LSpec is a Test-Driven Development tool for the Lasso language that gets its inspiration from RSpec.


<dl> <dt>Expectation</dt><dd>Used to define expected outcomes within a test. (Each [expect] statement)</dd> <dt>Test</dt><dd>A grouping of expectations and related code to test specific functionality. (Each [it] block.)</dd> <dt>Test Group</dt><dd>A grouping of related tests. (Each [describe] block.)</dd> <dt>Test Suite</dt><dd>Compilation of all the test groups.</dd> </dl>


Pre-compiled Libraries

  1. Click the "Downloads" menu option at the top of this page.
  2. Choose the proper download for your platform
  3. Decompress the files and move lspec to $LASSO9_HOME/bin/ and or lspec.dylib into $LASSO9_HOME/LassoLibraries/

Compile From Source

$> cd where/you/want/the/source/installed/
$> git clone
$> cd lspec
$> make
$> make install

Note: If you're compiling on Mac OS X, you'll need the 10.5 SDK installed. You can follow the instructions here to restore the 10.5 SDK to Xcode 4.

Set Your Path

The installation instructions above specified that the lspec command utility be installed into $LASSO9_HOME/bin/. You may want to add that to your shell's PATH so you can just type lspec and not $LASSO9_HOME/bin/lspec from the command-line. (Check your shell's documentation to determine how to setup your PATH environment variable.)


First, create a file named and write a test describing functionality you wish you had. (It's important that the test file ends with the extension ''.)

describe('Zoo') => {
    describe('addAnimal') => {
        it('inserts an animal into the zoo and increases numberOfAnimals by 1') => {
            local(menagerie) = zoo
            local(num_animals_start) = #menagerie->numberOfAnimals

            #num_animals_end = #menagerie->numberOfAnimals

            expect(#num_animals_end == 1 + #num_animals_start)

Then run the test and watch it fail.

$> lspec


    1) Zoo addAnimal inserts an animal into the zoo and increases numberOfAnimals by 1
       Failure/Error: Unexpcted Error!
           Error Code: -9948
            Error Msg: Definition Not Found: zoo()
       # 3:9 /Path/To/

Finished in 0.206136 seconds
1 test, 1 failure

Now add the following code to the beginning of (Usually you would keep the tests in separate files and have them first include the code you are testing.)

define zoo => type {
    data private animals = array

    public hasA(name::string) => {
        with animal in .animals do {
            #name == #animal->name?
                return true
        return false

    public addAnimal(creature::animal) => {

    public numberOfAnimals => .animals->size

define animal => type {
    data private name::string
    public name => .'name'

    public onCreate(name::string) => {
        .'name' = #name

With this code in place, re-run the test and watch it pass.

$> lspec

Finished in 0.147116 seconds
1 test, 0 failures


Copyright 2011 Bradley Lindsay

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.