eclipse code recommenders @ majug 2011

Eclipse Code Recommenders

IDE 2.0: Leveraging the Wisdomof the So:ware Engineering Crowdstw: @MarcelBruchg+: +Marcel Bruch

Java U

ser Group M

annhei

m

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

CodeAll Frameworks

Eclipse Code Recommenders Code

3

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

@Overrideprotected Control createDialogArea(final Composite parent) { Composite container = (Composite) super.createDialogArea(parent); swtTextWidget = new Text(container, SWT.BORDER); swtTextWidget.| return container;}

Code Comple+on…

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

5

All 164 Methods of Text ?

JBuSon? 381 Methods.

@Override protected Control createDialogArea(final Composite parent) { final Composite container = (Composite) super.createDialogArea(parent); swtTextWidget = new Text(container, SWT.BORDER); swtTextWidget.| return container; }

Code Comple+on…

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

8

Intelligent Code Comple+on

… or just the three missing ones?

9

How it works -‐ in a nutshell

10


10

Framework


10

Framework

Example ApplicaKon 1

Example ApplicaKon n...


10

extract facts about how the framework is reused

...«extends:A»

«overrides:A.d»«calls:B.c»

…

«extends:A»«overrides:A.b»

«calls:B.c»…

Framework




10

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»…

Framework



From code to models...

11

class Example extends Page { Text t; @Override void createContents() { t = new Text(); t.setText(..); .. }}

in:Page.createContents()

in:Page.performOk()

Text.<init>()

Text.getText()

Text.setFont()

...

Text.setText()

1 0 1 1

1 1

0 0

0 0 0 0… … … … … …

……

…

From code to models...

12

class Example extends Page { Text t; @Override void performOk() { t.getText(); ..

}}


in:Page.performOk()

Text.<init>()

Text.getText()

Text.setFont()

...

Text.setText()

1 0 1 1

1 1

0 0

0 0 0 0… … … … … …

……

…

From models to recommenda+ons...

13

class MyPage extends Page { Text t; @Override void createContents() { t = new Text(); t.|<^space> }}

1 …1 ?? ?0in:Page.createContents()

in:Page.performOk()

Text.<init>()

Text.getText()

Text.setFont()

...

Text.setText()


14

1 …1 ?? ?0


in:Page.performOk()

Text.<init>()

Text.getText()

Text.setFont()

...

Text.setText()

01 10 0 …1 10 0 0 0

… … … … … ………

1

0 1 1 1 0 …101 00 0 …1


14

1 …1 ?? ?0


in:Page.performOk()

Text.<init>()

Text.getText()

Text.setFont()

...

Text.setText()

01 10 0 …1 10 0 0 0

… … … … … ………

1

0 1 1 1 0 …101 00 0 …1

⅔


14

1 …1 ?? ?0


in:Page.performOk()

Text.<init>()

Text.getText()

Text.setFont()

...

Text.setText()

01 10 0 …1 10 0 0 0

… … … … … ………

1

0 1 1 1 0 …101 00 0 …1

⅔ ⅓


14

1 …1 ?? ?0


in:Page.performOk()

Text.<init>()

Text.getText()

Text.setFont()

...

Text.setText()

01 10 0 …1 10 0 0 0

… … … … … ………

1

0 1 1 1 0 …101 00 0 …1

⅔ ⅓ 0

CALL-‐CHAIN COMPLETION“Welcome to the forest...”

How to obtain an instance of...

public class MyView extends ViewPart { public void updateMessage(final String newMessage) {

// How do I get an instance of IStatusLineManager? final IStatusLineManager manager = | manager.setMessage(newMessage); }

There is no trivial solution anymore.Again, what should code completion return?

What we need...

