[NTI] Implement JSType#getSubTypes

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=159773350

src/com/google/javascript/jscomp/AmbiguateProperties.java

@@ -30,6 +30,7 @@
 import com.google.javascript.jscomp.graph.GraphColoring.GreedyGraphColoring;
 import com.google.javascript.jscomp.graph.GraphNode;
 import com.google.javascript.jscomp.graph.SubGraph;
+import com.google.javascript.rhino.FunctionTypeI;
 import com.google.javascript.rhino.Node;
 import com.google.javascript.rhino.TypeI;
 import com.google.javascript.rhino.jstype.FunctionType;
@@ -337,17 +338,11 @@ private void computeRelatedTypes(JSType type) {
 
     // An instance is related to its subclasses.
     FunctionType constructor = type.toObjectType().getConstructor();
-    if (constructor != null && constructor.getSubTypes() != null) {
-      for (FunctionType subType : constructor.getSubTypes()) {
-        addRelatedInstance(subType, related);
+    if (constructor != null) {
+      for (FunctionTypeI subType : constructor.getSubTypes()) {
+        addRelatedInstance((FunctionType) subType, related);
       }
     }
-
-    // An interface is related to its implementors.
-    for (FunctionType implementor : compiler.getTypeRegistry()
-        .getDirectImplementors(type.toObjectType())) {
-      addRelatedInstance(implementor, related);
-    }
   }
 
   /**

src/com/google/javascript/jscomp/DisambiguateProperties.java

@@ -17,6 +17,7 @@
 
 import static com.google.common.base.Preconditions.checkState;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Joiner;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.ImmutableSet;
@@ -779,6 +780,7 @@ private Map<TypeI, String> buildPropNames(Property prop) {
   }
 
   /** Returns a map from field name to types for which it will be renamed. */
+  @VisibleForTesting
   Multimap<String, Collection<TypeI>> getRenamedTypesForTesting() {
     Multimap<String, Collection<TypeI>> ret = HashMultimap.create();
     for (Map.Entry<String, Property> entry : properties.entrySet()) {
@@ -886,11 +888,10 @@ private Iterable<? extends TypeI> getTypeAlternatives(TypeI type) {
       return type.getUnionMembers();
     } else {
       ObjectTypeI objType = type.toMaybeObjectType();
-      if (objType != null
-          && objType.getConstructor() != null
-          && objType.getConstructor().isInterface()) {
+      FunctionTypeI constructor = objType != null ? objType.getConstructor() : null;
+      if (constructor != null && constructor.isInterface()) {
         List<TypeI> list = new ArrayList<>();
-        for (FunctionTypeI impl : objType.getDirectImplementors()) {
+        for (FunctionTypeI impl : constructor.getSubTypes()) {
           list.add(impl.getInstanceType());
         }
         return list.isEmpty() ? null : list;

src/com/google/javascript/jscomp/newtypes/JSType.java

@@ -1856,8 +1856,17 @@ public final Node getSource() {
   }
 
   @Override
-  public final List<? extends FunctionTypeI> getSubTypes() {
-    throw new UnsupportedOperationException("getSubTypes not implemented yet");
+  public final Collection<FunctionTypeI> getSubTypes() {
+    Preconditions.checkState(this.isConstructor() || this.isInterface());
+    ImmutableList.Builder<FunctionTypeI> result = ImmutableList.builder();
+    NominalType nt =
+        getFunTypeIfSingletonObj().getInstanceTypeOfCtor().getNominalTypeIfSingletonObj();
+    if (nt != null) {
+      for (RawNominalType rawType : nt.getSubtypes()) {
+        result.add(this.commonTypes.fromFunctionType(rawType.getConstructorFunction()));
+      }
+    }
+    return result.build();
   }
 
   @Override
@@ -2182,18 +2191,6 @@ public final TypeI getGreatestSubtypeWithProperty(String pname) {
     return joinManyTypes(this.commonTypes, getSubtypesWithProperty(new QualifiedName(pname)));
   }
 
-  @Override
-  public final Collection<JSType> getDirectImplementors() {
-    Set<JSType> result = new HashSet<>();
-    NominalType nt = getNominalTypeIfSingletonObj();
-    if (nt != null) {
-      for (RawNominalType rawType : nt.getSubtypes()) {
-        result.add(this.commonTypes.fromFunctionType(rawType.getConstructorFunction()));
-      }
-    }
-    return result;
-  }
-
   @Override
   public final ObjectTypeI getPrototypeProperty() {
     return getProp(new QualifiedName("prototype"));

src/com/google/javascript/rhino/FunctionTypeI.java

@@ -76,11 +76,12 @@ public interface FunctionTypeI extends TypeI {
   Node getSource();
 
