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How to use Interface MethodRule class of org.junit.rules package

Best junit code snippet using org.junit.rules.Interface MethodRule

Source:RuleMemberValidator.java

1package org.junit.internal.runners.rules;2import org.junit.ClassRule;3import org.junit.Rule;4import org.junit.rules.MethodRule;5import org.junit.rules.TestRule;6import org.junit.runners.model.FrameworkMember;7import org.junit.runners.model.TestClass;8import java.lang.annotation.Annotation;9import java.lang.reflect.Modifier;10import java.util.ArrayList;11import java.util.List;12/**13 * A RuleMemberValidator validates the rule fields/methods of a14 * {@link org.junit.runners.model.TestClass}. All reasons for rejecting the15 * {@code TestClass} are written to a list of errors.16 *17 * <p>There are four slightly different validators. The {@link #CLASS_RULE_VALIDATOR}18 * validates fields with a {@link ClassRule} annotation and the19 * {@link #RULE_VALIDATOR} validates fields with a {@link Rule} annotation.</p>20 *21 * <p>The {@link #CLASS_RULE_METHOD_VALIDATOR}22 * validates methods with a {@link ClassRule} annotation and the23 * {@link #RULE_METHOD_VALIDATOR} validates methods with a {@link Rule} annotation.</p>24 */25public class RuleMemberValidator {26    /**27     * Validates fields with a {@link ClassRule} annotation.28     */29    public static final RuleMemberValidator CLASS_RULE_VALIDATOR =30            classRuleValidatorBuilder()31            .withValidator(new DeclaringClassMustBePublic())32            .withValidator(new MemberMustBeStatic())33            .withValidator(new MemberMustBePublic())34            .withValidator(new FieldMustBeATestRule())35            .build();36    /**37     * Validates fields with a {@link Rule} annotation.38     */39    public static final RuleMemberValidator RULE_VALIDATOR =40            testRuleValidatorBuilder()41            .withValidator(new MemberMustBeNonStaticOrAlsoClassRule())42            .withValidator(new MemberMustBePublic())43            .withValidator(new FieldMustBeARule())44            .build();45    /**46     * Validates methods with a {@link ClassRule} annotation.47     */48    public static final RuleMemberValidator CLASS_RULE_METHOD_VALIDATOR =49            classRuleValidatorBuilder()50            .forMethods()51            .withValidator(new DeclaringClassMustBePublic())52            .withValidator(new MemberMustBeStatic())53            .withValidator(new MemberMustBePublic())54            .withValidator(new MethodMustBeATestRule())55            .build();56    /**57     * Validates methods with a {@link Rule} annotation.58     */59    public static final RuleMemberValidator RULE_METHOD_VALIDATOR =60            testRuleValidatorBuilder()61            .forMethods()62            .withValidator(new MemberMustBeNonStaticOrAlsoClassRule())63            .withValidator(new MemberMustBePublic())64            .withValidator(new MethodMustBeARule())65            .build();66    private final Class<? extends Annotation> annotation;67    private final boolean methods;68    private final List<RuleValidator> validatorStrategies;69    RuleMemberValidator(Builder builder) {70        this.annotation = builder.annotation;71        this.methods = builder.methods;72        this.validatorStrategies = builder.validators;73    }74    /**75     * Validate the {@link org.junit.runners.model.TestClass} and adds reasons76     * for rejecting the class to a list of errors.77     *78     * @param target the {@code TestClass} to validate.79     * @param errors the list of errors.80     */81    public void validate(TestClass target, List<Throwable> errors) {82        List<? extends FrameworkMember<?>> members = methods ? target.getAnnotatedMethods(annotation)83                : target.getAnnotatedFields(annotation);84        for (FrameworkMember<?> each : members) {85            validateMember(each, errors);86        }87    }88    private void validateMember(FrameworkMember<?> member, List<Throwable> errors) {89        for (RuleValidator strategy : validatorStrategies) {90            strategy.validate(member, annotation, errors);91        }92    }93    private static Builder classRuleValidatorBuilder() {94        return new Builder(ClassRule.class);95    }96    private static Builder testRuleValidatorBuilder() {97        return new Builder(Rule.class);98    }99    private static class Builder {100        private final Class<? extends Annotation> annotation;101        private boolean methods;102        private final List<RuleValidator> validators;103        private Builder(Class<? extends Annotation> annotation) {104            this.annotation = annotation;105            this.methods = false;106            this.validators = new ArrayList<RuleValidator>();107        }108        Builder forMethods() {109            methods = true;110            return this;111        }112        Builder withValidator(RuleValidator validator) {113            validators.add(validator);114            return this;115        }116        RuleMemberValidator build() {117            return new RuleMemberValidator(this);118        }119    }120    private static boolean isRuleType(FrameworkMember<?> member) {121        return isMethodRule(member) || isTestRule(member);122    }123    private static boolean isTestRule(FrameworkMember<?> member) {124        return TestRule.class.isAssignableFrom(member.getType());125    }126    private static boolean isMethodRule(FrameworkMember<?