17

public void updateMessage(final String newMessage) {

// How do I get an instance of final IStatusLineManager manager = this .getViewSite() .getActionBars() .getStatusLineManager();

manager.setMessage(newMessage);}

!"#$%&'(

)!"#$*"(#

)+,-./0&'1

)*(&(213"/#4&/&5#'

5#(*(&(213"/#4&/&5#'67

5#(+,-./8&'167

5#(!"#$*"(#67

!"#$%&'(

)#*"+#

,#+(&-./#

01/1'

234(#-5"1-

201-('"67(1'

28+91-:&'5

2;1'<6#-+=;"->1$

2?#/#+91-%'1*">#'

2;1'<6#-+=%&.#

?=#//

2;1'<6#-+=%&'(

2@#A:"->"-.?#'*"+#2;1'<6#-+=%&'(?"(#

2B&.#

201-C.7'&91-3/#B#-(

2!"#$?"(#

2B&.#)&(&

%1"-(

2D#-7D&-&.#'

2?#'*"+#E1+&(1'

2%&'(?#'*"+#

2;1'<6#-+=

28>&F(&6/#

2?#/#+91-

2;1'<6#-+=;"->1$

2G&*".&91-H"5(1'A

2;1'<"-.?#(

234(#-5"1-I'&+<#'

2!"#$,#J#'#-+#

2!"#$%&'(

23>"(1',#J#'#-+#

23>"(1'%&'(

,#."1-

01BF15"(#

D#-7

E"5(#-#'

E&A17(

2D3

)"5F/&A

?+'1//:&'

01-('1/

2?#'*"+#E1+&(1'

2D#-7D&-&.#'

2?(&(75E"-#D&-&.#'

28+91-

2I11/:&'D&-&.#'

2?#/#+91-?#'*"+#

However, someEmes you get...

Here, implicit user feedbacks (“clicks”) will help to find the right (read “the most commonly used”) paths.

In deve

lopme

nt...

Tools Outline

20

x=

Tools Outline

Intelligent Code CompleEon

20

x=

Smart Bug DetecEon

What have I missed?

Tools Outline


20

x=

Smart Bug DetecEon

What have I missed?

Tools Outline

Extended DocumentaEon


20

x=

Smart Bug DetecEon

What have I missed?

Tools Outline



Code Example Recommender

How do I get an instance of…?

20

x=

Smart Bug DetecEon

What have I missed?

Tools Outline





Stacktrace Search Engine

What caused that stacktrace?

20

x=

SMART BUG DETECTION – DRIVEN BY REAL USAGES

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

What’s wrong with this code?

“Hello!”

“id”

22

At run+me you get…

23

...and a lengthy stacktrace

24

org.eclipse.core.runEme.AsserEonFailedExcepEon: null argument:at org.eclipse.core.runEme.Assert.isNotNull(Assert.java:85)at org.eclipse.core.runEme.Assert.isNotNull(Assert.java:73)at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:174)at org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:734)at org.eclipse.jface.wizard.WizardDialog.setWizard(WizardDialog.java:1162)at org.eclipse.jface.wizard.WizardDialog.updateForPage(WizardDialog.java:1221)at org.eclipse.jface.wizard.WizardDialog.access$4(WizardDialog.java:1218)at org.eclipse.jface.wizard.WizardDialog$6.run(WizardDialog.java:1207)at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)at org.eclipse.jface.wizard.WizardDialog.showPage(WizardDialog.java:1205)at org.eclipse.ui.internal.dialogs.ImportExportPage.treeDoubleClicked(ImportExportPage.java)at org.eclipse.ui.internal.dialogs.ImportPage$2.doubleClick(ImportPage.java:72)at org.eclipse.jface.viewers.StructuredViewer$1.run(StructuredViewer.java:824)at org.eclipse.core.runEme.SafeRunner.run(SafeRunner.java:42)at org.eclipse.ui.internal.JFaceUEl$1.run(JFaceUEl.java:49)at org.eclipse.jface.uEl.SafeRunnable.run(SafeRunnable.java:175)at org.eclipse.jface.viewers.StructuredViewer.fireDoubleClick(StructuredViewer.java:822)at org.eclipse.jface.viewers.AbstractTreeViewer.handleDoubleSelect(AbstractTreeViewer.java)at org.eclipse.jface.viewers.StructuredViewer$4.widgetDefaultSelected(StructuredViewer.java)

...

So what have we missed?25

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

26

How to detect such wrong uses?

27


That’s “strange”

27


28

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}29

10 .9.5

Missing Calls Detector in Eclipse

30In d

evelop

ment...

Applied on Eclipse 3.5...

31

USAGE-‐DRIVEN JAVADOC“Developers who bought overwrote this method typically also overwrote...”

In good documenta+on we trust...

