Testing The Impossible: Inserting Into Database

5. June, 2009 at 19:34 | In Software | Leave a Comment
Tags: , , ,

Tests run slow when you need a database. An in-memory database like HSQLDB or Derby helps but at a cost: Your real database will accept some SQL which your test database won’t. So the question is: How can you write a performant test which uses the SQL of the real database?

My solution is to wrap the JDBC layer. Either use a mock JDBC interface like the one provided by mockrunner. Or write your own. With Java 5 and varargs, this is simple:

public int update (Connection conn, String sql, Object... params) throws SQLException {
    PreparedStatement stmt = null;
    try {
        stmt = conn.prepareStatement (sql);
        int i = 1;
        for (Object p: params) {
            stmt.setObject(i++, p);
        }
        return stmt.executeUpdate ();
    }
    finally {
        stmt.close ();
    }
}

Put all these methods into an object that you can pass around. In your tests, override this object with a mockup that simply collects the SQL strings and parameter arrays. You can even mix and match: By examining the SQL string, you can decide whether you want to run a query against the database or handle it internally.

This way, you can collect any newly created objects but still load some background data from the database (until you get bored and make the query methods return predefined results).

In the asserts, just collect all the results into a big String and compare them all at once.

Notes: The code above is a bit more complicated if you allow null values. In this case, you need to tell JDBC what the column type is. My solution is a NullParameter class which contains the type. If the loop encounters this class, then it calls setNull() instead of setObject().

Testing the Impossible: JavaScript in a Web Page

18. November, 2008 at 11:15 | In Software | 1 Comment
Tags: , , ,

How do you run JUnit tests on JavaScript in a web page? Impossible?

Here is what you need: First, get a copy of Rhino (at least 1.6R7). Then, save a copy of the JavaScript code at the bottom as “env.js“. And here is the setup code for the JUnit test:

    Context cx;
    Global scope;

    public void setupContext () throws IllegalAccessException,
            InstantiationException, InvocationTargetException
    {
        cx = Context.enter();
        scope = new Global();
        scope.init (cx);

        addScript(cx, scope, new File ("html/env.js"));

        File f = new File ("html/demo.html");
        cx.evaluateString(scope,
                "window.location = '"+f.toURL()+"';\n"
                + "", "setupContext", 1, null);
    }

    public void addScript (Context cx, Scriptable scope, File file) throws IOException
    {
        Reader in = new FileReader (file);
        cx.evaluateReader(scope, in, file.getAbsolutePath(), 1, null);
    }

This will load “demo.html” into the browser simulation. The problem here: The loading is asynchronous (just like in a real browser). Now what? We need synchronization:

import org.mozilla.javascript.ScriptableObject;

public class JSJSynchronize extends ScriptableObject
{
    public Object data;
    public Object lock = new Object ();

    public JSJSynchronize()
    {
    }

    @Override
    public String getClassName ()
    {
        return "JSJSynchronize";
    }

    public Object jsGet_data()
    {
        synchronized (lock)
        {
            try
            {
                lock.wait ();
            }
            catch (InterruptedException e)
            {
                throw new RuntimeException ("Should not happen", e);
            }

            return data;
        }
    }

    public void jsSet_data(Object data)
    {
        synchronized (lock)
        {
            this.data = data;
            lock.notify ();
        }
    }

    public Object getData()
    {
        synchronized (lock)
        {
            try
            {
                lock.wait ();
            }
            catch (InterruptedException e)
            {
                throw new RuntimeException ("Should not happen", e);
            }

            return data;
        }
    }

    public void setData(Object data)
    {
        synchronized (lock)
        {
            this.data = data;
            lock.notify ();
        }
    }

}

With this code and “window.onload”, we can wait for the html to load:

        JSJSynchronize jsjSynchronize;
        ScriptableObject.defineClass(scope, JSJSynchronize.class);

        jsjSynchronize = (JSJSynchronize)cx.newObject (scope, "JSJSynchronize");
        scope.put("jsjSynchronize", scope, jsjSynchronize);

        cx.evaluateString(scope,
                "window.location = '"+f.toURL()+"';\n" +
                "window.onload = function(){\n" +
                "    print('Window loaded');\n" +
                "    jsjSynchronize.data = window;\n" +
                "};\n" +
                "", "", 1, null);

