The Tor Browser / file revision

 // |reftest| skip-if(!xulRuntime.shell)

 // Any copyright is dedicated to the Public Domain.

 // http://creativecommons.org/licenses/publicdomain/

 function viewToString(view)

 {

   return String.fromCharCode.apply(null, view);

 }

 function assertThrows(f, wantException)

 {

     try {

       f();

       assertEq(true, false, "expected " + wantException + " exception");

     } catch (e) {

       assertEq(e.name, wantException.name, e.toString());

     }

 }

 function test() {

     var filename = "file-mapped-arraybuffers.txt";

     var buffer = createMappedArrayBuffer(filename);

     var view = new Uint8Array(buffer);

     assertEq(viewToString(view), "01234567abcdefghijkl");

     var buffer2 = createMappedArrayBuffer(filename, 8);

     view = new Uint8Array(buffer2);

     assertEq(viewToString(view), "abcdefghijkl");

     var buffer3 = createMappedArrayBuffer(filename, 0, 8);

     view = new Uint8Array(buffer3);

     assertEq(viewToString(view), "01234567");

     // Check that invalid sizes and offsets are caught

     assertThrows(() => createMappedArrayBuffer("empty.txt", 8), RangeError);

     assertThrows(() => createMappedArrayBuffer("empty.txt", 0, 8), Error);

 }

 test();

 reportCompare(0, 0, 'ok');