Marty Kube

1
Scripting Approaches For Java Application Test
Automation

• Marty Kube
• Beaver Creek Consulting Corp
• NoVa Test Automation Interest Group
• 2009-04-08

http//beavercreekconsulting.com/
http//www.novataig.net/
2
Scripting and Test Automation

• Scripting is the way to go for test automation
• High Level languages - More functionality with
  less code
• How scripting interacts with the application
• External interfaces
• Win runner
• JMeter
• Expose Internals
• JavaScript in the Browser
• SQL

3
Survey a Few DSL Approaches

• Small example application
• Use scripting and Domain Specific Language to
  drive application
• Groovy
• JavaScript
• JavaCC
• Hands on with code examples

4
Contrasting the DSL approaches

• Focus on Strategy Using Java as an example
  similar tactics should apply for other
  environments.
• Three types of resources
• Expertise for set-up, Integration effort,
  Expertise for test authoring
• Trade offs
• General Trade offs
• Less front end setup
• More complex test authoring
• More front end setup
• Less complex test authoring

5
Scripting Languages

• Type-less or easy to use type system
• High Level more productive and less defects
• Interpreted
• Interactive shell for rapid exploration or
  development
• Text processing - AWK, SED
• General Purpose - Perl, Python, TCL, Emacs LISP

http//en.wikipedia.org/wiki/Scripting
6
Domain Specific Languages (DSL)

• Smaller language dedicated to a particular
  situation
• SQL
• Second Life/MORPHS
• Spotted in the wild
• Less general
• Lack low level functionality
• More expressive in the particular domain
• Really blurry line between scripting language and
  DSL

http//en.wikipedia.org/wiki/Domain_specific_langu
age
7
Example Application
8
The Java Code

• package com.beavercreekconsulting.novataig
• public class TestLedger
• public static void main(String args)
• Ledger subLedger new Ledger()
• // Open the period
• subLedger.setBalance(Account.CHECKING,
  1000.00)
• subLedger.setBalance(Account.TRAVEL_AND_ENTERTAI
  NMENT, 200.00)
• subLedger.setBalance(Account.SLUSH_FUND,
  -500.00)
• // Post activity
• JournalEntry activity
• new JournalEntry(Account.CHECKING,
  Ind.CREDIT, 100.00),
• new JournalEntry(Account.TRAVEL_AND_ENTERTAINM
  ENT, Ind.DEBIT, 100.00),
• new JournalEntry(Account.CHECKING,
  Ind.CREDIT, 2000.00),
• new JournalEntry(Account.SLUSH_FUND,
  Ind.DEBIT, 2000.00)

9
The Groovy Code

• package com.beavercreekconsulting.novataig
• public class TestLedger
• public static void main(String args)
• Ledger subLedger new Ledger()
• // Open the period
• subLedger.setBalance(Account.CHECKING,
  1000.00)
• subLedger.setBalance(Account.TRAVEL_AND_ENTERTAI
  NMENT, 200.00)
• subLedger.setBalance(Account.SLUSH_FUND,
  -500.00)
• // Post activity
• JournalEntry activity
• new JournalEntry(Account.CHECKING,
  Ind.CREDIT, 100.00),
• new JournalEntry(Account.TRAVEL_AND_ENTERTAINM
  ENT, Ind.DEBIT, 100.00),
• new JournalEntry(Account.CHECKING,
  Ind.CREDIT, 2000.00),
• new JournalEntry(Account.SLUSH_FUND,
  Ind.DEBIT, 2000.00)

10
Groovy Up Close

• Super set of Java
• Plus
• Dynamic typing
• Enhanced API Java Classes
• String interpolation
• def x Bob print Hello x
• Closures
• square it it
• 1..9.collect(square)
• XML builders and groovy SQL
• Script MS Office with COM Bridge (Scriptom)

http//groovy.codehaus.org/Tutorial2-Codeasda
ta,orclosures
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Groovy Architecture Whats in the JVM
gtgroovy.bat -classpath bin TestLedger.groovy
12
Really Groovy Code

