// Copyright (C) 2017 Josh Wolfe. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
description: Prefix decrement for references to BigInt values
esid: sec-prefix-decrement-operator-runtime-semantics-evaluation
info: |
  1. Let expr be the result of evaluating UnaryExpression.
  2. Let oldValue be ? ToNumeric(? GetValue(expr)).
  3. Let newValue be ? Type(oldvalue)::subtract(oldValue, Type(oldValue)::unit).
  4. Perform ? PutValue(expr, newValue).
  5. Return newValue.
features: [BigInt]
---*/

var x = 1n;
assert.sameValue(--x, 0n, "var x = 1n; --x === 0n");
assert.sameValue(x, 0n, "var x = 1n; --x; x === 0n");

var x = 0n;
assert.sameValue(--x, -1n, "var x = 0n; --x === -1n");
assert.sameValue(x, -1n, "var x = 0n; --x; x === -1n");

var x = 123457n;
assert.sameValue(--x, 123456n, "var x = 123457n; --x === 123456n");
assert.sameValue(x, 123456n, "var x = 123457n; --x; x === 123456n");

var x = -123456n;
assert.sameValue(--x, -123457n, "var x = -123456n; --x === -123457n");
assert.sameValue(x, -123457n, "var x = -123456n; --x; x === -123457n");

var x = 0x1fffffffffffff01n;
assert.sameValue(--x, 0x1fffffffffffff00n, "var x = 0x1fffffffffffff01n; --x === 0x1fffffffffffff00n");
assert.sameValue(x, 0x1fffffffffffff00n, "var x = 0x1fffffffffffff01n; --x; x === 0x1fffffffffffff00n");

var x = -0x1fffffffffffff00n;
assert.sameValue(--x, -0x1fffffffffffff01n, "var x = -0x1fffffffffffff00n; --x === -0x1fffffffffffff01n");
assert.sameValue(x, -0x1fffffffffffff01n, "var x = -0x1fffffffffffff00n; --x; x === -0x1fffffffffffff01n");

var x = {y:1n};
assert.sameValue(--x.y, 0n, "var x = {y:1n}; --x.y === 0n");
assert.sameValue(x.y, 0n, "var x = {y:1n}; --x.y; x.y === 0n");

var x = {y:{z:1n}};
assert.sameValue(--x.y.z, 0n, "var x = {y:{z:1n}}; --x.y.z === 0n");
assert.sameValue(x.y.z, 0n, "var x = {y:{z:1n}}; --x.y.z; x.y.z === 0n");

var x = [1n];
assert.sameValue(--x[0], 0n, "var x = [1n]; --x[0] === 0n");
assert.sameValue(x[0], 0n, "var x = [1n]; --x[0]; x[0] === 0n");

var x = [null, [null, null, 1n]];
assert.sameValue(--x[1][2], 0n, "var x = [null, [null, null, 1n]]; --x[1][2] === 0n");
assert.sameValue(x[1][2], 0n, "var x = [null, [null, null, 1n]]; --x[1][2]; x[1][2] === 0n");

var x = {y:[1n]};
assert.sameValue(--x.y[0], 0n, "var x = {y:[1n]}; --x.y[0] === 0n");
assert.sameValue(x.y[0], 0n, "var x = {y:[1n]}; --x.y[0]; x.y[0] === 0n");

var x = [{z:1n}];
assert.sameValue(--x[0].z, 0n, "var x = [{z:1n}]; --x[0].z === 0n");
assert.sameValue(x[0].z, 0n, "var x = [{z:1n}]; --x[0].z; x[0].z === 0n");