Support getting dependencies info for a test

Closes #893

CHANGES.txt

@@ -1,4 +1,5 @@
 Current
+Fixed: GITHUB-893: TestNG should provide an Api which allow to find all dependent of a specific test (Krishnan Mahadevan)
 New: Added .yml file extension for yaml suite files, previously only .yaml was allowed for yaml (Steven Jubb)
 Fixed: GITHUB-2770: FileAlreadyExistsException when report is generated (melloware)
 Fixed: GITHUB-2825: Programically Loading TestNG Suite from JAR File Fails to Delete Temporary Copy of Suite File (Steven Jubb)

testng-core-api/src/main/java/org/testng/IDynamicGraph.java

@@ -21,6 +21,10 @@ public interface IDynamicGraph<T> {
 
   List<T> getFreeNodes();
 
+  default List<T> getUpstreamDependenciesFor(T node) {
+    throw new UnsupportedOperationException("Pending implementation");
+  }
+
   List<T> getDependenciesFor(T node);
 
   void setStatus(Collection<T> nodes, Status status);

testng-core-api/src/main/java/org/testng/ITestNGMethod.java

@@ -2,6 +2,7 @@
 
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.Callable;
 import org.testng.annotations.CustomAttribute;
 import org.testng.internal.ConstructorOrMethod;
@@ -71,6 +72,24 @@ public interface ITestNGMethod extends Cloneable {
    */
   String[] getMethodsDependedUpon();
 
+  /**
+   * @return - The set of methods that are dependent on the current method. This information can
+   *     help in deciding what other TestNG methods will be skipped if the current method fails. If
+   *     the current method is a configuration method, then an empty set is returned.
+   */
+  default Set<ITestNGMethod> downstreamDependencies() {
+    throw new UnsupportedOperationException("Pending implementation");
+  }
+
+  /**
+   * @return - The set of methods upon which the current method has a dependency. This information
+   *     can help in deciding what all TestNG methods need to pass before the current method can be
+   *     executed. If the current method is a configuration method, then an empty set is returned.
+   */
+  default Set<ITestNGMethod> upstreamDependencies() {
+    throw new UnsupportedOperationException("Pending implementation");
+  }
+
   void addMethodDependedUpon(String methodName);
 
   /** @return true if this method was annotated with @Test */

testng-core/src/main/java/org/testng/TestRunner.java

@@ -24,6 +24,7 @@
 import org.testng.collections.Maps;
 import org.testng.collections.Sets;
 import org.testng.internal.Attributes;
+import org.testng.internal.BaseTestMethod;
 import org.testng.internal.ClassBasedWrapper;
 import org.testng.internal.ClassInfoMap;
 import org.testng.internal.ConfigurationGroupMethods;
@@ -746,6 +747,17 @@ private void privateRun(XmlTest xmlTest) {
         });
     IDynamicGraph<ITestNGMethod> graph = reference.get();
 
+    for (ITestNGMethod each : interceptedOrder) {
+      if (each instanceof BaseTestMethod) {
+        // We don't want our users to change this vital info. That is why the setter is NOT
+        // being exposed via the interface, and so we resort to an "instanceof" check.
+        Set<ITestNGMethod> downstream = Sets.newHashSet(graph.getDependenciesFor(each));
+        ((BaseTestMethod) each).setDownstreamDependencies(downstream);
+        Set<ITestNGMethod> upstream = Sets.newHashSet(graph.getUpstreamDependenciesFor(each));
+        ((BaseTestMethod) each).setUpstreamDependencies(upstream);
+      }
+    }
+
     graph.setVisualisers(this.visualisers);
     // In some cases, additional sorting is needed to make sure tests run in the appropriate order.
     // If the user specified a method interceptor, or if we have any methods that have a non-default

testng-core/src/main/java/org/testng/internal/BaseTestMethod.java

@@ -70,6 +70,8 @@ public abstract class BaseTestMethod implements ITestNGMethod, IInvocationStatus
   private long m_invocationTimeOut = 0L;
 
   private List<Integer> m_invocationNumbers = Lists.newArrayList();
+  private final Set<ITestNGMethod> downstreamDependencies = Sets.newHashSet();
+  private final Set<ITestNGMethod> upstreamDependencies = Sets.newHashSet();
   private final Collection<Integer> m_failedInvocationNumbers = new ConcurrentLinkedQueue<>();
   private long m_timeOut = 0;
 