        ScriptableObject window = (ScriptableObject)jsjSynchronize.getData();
        System.out.println ("window="+window);
        ScriptableObject document = (ScriptableObject)scope.get ("document", scope);
        System.out.println ("document="+document);
        System.out.println ("document.forms="+document.get ("forms", document));
        ScriptableObject navigator = (ScriptableObject)scope.get ("navigator", scope);
        System.out.println ("navigator="+navigator);
        System.out.println ("navigator.location="+navigator.get ("location", navigator));

        // I've been too lazy to parse the HTML for the scripts:
        addScript(cx, scope, new File ("src/main/webapp/script/prototype.js"));

Slightly modified version of env.js, original by John Resig (original code):

/*
 * Simulated browser environment for Rhino
 *   By John Resig <http://ejohn.org/>
 * Copyright 2007 John Resig, under the MIT License
 * http://jqueryjs.googlecode.com/svn/trunk/jquery/build/runtest/
 * Revision 5251
 */

// The window Object
var window = this;

// generic enumeration
Function.prototype.forEach = function(object, block, context) {
 for (var key in object) {
  if (typeof this.prototype[key] == "undefined") {
   block.call(context, object[key], key, object);
  }
 }
};

// globally resolve forEach enumeration
var forEach = function(object, block, context) {
 if (object) {
  var resolve = Object; // default
  if (object instanceof Function) {
   // functions have a "length" property
   resolve = Function;
  } else if (object.forEach instanceof Function) {
   // the object implements a custom forEach method so use that
   object.forEach(block, context);
   return;
  } else if (typeof object.length == "number") {
   // the object is array-like
   resolve = Array;
  }
  resolve.forEach(object, block, context);
 }
};

function collectForms(document) {
 var result = document.body.getElementsByTagName('form');
 //print('collectForms');
 document.forms = result;

 for (var i=0; i<result.length; i++) {
     var f = result[i];
     f.name = f.attributes['name'];
     //print('Form '+f.name);
     document[f.name] = f;
     f.elements = f.getElementsByTagName('input');

     for(var j=0; j<f.elements.length; j++) {
         var e = f.elements[j];
         var attr = e.attributes;

         //forEach(attr, print);
         e.type = attr['type'];
         e.name = attr['name'];
         e.className = attr['class'];

         f[e.name] = e;
  //print('    Input '+e.name);
     }
 }
}

(function(){

 // Browser Navigator

 window.navigator = {
  get userAgent(){
   return "Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3";
  },
  get appVersion(){
   return "Mozilla/5.0";
  }
 };

 var curLocation = (new java.io.File("./")).toURL();

 window.__defineSetter__("location", function(url){
  var xhr = new XMLHttpRequest();
  xhr.open("GET", url);
  xhr.onreadystatechange = function(){
   curLocation = new java.net.URL( curLocation, url );
   window.document = xhr.responseXML;
   collectForms(window.document);

   var event = document.createEvent();
   event.initEvent("load");
   window.dispatchEvent( event );
  };
  xhr.send();
 });

 window.__defineGetter__("location", function(url){
  return {
   get protocol(){
    return curLocation.getProtocol() + ":";
   },
   get href(){
    return curLocation.toString();
   },
   toString: function(){
    return this.href;
   }
  };
 });

 // Timers

 var timers = [];

 window.setTimeout = function(fn, time){
  var num;
  return num = setInterval(function(){
   fn();
   clearInterval(num);
  }, time);
 };

 window.setInterval = function(fn, time){
  var num = timers.length;

  timers[num] = new java.lang.Thread(new java.lang.Runnable({
   run: function(){
    while (true){
     java.lang.Thread.currentThread().sleep(time);
     fn();
    }
   }
  }));

  timers[num].start();

  return num;
 };

 window.clearInterval = function(num){
  if ( timers[num] ) {
   timers[num].stop();
   delete timers[num];
  }
 };

