Implementing ability to pass information about test method to a data provider method

src/main/java/com/tngtech/java/junit/dataprovider/internal/TestGenerator.java

@@ -63,7 +63,12 @@ public List<FrameworkMethod> generateExplodedTestMethodsFor(FrameworkMethod test
     List<FrameworkMethod> explodeTestMethod(FrameworkMethod testMethod, FrameworkMethod dataProviderMethod) {
         Object data;
         try {
-            data = dataProviderMethod.invokeExplosively(null);
+          Class<?>[] parameterTypes = dataProviderMethod.getMethod().getParameterTypes();
+          if (parameterTypes.length > 0) {
+              data = dataProviderMethod.invokeExplosively(null, testMethod);
+          } else {
+              data = dataProviderMethod.invokeExplosively(null);
+          }
         } catch (Throwable t) {
             throw new Error(String.format("Exception while invoking data provider method '%s': %s",
                     dataProviderMethod.getName(), t.getMessage()), t);

src/main/java/com/tngtech/java/junit/dataprovider/internal/TestValidator.java

@@ -100,7 +100,9 @@ public void validateDataProviderMethod(FrameworkMethod dataProviderMethod, DataP
             errors.add(new Exception(messageBasePart + " be static"));
         }
         if (method.getParameterTypes().length != 0) {
-            errors.add(new Exception(messageBasePart + " have no parameters"));
+            if (! method.getParameterTypes()[0].equals(FrameworkMethod.class)) {
+                errors.add(new Exception(messageBasePart + " have no parameters or a single FrameworkMethod parameter"));
+            }
         }
         if (!dataConverter.canConvert(method.getGenericReturnType())) {
             errors.add(new Exception(messageBasePart + " either return Object[][] or List<List<Object>>"));

src/test/java/com/tngtech/java/junit/dataprovider/internal/TestValidatorTest.java

@@ -238,6 +238,25 @@ public void testValidateDataProviderMethodShouldAddNoErrorIfDataProviderMethodIs
         assertThat(errors).isEmpty();
     }
 
+    @Test
+    public void testValidateDataProviderMethodShouldAddNoErrorIfDataProviderMethodWithTestMethodParameterIsValid() {
+        // Given:
+        String dataProviderName = "validDataProvider";
+
+        List<Throwable> errors = new ArrayList<Throwable>();
+
+        doReturn(dataProviderName).when(dataProviderMethod).getName();
+        doReturn(getMethod("validDataProviderMethodWithTestMethodParameter")).when(dataProviderMethod).getMethod();
+        doReturn(true).when(dataConverter).canConvert(any(Type.class));
+        doReturn(new String[0]).when(dataProvider).value();
+
+        // When:
+        underTest.validateDataProviderMethod(dataProviderMethod, dataProvider, errors);
+
+        // Then:
+        assertThat(errors).isEmpty();
+    }
+
     @Test
     public void testValidateDataProviderMethodShouldAddErrorIfDataProviderMethodIsNotPublic() {
         // Given:
@@ -398,4 +417,8 @@ String nonPublicNonStaticNonNoArgDataProviderMethod(String arg1) {
     public static Object[][] validDataProviderMethod() {
         return null;
     }
+
+    public static Object[][] validDataProviderMethodWithTestMethodParameter(FrameworkMethod testMethod) {
+        return null;
+    }
 }

src/test/java/com/tngtech/test/java/junit/dataprovider/DataProviderJavaAcceptanceTest.java

@@ -14,6 +14,7 @@
 import com.tngtech.java.junit.dataprovider.DataProvider;
 import com.tngtech.java.junit.dataprovider.DataProviderRunner;
 import com.tngtech.java.junit.dataprovider.UseDataProvider;
+import org.junit.runners.model.FrameworkMethod;
 
 @RunWith(DataProviderRunner.class)
 public class DataProviderJavaAcceptanceTest {
@@ -230,4 +231,19 @@ public void testIsEmptyString2(String str) {
         // Then:
         assertThat(isEmpty).isTrue();
     }
+
+    @Test
+    @UseDataProvider("loadFromExternalFile")
+    @ExternalFile(format = ExternalFile.Format.CSV, value = "testdata.csv")
+    public void testThatUsesUniversalDataProvider(String testData) {
+        assertThat(testData).isEqualTo("testdata.csv");
+    }
+
+    @DataProvider
+    public static Object[][] loadFromExternalFile(FrameworkMethod testMethod) {
+        String testDataFile = testMethod.getAnnotation(ExternalFile.class).value();
+        return new Object[][]{
+            { testDataFile }
+        };
+    }
 }

src/test/java/com/tngtech/test/java/junit/dataprovider/ExternalFile.java

@@ -0,0 +1,15 @@
+package com.tngtech.test.java.junit.dataprovider;
+
+import java.lang.annotation.*;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface ExternalFile {
+
+  public enum Format {
+    CSV, XML, XLS
+  }
+
+  Format format();
+  String value();
+}