v8/test/mjsunit/wasm/gc-experimental-string-conversions.js

// Copyright 2022 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Flags: --experimental-wasm-gc --allow-natives-syntax

d8.file.execute('test/mjsunit/wasm/wasm-module-builder.js');

var builder = new WasmModuleBuilder();

let i16Array = builder.addArray(kWasmI16, true);

builder.addFunction('getHelloArray', makeSig([], [kWasmArrayRef]))
    .addBody([
      ...wasmI32Const(72), ...wasmI32Const(69), ...wasmI32Const(76),
      ...wasmI32Const(76), ...wasmI32Const(79),
      kGCPrefix, kExprArrayNewFixed, i16Array, 5
    ])
    .exportFunc();

builder.addFunction('getChar', makeSig([kWasmArrayRef, kWasmI32], [kWasmI32]))
    .addBody([
      kExprLocalGet, 0, kGCPrefix, kExprRefAsArray, kGCPrefix,
      kExprRefCast, i16Array, kExprLocalGet, 1, kGCPrefix, kExprArrayGetS,
      i16Array
    ])
    .exportFunc();

const instance = builder.instantiate();
const getHelloArray = instance.exports.getHelloArray;
const getChar = instance.exports.getChar;

assertEquals(
    WebAssembly.experimentalConvertArrayToString(getHelloArray(), 0, 5),
    'HELLO');
assertEquals(
    WebAssembly.experimentalConvertArrayToString(getHelloArray(), 1, 4),
    'ELLO');
assertEquals(
    WebAssembly.experimentalConvertArrayToString(getHelloArray(), 0, 3), 'HEL');

const string = 'foobar'
const array =
    WebAssembly.experimentalConvertStringToArray('foobar', getHelloArray());
for (let i = 0; i < string.length; ++i) {
  assertEquals(getChar(array, i), string.charCodeAt(i));
}

// Test calling built-ins with different amount of (invalid) arguments.
function arrayToString() {
  WebAssembly.experimentalConvertArrayToString(...arguments);
}
function stringToArray() {
  WebAssembly.experimentalConvertStringToArray(...arguments);
}

let args = [];
for (let i = 1; i <= 5; ++i) {
  assertThrows(() => arrayToString(...args));
  assertThrows(() => stringToArray(...args));
  %PrepareFunctionForOptimization(arrayToString);
  %PrepareFunctionForOptimization(stringToArray);
  %OptimizeFunctionOnNextCall(arrayToString);
  %OptimizeFunctionOnNextCall(stringToArray);
  assertThrows(() => arrayToString(...args));
  assertThrows(() => stringToArray(...args));
  args.push(i);
}