   /**
-   * Returns a list of types that are subtypes of this type. This is only
-   * valid for constructor functions, and may be null. This allows a downward
-   * traversal of the subtype graph.
+   * Returns an iterable of direct types that are subtypes of this type.
+   * This is only valid for constructors and interfaces, and will not be
+   * null. This allows a downward traversal of the subtype graph.
    */
-  List<? extends FunctionTypeI> getSubTypes();
+  // TODO(sdh): change the name to getDirectSubTypes()
+  Iterable<FunctionTypeI> getSubTypes();
 
   /** Gets the type of {@code this} in this function. */
   TypeI getTypeOfThis();

src/com/google/javascript/rhino/ObjectTypeI.java

@@ -40,7 +40,6 @@
 package com.google.javascript.rhino;
 
 import com.google.common.collect.ImmutableList;
-import java.util.Collection;
 
 /**
  * @author blickly@google.com (Ben Lickly)
@@ -133,8 +132,6 @@ public interface ObjectTypeI extends TypeI {
    */
   TypeI getLegacyResolvedType();
 
-  Collection<? extends FunctionTypeI> getDirectImplementors();
-
   /**
    * Given an interface and a property, finds a top-most super interface
    * that has the property defined (including this interface).

src/com/google/javascript/rhino/jstype/FunctionType.java

@@ -48,6 +48,7 @@
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterables;
 import com.google.javascript.rhino.ErrorReporter;
 import com.google.javascript.rhino.FunctionTypeI;
 import com.google.javascript.rhino.Node;
@@ -150,7 +151,7 @@ private enum PropAccess { ANY, STRUCT, DICT }
    * The types which are subtypes of this function. It is only relevant for
    * constructors and may be {@code null}.
    */
-  private List<FunctionType> subTypes;
+  private List<FunctionTypeI> subTypes;
 
   /** Creates an instance for a function that might be a constructor. */
   FunctionType(
@@ -1246,8 +1247,8 @@ public void clearCachedValues() {
     super.clearCachedValues();
 
     if (subTypes != null) {
-      for (FunctionType subType : subTypes) {
-        subType.clearCachedValues();
+      for (FunctionTypeI subType : subTypes) {
+        ((FunctionType) subType).clearCachedValues();
       }
     }
 
@@ -1262,14 +1263,11 @@ public void clearCachedValues() {
     }
   }
 
-  /**
-   * Returns a list of types that are subtypes of this type. This is only valid
-   * for constructor functions, and may be null. This allows a downward
-   * traversal of the subtype graph.
-   */
   @Override
-  public List<FunctionType> getSubTypes() {
-    return subTypes;
+  public Iterable<FunctionTypeI> getSubTypes() {
+    return Iterables.concat(
+        subTypes != null ? subTypes : ImmutableList.<FunctionTypeI>of(),
+        this.registry.getDirectImplementors(this));
   }
 
   @Override
@@ -1318,8 +1316,9 @@ JSType resolveInternal(ErrorReporter t, StaticTypedScope<JSType> scope) {
 
     if (subTypes != null) {
       for (int i = 0; i < subTypes.size(); i++) {
+        FunctionType subType = (FunctionType) subTypes.get(i);
         subTypes.set(
-            i, JSType.toMaybeFunctionType(subTypes.get(i).resolve(t, scope)));
+            i, JSType.toMaybeFunctionType(subType.resolve(t, scope)));
       }
     }
 

src/com/google/javascript/rhino/jstype/JSTypeRegistry.java

@@ -56,6 +56,7 @@
 import com.google.common.collect.LinkedHashMultimap;
 import com.google.common.collect.Multimap;
 import com.google.javascript.rhino.ErrorReporter;
+import com.google.javascript.rhino.FunctionTypeI;
 import com.google.javascript.rhino.JSDocInfo;
 import com.google.javascript.rhino.JSTypeExpression;
 import com.google.javascript.rhino.Node;
@@ -184,7 +185,7 @@ public class JSTypeRegistry implements TypeIRegistry {
        new HashMap<>();
 
   // A map from interface name to types that implement it.
-  private final Multimap<String, FunctionType> interfaceToImplementors =
+  private final Multimap<String, FunctionTypeI> interfaceToImplementors =
       LinkedHashMultimap.create();
 
   // All the unresolved named types.
@@ -954,7 +955,7 @@ void registerTypeImplementingInterface(
    * be returned.  {@code interfaceInstance} must be an ObjectType for the
    * instance of the interface.
    */
-  public Collection<FunctionType> getDirectImplementors(ObjectType interfaceInstance) {
+  public Collection<FunctionTypeI> getDirectImplementors(ObjectType interfaceInstance) {
     return interfaceToImplementors.get(interfaceInstance.getReferenceName());
   }
 

src/com/google/javascript/rhino/jstype/ObjectType.java

@@ -53,7 +53,6 @@
 import com.google.javascript.rhino.Node;
 import com.google.javascript.rhino.ObjectTypeI;
 import com.google.javascript.rhino.TypeI;
-import java.util.Collection;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
@@ -253,7 +252,7 @@ public boolean hasReferenceName() {
   }
 