@@ -176,6 +178,38 @@ public String[] getMethodsDependedUpon() {
     return m_methodsDependedUpon;
   }
 
+  @Override
+  public Set<ITestNGMethod> downstreamDependencies() {
+    return Collections.unmodifiableSet(downstreamDependencies);
+  }
+
+  @Override
+  public Set<ITestNGMethod> upstreamDependencies() {
+    return Collections.unmodifiableSet(upstreamDependencies);
+  }
+
+  public void setDownstreamDependencies(Set<ITestNGMethod> methods) {
+    if (!downstreamDependencies.isEmpty()) {
+      downstreamDependencies.clear();
+    }
+    Set<ITestNGMethod> toAdd = methods;
+    if (RuntimeBehavior.isMemoryFriendlyMode()) {
+      toAdd = methods.stream().map(LiteWeightTestNGMethod::new).collect(Collectors.toSet());
+    }
+    downstreamDependencies.addAll(toAdd);
+  }
+
+  public void setUpstreamDependencies(Set<ITestNGMethod> methods) {
+    if (!upstreamDependencies.isEmpty()) {
+      upstreamDependencies.clear();
+    }
+    Set<ITestNGMethod> toAdd = methods;
+    if (RuntimeBehavior.isMemoryFriendlyMode()) {
+      toAdd = methods.stream().map(LiteWeightTestNGMethod::new).collect(Collectors.toSet());
+    }
+    upstreamDependencies.addAll(toAdd);
+  }
+
   /** {@inheritDoc} */
   @Override
   public boolean isTest() {

testng-core/src/main/java/org/testng/internal/DynamicGraph.java

@@ -4,6 +4,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import org.testng.IDynamicGraph;
@@ -76,12 +77,19 @@ public List<T> getFreeNodes() {
     return finalResult;
   }
 
+  @Override
+  public List<T> getUpstreamDependenciesFor(T node) {
+    return dependencies(m_edges.from(node));
+  }
+
   public List<T> getDependenciesFor(T node) {
-    Map<T, Integer> data = m_edges.to(node);
-    if (data == null) {
-      return Lists.newArrayList();
-    }
-    return Lists.newArrayList(data.keySet());
+    return dependencies(m_edges.to(node));
+  }
+
+  private List<T> dependencies(Map<T, Integer> dependencies) {
+    return Optional.ofNullable(dependencies)
+        .map(found -> Lists.newArrayList(found.keySet()))
+        .orElse(Lists.newArrayList());
   }
 
   /** Set the status for a set of nodes. */

testng-core/src/test/java/test/dependent/DependentTest.java

@@ -5,6 +5,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 import java.util.function.Function;
 import org.testng.Assert;
 import org.testng.ITestListener;
@@ -23,6 +24,9 @@
 import test.dependent.github1380.GitHub1380Sample4;
 import test.dependent.issue2658.FailingClassSample;
 import test.dependent.issue2658.PassingClassSample;
+import test.dependent.issue893.DependencyTrackingListener;
+import test.dependent.issue893.MultiLevelDependenciesTestClassSample;
+import test.dependent.issue893.TestClassSample;
 
 public class DependentTest extends SimpleBaseTest {
 
@@ -218,6 +222,64 @@ public void testMethodDependencyAmidstInheritance() {
     assertThat(listener.getSkippedMethodNames()).containsExactly("failingMethod");
   }
 