 // Window Events

 var events = [{}];

 window.addEventListener = function(type, fn){
  if ( !this.uuid || this == window ) {
   this.uuid = events.length;
   events[this.uuid] = {};
  }

  if ( !events[this.uuid][type] )
   events[this.uuid][type] = [];

  if ( events[this.uuid][type].indexOf( fn ) < 0 )
   events[this.uuid][type].push( fn );
 };

 window.removeEventListener = function(type, fn){
    if ( !this.uuid || this == window ) {
        this.uuid = events.length;
        events[this.uuid] = {};
    }

    if ( !events[this.uuid][type] )
   events[this.uuid][type] = [];

  events[this.uuid][type] =
   events[this.uuid][type].filter(function(f){
    return f != fn;
   });
 };

 window.dispatchEvent = function(event){
  if ( event.type ) {
   if ( this.uuid && events[this.uuid][event.type] ) {
    var self = this;

    events[this.uuid][event.type].forEach(function(fn){
     fn.call( self, event );
    });
   }

   if ( this["on" + event.type] )
    this["on" + event.type].call( self, event );
  }
 };

 // DOM Document

 window.DOMDocument = function(file){
  this._file = file;
  var factory = Packages.javax.xml.parsers.DocumentBuilderFactory.newInstance();
  factory.setValidating(false);
  this._dom = factory.newDocumentBuilder().parse(file);

  if ( !obj_nodes.containsKey( this._dom ) )
   obj_nodes.put( this._dom, this );
 };

 DOMDocument.prototype = {
  createTextNode: function(text){
   return makeNode( this._dom.createTextNode(
    text.replace(/&/g, "&").replace(/</g, "<").replace(/>/g, ">")) );
  },
  createElement: function(name){
   return makeNode( this._dom.createElement(name.toLowerCase()) );
  },
  getElementsByTagName: function(name){
   return new DOMNodeList( this._dom.getElementsByTagName(
    name.toLowerCase()) );
  },
  getElementById: function(id){
   var elems = this._dom.getElementsByTagName("*");

   for ( var i = 0; i < elems.length; i++ ) {
    var elem = elems.item(i);
    if ( elem.getAttribute("id") == id )
     return makeNode(elem);
   }

   return null;
  },
  get body(){
   return this.getElementsByTagName("body")[0];
  },
  get documentElement(){
   return makeNode( this._dom.getDocumentElement() );
  },
  get ownerDocument(){
   return null;
  },
  addEventListener: window.addEventListener,
  removeEventListener: window.removeEventListener,
  dispatchEvent: window.dispatchEvent,
  get nodeName() {
   return "#document";
  },
  importNode: function(node, deep){
   return makeNode( this._dom.importNode(node._dom, deep) );
  },
  toString: function(){
   return "Document" + (typeof this._file == "string" ?
    ": " + this._file : "");
  },
  get innerHTML(){
   return this.documentElement.outerHTML;
  },

  get defaultView(){
   return {
    getComputedStyle: function(elem){
     return {
      getPropertyValue: function(prop){
       prop = prop.replace(/-(w)/g,function(m,c){
        return c.toUpperCase();
       });
       var val = elem.style[prop];

       if ( prop == "opacity" && val == "" )
        val = "1";

       return val;
      }
     };
    }
   };
  },

  createEvent: function(){
   return {
    type: "",
    initEvent: function(type){
     this.type = type;
    }
   };
  }
 };

 function getDocument(node){
  return obj_nodes.get(node);
 }

 // DOM NodeList

 window.DOMNodeList = function(list){
  this._dom = list;
  this.length = list.getLength();

  for ( var i = 0; i < this.length; i++ ) {
   var node = list.item(i);
   this[i] = makeNode( node );
  }
 };

 DOMNodeList.prototype = {
  toString: function(){
   return "[ " +
    Array.prototype.join.call( this, ", " ) + " ]";
  },
  get outerHTML(){
   return Array.prototype.map.call(
    this, function(node){return node.outerHTML;}).join('');
  }
 };

 // DOM Node

 window.DOMNode = function(node){
  this._dom = node;
 };