33

/** * Rollsback the transaction if any and clears different lists to * start with an empty resource again. * Note that the super.doUnload is not called because that clears * the list resulting in all kinds of undesirable inverseremoves. */ @Override protected void doUnload() { super.doUnload(); }


33


No? Are you sure?


33


No? Are you sure?

good

Genera+ng high-‐quality API documenta+on

34

/** * The number of questions. */ private int numberOfQuestions;

/** * Sets the number of questions. * * @param numberOfQuestions the number of questions * @throws IllegalArgumentException the illegal argument exception */ public void setNumberOfQuestions(int numberOfQuestions)

throws IllegalArgumentException { if (numberOfQuestions < 0) { throw new IllegalArgumentException("numberOfQuestions < 0"); } this.numberOfQuestions = numberOfQuestions; }


34

/** * The number of questions. */ private int numberOfQuestions;

/** * Sets the number of questions. * * @param numberOfQuestions the number of questions * @throws IllegalArgumentException the illegal argument exception */ public void setNumberOfQuestions(int numberOfQuestions)

throws IllegalArgumentException { if (numberOfQuestions < 0) { throw new IllegalArgumentException("numberOfQuestions < 0"); } this.numberOfQuestions = numberOfQuestions; }


35

high-‐quality

What people say about JAutodoc...

36


36

User: Anonymous Rating: 9 2009-08-02 11:32:37

Wow exactly what I needed!Wow exactly what I needed!Wow exactly what I needed!


36




Thank you... this plugin rocks!Thank you... this plugin rocks!Thank you... this plugin rocks!


36






Works perfectly. Smarter than I expected!Works perfectly. Smarter than I expected!Works perfectly. Smarter than I expected!


36






Works perfectly. Smarter than I expected!Works perfectly. Smarter than I expected!Works perfectly. Smarter than I expected!

WTH? What did you expect?!

How Recommenders is coming to rescue...

37

Some facts about thedocumentaEon of overridable methods

38

Overridable

Overridden

0 700 1400 2100

623

2.074

What clients do with your API...

39

Overridden

Documented *

0 325 650

155

623

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

What clients do with your API...

39

Overridden

Documented *

0 325 650

155

623

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

468

What documenta+on would you expect when subclassing Dialog?

40

package org.eclipse.recommenders.examples.demo;

import org.eclipse.jface.dialogs.Dialog;import org.eclipse.jface.window.IShellProvider;

public class MyDialog extends Dialog {

protected MyDialog(final IShellProvider parentShell) { super(parentShell); } }

What Javadoc gives you...

41

org.eclipse.jface.dialogs.Dialog


41

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



41


Dialogs are usually modal. Consequently, it is generally bad pracEce to open a dialog without a parent. A modal dialog without a parent is not prevented from disappearing behind the applicaEon'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 cus to the first dialog potenEally blocking the UI.



41


Dialogs are usually modal. Consequently, it is generally bad pracEce to open a dialog without a parent. A modal dialog without a parent is not prevented from disappearing behind the applicaEon'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 cus to the first dialog potenEally blocking the UI.

But what are the hot-spots of Dialog?


What code comple+on offers...

42

What code comple+on offers...

42

Which of the 56 methods should we override?

Recommending method overrides...

43

public class MyDialog extends Dialog {

public class MyWizard extends Wizard {

! @Override public void addPages() { };

Recommending Self-‐Calls

44

public class MyViewerSorter extends ViewerSorter {

Mining for Subclassing pa`erns

45

public class MyDialog extends Dialog { @Override protected Control createDialogArea(Composite parent) {

Mining example code snippets

46

Sca`ered Resources

47

Extended Documenta+on Plaaorm

48

+ Machine Learning

Extended Documenta+on

49


50

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

How many request per minutes docode search engines have?

52

53

20Number for koders.com in 2009 according to “Analyzing and mining a code search engine usage log”

h`p://dx.doi.org/10.1007/s10664-‐010-‐9144-‐6

Naviga+ng the API jungle…

54

private CompilationUnit createCompilationUnit(String source) {

// how can I create and configure an ASTParser? ASTParser parser = null; parser.setSource(source.toCharArray());

// ASTParser --> CompilationUnit: how? CompilationUnit cu = null; return cu; }

Naviga+ng the API jungle…

How to solveString -‐> ASTParser -‐> CompilaKonUnit?

