nodejs/test/parallel/test-buffer-compare.js

'use strict';

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

const b = Buffer.alloc(1, 'a');
const c = Buffer.alloc(1, 'c');
const d = Buffer.alloc(2, 'aa');
const e = new Uint8Array([ 0x61, 0x61 ]); // ASCII 'aa', same as d

assert.strictEqual(b.compare(c), -1);
assert.strictEqual(c.compare(d), 1);
assert.strictEqual(d.compare(b), 1);
assert.strictEqual(d.compare(e), 0);
assert.strictEqual(b.compare(d), -1);
assert.strictEqual(b.compare(b), 0);

assert.strictEqual(Buffer.compare(b, c), -1);
assert.strictEqual(Buffer.compare(c, d), 1);
assert.strictEqual(Buffer.compare(d, b), 1);
assert.strictEqual(Buffer.compare(b, d), -1);
assert.strictEqual(Buffer.compare(c, c), 0);
assert.strictEqual(Buffer.compare(e, e), 0);
assert.strictEqual(Buffer.compare(d, e), 0);
assert.strictEqual(Buffer.compare(d, b), 1);

assert.strictEqual(Buffer.compare(Buffer.alloc(0), Buffer.alloc(0)), 0);
assert.strictEqual(Buffer.compare(Buffer.alloc(0), Buffer.alloc(1)), -1);
assert.strictEqual(Buffer.compare(Buffer.alloc(1), Buffer.alloc(0)), 1);

const errMsg = common.expectsError({
  code: 'ERR_INVALID_ARG_TYPE',
  type: TypeError,
  message: 'The "buf1", "buf2" arguments must be one of ' +
             'type Buffer or Uint8Array'
}, 2);
assert.throws(() => Buffer.compare(Buffer.alloc(1), 'abc'), errMsg);

assert.throws(() => Buffer.compare('abc', Buffer.alloc(1)), errMsg);

common.expectsError(() => Buffer.alloc(1).compare('abc'), {
  code: 'ERR_INVALID_ARG_TYPE',
  type: TypeError,
  message: 'The "target" argument must be one of ' +
           'type Buffer or Uint8Array. Received type string'
});