1 files changed, 94 insertions, 0 deletions
diff --git a/junit4/src/main/java/com/google/testing/junit/testparameterinjector/TestParameterValueProvider.java b/junit4/src/main/java/com/google/testing/junit/testparameterinjector/TestParameterValueProvider.java
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index 0000000..38c3356
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+++ b/junit4/src/main/java/com/google/testing/junit/testparameterinjector/TestParameterValueProvider.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2021 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.google.testing.junit.testparameterinjector;
+
+import com.google.common.base.Optional;
+import java.lang.annotation.Annotation;
+import java.util.List;
+
+/**
+ * Interface which allows {@link TestParameterAnnotation} annotations to provide the values to test
+ * in a dynamic way.
+ */
+interface TestParameterValueProvider {
+
+  /**
+   * Returns the parameter values for which the test should run.
+   *
+   * @param annotation The annotation instance that was encountered in the test class. The
+   *     definition of this annotation is itself annotated with the {@link TestParameterAnnotation}
+   *     annotation.
+   * @param parameterClass The class of the parameter or field that is being annotated. In case the
+   *     annotation is annotating a method, constructor or class, {@code parameterClass} is an empty
+   *     optional.
+   */
+  default List<Object> provideValues(Annotation annotation, Optional<Class<?>> parameterClass) {
+    throw new UnsupportedOperationException(
+        "If this is called by TestParameterInjector, it means that neither of the"
+            + " provideValues()-type methods have been implemented");
+  }
+
+  /**
+   * Extension of {@link #provideValues(Annotation, Optional<Class<?>>)} with extra context.
+   *
+   * @param annotation The annotation instance that was encountered in the test class. The
+   *     definition of this annotation is itself annotated with the {@link TestParameterAnnotation}
+   *     annotation.
+   * @param otherAnnotations A list of all other annotations on the field or parameter that was
+   *     annotated with {@code annotation}.
+   *     <p>For example, if the test code is as follows:
+   *     <pre>
+   *       @Test
+   *       public void myTest_success(
+   *           @CustomAnnotation(123) @TestParameter(valuesProvider=MyProvider.class) Foo foo) {
+   *         ...
+   *       }
+   *     </pre>
+   *     then this list will contain a single element: @CustomAnnotation(123).
+   *     <p>In case the annotation is annotating a method, constructor or class, {@code
+   *     parameterClass} is an empty list.
+   * @param parameterClass The class of the parameter or field that is being annotated. In case the
+   *     annotation is annotating a method, constructor or class, {@code parameterClass} is an empty
+   *     optional.
+   * @param testClass The class that contains the test that is currently being run.
+   *     <p>Having this can be useful when sharing providers between tests that have the same base
+   *     class. In those cases, an abstract method can be called as follows:
+   *     <pre>
+   *       ((MyBaseClass) context.testClass().newInstance()).myAbstractMethod()
+   *     </pre>
+   *
+   * @deprecated Don't use this method outside of the testparameterinjector codebase, as it is prone
+   *     to being changed.
+   */
+  @Deprecated
+  default List<Object> provideValues(
+      Annotation annotation, Optional<Class<?>> parameterClass, GenericParameterContext context) {
+    return provideValues(annotation, parameterClass);
+  }
+
+  /**
+   * Returns the class of the list elements returned by {@link #provideValues(Annotation,
+   * Optional)}.
+   *
+   * @param annotationType The type of the annotation that was encountered in the test class. The
+   *     definition of this annotation is itself annotated with the {@link TestParameterAnnotation}
+   *     annotation.
+   * @param parameterClass The class of the parameter or field that is being annotated. In case the
+   *     annotation is annotating a method, constructor or class, {@code parameterClass} is an empty
+   *     optional.
+   */
+  Class<?> getValueType(
+      Class<? extends Annotation> annotationType, Optional<Class<?>> parameterClass);
+}