> member) {127        return MethodRule.class.isAssignableFrom(member.getType());128    }129    /**130     * Encapsulates a single piece of validation logic, used to determine if {@link org.junit.Rule} and131     * {@link org.junit.ClassRule} annotations have been used correctly132     */133    interface RuleValidator {134        /**135         * Examine the given member and add any violations of the strategy's validation logic to the given list of errors136         * @param member The member (field or member) to examine137         * @param annotation The type of rule annotation on the member138         * @param errors The list of errors to add validation violations to139         */140        void validate(FrameworkMember<?> member, Class<? extends Annotation> annotation, List<Throwable> errors);141    }142    /**143     * Requires the validated member to be non-static144     */145    private static final class MemberMustBeNonStaticOrAlsoClassRule implements RuleValidator {146        public void validate(FrameworkMember<?> member, Class<? extends Annotation> annotation, List<Throwable> errors) {147            boolean isMethodRuleMember = isMethodRule(member);148            boolean isClassRuleAnnotated = (member.getAnnotation(ClassRule.class) != null);149            // We disallow:150            //  - static MethodRule members151            //  - static @Rule annotated members152            //    - UNLESS they're also @ClassRule annotated153            // Note that MethodRule cannot be annotated with @ClassRule154            if (member.isStatic() && (isMethodRuleMember || !isClassRuleAnnotated)) {155                String message;156                if (isMethodRule(member)) {157                    message = "must not be static.";158                } else {159                    message = "must not be static or it must be annotated with @ClassRule.";160                }161                errors.add(new ValidationError(member, annotation, message));162            }163        }164    }165    /**166     * Requires the member to be static167     */168    private static final class MemberMustBeStatic implements RuleValidator {169        public void validate(FrameworkMember<?> member, Class<? extends Annotation> annotation, List<Throwable> errors) {170            if (!member.isStatic()) {171                errors.add(new ValidationError(member, annotation,172                        "must be static."));173            }174        }175    }176    /**177     * Requires the member's declaring class to be public178     */179    private static final class DeclaringClassMustBePublic implements RuleValidator {180        public void validate(FrameworkMember<?> member, Class<? extends Annotation> annotation, List<Throwable> errors) {181            if (!isDeclaringClassPublic(member)) {182                errors.add(new ValidationError(member, annotation,183                        "must be declared in a public class."));184            }185        }186        private boolean isDeclaringClassPublic(FrameworkMember<?> member) {187            return Modifier.isPublic(member.getDeclaringClass().getModifiers());188        }189    }190    /**191     * Requires the member to be public192     */193    private static final class MemberMustBePublic implements RuleValidator {194        public void validate(FrameworkMember<?> member, Class<? extends Annotation> annotation, List<Throwable> errors) {195            if (!member.isPublic()) {196                errors.add(new ValidationError(member, annotation,197                        "must be public."));198            }199        }200    }201    /**202     * Requires the member is a field implementing {@link org.junit.rules.MethodRule} or {@link org.junit.rules.TestRule}203     */204    private static final class FieldMustBeARule implements RuleValidator {205        public void validate(FrameworkMember<?> member, Class<? extends Annotation> annotation, List<Throwable> errors) {206            if (!isRuleType(member)) {207                errors.add(new ValidationError(member, annotation,208                        "must implement MethodRule or TestRule."));209            }210        }211    }212    /**213     * Require the member to return an implementation of {@link org.junit.rules.MethodRule} or214     * {@link org.junit.rules.TestRule}215     */216    private static final class MethodMustBeARule implements RuleValidator {217        public void validate(FrameworkMember<?> member, Class<? extends Annotation> annotation, List<Throwable> errors) {218            if (!isRuleType(member)) {219                errors.add(new ValidationError(member, annotation,220                        "must return an implementation of MethodRule or TestRule."));221            }222        }223    }224    225    /**226     * Require the member to return an implementation of {@link org.junit.rules.TestRule}227     */228    private static final class MethodMustBeATestRule implements RuleValidator {229        public void validate(FrameworkMember<?> member,230                Class<? extends Annotation> annotation, List<Throwable> errors) {231            if (!isTestRule(member)) {232                errors.add(new ValidationError(member, annotation, 233                        "must return an implementation of TestRule."));234            }235        }236    }237    238    /**239     * Requires the member is a field implementing {@link org.junit.rules.TestRule}240     */241    private static final class FieldMustBeATestRule implements RuleValidator {242        public void validate(FrameworkMember<?> member,243                Class<? extends Annotation> annotation, List<Throwable> errors) {244            if (!isTestRule(member)) {245                errors.add(new ValidationError(member, annotation,246                        "must implement TestRule."));247            }248        }249    }250}...

