# Namespace: joker.test

v1.0

## Contents

- Summary
- Index
- Constants
- Variables
- Functions, Macros, and Special Forms

## Summary

A unit testing framework.
ASSERTIONS
The core of the library is the "is" macro, which lets you make
assertions of any arbitrary expression:
(is (= 4 (+ 2 2)))
(is (instance? Integer 256))
(is (.startsWith "abcde" "ab"))
You can type an "is" expression directly at the REPL, which will
print a message if it fails.
user> (is (= 5 (+ 2 2)))
FAIL in (:1)
expected: (= 5 (+ 2 2))
actual: (not (= 5 4))
false
The "expected:" line shows you the original expression, and the
"actual:" shows you what actually happened. In this case, it
shows that (+ 2 2) returned 4, which is not = to 5. Finally, the
"false" on the last line is the value returned from the
expression. The "is" macro always returns the result of the
inner expression.
There are two special assertions for testing exceptions. The
"(is (thrown? c ...))" form tests if an exception of class c is
thrown:
(is (thrown? ArithmeticException (/ 1 0)))
"(is (thrown-with-msg? c re ...))" does the same thing and also
tests that the message on the exception matches the regular
expression re:
(is (thrown-with-msg? ArithmeticException #"Divide by zero"
(/ 1 0)))
DOCUMENTING TESTS
"is" takes an optional second argument, a string describing the
assertion. This message will be included in the error report.
(is (= 5 (+ 2 2)) "Crazy arithmetic")
In addition, you can document groups of assertions with the
"testing" macro, which takes a string followed by any number of
assertions. The string will be included in failure reports.
Calls to "testing" may be nested, and all of the strings will be
joined together with spaces in the final report, in a style
similar to RSpec <http://rspec.info/>
(testing "Arithmetic"
(testing "with positive integers"
(is (= 4 (+ 2 2)))
(is (= 7 (+ 3 4))))
(testing "with negative integers"
(is (= -4 (+ -2 -2)))
(is (= -1 (+ 3 -4)))))
Note that, unlike RSpec, the "testing" macro may only be used
INSIDE a "deftest" or "with-test" form (see below).
DEFINING TESTS
There are two ways to define tests. The "with-test" macro takes
a defn or def form as its first argument, followed by any number
of assertions. The tests will be stored as metadata on the
definition.
(with-test
(defn my-function [x y]
(+ x y))
(is (= 4 (my-function 2 2)))
(is (= 7 (my-function 3 4))))
As of Clojure SVN rev. 1221, this does not work with defmacro.
See http://code.google.com/p/clojure/issues/detail?id=51
The other way lets you define tests separately from the rest of
your code, even in a different namespace:
(deftest addition
(is (= 4 (+ 2 2)))
(is (= 7 (+ 3 4))))
(deftest subtraction
(is (= 1 (- 4 3)))
(is (= 3 (- 7 4))))
This creates functions named "addition" and "subtraction", which
can be called like any other function. Therefore, tests can be
grouped and composed, in a style similar to the test framework in
Peter Seibel's "Practical Common Lisp"
<http://www.gigamonkeys.com/book/practical-building-a-unit-test-framework.html>
(deftest arithmetic
(addition)
(subtraction))
The names of the nested tests will be joined in a list, like
"(arithmetic addition)", in failure reports. You can use nested
tests to set up a context shared by several tests.
RUNNING TESTS
Run tests with the function "(run-tests namespaces...)":
(run-tests 'your.namespace 'some.other.namespace)
If you don't specify any namespaces, the current namespace is
used. To run all tests in all namespaces, use "(run-all-tests)".
By default, these functions will search for all tests defined in
a namespace and run them in an undefined order. However, if you
are composing tests, as in the "arithmetic" example above, you
probably do not want the "addition" and "subtraction" tests run
separately. In that case, you must define a special function
named "test-ns-hook" that runs your tests in the correct order:
(defn test-ns-hook []
(arithmetic))
Note: test-ns-hook prevents execution of fixtures (see below).
OMITTING TESTS FROM PRODUCTION CODE
You can bind the variable "*load-tests*" to false when loading or
compiling code in production. This will prevent any tests from
being created by "with-test" or "deftest".
FIXTURES
Fixtures allow you to run code before and after tests, to set up
the context in which tests should be run.
A fixture is just a function that calls another function passed as
an argument. It looks like this:
(defn my-fixture [f]
Perform setup, establish bindings, whatever.
(f) Then call the function we were passed.
Tear-down / clean-up code here.
)
Fixtures are attached to namespaces in one of two ways. "each"
fixtures are run repeatedly, once for each test function created
with "deftest" or "with-test". "each" fixtures are useful for
establishing a consistent before/after state for each test, like
clearing out database tables.
"each" fixtures can be attached to the current namespace like this:
(use-fixtures :each fixture1 fixture2 ...)
The fixture1, fixture2 are just functions like the example above.
They can also be anonymous functions, like this:
(use-fixtures :each (fn [f] setup... (f) cleanup...))
The other kind of fixture, a "once" fixture, is only run once,
around ALL the tests in the namespace. "once" fixtures are useful
for tasks that only need to be performed once, like establishing
database connections, or for time-consuming tasks.
Attach "once" fixtures to the current namespace like this:
(use-fixtures :once fixture1 fixture2 ...)
Note: Fixtures and test-ns-hook are mutually incompatible. If you
are using test-ns-hook, fixture functions will *never* be run.
SAVING TEST OUTPUT TO A FILE
All the test reporting functions write to the var *test-out*. By
default, this is the same as *out*, but you can rebind it to any
PrintWriter. For example, it could be a file opened with
clojure.java.io/writer.
EXTENDING TEST-IS (ADVANCED)
You can extend the behavior of the "is" macro by defining new
methods for the "assert-expr" multimethod. These methods are
called during expansion of the "is" macro, so they should return
quoted forms to be evaluated.
You can plug in your own test-reporting framework by rebinding
the "report" function: (report event)
The 'event' argument is a map. It will always have a :type key,
whose value will be a keyword signaling the type of event being
reported. Standard events with :type value of :pass, :fail, and
:error are called when an assertion passes, fails, and throws an
exception, respectively. In that case, the event will also have
the following keys:
:expected The form that was expected to be true
:actual A form representing what actually occurred
:message The string message given as an argument to 'is'
The "testing" strings will be a list in "*testing-contexts*", and
the vars being tested will be a list in "*testing-vars*".
Your "report" function should wrap any printing calls in the
"with-test-out" macro, which rebinds *out* to the current value
of *test-out*.
For additional event types, see the examples in the code.

