2010 06-24 karlsruher entwicklertag

Eclipse Code Recommenders

“IDE 2.0” Collective Intelligence in Software DevelopmentLeveraging the Wisdom of the Crowds

Marcel Bruch

Developers Who Called “new Text()” Method Also Called

What Do Developers Ultimately Override After Extending This Class?

setText()

89%

addListener()

53%

setLayout()

99%

setFont()

35%

100 % overwrotePreferencePage.createContents()

96 % overwrotePreferencePage.performOk()

5 % overwrotePreferencePage.performCancel()

Eclipse Code Recommenders – do what most people do! (where appropriate)

CodeAll Frameworks


Code

INTELLIGENT CODE COMPLETION“Other developers frequently bought used the following methods…”

Code Completion…

What does the developer need, i.e., which methods should the code completion present to the user?

All 164 Methods of Text ?

JButton? 381 Methods.

Code Completion…

What does the developer need, i.e., which methods should the code completion present to the user?

Intelligent Code Completion

… or just the three missing ones?


Why just one when you can have templates…

How it works – in a nutshell…

Framework

FrameworkInstantiation 1 … Framework

Instantiation n

Mining

RecommenderModel

If you extend A,you should

call B.c

…

extract facts about how the framework is reused

<extends:A><overrides:A.d>

<calls:B.c>…

<extends:A><overrides:A.b>

<calls:B.c>…



Observation Recommendations

USAGE-DRIVEN JAVADOCS“What do Developers Ultimately buy override after extending this class?”

Some Facts About TheDocumentation of Overridable Methods

623

2074overridable

overridden

What Clients Do With Your API…

overridden

documented*155

623

*: documented as overridable by using phrases like “clients may/should/must override/extend this method”

478

What documentation would you expect when subclassing a Dialog?

What Javadoc gives to you…

A dialog is a specialized window used for narrow-focused communication with the user.

Dialogs are usually modal. Consequently, it is generally bad practice to open a dialog without a parent. A modal dialog without a parent is not prevented from disappearing behind the application's other windows, making it very confusing for the user.

If there is more than one modal dialog is open the second one should be parented off of the shell of the first one otherwise it is possible that the OS will give focus to the first dialog potentially blocking the UI.

But what are the hot-spots of Dialog?

What Code Completion offers…

Which of the 56 methods should we override?

What You Need…

Method-level Subclassing Directives

This way, or that way? Subclassing Patterns for ViewerSorter

How it works? Clustering in a nutshell

http://upload.wikimedia.org/wikipedia/en/2/29/Bernoulli-Mixture-Model.gif

SMART BUG DETECTION – DRIVEN BY REAL USAGES

“The good ones in the potty, the bad ones in… the problem view.”

What’s wrong with this code?

At runtime your error log shows…

An error has occurred. See error log for more details. org.eclipse.core.runtime.AssertionFailedException

null argument:

At runtime your error log shows…

So what have we missed?

If all of your colleagues do it – why don’t you?

How it works – a conceptual view

That’s “strange”

How it works – a conceptual view

Just one formula…

x = {observed method calls on a variable}

E(x) = {exact similar usages for variables of type x in the code base}

A(x) = {almost similar usages, i.e., x+1 method call}

|)(||)(|

|)(|1)(

xAxE

xExsstrangenes

Find your bugs… during development!

Find your bugs… during development!

CODE SEARCH ENGINES – LIFT OFF!“Why is Google Codesearch not ‘google for code search’? ”

Navigating the API jungle…

How do I get an IStatusLineManager?

When asking Google Codesearch

No IDEintegration

Manual query creation

Text-basedretrieval

Ignores prior knowledge

Code Example Recommender

Query



LEVERAGING USER FEEDBACK TO IMPROVE CODE SEARCH ENGINES

“Why is Google Codesearch not ‘google for code search’? ”

Leveraging User Feedback

42

...

...

...

...

Refine the ranking based on feedback

Leveraging User Feedback

44

1

3

2

2

3

1

Support Vector MachineSkipped

SVMRank

WHAT CAUSEDTHAT STACKTRACE?

