org.rnorth.visibleassertions

Class VisibleAssertions

java.lang.Object

org.rnorth.visibleassertions.VisibleAssertions

public class VisibleAssertions
extends Object

Assertions for use in Java tests, with contextual information on each assertion performed.

Output is to stdout, and is coloured if the terminal supports it.

Author:

rnorth

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	VisibleAssertions()

Method Summary

Modifier and Type	Method and Description
static void	assertEquals(String message, Object expected, Object actual) Assert that an actual value is equal to an expected value.
static void	assertFalse(String message, boolean value) Assert that a value is false.
static void	assertNotEquals(String message, Object expected, Object actual) Assert that an actual value is not equal to an expected value.
static void	assertNotNull(String message, Object o) Assert that a value is not null.
static void	assertNull(String message, Object o) Assert that a value is null.
static void	assertRoughlyEquals(String message, Double expected, Double actual, Double epsilon) Assert that an actual value is approximately equal to an expected value - determined by whether the difference between the two values is less than a provided epsilon value.
static void	assertSame(String message, Object expected, Object actual) Assert that an actual value is the same object as an expected value.
static <T> void	assertThat(String whatTheObjectIs, T actual, org.hamcrest.Matcher<? super T> matcher) Assert using a Hamcrest matcher.
static <T> void	assertThrows(String message, Class<? extends Exception> exceptionClass, Callable<T> callable) Assert that a given callable throws an exception of a particular class.
static void	assertThrows(String message, Class<? extends Exception> exceptionClass, Runnable runnable) Assert that a given runnable throws an exception of a particular class.
static void	assertTrue(String message, boolean value) Assert that a value is true.
static void	assertVisiblyEquals(String message, Object expected, Object actual) Assert that an actual value is visibly equal to an expected value, following conversion to a String via toString().
static void	context(CharSequence context) Log a contextual message, in the style of a 'dividing line' in the test output.
static void	context(CharSequence context, int indent) Log a contextual message, in the style of a 'dividing line' in the test output.
static void	fail(String message) Just fail with an AssertionError, citing a given message.
static void	fail(String message, String hint)
static void	info(String message) Log an informational message.
static void	pass(String message) Indicate that something passed.
static void	warn(String message) Log a warning message.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VisibleAssertions

protected VisibleAssertions()

Method Detail

info

public static void info(String message)

Log an informational message.

The output will be in white, following an 'i' symbol.

Parameters:

message - message to output

warn

public static void warn(String message)

Log a warning message.

The output will be in yellow, following a '!' symbol.

Parameters:

message - message to output

context

public static void context(CharSequence context)

Log a contextual message, in the style of a 'dividing line' in the test output.

The output will be in grey, surrounded by a horizontal line the full width of the current terminal (or 80 chars).

Parameters:

context - contextual message to output.

context

public static void context(CharSequence context,
                           int indent)

Log a contextual message, in the style of a 'dividing line' in the test output.

The output will be in grey, surrounded by a horizontal line the full width of the current terminal (or 80 chars).

Parameters:

context - contextual message to output

indent - number of space characters to indent this line by

assertTrue

public static void assertTrue(String message,
                              boolean value)

Assert that a value is true.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

value - value to test

assertFalse

public static void assertFalse(String message,
                               boolean value)

Assert that a value is false.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

value - value to test

assertEquals

public static void assertEquals(String message,
                                Object expected,
                                Object actual)

Assert that an actual value is equal to an expected value.

Equality is tested with the standard Object equals() method, unless both values are null.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

expected - the expected value

actual - the actual value

assertVisiblyEquals

public static void assertVisiblyEquals(String message,
                                       Object expected,
                                       Object actual)

Assert that an actual value is visibly equal to an expected value, following conversion to a String via toString().

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

expected - the expected value

actual - the actual value

assertRoughlyEquals

public static void assertRoughlyEquals(String message,
                                       Double expected,
                                       Double actual,
                                       Double epsilon)

Assert that an actual value is approximately equal to an expected value - determined by whether the difference between the two values is less than a provided epsilon value.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

expected - the expected value

actual - the actual value

epsilon - the allowable absolute difference between expected and actual values

assertNotEquals

public static void assertNotEquals(String message,
                                   Object expected,
                                   Object actual)

Assert that an actual value is not equal to an expected value.

Equality is tested with the standard Object equals() method, unless both values are null.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

expected - the expected value

actual - the actual value

assertNull

public static void assertNull(String message,
                              Object o)

Assert that a value is null.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

o - value to test

assertNotNull

public static void assertNotNull(String message,
                                 Object o)

Assert that a value is not null.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

o - value to test

assertSame

public static void assertSame(String message,
                              Object expected,
                              Object actual)

Assert that an actual value is the same object as an expected value.

Sameness is tested with the == operator.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

expected - the expected value

actual - the actual value

fail

public static void fail(String message)

Just fail with an AssertionError, citing a given message.

A red cross will be shown.

Parameters:

message - message to display alongside the red cross

assertThat

public static <T> void assertThat(String whatTheObjectIs,
                                  T actual,
                                  org.hamcrest.Matcher<? super T> matcher)

Assert using a Hamcrest matcher.

Type Parameters:

T - class of the actual value

Parameters:

whatTheObjectIs - what is the thing being tested, in a logical sense

actual - the actual value

matcher - a matcher to check the actual value against

assertThrows

public static <T> void assertThrows(String message,
                                    Class<? extends Exception> exceptionClass,
                                    Callable<T> callable)

Assert that a given callable throws an exception of a particular class.

The assertion passes if the callable throws exactly the same class of exception (not a subclass).

If the callable doesn't throw an exception at all, or if another class of exception is thrown, the assertion fails.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Type Parameters:

T - return type of the callable

Parameters:

message - message to display alongside the assertion outcome

exceptionClass - the expected exception class

callable - a Callable to invoke

assertThrows

public static void assertThrows(String message,
                                Class<? extends Exception> exceptionClass,
                                Runnable runnable)

Assert that a given runnable throws an exception of a particular class.

The assertion passes if the runnable throws exactly the same class of exception (not a subclass).

If the runnable doesn't throw an exception at all, or if another class of exception is thrown, the assertion fails.

If the assertion passes, a green tick will be shown. If the assertion fails, a red cross will be shown.

Parameters:

message - message to display alongside the assertion outcome

exceptionClass - the expected exception class

runnable - a Runnable to invoke

pass

public static void pass(String message)

Indicate that something passed.

Parameters:

message - message to display alongside a green tick

fail

public static void fail(String message,
                        String hint)