## Index

- *initial-report-counters*
- *load-tests*
- *report-counters*
- *stack-trace-depth*
- *test-out*
- *testing-contexts*
- *testing-vars*
- are
- assert-any
- assert-expr
- assert-predicate
- compose-fixtures
- deftest
- deftest-
- do-report
- function?
- get-possibly-unbound-var
- inc-report-counter
- is
- join-fixtures
- report
- run-all-tests
- run-tests
- set-test
- successful?
- test-all-vars
- test-ns
- test-var
- test-vars
- testing
- testing-contexts-str
- testing-vars-str
- try-expr
- use-fixtures
- with-test
- with-test-out

## Constants

Constants are variables with `:const true` in their metadata. Joker currently does not recognize them as special; as such, it allows redefining them or their values.

- ### *initial-report-counters*

  Constant ArrayMap v1.0

  Used to initialize *report-counters*

  source

## Variables

- ### *load-tests*

  Boolean v1.0

  True by default. If set to false, no test functions will
  be created by deftest, set-test, or with-test. Use this to omit
  tests when compiling or loading production code.

  source

- ### *report-counters*

  Atom v1.0

  Bound to an atom of a map in test-ns

  source

- ### *stack-trace-depth*

  Int v1.0

  The maximum depth of stack traces to print when an Exception
  is thrown during a test. Defaults to nil, which means print the
  complete stack trace.

  source

- ### *test-out*

  IOWriter v1.0

  PrintWriter for test reporting output

  source

- ### *testing-contexts*

  List v1.0

  Bound to hierarchy of "testing" strings

  source

- ### *testing-vars*

  List v1.0

  Bound to hierarchy of vars being tested

  source

## Functions, Macros, and Special Forms

- ### are

  Macro v1.0

      (are argv expr & args)

  Checks multiple assertions with a template expression.
  See clojure.template/do-template for an explanation of
  templates.
  Example: (are [x y] (= x y)
  2 (+ 1 1)
  4 (* 2 2))
  Expands to:
  (do (is (= 2 (+ 1 1)))
  (is (= 4 (* 2 2))))
  Note: This breaks some reporting features, such as line numbers.

  source

- ### assert-any

  Function v1.0

      (assert-any msg form)

  Returns generic assertion code for any test, including macros, Java
  method calls, or isolated symbols.

  source

- ### assert-expr

  Function v1.0

  Don't call this; add methods to extend the 'is' macro.

  source

- ### assert-predicate

  Function v1.0

      (assert-predicate msg form)

  Returns generic assertion code for any functional predicate. The
  'expected' argument to 'report' will contains the original form, the
  'actual' argument will contain the form with all its sub-forms
  evaluated. If the predicate returns false, the 'actual' form will
  be wrapped in (not...).

  source

- ### compose-fixtures

  Function v1.0

      (compose-fixtures f1 f2)

  Composes two fixture functions, creating a new fixture function
  that combines their behavior.

  source

- ### deftest

  Macro v1.0

      (deftest name & body)

  Defines a test function with no arguments. Test functions may call
  other tests, so tests may be composed. If you compose tests, you
  should also define a function named test-ns-hook; run-tests will
  call test-ns-hook instead of testing all vars.
  Note: Actually, the test body goes in the :test metadata on the var,
  and the real function (the value of the var) calls test-var on
  itself.
  When *load-tests* is false, deftest is ignored.

  source

- ### deftest-

  Macro v1.0

      (deftest- name & body)

  Like deftest but creates a private var.

  source

- ### do-report

  Function v1.0

      (do-report m)

  Add file and line information to a test result and call report.
  If you are writing a custom assert-expr method, call this function
  to pass test results to report.

  source

- ### function?