54




When asking Google code search...

55

Why?

56

Why?

Text-basedretrieval!

56

Why?


56

Inexpressive query language!

Why?


Ignores prior knowledge!

56

Inexpressive query language!

Example code search engine

public class MyJavaEditor extends EditorPart {




57

Example code search engine

public class MyJavaEditor extends EditorPart {




57

Query

Sample search query

58

Extracted from MyJavaEditor.createCompilationUnit():

--- data ---extends: org.eclipse.ui.EditorPartuses: org.eclipse.jdt.core.CompilationUnituses: org.eclipse.jdt.core.ASTParsercalls: org.eclipse.jdt.core.ASTParser.setSource(char[])

--- requested ---def: org.eclipse.jdt.core.CompilationUnit (def=null)def: org.eclipse.jdt.core.ASTParser (def=null)

In deve

lopme

nt...

LEVERAGING USER FEEDBACK TOIMPROVE CODE SEARCH ENGINES

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

Leveraging user feedback

60

Refine the ranking based on feedback

61

Learning how to rank

62

Ranking the examples

63


63

document


63

documentquery


63

feature-‐score i[0..1]

documentquery


63

weight (-‐∞..+∞)

feature-‐score i[0..1]

documentquery

Upda+ng the feature weights...

64

Upda+ng the feature weights...

64

10.000 ∗

Benefits of automated tweaking

65

baselineclick-‐through

# queries

# kend

all’s ι

Interac+ons diagram

66

ServerClient

1

«triggers»Developer

3 Code Snippet Ranking2 Search Invocation

«triggers»Developer

SearchIndex

RankingFunction

IncompleteSource Code Query

5 Feedback Processing

4 Code Snippet Presentation Code Examples

«updates»

Weights LearningFunction

5 Feedback ProcessingCode

Summarization

Cli kth h

CodeHighlighter

FunctionClickthroughdata

Applica+on scenarios for your company

67

Open SourceRepositories

CompanyRepositories


67

Filesystem

Open SourceRepositories

CompanyRepositories

WHAT CAUSED THAT STACKTRACE?“People that bought had this NullPointerExcepKon, made this mistake:...”

So far we have…

69

So far we have…

69

Extended DocumentaEonIntelligent Code CompleEon

So far we have…

69




So far we have…

69

Smart Bug DetecEon

What have I missed?




But what if you get this?

70

Debugging – the old way

71

Debugging – the old way

72

But more ojen we get…

73

How can we fix that? Don’t stacktraces share some commonali+es?

74


74

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)


74

excepEon type



74

excepEon type message



74


stackframes



74


stackframes other informaEon


How about stacktraces.org?

75

Knowledge sources

76

Eclipse Forums

Mailing ListsWebplasorm

htp://stacktraces.org

http://stacktraces.org

http://stacktraces.org


77

Community-‐driven (forums, mailinglists,...)

CompanyKnowledgebase

SNIPMATCH“Templates meet Social -‐ reloaded!”

Eclipse Java Editor Templates


42x Java Templates.


42x Java Templates.35x SWT Templates.


42x Java Templates.35x SWT Templates.

7 Years.

The rise of code snippet repositories

and many more...

Searching snippets in your IDE...

ECLIPSE CODE RECOMMENDERS“IDE 2.0? Leveraging the wisdom of the (Eclipse) community…”

From IDE 1.0 to IDE 2.0

83

Build directly from version control-‐ or p2/m2 repository...

84

P2

Leveraging your IDE’s build environment

85


project environment

85


project environment

context

85


object usage

project environment

context

85


object usage

selectedproposals

project environment

context

85


object usage

selectedproposals

project environment

context

clickfeedback

85


object usage

selectedproposals

project environment

context

Stacktraces

clickfeedback

85

Crowd-‐sourcing...

86

BUT HOW ABOUT PRIVACY?“Yours is ours and mine is mine...”

