test-buffer-compare-offset.js

'use strict';

const common = require('../common');
const assert = require('assert');

const a = Buffer.from([1, 2, 3, 4, 5, 6, 7, 8, 9, 0]);
const b = Buffer.from([5, 6, 7, 8, 9, 0, 1, 2, 3, 4]);

assert.strictEqual(a.compare(b), -1);

// Equivalent to a.compare(b).
assert.strictEqual(a.compare(b, 0), -1);
assert.throws(() => a.compare(b, '0'), { code: 'ERR_INVALID_ARG_TYPE' });
assert.strictEqual(a.compare(b, undefined), -1);

// Equivalent to a.compare(b).
assert.strictEqual(a.compare(b, 0, undefined, 0), -1);

// Zero-length target, return 1
assert.strictEqual(a.compare(b, 0, 0, 0), 1);
assert.throws(
  () => a.compare(b, 0, '0', '0'),
  { code: 'ERR_INVALID_ARG_TYPE' }
);

// Equivalent to Buffer.compare(a, b.slice(6, 10))
assert.strictEqual(a.compare(b, 6, 10), 1);

// Zero-length source, return -1
assert.strictEqual(a.compare(b, 6, 10, 0, 0), -1);

// Zero-length source and target, return 0
assert.strictEqual(a.compare(b, 0, 0, 0, 0), 0);
assert.strictEqual(a.compare(b, 1, 1, 2, 2), 0);

// Equivalent to Buffer.compare(a.slice(4), b.slice(0, 5))
assert.strictEqual(a.compare(b, 0, 5, 4), 1);

// Equivalent to Buffer.compare(a.slice(1), b.slice(5))
assert.strictEqual(a.compare(b, 5, undefined, 1), 1);

// Equivalent to Buffer.compare(a.slice(2), b.slice(2, 4))
assert.strictEqual(a.compare(b, 2, 4, 2), -1);

// Equivalent to Buffer.compare(a.slice(4), b.slice(0, 7))
assert.strictEqual(a.compare(b, 0, 7, 4), -1);

// Equivalent to Buffer.compare(a.slice(4, 6), b.slice(0, 7));
assert.strictEqual(a.compare(b, 0, 7, 4, 6), -1);

// Null is ambiguous.
assert.throws(
  () => a.compare(b, 0, null),
  { code: 'ERR_INVALID_ARG_TYPE' }
);

// Values do not get coerced.
assert.throws(
  () => a.compare(b, 0, { valueOf: () => 5 }),
  { code: 'ERR_INVALID_ARG_TYPE' }
);

// Infinity should not be coerced.
assert.throws(
  () => a.compare(b, Infinity, -Infinity),
  { code: 'ERR_OUT_OF_RANGE' }
);

// Zero length target because default for targetEnd <= targetSource
assert.strictEqual(a.compare(b, 0xff), 1);

assert.throws(
  () => a.compare(b, '0xff'),
  { code: 'ERR_INVALID_ARG_TYPE' }
);
assert.throws(
  () => a.compare(b, 0, '0xff'),
  { code: 'ERR_INVALID_ARG_TYPE' }
);

const oor = { code: 'ERR_OUT_OF_RANGE' };

assert.throws(() => a.compare(b, 0, 100, 0), oor);
assert.throws(() => a.compare(b, 0, 1, 0, 100), oor);
assert.throws(() => a.compare(b, -1), oor);
assert.throws(() => a.compare(b, 0, Infinity), oor);
assert.throws(() => a.compare(b, 0, 1, -1), oor);
assert.throws(() => a.compare(b, -Infinity, Infinity), oor);
common.expectsError(() => a.compare(), {
  code: 'ERR_INVALID_ARG_TYPE',
  type: TypeError,
  message: 'The "target" argument must be one of ' +
           'type Buffer or Uint8Array. Received type undefined'
});