wadec 0.0.1

A library for decoding WebAssembly modules.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99

// META: global=window,dedicatedworker,jsshell
// META: script=/wasm/jsapi/wasm-module-builder.js

let emptyModuleBinary;
setup(() => {
  emptyModuleBinary = new WasmModuleBuilder().toBuffer();
});

test(() => {
  assert_throws_js(TypeError, () => WebAssembly.validate());
}, "Missing argument");

test(() => {
  const invalidArguments = [
    undefined,
    null,
    true,
    "",
    Symbol(),
    1,
    {},
    ArrayBuffer,
    ArrayBuffer.prototype,
    Array.from(emptyModuleBinary),
  ];
  for (const argument of invalidArguments) {
    assert_throws_js(TypeError, () => WebAssembly.validate(argument),
                     `validate(${format_value(argument)})`);
  }
}, "Invalid arguments");

test(() => {
  const fn = WebAssembly.validate;
  const thisValues = [
    undefined,
    null,
    true,
    "",
    Symbol(),
    1,
    {},
    WebAssembly,
  ];
  for (const thisValue of thisValues) {
    assert_true(fn.call(thisValue, emptyModuleBinary), `this=${format_value(thisValue)}`);
  }
}, "Branding");

const modules = [
  // Incomplete header.
  [[], false],
  [[0x00], false],
  [[0x00, 0x61], false],
  [[0x00, 0x61, 0x73], false],
  [[0x00, 0x61, 0x73, 0x6d], false],
  [[0x00, 0x61, 0x73, 0x6d, 0x01], false],
  [[0x00, 0x61, 0x73, 0x6d, 0x01, 0x00], false],
  [[0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00], false],

  // Complete header.
  [[0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00], true],

  // Invalid version.
  [[0x00, 0x61, 0x73, 0x6d, 0x00, 0x00, 0x00, 0x00], false],
  [[0x00, 0x61, 0x73, 0x6d, 0x02, 0x00, 0x00, 0x00], false],

  // Nameless custom section.
  [[0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00], false],

  // Custom section with empty name.
  [[0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00], true],

  // Custom section with name "a".
  [[0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x00, 0x02, 0x01, 0x61], true],
];
const bufferTypes = [
  Uint8Array,
  Int8Array,
  Uint16Array,
  Int16Array,
  Uint32Array,
  Int32Array,
];
for (const [module, expected] of modules) {
  const name = module.map(n => n.toString(16)).join(" ");
  for (const bufferType of bufferTypes) {
    if (module.length % bufferType.BYTES_PER_ELEMENT === 0) {
      test(() => {
        const bytes = new Uint8Array(module);
        const moduleBuffer = new bufferType(bytes.buffer);
        assert_equals(WebAssembly.validate(moduleBuffer), expected);
      }, `Validating module [${name}] in ${bufferType.name}`);
    }
  }
}

test(() => {
  assert_true(WebAssembly.validate(emptyModuleBinary, {}));
}, "Stray argument");