 DOMNode.prototype = {
  get nodeType(){
   return this._dom.getNodeType();
  },
  get nodeValue(){
   return this._dom.getNodeValue();
  },
  get nodeName() {
   return this._dom.getNodeName();
  },
  cloneNode: function(deep){
   return makeNode( this._dom.cloneNode(deep) );
  },
  get ownerDocument(){
   return getDocument( this._dom.ownerDocument );
  },
  get documentElement(){
   return makeNode( this._dom.documentElement );
  },
  get parentNode() {
   return makeNode( this._dom.getParentNode() );
  },
  get nextSibling() {
   return makeNode( this._dom.getNextSibling() );
  },
  get previousSibling() {
   return makeNode( this._dom.getPreviousSibling() );
  },
  toString: function(){
   return '"' + this.nodeValue + '"';
  },
  get outerHTML(){
   return this.nodeValue;
  }
 };

 // DOM Element

 window.DOMElement = function(elem){
  this._dom = elem;
  this.style = {
   get opacity(){ return this._opacity; },
   set opacity(val){ this._opacity = val + ""; }
  };

  // Load CSS info
  var styles = (this.getAttribute("style") || "").split(/s*;s*/);

  for ( var i = 0; i < styles.length; i++ ) {
   var style = styles[i].split(/s*:s*/);
   if ( style.length == 2 )
    this.style[ style[0] ] = style[1];
  }
 };

 DOMElement.prototype = extend( new DOMNode(), {
  get nodeName(){
   return this.tagName.toUpperCase();
  },
  get tagName(){
   return this._dom.getTagName();
  },
  toString: function(){
   return "<" + this.tagName + (this.id ? "#" + this.id : "" ) + ">";
  },
  get outerHTML(){
   var ret = "<" + this.tagName, attr = this.attributes;

   for ( var i in attr )
    ret += " " + i + "='" + attr[i] + "'";

   if ( this.childNodes.length || this.nodeName == "SCRIPT" )
    ret += ">" + this.childNodes.outerHTML +
     "</" + this.tagName + ">";
   else
    ret += "/>";

   return ret;
  },

  get attributes(){
   var attr = {}, attrs = this._dom.getAttributes();

   for ( var i = 0; i < attrs.getLength(); i++ )
    attr[ attrs.item(i).nodeName ] = attrs.item(i).nodeValue;

   return attr;
  },

  get innerHTML(){
   return this.childNodes.outerHTML;
  },
  set innerHTML(html){
   html = html.replace(/</?([A-Z]+)/g, function(m){
    return m.toLowerCase();
   });

   var nodes = this.ownerDocument.importNode(
    new DOMDocument( new java.io.ByteArrayInputStream(
     (new java.lang.String("<wrap>" + html + "</wrap>"))
      .getBytes("UTF8"))).documentElement, true).childNodes;

   while (this.firstChild)
    this.removeChild( this.firstChild );

   for ( var i = 0; i < nodes.length; i++ )
    this.appendChild( nodes[i] );
  },

  get textContent(){
   return nav(this.childNodes);

   function nav(nodes){
    var str = "";
    for ( var i = 0; i < nodes.length; i++ )
     if ( nodes[i].nodeType == 3 )
      str += nodes[i].nodeValue;
     else if ( nodes[i].nodeType == 1 )
      str += nav(nodes[i].childNodes);
    return str;
   }
  },
  set textContent(text){
   while (this.firstChild)
    this.removeChild( this.firstChild );
   this.appendChild( this.ownerDocument.createTextNode(text));
  },

  style: {},
  clientHeight: 0,
  clientWidth: 0,
  offsetHeight: 0,
  offsetWidth: 0,

  get disabled() {
   var val = this.getAttribute("disabled");
   return val != "false" && !!val;
  },
  set disabled(val) { return this.setAttribute("disabled",val); },

  get checked() {
   var val = this.getAttribute("checked");
   return val != "false" && !!val;
  },
  set checked(val) { return this.setAttribute("checked",val); },

  get selected() {
   if ( !this._selectDone ) {
    this._selectDone = true;

