Help, my tests are killing me!!

HELP
MY Tests ARE
KILLING ME!!

brian swan @bgswan
follow me
on twitter

Contains code some
people may ﬁnd offensive

Testsuite: org.springframework.util.StopWatchTests
Tests run: 1, Failures: 1, Errors: 0, Time elapsed: 0.177 sec
Testcase: testValidUsage took 0.171 sec

FAILED
Unexpected timing 167
junit.framework.AssertionFailedError: Unexpected timing 167

at
org.springframework.util.StopWatchTests.testValidUsage(StopWatchTests.java:48)

public void testValidUsage() throws Exception {
StopWatch sw = new StopWatch();
long int1 = 166L;
long int2 = 45L;
String name1 = "Task 1";
assertFalse(sw.isRunning());
sw.start(name1);
Thread.sleep(int1);
assertTrue(sw.isRunning());
sw.stop();
long fudgeFactor = 0L;
assertTrue("Unexpected
sw.start(name2);
Thread.sleep(int2);
sw.stop();

timing " + sw.getTotalTimeMillis(), sw.getTotalTimeMillis() >= int1);
timing " + sw.getTotalTimeMillis(), sw.getTotalTimeMillis() <= int1 + fudgeFactor);

timing " + sw.getTotalTimeMillis(), sw.getTotalTimeMillis() >= int1 + int2);
timing " + sw.getTotalTimeMillis(), sw.getTotalTimeMillis() <= int1 + int2 + fudgeFactor);

assertTrue(sw.getTaskCount() == 2);
String pp = sw.prettyPrint();
assertTrue(pp.indexOf(name1) != -1);
StopWatch.TaskInfo[] tasks = sw.getTaskInfo();
assertTrue(tasks.length == 2);
assertTrue(tasks[0].getTaskName().equals(name1));
sw.toString();
}

public void testValidUsage() throws Exception {
long int1 = 166L;
long int2 = 45L;
sw.start(name1);
Thread.sleep(int1);
sw.stop();
// TODO are timings off in JUnit? Why do these assertions sometimes fail
// under both Ant and Eclipse?
//long fudgeFactor = 5L;
//assertTrue("Unexpected
sw.start(name2);
Thread.sleep(int2);
sw.stop();

timing " + sw.getTotalTime(), sw.getTotalTime() >= int1);
timing " + sw.getTotalTime(), sw.getTotalTime() <= int1 + fudgeFactor);

timing " + sw.getTotalTime(), sw.getTotalTime() >= int1 + int2);
timing " + sw.getTotalTime(), sw.getTotalTime() <= int1 + int2 + fudgeFactor);

sw.toString();
}

https://github.com/SpringSource/spring-framework/blob/master/spring-core/src/test/java/org/springframework/util/
StopWatchTests.java

The UnREADABLE TEST
Long Test Methods featuring Undecipherable Failures
introducing Developer Confusion and Wasted Developer Time
produced by

Flesch Reading Ease

http://en.wikipedia.org/wiki/Flesch–Kincaid_Readability_Test

MORE READABILITY
Produced By

SMALL WORDS and SHORT SENTENCES

http://www.arrestedcomputing.com/pubs/readability-issta.pdf

“ THE

LINE LENGTH
IDENTIFIER MASSACRE”

it "adds items to top" do
stack = Stack.new
stack.add "thing"
assert_equal "thing", stack.top
stack = nil
end

#
#
#
#

Setup
Exercise
Verify
Teardown

stack = Stack.new
stack.add "thing"
end

# Setup
# Exercise
# Verify

stack = Stack.new
stack.add "thing"
end

# Arrange
# Act
# Assert

stack = Stack.new
stack.add "thing"
end

# Given
# When
# Then

before do
@stack = Stack.new
end

# Given

@stack.add "thing"
assert_equal "thing", @stack.top
end

# When
# Then

before do
@stack = Stack.new
end

# Given

it "is initially empty" do
assert_empty @stack # Then
end

it "returns the total timesheet hours worked of the timesheet" do
timesheet = Timesheet.new
task_items = [stub(start_time: 1359291600, end_time: 1359295200),
stub(start_time: 1359295200, end_time: 1359298900)]
timesheet.stub(:task_items) { task_items }
timesheet.calculate_total_hours.should == 2.0
end

http://www.superpumpup.com/sub-ms-test

end

Extract Given
You have a long, confusing or poorly named test
setup.
Turn the fragment into a method or member variable
whose name describes the “given”.

http://martinfowler.com/bliki/ObjectMother.html

http://nat.truemesh.com/archives/000714.html

def timesheet_with_two_one_hour_tasks
timesheet
end
timesheet_with_two_one_hour_tasks.calculate_total_hours.should == 2.0
end