   @Override
-  public boolean isUnknownObject() {
+  public final boolean isUnknownObject() {
     return !hasReferenceName();
   }
 
@@ -316,11 +315,6 @@ public ObjectType getTopDefiningInterface(String propertyName) {
     return foundType;
   }
 
-  @Override
-  public Collection<FunctionType> getDirectImplementors() {
-    return this.registry.getDirectImplementors(this);
-  }
-
   /**
    * Gets the implicit prototype (a.k.a. the {@code [[Prototype]]} property).
    */

test/com/google/javascript/jscomp/AmbiguatePropertiesTest.java

@@ -687,6 +687,22 @@ public void testExtendsInterface() {
     test(js, output);
   }
 
+  public void testInterfaceWithSubInterfaceAndDirectImplementors() {
+    test(
+        LINE_JOINER.join(
+            "/** @interface */ function Foo(){};",
+            "Foo.prototype.foo = function(){};",
+            "/** @interface @extends {Foo} */ function Bar(){};",
+            "/** @suppress {checkTypes}\n @constructor @implements {Foo} */ function Baz(){};",
+            "Baz.prototype.baz = function(){};"),
+        LINE_JOINER.join(
+            "/** @interface */ function Foo(){};",
+            "Foo.prototype.b = function(){};",
+            "/** @interface @extends {Foo} */ function Bar(){};",
+            "/** @suppress {checkTypes}\n @constructor @implements {Foo} */ function Baz(){};",
+            "Baz.prototype.a = function(){};"));
+  }
+
   public void testFunctionSubType() {
     String js = LINE_JOINER.join(
         "Function.prototype.a = 1;",

test/com/google/javascript/jscomp/DisambiguatePropertiesTest.java

@@ -1297,6 +1297,17 @@ public void testInterface_noDirectImplementors() {
             + " b=[[Foo.prototype, I.prototype], [Z.prototype]]}");
   }
 
+  public void testInterface_subInterfaceAndDirectImplementors() {
+    String js = LINE_JOINER.join(
+        "/** @interface */ function I() {};",
+        "I.prototype.a;",
+        "/** @constructor @implements {I} */ function Foo() {};",
+        "Foo.prototype.a;",
+        "/** @interface @extends {I} */ function Bar() {};",
+        "Bar.prototype.a;");
+    testSets(js, "{a=[[Bar.prototype, Foo.prototype, I.prototype]]}");
+  }
+
   public void testInterfaceOfSuperclass() {
     String js = ""
         + "/** @interface */ function I() {};\n"

test/com/google/javascript/jscomp/FunctionTypeBuilderTest.java

@@ -18,6 +18,8 @@
 
 import static com.google.javascript.rhino.testing.BaseJSTypeTestCase.ALL_NATIVE_EXTERN_TYPES;
 
+import com.google.common.collect.ImmutableList;
+import com.google.javascript.rhino.FunctionTypeI;
 import com.google.javascript.rhino.Node;
 import com.google.javascript.rhino.jstype.FunctionType;
 import com.google.javascript.rhino.jstype.ObjectType;
@@ -139,9 +141,11 @@ public void testInlineJsDoc2() throws Exception {
   public void testExternSubTypes() throws Exception {
     testSame(ALL_NATIVE_EXTERN_TYPES, "");
 
-    List<FunctionType> subtypes = ((ObjectType) getLastCompiler()
-        .getTypeRegistry().getType("Error")).getConstructor().getSubTypes();
-    for (FunctionType type : subtypes) {
+    List<FunctionTypeI> subtypes =
+        ImmutableList.copyOf(
+            ((ObjectType) getLastCompiler().getTypeRegistry().getType("Error"))
+                .getConstructor().getSubTypes());
+    for (FunctionTypeI type : subtypes) {
       String typeName = type.getInstanceType().toString();
       FunctionType typeInRegistry = ((ObjectType) getLastCompiler()
           .getTypeRegistry().getType(typeName)).getConstructor();

test/com/google/javascript/rhino/jstype/JSTypeTest.java

@@ -51,6 +51,7 @@
 import com.google.javascript.rhino.Node;
 import com.google.javascript.rhino.SimpleErrorReporter;
 import com.google.javascript.rhino.Token;
+import com.google.javascript.rhino.TypeI;
 import com.google.javascript.rhino.jstype.JSType.TypePair;
 import com.google.javascript.rhino.testing.AbstractStaticScope;
 import com.google.javascript.rhino.testing.Asserts;
@@ -6365,9 +6366,9 @@ public void testCanCastTo() {
   }
 
   private static boolean containsType(
-      Iterable<? extends JSType> types, JSType type) {
-    for (JSType alt : types) {
-      if (alt.isEquivalentTo(type)) {
+      Iterable<? extends TypeI> types, JSType type) {
+    for (TypeI alt : types) {
+      if (alt.equals(type)) {
         return true;
       }
     }