• import com.beavercreekconsulting.novataig.
• def subLedger new Ledger()
• Account.CHECKING, 1000.00,
• Account.TRAVEL_AND_ENTERTAINMENT, 200.00,
• Account.SLUSH_FUND, -500.00
• .each() subLedger.setBalance(it0, it1)
• new JournalEntry(Account.CHECKING, Ind.CREDIT,
  100.00),
• new JournalEntry(Account.TRAVEL_AND_ENTERTAINMENT
  , Ind.DEBIT, 100.00),
• new JournalEntry(Account.CHECKING, Ind.CREDIT,
  2000.00),
• new JournalEntry(Account.SLUSH_FUND, Ind.DEBIT,
  2000.00)
• .each() je -gt subLedger.post(je)
• Account.CHECKING, -1100.00,
• Account.TRAVEL_AND_ENTERTAINMENT, 300.00,

13
JavaScript

• JavaScript is a small language ECMA Script
• Easy to integrate
• Easy to find JavaScript Fan boys
• Rhino is a JavaScript interpreter written in Java
• Other JavaScript Engines, Mozilla, V8

http//en.wikipedia.org/wiki/Javascript
http//www.mozilla.org/rhino/
14
Rhino Architecture
gtjava -classpath lib\js.jarbin
org.mozilla.javascript.tools.shell.Main -f
TestLedger.js
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The JavaScript Code

• importPackage(com.beavercreekconsulting.novataig)
• function assertEquals(a, b)
• if(a ! b) throw new TestFailure()
• var subLedger new Ledger()
• subLedger.setBalance(Account.CHECKING, 1000.00)
• subLedger.setBalance(Account.TRAVEL_AND_ENTERTAINM
  ENT, 200.00)
• subLedger.setBalance(Account.SLUSH_FUND, -500.00)
• activity
• new JournalEntry(Account.CHECKING, Ind.CREDIT,
  100.00),
• new JournalEntry(Account.TRAVEL_AND_ENTERTAINMENT
  , Ind.DEBIT, 100.00),
• new JournalEntry(Account.CHECKING, Ind.CREDIT,
  2000.00),
• new JournalEntry(Account.SLUSH_FUND, Ind.DEBIT,
  2000.00)

16
JavaCC Create a DSL

• Test case 16,678
• Author Marty
• Checking set 1000.00
• travel_and_entertainment set 200.00
• slush_fund set -500.00
• checking post credit 100.00
• travel_and_entertainment post debit 100.00
• checking post credit 2000.00
• slush_fund post debit 2000.00
• Checking verify -1100.00
• travel_and_entertainment verify 300.00
• slush_fund verify 1500.00
• print happy day!

https//javacc.dev.java.net/
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JavaCC
18
JavaCC Lexer

• SKIP " "
• TOKEN lt CHECKING "checking" gt
• TOKEN lt OP_SET "set" gt
• TOKEN lt NUMBER ("0"-"9") gt
• TOKEN lt EOL "" gt
• ltCHECKINGgt ltOP_SETgt ltNUMBERgt ltEOLgt
• Checking set 1000.00

19
JavaCC Parser

• Accepts the token stream
• ltCHECKINGgt ltOP_SETgt ltNUMBERgt ltEOLgt
• ltTRAVELgt ltOP_POSTgt ltNUMBERgt ltEOLgt
• ltEOFgt
• And enforces order the grammar
• (ltCHECKINGgt ltOP_SETgt ltNUMBERgt ltEOLgt )
• ltEOFgt

20
Recognize Statements Invoke Application

• (
• ltCHECKINGgt
• ltOP_SETgt
• tltNUMBERgt
• amount new Double(t.image)
• ltEOLgt
• System.out.println("Posting " amount)
• ledger.setBalance(Account.CHECKING, amount)
• )
• ltEOFgt
• System.out.println("Happy Day")

21
Running

• gtjavacc TestLedger.jj
• gtjavac -d bin -cp "../bin" gen\.java
• gtjava -classpath "bin../bin" LedgerLanguage
  TestCase.txt

22
Comparison - LOE
23
Honorable mentions

• SWIG
• Antlr
• JavaScript Mozilla v8
• Most scripting languages cross language
  interfaces, Perl, Python, etc.
• Bean Shell
• Jython

24
Wrap up

• JVM is a target for many scripting languages
• Using a JVM based language make integration easy
• DSL can make it easy to author test cases
• Setup can be a hurdle