Usage data sharing example

88

import com.mycompany.*;import org.eclipse.*;

public class MyCompanyDialog extends Dialog implements ICompanyService {

MyCompanyController controller = new MyCompanyController();

@Override protected Control createDialogArea(Composite parent) { Composite container = (Composite) super.createDialogArea(parent); Button sync = new Button(container, SWT.CHECK); sync.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(final SelectionEvent e) { if (sync.getSelection()) { controller.synchronize(); // lot of more things done with controller } } }); return container; }

@Override public void myCompanyServiceMethod() { controller.setup(); }}

Informa+on cleared by privacy selngs

89




@Override protected Control createDialogArea(Composite parent) { Composite container = (Composite) super.createDialogArea(parent); Button sync = new Button(container, SWT.CHECK); sync.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(final SelectionEvent e) { if (sync.getSelection()) { controller.synchronize(); // lot of more things done with controller } } }); return container; }


Effec+ve usage data shared

90




@Override protected Control createDialogArea(Composite parent) { Composite container = (Composite) super.createDialogArea(parent); Button sync = new Button(container, SWT.CHECK); sync.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(final SelectionEvent e) { if (sync.getSelection()) { controller.synchronize();

} } }); return container; }


Effec+ve usage data shared

90




@Override protected Control createDialogArea(Composite parent) { Composite container = (Composite) super.createDialogArea(parent); Button sync = new Button(container, SWT.CHECK); sync.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(final SelectionEvent e) { if (sync.getSelection()) { controller.synchronize();

} } }); return container; }


Only the informaKon how you used Eclipse is shared.

RECOMMENDERS FOR ANDROID“Support your own framework. Live walk-‐through...”

92

ListAcEvity

TextViews

LinearLayout

TEAM SERVER FOR ANDROID“Support your own framework. Live walk-‐through...”

Code Recommenders team server

PowerBook G4

PowerBook G4PowerBook G4

server

devel #1

devel #2 devel #3

In deve

lopme

nt...

Demo setup

PowerBook G4

PowerBook G4

Eclipse “blue” Eclipse “red”

developer ws

examples ws

Summary

Smart Bug DetecEon

What have I missed?

Usage-‐Driven JavadocsIntelligent Code CompleEon





96

x=

A developer’s day...

97

Edit Code

Testing

Comprehend Task

Handling Interruptions Comprehending

Code

Reading API Doc

Navigate Dependencies

Searching Code

Switching Applications

Source: Eclipse Mylyn Developer Techtalk 2011, IEEE TSE, Vol. 32, No. 12, 2006

Where does IDE 2.0 improve the process?

98

Edit Code Testing

Comprehend Task

Handling Interruptions

…

99

Contributors so far…Jan Kassens, Peter Schroeder, Daniel Glöckner, Maik Görtz, Johannes Lerch, Johannes Born, Mohsen Parisay, Andreas Sewe, SebasKan Ahlfeld, SebasKan Kasten, Daniel Staesche, David Kalnischkies, SebasKan Wörner, Boyan Yurukov, Jan Stolzenburg, Nico Wombacher, Dirk Kröhan, Florianrian Jakob, Julius Rückert, Steffen Remus, Christopher Mann, Stefan Henss, Andreas Kaluza, Nikolay Shindov, Michael Novotny, KrisKn Arand, Sinem Emeröz, Michael Kutschke, SebasKan Proksch, Tomasz Kalbarczyk, Marko MarKn, Sheip Dargutev, David Schuld, Jens Krause, KrisKjan Madunic, Daniel Brandtner, Roman GeSo, ChrisKan Kilb, Johannes Kastl, Dennis Sänger, Annie Liu, Markus Migenda, Tjark Vandommele, SebasKan Denel, Florian Nöll, Gary Fritz, Dennis Siebert, Peter Sinzig, Laura Altmüller, Paul Schatygin, Jan-‐Michael Heller, Minh Hoang Nguyen, Sascha Nordquist, Paul Emmanuel Faidherbe, ...

Q & A

100

Q & A

Smart Bug DetecEon

What have I missed?

Usage-‐Driven JavadocsIntelligent Code CompleEon





101

It’s there.

htp://eclipse.org/recommenders/Follow me on twiter: @MarcelBruch

google+: +Marcel Bruch 102

eclipse code recommenders @ majug 2011

Technology

c applicakon

p ni tt tf tte

c calls

d calls

applicakon n

rmte fo t t tea

extext t cr

code complekon present