    if ( this.nodeName == "OPTION" && !this.parentNode.getAttribute("multiple") ) {
     var opt = this.parentNode.getElementsByTagName("option");

     if ( this == opt[0] ) {
      var select = true;

      for ( var i = 1; i < opt.length; i++ )
       if ( opt[i].selected ) {
        select = false;
        break;
       }

      if ( select )
       this.selected = true;
     }
    }
   }

   var val = this.getAttribute("selected");
   return val != "false" && !!val;
  },
  set selected(val) { return this.setAttribute("selected",val); },

  get className() { return this.getAttribute("class") || ""; },
  set className(val) {
   if (typeof val != 'string') { val = "" + val; }
   return this.setAttribute("class",
    val.replace(/(^s*|s*$)/g,""));
  },

  get type() { return this.getAttribute("type") || ""; },
  set type(val) { return this.setAttribute("type",val); },

  get value() { return this.getAttribute("value") || ""; },
  set value(val) { return this.setAttribute("value",val); },

  get src() { return this.getAttribute("src") || ""; },
  set src(val) { return this.setAttribute("src",val); },

  get id() { return this.getAttribute("id") || ""; },
  set id(val) { return this.setAttribute("id",val); },

  getAttribute: function(name){
   return this._dom.hasAttribute(name) ?
    new String( this._dom.getAttribute(name) ) :
    null;
  },
  setAttribute: function(name,value){
   this._dom.setAttribute(name,value);
  },
  removeAttribute: function(name){
   this._dom.removeAttribute(name);
  },

  get childNodes(){
   return new DOMNodeList( this._dom.getChildNodes() );
  },
  get firstChild(){
   return makeNode( this._dom.getFirstChild() );
  },
  get lastChild(){
   return makeNode( this._dom.getLastChild() );
  },
  appendChild: function(node){
   this._dom.appendChild( node._dom );
  },
  insertBefore: function(node,before){
   this._dom.insertBefore( node._dom, before ? before._dom : before );
  },
  removeChild: function(node){
   this._dom.removeChild( node._dom );
  },

  getElementsByTagName: DOMDocument.prototype.getElementsByTagName,

  addEventListener: window.addEventListener,
  removeEventListener: window.removeEventListener,
  dispatchEvent: window.dispatchEvent,

  click: function(){
   var event = document.createEvent();
   event.initEvent("click");
   this.dispatchEvent(event);
  },
  submit: function(){
   var event = document.createEvent();
   event.initEvent("submit");
   this.dispatchEvent(event);
  },
  focus: function(){
   var event = document.createEvent();
   event.initEvent("focus");
   this.dispatchEvent(event);
  },
  blur: function(){
   var event = document.createEvent();
   event.initEvent("blur");
   this.dispatchEvent(event);
  },
  get elements(){
   return this.getElementsByTagName("*");
  },
  get contentWindow(){
   return this.nodeName == "IFRAME" ? {
    document: this.contentDocument
   } : null;
  },
  get contentDocument(){
   if ( this.nodeName == "IFRAME" ) {
    if ( !this._doc )
     this._doc = new DOMDocument(
      new java.io.ByteArrayInputStream((new java.lang.String(
      "<html><head><title></title></head><body></body></html>"))
      .getBytes("UTF8")));
    return this._doc;
   } else
    return null;
  }
 });

 // Helper method for extending one object with another

 function extend(a,b) {
  for ( var i in b ) {
   var g = b.__lookupGetter__(i), s = b.__lookupSetter__(i);

   if ( g || s ) {
    if ( g )
     a.__defineGetter__(i, g);
    if ( s )
     a.__defineSetter__(i, s);
   } else
    a[i] = b[i];
  }
  return a;
 }

 // Helper method for generating the right
 // DOM objects based upon the type

 var obj_nodes = new java.util.HashMap();

 function makeNode(node){
  if ( node ) {
   if ( !obj_nodes.containsKey( node ) )
    obj_nodes.put( node, node.getNodeType() ==
     Packages.org.w3c.dom.Node.ELEMENT_NODE ?
      new DOMElement( node ) : new DOMNode( node ) );

   return obj_nodes.get(node);
  } else
   return null;
 }

 // XMLHttpRequest
 // Originally implemented by Yehuda Katz

 window.XMLHttpRequest = function(){
  this.headers = {};
  this.responseHeaders = {};
 };

