feat: add utility functions for dealing with Uint8Arrays

package.json

@@ -42,6 +42,7 @@
     "iso-url": "^0.4.7",
     "it-glob": "0.0.8",
     "merge-options": "^2.0.0",
+    "multibase": "^2.0.0",
     "nanoid": "^3.1.3",
     "node-fetch": "^2.6.0",
     "stream-to-it": "^0.2.0"

src/uint8arrays/compare.js

@@ -0,0 +1,32 @@
+'use strict'
+
+/**
+ * Can be used with Array.sort to sort and array with Uint8Array entries
+ *
+ * @param {Uint8Array} a
+ * @param {Uint8Array} b
+ * @returns {Number}
+ */
+function compare (a, b) {
+  for (let i = 0; i < a.byteLength; i++) {
+    if (a[i] < b[i]) {
+      return -1
+    }
+
+    if (a[i] > b[i]) {
+      return 1
+    }
+  }
+
+  if (a.byteLength > b.byteLength) {
+    return 1
+  }
+
+  if (a.byteLength < b.byteLength) {
+    return -1
+  }
+
+  return 0
+}
+
+module.exports = compare

src/uint8arrays/concat.js

@@ -0,0 +1,41 @@
+'use strict'
+
+/**
+ * Returns a new Uint8Array created by concatenating the passed Arrays
+ *
+ * @param {Array<Array|TypedArray>} arrs
+ * @param {Number} length
+ * @returns {Uint8Array}
+ */
+function concat (arrs, length) {
+  if (!length) {
+    length = arrs.reduce((acc, curr) => {
+      if (ArrayBuffer.isView(curr)) {
+        return acc + curr.byteLength
+      } else if (Array.isArray(curr)) {
+        return acc + curr.length
+      }
+
+      throw new Error('Invalid input passed to concat, should be an Array or ArrayBuffer view')
+    }, 0)
+  }
+
+  const output = new Uint8Array(length)
+  let offset = 0
+
+  arrs.forEach(arr => {
+    output.set(arr, offset)
+
+    if (ArrayBuffer.isView(arr)) {
+      offset += arr.byteLength
+    } else if (Array.isArray(arr)) {
+      offset += arr.length
+    } else {
+      throw new Error('Invalid input passed to concat, should be an Array or ArrayBuffer view')
+    }
+  })
+
+  return output
+}
+
+module.exports = concat

src/uint8arrays/equals.js

@@ -0,0 +1,28 @@
+'use strict'
+
+/**
+ * Returns true if the two passed Uint8Arrays have the same content
+ *
+ * @param {Uint8Array} a
+ * @param {Uint8Array} b
+ * @returns {boolean}
+ */
+function equals (a, b) {
+  if (a === b) {
+    return true
+  }
+
+  if (a.byteLength !== b.byteLength) {
+    return false
+  }
+
+  for (let i = 0; i < a.byteLength; i++) {
+    if (a[i] !== b[i]) {
+      return false
+    }
+  }
+
+  return true
+}
+
+module.exports = equals

src/uint8arrays/from-string.js

@@ -0,0 +1,24 @@
+'use strict'
+
+const multibase = require('multibase')
+const { names } = require('multibase/src/constants')
+const TextEncoder = require('../text-encoder')
+const utf8Encoder = new TextEncoder('utf8')
+
+function fromString (string, encoding = 'utf8') {
+  if (encoding !== 'utf8') {
+    const base = names[encoding]
+
+    if (!base) {
+      throw new Error('Unknown base')
+    }
+
+    string = `${base.code}${string}`
+
+    return Uint8Array.from(multibase.decode(string))
+  }
+
+  return utf8Encoder.encode(string)
+}
+
+module.exports = fromString

src/uint8arrays/to-string.js

@@ -0,0 +1,15 @@
+'use strict'
+
+const multibase = require('multibase')
+const TextDecoder = require('../text-decoder')
+const utf8Decoder = new TextDecoder('utf8')
+
+function toString (buf, encoding = 'utf8') {
+  if (encoding !== 'utf8') {
+    buf = multibase.encode(encoding, buf).subarray(1)
+  }
+
+  return utf8Decoder.decode(buf)
+}
+
+module.exports = toString

test/uint8array/compare.spec.js

@@ -0,0 +1,49 @@
+'use strict'
+
+/* eslint-env mocha */
+const { expect } = require('aegir/utils/chai')
+const compare = require('../../src/uint8arrays/compare')
+
+describe('Uint8Array compare', () => {
+  it('is stable', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = Uint8Array.from([0, 1, 2, 3])
+
+    expect([a, b].sort(compare)).to.deep.equal([
+      a,
+      b
+    ])
+    expect([b, a].sort(compare)).to.deep.equal([
+      b,
+      a
+    ])
+  })
+
+  it('compares two Uint8Arrays', () => {
+    const a = Uint8Array.from([0, 1, 2, 4])
+    const b = Uint8Array.from([0, 1, 2, 3])
+
+    expect([a, b].sort(compare)).to.deep.equal([
+      b,
+      a
+    ])
+    expect([b, a].sort(compare)).to.deep.equal([
+      b,
+      a
+    ])
+  })
+
+  it('compares two Uint8Arrays with different lengths', () => {
+    const a = Uint8Array.from([0, 1, 2, 3, 4])
+    const b = Uint8Array.from([0, 1, 2, 3])
+
+    expect([a, b].sort(compare)).to.deep.equal([
+      b,
+      a
+    ])
+    expect([b, a].sort(compare)).to.deep.equal([
+      b,
+      a
+    ])
+  })
+})