Stackoverflow.com – Reloaded!

So far we have…

Usage-Driven JavadocsIntelligent Code Completion

Code Example Recommender Smart Bug Dectection

But what if you get this?

Debugging – the old way

Debugging – the old way

But more often we get…

How can we fix that? Don’t stacktraces share some commonalities?

org.eclipse.swt.SWTException: Invalid thread access at org.eclipse.swt.SWT.error(SWT.java:3884) at org.eclipse.swt.SWT.error(SWT.java:3799) at org.eclipse.swt.SWT.error(SWT.java:3770) at org.eclipse.swt.widgets.Widget.error(Widget.java:463) at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:355) at org.eclipse.swt.widgets.ProgressBar.setSelection(ProgressBar.java:317) at org.eclipselabs.cr.stacktraces.demo.ThreadDemo$1.run(Unknown Source) at java.lang.Thread.run(Thread.java:619)

ExceptionType Feature(evaluates identical exception type) Message Similarity Feature

(counts of similar words)

TraceDiff Similarity Feature(counts similar stackframes per trace)

Having a central exception repository

How about stacktraces.org?

LAST.FM 4 ECLIPSE“IDE 2.0? Leveraging the wisdom of the (Eclipse) community…”

How It Works Today

Framework


Instantiation n

Mining

RecommenderModel


call B.c

…



<calls:B.c>…


<calls:B.c>…

How it Works Tomorrow

Framework


Instantiation n

Mining

RecommenderModel


call B.c

…



<calls:B.c>…


<calls:B.c>…

Leveraging your IDE’s build environment

framework indication

object usage

selected proposals

project environment

context

WRAP UP“I’ve seen much but why do you call it IDE 2.0 ?”

From IDE 1.0 to IDE 2.0

From Web 2.0 to IDE 2.0

Let’s map the Web 2.0 principles to IDE 2.0 to see how this analogy fits:

1. The Web as Platform…

2. Data as “Intel inside”…

3. Harnessing Collective Intelligence…

4. Rich User Experiences…

5. Lightweight Programming Models…

Milestones

21.03.2009v0.1 Release

01.07.2010v0.1 Example Code

Recommender

01.12.2010Stacktrace

Recommender

01.09.2010Moving to Eclipse.org

01.02.2011v0.1 Last.FM

01.10.2010v0.1 Bugs

Recommender

…

Resources

• Contact

• Marcel Bruch [email protected]•

• Project homepage

• http://www.stg.tu-darmstadt.de/research/core/

• Download Release “LISBON” (V.0.2.105)

• http://www.stg.tu-darmstadt.de/research/core/download

• Source Code

• http://eclipselabs.org/p/code-recommenders/

Credits – innumerable hours have spent…

Daniel Staesche

Jan Stolzenburg

Julius Rückert

Minh Hoang Nguyen

Nico Wombacher

Sebastian Ahlfeld

Gary Fritz

Laura Altmüller

Dirk KröhanChristopher Mann

Florian Jakob

Jan KassensJohannes Born

Kristijan Madunic

Mohsen Parisay

Sinem Emeröz

Tjark VandommeleDennis Siebert

Roman Getto

Florian Nöll

Markus Migenda

Paul Schatygin

Sheip Dargutev

Nikolay Shindov

Peter Schroeder Johannes LerchMaik Görtz

Christian KilbDaniel Brandtner

David Kalnischkies

Jan-Michael Heller

Michael KutschkeMichael Novotny

Sascha Nordquist

Sebastian Denel

Sebastian Kasten

Steffen Remus Sebastian Proksch

Dennis Sänger

Boyan Yurukov

Jens KrauseDavid Schuld

Tomasz Kalbarczyk

Daniel Glöckner

Sebastian Wörner

Peter Sinzig

Johannes Kastl

Veronika Kostadinova

Q & A

Summary

Usage-Driven JavadocsIntelligent Code Completion

Code Example Recommender Smart Bug Dectection

Affiliation

Prof. Dr. Mira MeziniSoftware Technology GroupFachbereich InformatikTechnische Universität Darmstadt

Documents

2010 06-24 karlsruher entwicklertag