[wasm] Implement WebAssembly.Module.customSections.

test/mjsunit/wasm/js-api.js

Index: test/mjsunit/wasm/js-api.js
diff --git a/test/mjsunit/wasm/js-api.js b/test/mjsunit/wasm/js-api.js
index 1106853b43b8cf1c8fef8af5d9b7f20471de83d5..05b7d6146eb25f3116f96ca54c5ee59e701ff1d7 100644
--- a/test/mjsunit/wasm/js-api.js
+++ b/test/mjsunit/wasm/js-api.js
@@ -14,6 +14,14 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
 function assertEq(val, expected) {
   assertEquals(expected, val);
 }
+function assertArrayBuffer(val, expected) {
+  assertTrue(val instanceof ArrayBuffer);
+  assertEq(expected.length, val.byteLength);
+  var input = new Int8Array(val);
+  for (var i = 0; i < expected.length; i++) {
+    assertEq(expected[i], input[i]);
+  }
+}
 function wasmIsSupported() {
   return (typeof WebAssembly.Module) == "function";
 }
@@ -244,6 +252,41 @@ assertEq(arr[2].name, "c");
 assertEq(arr[3].kind, "global");
 assertEq(arr[3].name, "x");
 
+// 'WebAssembly.Module.customSections' data property
+let moduleCustomSectionsDesc = Object.getOwnPropertyDescriptor(Module, 'customSections');
+assertEq(typeof moduleCustomSectionsDesc.value, "function");
+assertEq(moduleCustomSectionsDesc.writable, true);
+assertEq(moduleCustomSectionsDesc.enumerable, false);
+assertEq(moduleCustomSectionsDesc.configurable, true);
+
+let moduleCustomSections = moduleCustomSectionsDesc.value;
+assertEq(moduleCustomSections.length, 1);
+assertErrorMessage(() => moduleCustomSections(), TypeError, /requires more than 0 arguments/);
+assertErrorMessage(() => moduleCustomSections(undefined), TypeError, /first argument must be a WebAssembly.Module/);
+assertErrorMessage(() => moduleCustomSections({}), TypeError, /first argument must be a WebAssembly.Module/);
+var arr = moduleCustomSections(emptyModule);
+assertEq(arr instanceof Array, true);
+assertEq(arr.length, 0);
+
+let customSectionModuleBinary2 = (() => {
+  let builder = new WasmModuleBuilder();
+  builder.addExplicitSection([kUnknownSectionCode, 3, 1,
+                              'x'.charCodeAt(0), 2]);
+  builder.addExplicitSection([kUnknownSectionCode, 6, 3,
+                              'f'.charCodeAt(0),
+                              'o'.charCodeAt(0),
+                              'o'.charCodeAt(0),
+                              66, 77]);
+  return new Int8Array(builder.toBuffer());
+})();
+var arr = moduleCustomSections(new Module(customSectionModuleBinary2));
+assertEq(arr instanceof Array, true);
+assertEq(arr.length, 2);
+assertEq(arr[0].name, "x");
+assertArrayBuffer(arr[0].data, [2]);
+assertEq(arr[1].name, "foo");
+assertArrayBuffer(arr[1].data, [66, 77]);
+
 // 'WebAssembly.Instance' data property
 let instanceDesc = Object.getOwnPropertyDescriptor(WebAssembly, 'Instance');
 assertEq(typeof instanceDesc.value, "function");