Source:Rule.java

1package org.junit;2import java.lang.annotation.ElementType;3import java.lang.annotation.Retention;4import java.lang.annotation.RetentionPolicy;5import java.lang.annotation.Target;6/**7 * Annotates fields that reference rules or methods that return a rule. A field must be public, not8 * static, and a subtype of {@link org.junit.rules.TestRule} (preferred) or9 * {@link org.junit.rules.MethodRule}. A method must be public, not static,10 * and must return a subtype of {@link org.junit.rules.TestRule} (preferred) or11 * {@link org.junit.rules.MethodRule}.12 * <p>13 * The {@link org.junit.runners.model.Statement} passed14 * to the {@link org.junit.rules.TestRule} will run any {@link Before} methods,15 * then the {@link Test} method, and finally any {@link After} methods,16 * throwing an exception if any of these fail.  If there are multiple17 * annotated {@link Rule}s on a class, they will be applied in order of fields first, then methods.18 * However, if there are multiple fields (or methods) they will be applied in an order19 * that depends on your JVM's implementation of the reflection API, which is20 * undefined, in general. Rules defined by fields will always be applied21 * before Rules defined by methods. You can use a {@link org.junit.rules.RuleChain} if you want22 * to have control over the order in which the Rules are applied.23 * <p>24 * For example, here is a test class that creates a temporary folder before25 * each test method, and deletes it after each:26 * <pre>27 * public static class HasTempFolder {28 *     &#064;Rule29 *     public TemporaryFolder folder= new TemporaryFolder();30 *31 *     &#064;Test32 *     public void testUsingTempFolder() throws IOException {33 *         File createdFile= folder.newFile(&quot;myfile.txt&quot;);34 *         File createdFolder= folder.newFolder(&quot;subfolder&quot;);35 *         // ...36 *     }37 * }38 * </pre>39 * <p>40 * And the same using a method.41 * <pre>42 * public static class HasTempFolder {43 *     private TemporaryFolder folder= new TemporaryFolder();44 *45 *     &#064;Rule46 *     public TemporaryFolder getFolder() {47 *         return folder;48 *     }49 *50 *     &#064;Test51 *     public void testUsingTempFolder() throws IOException {52 *         File createdFile= folder.newFile(&quot;myfile.txt&quot;);53 *         File createdFolder= folder.newFolder(&quot;subfolder&quot;);54 *         // ...55 *     }56 * }57 * </pre>58 * <p>59 * For more information and more examples, see60 * {@link org.junit.rules.TestRule}.61 *62 * @since 4.763 */64@Retention(RetentionPolicy.RUNTIME)65@Target({ElementType.FIELD, ElementType.METHOD})66public @interface Rule {67}...