+  @Test(description = "GITHUB-893", dataProvider = "getTestData")
+  public void testDownstreamDependencyRetrieval(
+      Class<?> clazz, String independentMethod, String[] dependentMethods) {
+    TestNG testng = create(clazz);
+    DependencyTrackingListener listener = new DependencyTrackingListener();
+    testng.addListener(listener);
+    testng.run();
+    String cls = clazz.getCanonicalName();
+    String key = cls + "." + independentMethod;
+    Set<String> downstream = listener.getDownstreamDependencies().get(key);
+    dependentMethods =
+        Arrays.stream(dependentMethods).map(each -> cls + "." + each).toArray(String[]::new);
+    assertThat(downstream).containsExactly(dependentMethods);
+  }
+
+  @DataProvider(name = "getTestData")
+  public Object[][] getTestData() {
+    return new Object[][] {
+      {
+        TestClassSample.class,
+        "independentTest",
+        new String[] {"anotherDependentTest", "dependentTest"}
+      },
+      {MultiLevelDependenciesTestClassSample.class, "father", new String[] {"child"}},
+      {
+        MultiLevelDependenciesTestClassSample.class,
+        "grandFather",
+        new String[] {"father", "mother"}
+      },
+      {MultiLevelDependenciesTestClassSample.class, "child", new String[] {}}
+    };
+  }
+
+  @Test(description = "GITHUB-893", dataProvider = "getUpstreamTestData")
+  public void testUpstreamDependencyRetrieval(
+      Class<?> clazz, String independentMethod, String[] dependentMethods) {
+    TestNG testng = create(clazz);
+    DependencyTrackingListener listener = new DependencyTrackingListener();
+    testng.addListener(listener);
+    testng.run();
+    String cls = clazz.getCanonicalName();
+    String key = cls + "." + independentMethod;
+    Set<String> upstream = listener.getUpstreamDependencies().get(key);
+    dependentMethods =
+        Arrays.stream(dependentMethods).map(each -> cls + "." + each).toArray(String[]::new);
+    assertThat(upstream).containsExactly(dependentMethods);
+  }
+
+  @DataProvider(name = "getUpstreamTestData")
+  public Object[][] getUpstreamTestData() {
+    return new Object[][] {
+      {TestClassSample.class, "dependentTest", new String[] {"independentTest"}},
+      {MultiLevelDependenciesTestClassSample.class, "father", new String[] {"grandFather"}},
+      {MultiLevelDependenciesTestClassSample.class, "child", new String[] {"father", "mother"}},
+      {MultiLevelDependenciesTestClassSample.class, "grandFather", new String[] {}}
+    };
+  }
+
   public static class MethodNameCollector implements ITestListener {
 
     private static final Function<ITestResult, String> asString =

testng-core/src/test/java/test/dependent/issue893/DependencyTrackingListener.java

@@ -0,0 +1,44 @@
+package test.dependent.issue893;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import org.testng.ITestContext;
+import org.testng.ITestListener;
+import org.testng.ITestNGMethod;
+import org.testng.ITestResult;
+import org.testng.collections.Sets;
+
+public class DependencyTrackingListener implements ITestListener {
+  private final Map<String, Set<String>> downstreamDependencies = new HashMap<>();
+  private final Map<String, Set<String>> upstreamDependencies = new HashMap<>();
+
+  @Override
+  public void onTestStart(ITestResult result) {
+    ITestContext context = result.getTestContext();
+    for (ITestNGMethod method : context.getAllTestMethods()) {
+      String key = method.getQualifiedName();
+      downstreamDependencies
+          .computeIfAbsent(key, k -> Sets.newHashSet())
+          .addAll(
+              method.downstreamDependencies().stream()
+                  .map(ITestNGMethod::getQualifiedName)
+                  .collect(Collectors.toList()));
+      upstreamDependencies
+          .computeIfAbsent(key, k -> Sets.newHashSet())
+          .addAll(
+              method.upstreamDependencies().stream()
+                  .map(ITestNGMethod::getQualifiedName)
+                  .collect(Collectors.toList()));
+    }
+  }
+
+  public Map<String, Set<String>> getUpstreamDependencies() {
+    return upstreamDependencies;
+  }
+
+  public Map<String, Set<String>> getDownstreamDependencies() {
+    return downstreamDependencies;
+  }
+}

testng-core/src/test/java/test/dependent/issue893/MultiLevelDependenciesTestClassSample.java

@@ -0,0 +1,17 @@
+package test.dependent.issue893;
+
+import org.testng.annotations.Test;
+
+public class MultiLevelDependenciesTestClassSample {
+  @Test
+  public void grandFather() {}
+
+  @Test(dependsOnMethods = "grandFather")
+  public void father() {}
+
+  @Test(dependsOnMethods = "grandFather")
+  public void mother() {}
+
+  @Test(dependsOnMethods = {"father", "mother"})
+  public void child() {}
+}

testng-core/src/test/java/test/dependent/issue893/TestClassSample.java

@@ -0,0 +1,15 @@
+package test.dependent.issue893;
+
+import org.testng.annotations.Test;
+
+public class TestClassSample {
+
+  @Test
+  public void independentTest() {}
+
+  @Test(dependsOnMethods = "independentTest")
+  public void dependentTest() {}
+
+  @Test(dependsOnMethods = "independentTest")
+  public void anotherDependentTest() {}
+}