Testing

Why test?

Testing is an important part of getting correct software
It will expose bugs, but cannot guarantee s/w is free of them
Jacl defines 260 classes in 60,000 lines of Java
Jacl has 4,500 tests in 28,000 lines of tcl
In the Australian: "Test Analyst $65k"

Test language

Programmers don't like to test - their programs always work
Testing should be automated
Writing tests should be easier than writing programs
The test language should be simpler than the target language

tcl

Tool Command Language
Originally in C
Ported to Java as JACL
Can be used as an ordinary shell-type scripting language
Can be used to interact with Java classes

Simple tcl program


set n 1                              # assignment
set product 1                        # assignment
while {$n <= 10} {                   # loop - note spaces
                                     # before/after <=
    set product [expr $product * $n] # evaluate an expression
    incr n                           # increment n
}
set product                          # print product

Simple Java class for testing


public class Sum {
    private int total = 0;

    public void add(int n) {
        total += n;
    }

    public void subtract(int n) {
        total -= n;
    }

    public int getSum() {
        return total;
    }
}

Jacl tests


package require java

set sum [java::new Sum]

$sum add 10
$sum add 20
set total [$sum getSum]

if {$total == 30} {
    puts "test passed"
} else {
    puts "test failed"
}

Running the test program

The Java file must be compiled to a class file, Sum.class
The CLASSPATH must include the path to Sum.class
The CLASSPATH must include the path to tcljava.jar and jacl.jar
set CLASSPATH=.;N:\DosApps\jacl126\tcljava.jar;N:\DosApps\jacl126\jacl.jar
Run java tcl.lang.shell
To load and run a tcl program from a file such as sum.test,
%source sum.test

Tcl tutorial

A tcl tutorial is at http://www.sftw.umac.mo/~fstrpba/tcltut/

Java extensions to tcl - jacl

There are a number of additional commands to handle Java objects. These include

java::new to create a new object as in
set x [java::new String "abcd"]
java::call to call a static method as
set abs_x [java::call Math.abs x]
java::field get the value of a class or instance variable as in
set max_int [java::field Integer MAX_VALUE]
java::null for setting the null value as in
set x [java::null]
java::isnull tests for null as in
if {[java::isnull $x]} ...

A test framework

A test framework can be built in one page of tcl
Copy the file all from the IT Project directory to your test directory
Create test files in this directory, all ending in .test
Start the Jacl shell by java tcl.lang.Shell
Load the test framework by
source all
Fix the bugs in your code

Test file format

Each test file should consist of a series of procedure calls of the form
test {name} {description} {contents} {result}

A sample test file is


test sum-1.1 {addition test} {
    set sum [java::new Sum]

    $sum add 10
    $sum add 20
    set total [$sum getSum]
} {30}

test sum-1.2 {subtraction test} {
    set sum [java::new Sum]

    $sum subtract 10
    $sum subtract 20
    set total [$sum getSum]
} {-30}

test sum-1.3 {mixed test} {
    set sum [java::new Sum]

    $sum add 10
    $sum subtract 20
    set total [$sum getSum]
} {-10}

Jan Newmarch (http://pandonia.canberra.edu.au)