ucs2'));
+assert(twoByteString.includes('\u03a3', -6, 'ucs2'));
+assert(twoByteString.includes(
+  new Buffer('\u03a3', 'ucs2'), -6, 'ucs2'));
+assert(!twoByteString.includes('\u03a3', -2, 'ucs2'));
+
+const mixedByteStringUcs2 =
+    new Buffer('\u039a\u0391abc\u03a3\u03a3\u0395', 'ucs2');
+assert(mixedByteStringUcs2.includes('bc', 0, 'ucs2'));
+assert(mixedByteStringUcs2.includes('\u03a3', 0, 'ucs2'));
+assert(!mixedByteStringUcs2.includes('\u0396', 0, 'ucs2'));
+
+assert(
+    6, mixedByteStringUcs2.includes(new Buffer('bc', 'ucs2'), 0, 'ucs2'));
+assert(
+    10, mixedByteStringUcs2.includes(new Buffer('\u03a3', 'ucs2'), 0, 'ucs2'));
+assert(
+    -1, mixedByteStringUcs2.includes(new Buffer('\u0396', 'ucs2'), 0, 'ucs2'));
+
+twoByteString = new Buffer('\u039a\u0391\u03a3\u03a3\u0395', 'ucs2');
+
+// Test single char pattern
+assert(twoByteString.includes('\u039a', 0, 'ucs2'));
+assert(twoByteString.includes('\u0391', 0, 'ucs2'), 'Alpha');
+assert(twoByteString.includes('\u03a3', 0, 'ucs2'), 'First Sigma');
+assert(twoByteString.includes('\u03a3', 6, 'ucs2'), 'Second Sigma');
+assert(twoByteString.includes('\u0395', 0, 'ucs2'), 'Epsilon');
+assert(!twoByteString.includes('\u0392', 0, 'ucs2'), 'Not beta');
+
+// Test multi-char pattern
+assert(twoByteString.includes('\u039a\u0391', 0, 'ucs2'), 'Lambda Alpha');
+assert(twoByteString.includes('\u0391\u03a3', 0, 'ucs2'), 'Alpha Sigma');
+assert(twoByteString.includes('\u03a3\u03a3', 0, 'ucs2'), 'Sigma Sigma');
+assert(twoByteString.includes('\u03a3\u0395', 0, 'ucs2'), 'Sigma Epsilon');
+
+const mixedByteStringUtf8 = new Buffer('\u039a\u0391abc\u03a3\u03a3\u0395');
+assert(mixedByteStringUtf8.includes('bc'));
+assert(mixedByteStringUtf8.includes('bc', 5));
+assert(mixedByteStringUtf8.includes('bc', -8));
+assert(mixedByteStringUtf8.includes('\u03a3'));
+assert(!mixedByteStringUtf8.includes('\u0396'));
+
+
+// Test complex string includes algorithms. Only trigger for long strings.
+// Long string that isn't a simple repeat of a shorter string.
+var longString = 'A';
+for (var i = 66; i < 76; i++) {  // from 'B' to 'K'
+  longString =  longString + String.fromCharCode(i) + longString;
+}
+
+const longBufferString = new Buffer(longString);
+
+// pattern of 15 chars, repeated every 16 chars in long
+var pattern = 'ABACABADABACABA';
+for (var i = 0; i < longBufferString.length - pattern.length; i += 7) {
+  const includes = longBufferString.includes(pattern, i);
+  assert(includes, 'Long ABACABA...-string at index ' + i);
+}
+assert(longBufferString.includes('AJABACA'), 'Long AJABACA, First J');
+assert(longBufferString.includes('AJABACA', 511), 'Long AJABACA, Second J');
+
+pattern = 'JABACABADABACABA';
+assert(longBufferString.includes(pattern), 'Long JABACABA..., First J');
+assert(longBufferString.includes(pattern, 512), 'Long JABACABA..., Second J');
+
+// Search for a non-ASCII string in a pure ASCII string.
+const asciiString = new Buffer(
+    'arglebargleglopglyfarglebargleglopglyfarglebargleglopglyf');
+assert(!asciiString.includes('\x2061'));
+assert(asciiString.includes('leb', 0));
+
+// Search in string containing many non-ASCII chars.
+const allCodePoints = [];
+for (var i = 0; i < 65536; i++) allCodePoints[i] = i;
+const allCharsString = String.fromCharCode.apply(String, allCodePoints);
+const allCharsBufferUtf8 = new Buffer(allCharsString);
+const allCharsBufferUcs2 = new Buffer(allCharsString, 'ucs2');
+
+// Search for string long enough to trigger complex search with ASCII pattern
+// and UC16 subject.
+assert(!allCharsBufferUtf8.includes('notfound'));
+assert(!allCharsBufferUcs2.includes('notfound'));
+
+// Find substrings in Utf8.
+var lengths = [1, 3, 15];  // Single char, simple and complex.
+var indices = [0x5, 0x60, 0x400, 0x680, 0x7ee, 0xFF02, 0x16610, 0x2f77b];
+for (var lengthIndex = 0; lengthIndex < lengths.length; lengthIndex++) {
+  for (var i = 0; i < indices.length; i++) {
+    const index = indices[i];
+    var length = lengths[lengthIndex];
+
+    if (index + length > 0x7F) {
+      length = 2 * length;
+    }
+
+    if (index + length > 0x7FF) {
+      length = 3 * length;
+    }
+
+    if (index + length > 0xFFFF) {
+      length = 4 * length;
+    }
+
+    const patternBufferUtf8 = allCharsBufferUtf8.slice(index, index + length);
+    assert(index, allCharsBufferUtf8.includes(patternBufferUtf8));
+
+    const patternStringUtf8 = patternBufferUtf8.toString();
+    assert(index, allCharsBufferUtf8.includes(patternStringUtf8));
+  }
+}
+
+// Find substrings in Usc2.
+lengths = [2, 4, 16];  // Single char, simple and complex.
+indices = [0x5, 0x65, 0x105, 0x205, 0x285, 0x2005, 0x2085, 0xfff0];
+for (var lengthIndex = 0; lengthIndex < lengths.length; lengthIndex++) {
+  for (var i = 0; i < indices.length; i++) {
+    const index = indices[i] * 2;
+    var length = lengths[lengthIndex];
+
+    const patternBufferUcs2 =
+        allCharsBufferUcs2.slice(index, index + length);
+    assert(
+        index, allCharsBufferUcs2.includes(patternBufferUcs2, 0, 'ucs2'));
+
+    const patternStringUcs2 = patternBufferUcs2.toString('ucs2');
+    assert(
+        index, allCharsBufferUcs2.includes(patternStringUcs2, 0, 'ucs2'));
+  }
+}
+
+assert.throws(function() {
+  b.includes(function() { });
+});
+assert.throws(function() {
+  b.includes({});
+});
+assert.throws(function() {
+  b.includes([]);
+});