Feat find unit tests (#669)

* find unit tests

* Add to datatable method invocations used in unit tests

* Change accumulator unit test and its method invocations to a hasmap

* polish

* polish

* polish

* Apply formatter

* Light polish

* Use preconditions to tell tests and non tests apart

* Apply correct license headers

* Further polish

* Loop over entrySet

* Update src/main/java/org/openrewrite/java/testing/search/FindUnitTests.java

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

---------

Co-authored-by: Tim te Beek <[email protected]>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

src/main/java/org/openrewrite/java/testing/search/FindUnitTestTable.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://docs.moderne.io/licensing/moderne-source-available-license
+ * <p>
+ * 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 org.openrewrite.java.testing.search;
+
+import lombok.Value;
+import org.openrewrite.Column;
+import org.openrewrite.DataTable;
+import org.openrewrite.Recipe;
+
+ public class FindUnitTestTable extends DataTable<FindUnitTestTable.Row> {
+     public FindUnitTestTable(Recipe recipe) {
+         super(recipe,
+                 recipe.getName(),
+                 recipe.getDescription());
+     }
+
+     @Value
+     public static class Row {
+         @Column(displayName = "Full method name",
+                 description = "The fully qualified name of the method declaration")
+         String fullyQualifiedMethodName;
+
+         @Column(displayName = "Method name",
+                 description = "The name of the method declaration")
+         String methodName;
+
+         @Column(displayName = "Method invocation",
+                 description = "How the method declaration is used as method invocation in a unit test.")
+         String methodInvocationExample;
+
+         @Column(displayName = "Name of test",
+                 description = "The name of the unit test where the method declaration is used.")
+         String nameOfTest;
+
+         @Column(displayName = "Location of test",
+                 description = "The location of the unit test where the method declaration is used.")
+         String locationOfTest;
+     }
+ }
+

src/main/java/org/openrewrite/java/testing/search/FindUnitTests.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://docs.moderne.io/licensing/moderne-source-available-license
+ * <p>
+ * 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 org.openrewrite.java.testing.search;
+
+import lombok.Value;
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Preconditions;
+import org.openrewrite.ScanningRecipe;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.JavaVisitor;
+import org.openrewrite.java.search.IsLikelyNotTest;
+import org.openrewrite.java.search.IsLikelyTest;
+import org.openrewrite.java.tree.J;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import static java.util.Collections.singletonList;
+
+public class FindUnitTests extends ScanningRecipe<FindUnitTests.Accumulator> {
+
+    @Override
+    public String getDisplayName() {
+        return "Find unit tests";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Produces a data table showing examples of how methods declared get used in unit tests.";
+    }
+
+    transient FindUnitTestTable unitTestTable = new FindUnitTestTable(this);
+
+    public static class Accumulator {
+        Map<UnitTest, Set<J.MethodInvocation>> unitTestAndTheirMethods = new HashMap<>();
+    }
+
+    @Override
+    public Accumulator getInitialValue(ExecutionContext ctx) {
+        return new Accumulator();
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getScanner(Accumulator acc) {
+        JavaVisitor<ExecutionContext> scanningVisitor = new JavaVisitor<ExecutionContext>() {
+            @Override
+            public J visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
+                // get the method declaration the method invocation is in
+                J.MethodDeclaration methodDeclaration = getCursor().firstEnclosing(J.MethodDeclaration.class);
+                if (methodDeclaration != null &&
+                        methodDeclaration.getLeadingAnnotations().stream()
+                        .filter(o -> o.getAnnotationType() instanceof J.Identifier)
+                        .anyMatch(o -> "Test".equals(o.getSimpleName()))) {
+                    UnitTest unitTest = new UnitTest(
+                            getCursor().firstEnclosingOrThrow(J.ClassDeclaration.class).getType().getFullyQualifiedName(),
+                            methodDeclaration.getSimpleName(),
+                            methodDeclaration.printTrimmed(getCursor()));
+                    acc.unitTestAndTheirMethods.merge(unitTest,
+                            new HashSet<>(singletonList(method)),
+                            (a, b) -> {
+                                a.addAll(b);
+                                return a;
+                            });
+                }
+                return super.visitMethodInvocation(method, ctx);
+            }
+        };
+        return Preconditions.check(new IsLikelyTest().getVisitor(), scanningVisitor);
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor(Accumulator acc) {
+        JavaVisitor<ExecutionContext> tableRowVisitor = new JavaVisitor<ExecutionContext>() {
+            @Override
+            public J visitMethodDeclaration(J.MethodDeclaration methodDeclaration, ExecutionContext ctx) {
+                for (Map.Entry<UnitTest, Set<J.MethodInvocation>> entry : acc.unitTestAndTheirMethods.entrySet()) {
+                    for (J.MethodInvocation method : entry.getValue()) {
+                        if (method.getSimpleName().equals(methodDeclaration.getSimpleName())) {
+                            unitTestTable.insertRow(ctx, new FindUnitTestTable.Row(
+                                    methodDeclaration.getName().toString(),
+                                    methodDeclaration.getSimpleName(),
+                                    method.printTrimmed(getCursor()),
+                                    entry.getKey().getClazz(),
+                                    entry.getKey().getUnitTestName()
+                            ));
+                        }
+                    }
+                }
+                return super.visitMethodDeclaration(methodDeclaration, ctx);
+            }
+        };
+        return Preconditions.check(new IsLikelyNotTest().getVisitor(), tableRowVisitor);
+    }
+
+}
+
+@Value
+class UnitTest {
+    String clazz;
+    String unitTestName;
+    String unitTest;
+}

