pjs/docshell/test/browser/browser_bug134911.js

const Ci = Components.interfaces;
const Cc = Components.classes;

/* The test text decoded correctly as Shift_JIS */
const rightText="\u30E6\u30CB\u30B3\u30FC\u30C9\u306F\u3001\u3059\u3079\u3066\u306E\u6587\u5B57\u306B\u56FA\u6709\u306E\u756A\u53F7\u3092\u4ED8\u4E0E\u3057\u307E\u3059";

const enteredText1="The quick brown fox jumps over the lazy dog";
const enteredText2="\u03BE\u03B5\u03C3\u03BA\u03B5\u03C0\u03AC\u03B6\u03C9\u0020\u03C4\u1F74\u03BD\u0020\u03C8\u03C5\u03C7\u03BF\u03C6\u03B8\u03CC\u03C1\u03B1\u0020\u03B2\u03B4\u03B5\u03BB\u03C5\u03B3\u03BC\u03AF\u03B1";

var testPage;

function test() {
  testPage = Application.activeWindow.open(url("about:blank"));
  testPage.events.addListener("load", afterOpen);
  testPage.load(url("chrome://mochikit/content/browser/docshell/test/browser/test-form_sjis.html"));
  testPage.focus();

  waitForExplicitFinish();
}

function afterOpen() {
    testPage.events.removeListener("load", afterOpen);
    testPage.events.addListener("load", afterChangeCharset);
    testPage.document.getElementById("testtextarea").value=enteredText1;
    testPage.document.getElementById("testinput").value=enteredText2;

    /* Force the page encoding to Shift_JIS */
    SetForcedCharset("Shift_JIS");
}
  
function afterChangeCharset() {
    testPage.events.removeListener("load", afterChangeCharset);
    is(testPage.document.getElementById("testpar").innerHTML, rightText,
       "encoding successfully changed");
    is(testPage.document.getElementById("testtextarea").value, enteredText1,
       "text preserved in <textarea>");
    is(testPage.document.getElementById("testinput").value, enteredText2,
       "text preserved in <input>");

    testPage.close();
    finish();
}

function url(spec) {
  var ios = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
  return ios.newURI(spec, null, null);
}