Source:ExpectedTestFailureRule.java

1package com.baeldung.mockito.misusing;2import org.hamcrest.Matchers;3import org.junit.Assert;4import org.junit.rules.MethodRule;5import org.junit.runners.model.FrameworkMethod;6import org.junit.runners.model.Statement;7public class ExpectedTestFailureRule implements MethodRule {8    private final MethodRule testedRule;9    private FailureAssert failureAssert = null;10    public ExpectedTestFailureRule(MethodRule testedRule) {11        this.testedRule = testedRule;12    }13    @Override14    public Statement apply(final Statement base, final FrameworkMethod method, final Object target) {15        return new Statement() {16            public void evaluate() throws Throwable {17                try {18                    testedRule.apply(base, method, target)19                        .evaluate();20                } catch (Throwable t) {21                    if (failureAssert == null) {22                        throw t;23                    }24                    failureAssert.doAssert(t);25                    return;26                }27            }28        };29    }30    @SuppressWarnings("unchecked")31    public void expectedFailure(final Class<? extends Throwable> expected) {32        FailureAssert assertion = t -> Assert.assertThat(t, Matchers.isA((Class<Throwable>) expected));33        this.expectedFailure(assertion);34    }35    private void expectedFailure(FailureAssert failureAssert) {36        this.failureAssert = failureAssert;37    }38    @FunctionalInterface39    private interface FailureAssert {40        abstract void doAssert(Throwable t);41    }42}...

Source:ClassRule.java

1package org.junit;2import java.lang.annotation.Retention;3import java.lang.annotation.RetentionPolicy;4import org.junit.rules.MethodRule;5import org.junit.runners.model.Statement;6import org.junit.runners.model.TestClass;7/**8 * TODO: fix9 * 10 * Annotates fields that contain rules. Such a field must be public, not11 * static, and a subtype of {@link MethodRule}. For more information,12 * see {@link MethodRule}13 */14@Retention(RetentionPolicy.RUNTIME)15public @interface ClassRule {16	// TODO: check javadoc17	18	/**19	 * A ClassRule is the class-level analogue to a20	 * {@link org.junit.rules.MethodRule}.21	 * 22	 * @author Alistair A. Israel23	 */24	public static interface Value {25		/**26		 * Modifies the class-running {@link Statement} to implement an additional,27		 * class-level test-running rule.28		 * 29		 * @param base30		 *            The {@link Statement} to be modified31		 * @param method32		 *            The {@link TestClass} to be run33		 * @return a new statement, which may be the same as {@code base}, a wrapper34		 *         around {@code base}, or a completely new Statement.35		 */36		Statement apply(Statement base, TestClass testClass);37	}38}...

Source:MethodRule.java

1package org.junit.rules;2import org.junit.runners.model.FrameworkMethod;3import org.junit.runners.model.Statement;4public interface MethodRule {5  Statement apply(Statement paramStatement, FrameworkMethod paramFrameworkMethod, Object paramObject);6}7/* Location:              C:\Users\Tarik\OneDrive - fer.hr\FAKS\5. semestar\PPP\Testiranje\Test programi\jChess-1.5\jChess-1.5\jChess-1.5.jar!\org\junit\rules\MethodRule.class8 * Java compiler version: 5 (49.0)9 * JD-Core Version:       1.1.210 */...

