@GwtIncompatible("java.lang.reflect.Field")
public HasField hasField(final String fieldName) {
final T subject = getSubject();
if (subject == null) {
failureStrategy.fail("Cannot determine a field name from a null object.");
// Needed for Expect and other non-terminal failure strategies
return new HasField() {
@Override
public void withValue(Object value) {
Subject.this.fail("Cannot test the presence of a value in a null object.");
}
};
}
final Class<?> subjectClass = subject.getClass();
final Field field;
try {
field = ReflectionUtil.getField(subjectClass, fieldName);
field.setAccessible(true);
} catch (NoSuchFieldException e) {
StringBuilder message = new StringBuilder("Not true that ");
message.append("<").append(subjectClass.getSimpleName()).append(">");
message.append(" has a field named <").append(fieldName).append(">");
failureStrategy.fail(message.toString());
// Needed for Expect and other non-terminal failure strategies
return new HasField() {
@Override
public void withValue(Object value) {
Subject.this.fail("Cannot test the presence of a value in a non-present field.");
}
};
}
return new HasField() {
@Override
public void withValue(Object expected) {
try {
Object actual = field.get(subject);
if (expected == actual || (expected != null && expected.equals(actual))) {
return;
} else {
StringBuilder message = new StringBuilder("Not true that ");
message.append("<").append(subjectClass.getSimpleName()).append(">'s");
message.append(" field <").append(fieldName).append(">");
message.append(" contains expected value <").append(expected).append(">.");
message.append(" It contains value <").append(actual).append(">");
failureStrategy.fail(message.toString());
}
} catch (IllegalArgumentException e) {
throw new RuntimeException(
"Error checking field " + fieldName + " while testing for value " + expected);
} catch (IllegalAccessException e) {
throw new RuntimeException(
"Cannot access field " + fieldName + " to test for value " + expected);
}
}
};
}
/**
* Assembles a failure message with an alternative representation of the wrapped subject and
* passes it to the FailureStrategy
*
* @param verb the proposition being asserted
* @param expected the expected value of the proposition
* @param actual the custom representation of the subject to be reported in the failure.
*/
protected void failWithCustomSubject(String verb, Object expected, Object actual) {
String message =
format(
"Not true that <%s> %s <%s>",
((actual == null) ? "null reference" : actual), verb, expected);
failureStrategy.fail(message);
}
/**
* Assembles a failure message and passes such to the FailureStrategy
*
* @param verb the proposition being asserted
* @param messageParts the expectations against which the subject is compared
*/
protected void fail(String verb, Object... messageParts) {
StringBuilder message = new StringBuilder("Not true that ");
message.append(getDisplaySubject()).append(" ").append(verb);
for (Object part : messageParts) {
message.append(" <").append(part).append(">");
}
failureStrategy.fail(message.toString());
}
/**
* Assembles a failure message and passes it to the FailureStrategy
*
* @param verb the proposition being asserted
* @param messageParts the expectations against which the subject is compared
*/
protected void failWithBadResults(String verb, Object expected, String failVerb, Object actual) {
String message =
format(
"Not true that %s %s <%s>. It %s <%s>",
getDisplaySubject(),
verb,
expected,
failVerb,
((actual == null) ? "null reference" : actual));
failureStrategy.fail(message);
}
/**
* Passes through a failure message verbatim. Used for {@link Subject} subclasses which need to
* provide alternate language for more fit-to-purpose error messages.
*
* @param message the message template to be passed to the failure. Note, this method only
* guarantees to process {@code %s} tokens. It is not guaranteed to be compatible with {@code
* String.format()}. Any other formatting desired (such as floats or scientific notation)
* should be performed before the method call and the formatted value passed in as a string.
* @param paramters the object parameters which will be applied to the message template.
*/
protected void failWithRawMessage(String message, Object... parameters) {
failureStrategy.fail(format(message, parameters));
}
/**
* Assembles a failure message without a given subject and passes it to the FailureStrategy
*
* @param verb the proposition being asserted
*/
protected void failWithoutSubject(String verb) {
String subject = this.customName == null ? "the subject" : "\"" + customName + "\"";
failureStrategy.fail(format("Not true that %s %s", subject, verb));
}