com.tngtech.java.junit.dataprovider.internal.DefaultDataProviderMethodResolver Maven / Gradle / Ivy

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A TestNG like dataprovider runner for JUnit having a simplified syntax compared to all the existing JUnit4 features.
There is a newer version: 2.10
package com.tngtech.java.junit.dataprovider.internal;

import static com.tngtech.java.junit.dataprovider.common.Preconditions.checkNotNull;
import static java.util.Collections.singletonList;

import java.util.ArrayList;
import java.util.List;

import org.junit.runners.model.FrameworkMethod;
import org.junit.runners.model.TestClass;

import com.tngtech.java.junit.dataprovider.DataProvider;
import com.tngtech.java.junit.dataprovider.DataProviderMethodResolver;
import com.tngtech.java.junit.dataprovider.UseDataProvider;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;

/**
 * Default implementation to resolve the dataprovider method for a test method using {@link UseDataProvider} annotation.
 * 
 * It is being tried to resolve the dataprovider method using various strategies. The locations of the dataprovider can optionally
 * specified using {@link UseDataProvider#location()}. If no specific location is specified, test class itself is used (= where
 * {@code @}{@link UseDataProvider} annotation is used). If multiple locations are specified, each is searched for an appropriate
 * dataprovider.
 * 

 * The name of the dataprovider method can be explicitly set via {@link UseDataProvider#value()} or derived by convention. The first
 * found dataprovider method will be used. Here are the applied strategies:
 * 

 * Explicitly configured name using {@link UseDataProvider#value()}. (no fallback if dataprovider could not be found)
 * @{@link DataProvider} annotated method which name equals the test method name
 * @{@link DataProvider} annotated method whereby prefix is replaced by one out of the following:
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * prefix replacement
test dataProvider
test data
 * 
 * @{@link DataProvider} annotated method whereby additional prefix "dataProvider" or "data" is given. Also the first letter of the
 * original test method name is uppercased, e.g. {@code shouldReturnTwoForOnePlusOne} corresponds to
 * {@code dataProviderShouldReturnTwoForOnePlusOne}.
 * 
 */
@SuppressFBWarnings(value = "NM_SAME_SIMPLE_NAME_AS_SUPERCLASS", justification = "for backwards compatibility and easier migration to core")
public class DefaultDataProviderMethodResolver
        extends com.tngtech.junit.dataprovider.resolver.DefaultDataProviderMethodResolver
        implements DataProviderMethodResolver {

    /**
     * {@inheritDoc}
     * 
     * Look at the classes java doc for detailed description of the applied strategies.
     *
     * @return the resolved dataprovider method or an empty {@link List} if dataprovider could not be found (never null)
     * @see DefaultDataProviderMethodResolver
     */
    @Override
    public List resolve(FrameworkMethod testMethod, UseDataProvider useDataProvider) {
        checkNotNull(testMethod, "testMethod must not be null");
        checkNotNull(useDataProvider, "useDataProvider must not be null");

        List dataProviderLocations = findDataProviderLocations(testMethod, useDataProvider.location());
        return findDataProviderMethods(dataProviderLocations, testMethod.getName(), useDataProvider.value());
    }

    protected List findDataProviderLocations(FrameworkMethod testMethod, Class[] useDataProviderLocation) {
        if (useDataProviderLocation.length == 0) {
            return singletonList(new TestClass(testMethod.getMethod().getDeclaringClass()));
        }

        List result = new ArrayList();
        for (Class location : useDataProviderLocation) {
            result.add(new TestClass(location));
        }
        return result;
    }

    protected List findDataProviderMethods(List locations, String testMethodName, String useDataProviderValue) {
        List result = new ArrayList();
        for (TestClass location : locations) {
            FrameworkMethod method = findDataProviderMethod(location, testMethodName, useDataProviderValue);
            if (method != null) {
                result.add(method);
            }
        }
        return result;
    }

    protected FrameworkMethod findDataProviderMethod(TestClass location, String testMethodName, String useDataProviderValue) {
        List dataProviderMethods = location.getAnnotatedMethods(DataProvider.class);
        for (FrameworkMethod dataProviderMethod : dataProviderMethods) {
            if (UseDataProvider.DEFAULT_VALUE.equals(useDataProviderValue)) {
                if (isMatchingNameConvention(testMethodName, dataProviderMethod.getName())) {
                    return dataProviderMethod;
                }
            } else if (dataProviderMethod.getName().equals(useDataProviderValue)) {
                return dataProviderMethod;
            }
        }
        return null;
    }
}