Source:MethodRuleSupplier.java

1package org.specnaz.junit.rules;2import org.junit.rules.MethodRule;3/**4 * A {@link FunctionalInterface} used as the parameter to the5 * {@link Rule#of(MethodRuleSupplier)} static factory method.6 *7 * @param <T>8 *     the type of {@link MethodRule} returned by this Supplier9 */10@FunctionalInterface11public interface MethodRuleSupplier<T extends MethodRule> {12    T get();13}...

Interface MethodRule

Using AI Code Generation

1package com.junit;2import org.junit.rules.MethodRule;3import org.junit.runners.model.FrameworkMethod;4import org.junit.runners.model.Statement;5public class InterfaceMethodRule implements MethodRule {6	public Statement apply(Statement base, FrameworkMethod method, Object target) {7		System.out.println("Method Rule is applied");8		return base;9	}10}11package com.junit;12import org.junit.Rule;13import org.junit.Test;14import org.junit.rules.MethodRule;15public class TestInterfaceMethodRule {16	public MethodRule methodRule = new InterfaceMethodRule();17	public void test1() {18		System.out.println("Test1");19	}20	public void test2() {21		System.out.println("Test2");22	}23	public void test3() {24		System.out.println("Test3");25	}26}

Source: JUnit @Rule to pass parameter to test

1import java.lang.reflect.Field;2import java.util.ArrayList;34public class ArrayListAddInterceptor<T> extends ArrayList<T> {5    private static final long serialVersionUID = 1L;67    private AddInterceptor<T> interceptor;89    public ArrayListAddInterceptor(AddInterceptor<T> interceptor) {10        this.interceptor = interceptor;11    }1213    @Override14    public boolean add(T t) {15        interceptor.intercept(t);16        return false;17    }1819    public static interface AddInterceptor<T> {20        public void intercept(T t);21    }2223    public static void apply(AddInterceptor<?> interceptor, Object o, String property) {24        try {25            Field field = o.getClass().getDeclaredField(property);26            field.setAccessible(true);27            field.set(o, new ArrayListAddInterceptor(interceptor));28        } catch (Exception e) {29            throw new RuntimeException(e);30        }31    }3233}34

Source:JUnit @Rule to pass parameter to test

import java.lang.reflect.Field;
import java.util.ArrayList;

public class ArrayListAddInterceptor<T> extends ArrayList<T> {
    private static final long serialVersionUID = 1L;

    private AddInterceptor<T> interceptor;

    public ArrayListAddInterceptor(AddInterceptor<T> interceptor) {
        this.interceptor = interceptor;
    }

    @Override
    public boolean add(T t) {
        interceptor.intercept(t);
        return false;
    }

    public static interface AddInterceptor<T> {
        public void intercept(T t);
    }

    public static void apply(AddInterceptor<?> interceptor, Object o, String property) {
        try {
            Field field = o.getClass().getDeclaredField(property);
            field.setAccessible(true);
            field.set(o, new ArrayListAddInterceptor(interceptor));
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

}

Source: Wrapping JUnit Tests (in Eclipse)

1<container>2 <type1>...</type1>3 <type2>...</type2>4 <type1>...</type1>5 ...6</container>7

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Assertions in JUnit - Assertions are used to validate or test that the result of an action/functionality is the same as expected. Learn in detail what assertions are and how to use them while performing JUnit testing.
Parameterization in JUnit - Parameterized Test enables you to run the same automated test scripts with different variables. By collecting data on each method's test parameters, you can minimize time spent on writing tests. Learn how to use parameterization in JUnit.
Nested Tests In JUnit 5 - A nested class is a non-static class contained within another class in a hierarchical structure. It can share the state and setup of the outer class. Learn about nested annotations in JUnit 5 with examples.
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