Extract Collaborator
An object your test depends on is confusing or
poorly named.
Extract the collaborating object into a method or
member variable whose name describes its purpose.

def one_hour_task
stub(start_time: 1359291600, end_time: 1359295200)
end
task_items = [one_hour_task, one_hour_task]
timesheet
end
end

Inline Temp
You have a temp that is assigned to once with a
simple expression, and the temp is getting in the way
of other refactorings.
Replace all references to that temp with the
expression.
http://www.refactoring.com/catalog/inlineTemp.html

def one_hour_task
stub(start_time: 1359291600, end_time: 1359295200)
end
timesheet.stub(:task_items) { [one_hour_task, one_hour_task] }
timesheet
end
end

Use meaningful data
Your test uses arbitrary literal values as test data.
Replace arbitrary values with values that have
meaning in the domain of the test.

ONE_HOUR_IN_SECONDS = (60*60*1)
def one_hour_task
stub(start_time: 0, end_time: ONE_HOUR_IN_SECONDS)
end
timesheet
end
end

Extract Test
Your test method is checking multiple behaviours, or
checking behaviour of a collaborating object.
Extract a new test method for each behaviour.

describe Task do
it "knows duration in hours" do
task = Task.new(start_time: 0, end_time: 3600)
task.duration.should == 1.0
end
end

def one_hour_task
stub(duration: 1)
end
timesheet
end
end

one_hour_task = stub(duration: 1)
end

“

clarity trumps brevity
in test names
https://www.facebook.com/notes/kent-beck/shorts-not-always-sweet-the-case-for-long-test-names/
564493423583526

Rename Method
The name of a method does not reveal its purpose.
Change the name of the method.

http://www.refactoring.com/catalog/renameMethod.html

public void testIsRunningWhenStartedAndTimeMultipleTasksAndTaskCountAndPrettyPrintAndTaskInfo() throws Exception {
long int1 = 166L;
long int2 = 45L;
sw.start(name1);
Thread.sleep(int1);
sw.stop();
sw.start(name2);
Thread.sleep(int2);
sw.stop();



sw.toString();
}

public void testTimeMultipleTasks() throws Exception {
long int1 = 166L;
long int2 = 45L;
sw.start(name1);
Thread.sleep(int1);
sw.stop();
sw.start(name2);
Thread.sleep(int2);
sw.stop();
}



StopWatch.TaskInfo task1 = new StopWatch.TaskInfo("Task 1", 166L);
sw.start(task1.getTaskName());
Thread.sleep(task1.getTimeMillis());
sw.stop();
assertTrue("Unexpected timing " + sw.getTotalTimeMillis(), sw.getTotalTimeMillis() >=
task1.getTimeMillis());
assertTrue("Unexpected timing " + sw.getTotalTimeMillis(), sw.getTotalTimeMillis() <=
task1.getTimeMillis() + fudgeFactor);
sw.start(task2.getTaskName());
Thread.sleep(task2.getTimeMillis());
sw.stop();
task1.getTimeMillis() + task2.getTimeMillis());
task1.getTimeMillis() + task2.getTimeMillis() + fudgeFactor);
}

timeTask(sw, task1);
task1.getTimeMillis());
task1.getTimeMillis() + fudgeFactor);
task1.getTimeMillis() + task2.getTimeMillis());
task1.getTimeMillis() + task2.getTimeMillis() + fudgeFactor);
}
private void timeTask(StopWatch sw, StopWatch.TaskInfo task) throws Exception {
sw.start(task.getTaskName());
Thread.sleep(task.getTimeMillis());
sw.stop();
}

Replace Assertion
Your test method uses a basic assertion to check for
a specific condition.
Use a more specific assertion provided by your test
framework, or create a custom assert method.

assertElapsedTime(sw, task1.getTimeMillis());
assertElapsedTime(sw, task1.getTimeMillis() + task2.getTimeMillis());
}
private void assertElapsedTime(StopWatch sw, int expectedDuration) {
double tolerance = 10.0;
assertThat((double)sw.getTotalTimeMillis(), is(closeTo((double)expectedDuration, tolerance)));
}
private void timeTask(StopWatch sw, StopWatch.TaskInfo task) throws Exception {
sw.start(task.getTaskName());
Thread.sleep(task.getTimeMillis());
sw.stop();
}

assertElapsedTime(sw, task1.getTimeMillis());
assertElapsedTime(sw, task1.getTimeMillis() + task2.getTimeMillis());
}

Readability

Refactorings

Short Test Methods
Shorter Line Length
Fewer Identifiers
Clear Test Method Names
Extract Given
Extract Collaborator
Use Meaningful Data
Extract Test
Replace Assertion

Help, my tests are killing me!!

Recommandé

Recommandé

Contenu connexe

Dernier

Dernier (20)

En vedette

En vedette (20)

Help, my tests are killing me!!