test/uint8array/concat.spec.js

@@ -0,0 +1,53 @@
+'use strict'
+
+/* eslint-env mocha */
+const { expect } = require('aegir/utils/chai')
+const concat = require('../../src/uint8arrays/concat')
+
+describe('Uint8Array concat', () => {
+  it('concats two Uint8Arrays', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = Uint8Array.from([4, 5, 6, 7])
+    const c = Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7])
+
+    expect(concat([a, b])).to.deep.equal(c)
+  })
+
+  it('concats two Uint8Arrays with a length', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = Uint8Array.from([4, 5, 6, 7])
+    const c = Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7])
+
+    expect(concat([a, b], 8)).to.deep.equal(c)
+  })
+
+  it('concats mixed Uint8Arrays and Arrays', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = [4, 5, 6, 7]
+    const c = Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7])
+
+    expect(concat([a, b])).to.deep.equal(c)
+  })
+
+  it('concats mixed Uint8Arrays and Arrays with a length', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = [4, 5, 6, 7]
+    const c = Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7])
+
+    expect(concat([a, b], 8)).to.deep.equal(c)
+  })
+
+  it('throws when passed non ArrayBuffer views/Arrays', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = 'Hello world'
+
+    expect(() => concat([a, b])).to.throw(/Invalid input/)
+  })
+
+  it('throws when passed non ArrayBuffer views/Arrays with a length', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = 'Hello world'
+
+    expect(() => concat([a, b], 100)).to.throw(/Invalid input/)
+  })
+})

test/uint8array/equals.spec.js

@@ -0,0 +1,28 @@
+'use strict'
+
+/* eslint-env mocha */
+const { expect } = require('aegir/utils/chai')
+const equals = require('../../src/uint8arrays/equals')
+
+describe('Uint8Array equals', () => {
+  it('finds two Uint8Arrays equal', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = Uint8Array.from([0, 1, 2, 3])
+
+    expect(equals(a, b)).to.be.true()
+  })
+
+  it('finds two Uint8Arrays not equal', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = Uint8Array.from([0, 1, 2, 4])
+
+    expect(equals(a, b)).to.be.false()
+  })
+
+  it('finds two Uint8Arrays with different lengths not equal', () => {
+    const a = Uint8Array.from([0, 1, 2, 3])
+    const b = Uint8Array.from([0, 1, 2, 3, 4])
+
+    expect(equals(a, b)).to.be.false()
+  })
+})

test/uint8array/from-string.spec.js

@@ -0,0 +1,29 @@
+'use strict'
+
+/* eslint-env mocha */
+const { expect } = require('aegir/utils/chai')
+const fromString = require('../../src/uint8arrays/from-string')
+const TextEncoder = require('../../src/text-encoder')
+
+describe('Uint8Array fromString', () => {
+  it('creates a Uint8Array from a string', () => {
+    const str = 'hello world'
+    const arr = new TextEncoder('utf8').encode(str)
+
+    expect(fromString(str)).to.deep.equal(arr)
+  })
+
+  it('creates a Uint8Array from a base16 string', () => {
+    const str = '00010203aabbcc'
+    const arr = Uint8Array.from([0, 1, 2, 3, 170, 187, 204])
+
+    expect(fromString(str, 'base16')).to.deep.equal(arr)
+  })
+
+  it('creates a Uint8Array from a base64 string', () => {
+    const str = 'AAECA6q7zA'
+    const arr = Uint8Array.from([0, 1, 2, 3, 170, 187, 204])
+
+    expect(fromString(str, 'base64')).to.deep.equal(arr)
+  })
+})

test/uint8array/to-string.spec.js

@@ -0,0 +1,29 @@
+'use strict'
+
+/* eslint-env mocha */
+const { expect } = require('aegir/utils/chai')
+const toString = require('../../src/uint8arrays/to-string')
+const TextEncoder = require('../../src/text-encoder')
+
+describe('Uint8Array toString', () => {
+  it('creates a String from a Uint8Array', () => {
+    const str = 'hello world'
+    const arr = new TextEncoder('utf8').encode(str)
+
+    expect(toString(arr)).to.deep.equal(str)
+  })
+
+  it('creates a hex string from a Uint8Array', () => {
+    const str = '00010203aabbcc'
+    const arr = Uint8Array.from([0, 1, 2, 3, 170, 187, 204])
+
+    expect(toString(arr, 'base16')).to.deep.equal(str)
+  })
+
+  it('creates a base64 string from a Uint8Array', () => {
+    const str = 'AAECA6q7zA'
+    const arr = Uint8Array.from([0, 1, 2, 3, 170, 187, 204])
+
+    expect(toString(arr, 'base64')).to.deep.equal(str)
+  })
+})