  Function v1.0

      (function? x)

  Returns true if argument is a function or a symbol that resolves to
  a function (not a macro).

  source

- ### get-possibly-unbound-var

  Function v1.0

      (get-possibly-unbound-var v)

  Like var-get but returns nil if the var is unbound.

  source

- ### inc-report-counter

  Function v1.0

      (inc-report-counter name)

  Increments the named counter in *report-counters*, a ref to a map.
  Does nothing if *report-counters* is nil.

  source

- ### is

  Macro v1.0

      (is form)
      (is form msg)

  Generic assertion macro. 'form' is any predicate test.
  'msg' is an optional message to attach to the assertion.
  Example: (is (= 4 (+ 2 2)) "Two plus two should be 4")
  Special forms:
  (is (thrown? c body)) checks that an instance of c is thrown from
  body, fails if not; then returns the thing thrown.
  (is (thrown-with-msg? c re body)) checks that an instance of c is
  thrown AND that the message on the exception matches (with
  re-find) the regular expression re.

  source

- ### join-fixtures

  Function v1.0

      (join-fixtures fixtures)

  Composes a collection of fixtures, in order. Always returns a valid
  fixture function, even if the collection is empty.

  source

- ### report

  Function v1.0

  Generic reporting function, may be overridden to plug in
  different report formats (e.g., TAP, JUnit). Assertions such as
  'is' call 'report' to indicate results. The argument given to
  'report' will be a map with a :type key. See the documentation at
  the top of test_is.clj for more information on the types of
  arguments for 'report'.

  source

- ### run-all-tests

  Function v1.0

      (run-all-tests)
      (run-all-tests re)

  Runs all tests in all namespaces; prints results.
  Optional argument is a regular expression; only namespaces with
  names matching the regular expression (with re-matches) will be
  tested.

  source

- ### run-tests

  Function v1.0

      (run-tests)
      (run-tests & namespaces)

  Runs all tests in the given namespaces; prints results.
  Defaults to current namespace if none given. Returns a map
  summarizing test results.

  source

- ### set-test

  Macro v1.0

      (set-test name & body)

  Experimental.
  Sets :test metadata of the named var to a fn with the given body.
  The var must already exist. Does not modify the value of the var.
  When *load-tests* is false, set-test is ignored.

  source

- ### successful?

  Function v1.0

      (successful? summary)

  Returns true if the given test summary indicates all tests
  were successful, false otherwise.

  source

- ### test-all-vars

  Function v1.0

      (test-all-vars ns)

  Calls test-vars on every var interned in the namespace, with fixtures.

  source

- ### test-ns

  Function v1.0

      (test-ns ns)

  If the namespace defines a function named test-ns-hook, calls that.
  Otherwise, calls test-all-vars on the namespace. 'ns' is a
  namespace object or a symbol.
  Internally binds *report-counters* to a ref initialized to
  *initial-report-counters*. Returns the final, dereferenced state of
  *report-counters*.

  source

- ### test-var

  Function v1.0

      (test-var v)

  If v has a function in its :test metadata, calls that function,
  with *testing-vars* bound to (conj *testing-vars* v).

  source

- ### test-vars

  Function v1.0

      (test-vars vars)

  Groups vars by their namespace and runs test-vars on them with
  appropriate fixtures applied.

  source

- ### testing

  Macro v1.0

      (testing string & body)

  Adds a new string to the list of testing contexts. May be nested,
  but must occur inside a test function (deftest).

  source

- ### testing-contexts-str

  Function v1.0

      (testing-contexts-str)

  Returns a string representation of the current test context. Joins
  strings in *testing-contexts* with spaces.

  source

- ### testing-vars-str

  Function v1.0

      (testing-vars-str m)

  Returns a string representation of the current test. Renders names
  in *testing-vars* as a list, then the source file and line of
  current assertion.

  source

- ### try-expr

  Macro v1.0

      (try-expr msg form)

  Used by the 'is' macro to catch unexpected exceptions.
  You don't call this.

  source

- ### use-fixtures

  Function v1.0

  Wrap test runs in a fixture function to perform setup and
  teardown. Using a fixture-type of :each wraps every test
  individually, while :once wraps the whole run in a single function.

  source

- ### with-test

  Macro v1.0

      (with-test definition & body)

  Takes any definition form (that returns a Var) as the first argument.
  Remaining body goes in the :test metadata function for that Var.
  When *load-tests* is false, only evaluates the definition, ignoring
  the tests.

  source

- ### with-test-out

  Macro v1.0

      (with-test-out & body)

  Runs body with *out* bound to the value of *test-out*.

  source