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package com.nordstrom.automation.junit;
import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.concurrent.Callable;
import org.junit.experimental.theories.PotentialAssignment.CouldNotGenerateValueException;
import org.junit.experimental.theories.Theories.TheoryAnchor;
import org.junit.experimental.theories.internal.Assignments;
import org.junit.runner.Description;
import org.junit.runners.model.FrameworkMethod;
import net.bytebuddy.implementation.bind.annotation.Argument;
import net.bytebuddy.implementation.bind.annotation.SuperCall;
import net.bytebuddy.implementation.bind.annotation.This;
import junitparams.JUnitParamsRunner;
/**
* This class declares the interceptor for the {@link org.junit.runners.ParentRunner#describeChild
* describeChild} method.
*/
public class DescribeChild {
private static final Field uniqueId;
static {
Field field = null;
try {
field = Description.class.getDeclaredField("fUniqueId");
field.setAccessible(true);
} catch (NoSuchFieldException | SecurityException e) {
field = null;
}
uniqueId = field;
}
/**
* Interceptor for the {@link org.junit.runners.ParentRunner#describeChild describeChild} method.
*
* @param runner underlying test runner
* @param proxy callable proxy for the intercepted method
* @param child child object of the test runner
* @return a {@link Description} for {@code child}
* @throws Exception {@code anything} (exception thrown by the intercepted method)
*/
public static Description intercept(@This final Object runner,
@SuperCall final Callable proxy,
@Argument(0) final Object child) throws Exception {
Description description = LifecycleHooks.callProxy(proxy);
// if running with JUnitParams
if (runner instanceof JUnitParamsRunner) {
// fix description, adding test class and annotations
description = augmentDescription(child, description);
// otherwise, if able to override [uniqueId] of test
} else if ((uniqueId != null) && description.isTest()) {
try {
// get parent of test runner
Object parent = LifecycleHooks.getFieldValue(runner, "this$0");
// if child of TheoryAnchor statement
if (parent instanceof TheoryAnchor) {
// get assignments for this theory permutation
Assignments assignments = LifecycleHooks.getFieldValue(runner, "val$complete");
// inject permutation ID into description
injectPermutationId(description, assignments);
}
} catch (IllegalAccessException | NoSuchFieldException | SecurityException | IllegalArgumentException e) {
// nothing to do here
}
}
return description;
}
/**
* Inject permutation ID into the specified description, overriding its default ID.
*
* @param description description of "theory" method
* @param assignments arguments for this permutation
*/
private static void injectPermutationId(final Description description, final Assignments assignments) {
try {
Object[] args = assignments.getMethodArguments();
Object[] perm = new Object[args.length + 1];
perm[0] = description.getDisplayName();
System.arraycopy(args, 0, perm, 1, args.length);
int permutationId = Arrays.hashCode(perm);
String theoryId = String.format("theory-id: %08X", permutationId);
uniqueId.set(description, theoryId);
} catch (CouldNotGenerateValueException | SecurityException |
IllegalArgumentException | IllegalAccessException eaten) {
// nothing to do here
}
}
/**
* Make a childless copy of the specified description.
*
* @param description JUnit description
* @return copy of the specified description, including unique ID
*/
static Description makeChildlessCopyOf(final Description description) {
Description descripCopy = description.childlessCopy();
if (uniqueId != null) {
try {
uniqueId.set(descripCopy, uniqueId.get(description));
} catch (IllegalArgumentException | IllegalAccessException eaten) {
// nothing to do here
}
}
return descripCopy;
}
/**
* Augment incomplete description created by JUnitParams runner.
*
* NOTE: The description built by JUnitParams lack the test class and annotations.
*
* @param child child object of the test runner
* @param description JUnit description built by JUnitParams
* @return new augmented description object; if augmentation fails, returns original description
*/
private static Description augmentDescription(final Object child, final Description description) {
if ((child instanceof FrameworkMethod) && (uniqueId != null)) {
Description augmented = Description.createTestDescription(description.getTestClass(),
description.getMethodName(), ((FrameworkMethod) child).getAnnotations());
try {
uniqueId.set(augmented, uniqueId.get(description));
return augmented;
} catch (IllegalArgumentException | IllegalAccessException eaten) {
// nothing to do here
}
}
return description;
}
}