 XMLHttpRequest.prototype = {
  open: function(method, url, async, user, password){
   this.readyState = 1;
   if (async)
    this.async = true;
   this.method = method || "GET";
   this.url = url;
   this.onreadystatechange();
  },
  setRequestHeader: function(header, value){
   this.headers[header] = value;
  },
  getResponseHeader: function(header){ },
  send: function(data){
   var self = this;

   function makeRequest(){
    var url = new java.net.URL(curLocation, self.url);

    if ( url.getProtocol() == "file" ) {
     if ( self.method == "PUT" ) {
      var out = new java.io.FileWriter(
        new java.io.File( new java.net.URI( url.toString() ) ) ),
       text = new java.lang.String( data || "" );

      out.write( text, 0, text.length() );
      out.flush();
      out.close();
     } else if ( self.method == "DELETE" ) {
      var file = new java.io.File( new java.net.URI( url.toString() ) );
      file["delete"]();
     } else {
      var connection = url.openConnection();
      connection.connect();
      handleResponse();
     }
    } else {
     var connection = url.openConnection();

     connection.setRequestMethod( self.method );

     // Add headers to Java connection
     for (var header in self.headers)
      connection.addRequestProperty(header, self.headers[header]);

     connection.connect();

     // Stick the response headers into responseHeaders
     for (var i = 0; ; i++) {
      var headerName = connection.getHeaderFieldKey(i);
      var headerValue = connection.getHeaderField(i);
      if (!headerName && !headerValue) break;
      if (headerName)
       self.responseHeaders[headerName] = headerValue;
     }

     handleResponse();
    }

    function handleResponse(){
     self.readyState = 4;
     self.status = parseInt(connection.responseCode) || undefined;
     self.statusText = connection.responseMessage || "";

     var stream = new java.io.InputStreamReader(connection.getInputStream()),
      buffer = new java.io.BufferedReader(stream), line;

     while ((line = buffer.readLine()) != null)
      self.responseText += line;

     self.responseXML = null;

     if ( self.responseText.match(/^s*</) ) {
      //try {
       self.responseXML = new DOMDocument(
        new java.io.ByteArrayInputStream(
         (new java.lang.String(
          self.responseText)).getBytes("UTF8")));
      //} catch(e) {
      //}
     }
    }

    self.onreadystatechange();
   }

   if (this.async)
    (new java.lang.Thread(new java.lang.Runnable({
     run: makeRequest
    }))).start();
   else
    makeRequest();
  },
  abort: function(){},
  onreadystatechange: function(){},
  getResponseHeader: function(header){
   if (this.readyState < 3)
    throw new Error("INVALID_STATE_ERR");
   else {
    var returnedHeaders = [];
    for (var rHeader in this.responseHeaders) {
     if (rHeader.match(new Regexp(header, "i")))
      returnedHeaders.push(this.responseHeaders[rHeader]);
    }

    if (returnedHeaders.length)
     return returnedHeaders.join(", ");
   }

   return null;
  },
  getAllResponseHeaders: function(header){
   if (this.readyState < 3)
    throw new Error("INVALID_STATE_ERR");
   else {
    var returnedHeaders = [];

    for (var header in this.responseHeaders)
     returnedHeaders.push( header + ": " + this.responseHeaders[header] );

    return returnedHeaders.join("rn");
   }
  },
  async: true,
  readyState: 0,
  responseText: "",
  status: 0
 };
})();

Quickly disabling tests

25. July, 2007 at 07:56 | In Software | Leave a Comment
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Ever needed to disable all (or most) tests in a JUnit test case?

How about this: Using the editor of your choice, search for “void test” and replace all of them with “void dtest” (“d” as in disabled). Now, you can simply enable the few tests you need to run by deleting the “d” again.

I’m also using “x” to take out tests that won’t run for a while. Using global search in the whole project, it’s also simple to find them again just in case you’re wondering if there are any disabled tests left.

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