src/main/java/org/openrewrite/java/testing/search/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2024 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://docs.moderne.io/licensing/moderne-source-available-license
+ * <p>
+ * 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.
+ */
+@NullMarked
+package org.openrewrite.java.testing.search;
+
+import org.jspecify.annotations.NullMarked;

src/test/java/org/openrewrite/java/testing/search/FindUnitTestsTest.java

@@ -0,0 +1,125 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://docs.moderne.io/licensing/moderne-source-available-license
+ * <p>
+ * 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 org.openrewrite.java.testing.search;
+
+import org.intellij.lang.annotations.Language;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.openrewrite.DocumentExample;
+import org.openrewrite.InMemoryExecutionContext;
+import org.openrewrite.java.JavaParser;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.openrewrite.java.Assertions.java;
+
+class FindUnitTestsTest implements RewriteTest {
+
+    @Language("java")
+    private static final String CLASS_FOO = """
+      package foo;
+
+      public class Foo {
+          public void bar() {
+          }
+          public void baz() {
+          }
+      }
+      """;
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.recipe(new FindUnitTests())
+          .parser(JavaParser.fromJavaVersion().classpathFromResources(new InMemoryExecutionContext(),
+            "junit-jupiter-api-5.9"));
+    }
+
+    @DocumentExample
+    @Test
+    void dataTable() {
+        rewriteRun(
+          spec -> spec.dataTable(FindUnitTestTable.Row.class, rows -> assertThat(rows)
+            .extracting(FindUnitTestTable.Row::getFullyQualifiedMethodName)
+            .containsExactly("bar", "baz")),
+          java(CLASS_FOO),
+          //language=java
+          java(
+            """
+              import foo.Foo;
+              import org.junit.jupiter.api.Test;
+
+              public class FooTest {
+                 @Test
+                 public void test() {
+                     Foo foo = new Foo();
+                     foo.bar();
+                     foo.baz();
+                 }
+              }
+              """
+          )
+        );
+    }
+
+    @Nested
+    class NotFound {
+
+        @Test
+        void notATest() {
+            //language=java
+            rewriteRun(
+              spec -> spec.afterRecipe(run -> assertThat(run.getDataTables()).hasSize(1)), // stats table
+              java(CLASS_FOO),
+              java(
+                """
+                  import foo.Foo;
+
+                  public class FooTest {
+                     public void test() {
+                         new Foo().bar();
+                     }
+                  }
+                  """
+              )
+            );
+        }
+
+        @Test
+        void methodFromTest() {
+            //language=java
+            rewriteRun(
+              spec -> spec.afterRecipe(run -> assertThat(run.getDataTables()).hasSize(1)), // stats table
+              java(CLASS_FOO),
+              java(
+                """
+                  import org.junit.jupiter.api.Test;
+
+                  public class FooTest {
+                     @Test
+                     public void test() {
+                         beep();
+                     }
+
+                     public void beep() {
+                     }
+                  }
+                  """
+              )
+            );
+        }
+    }
+}