Improve SymbolTable handling of inheritance (interfaces, records).

When looking up property on a symbol try using  ObjectType.getPropertyNode() if available. That function handles interfaces/records with multiple parents.

1. Fixes inheritance in @records.
2. Supports multiple inheritance for interfaces.

PiperOrigin-RevId: 556971231

Author: nbeloglazov

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

@@ -53,7 +53,6 @@
 import com.google.javascript.rhino.jstype.SimpleSlot;
 import com.google.javascript.rhino.jstype.StaticTypedScope;
 import com.google.javascript.rhino.jstype.StaticTypedSlot;
-import com.google.javascript.rhino.jstype.UnionType;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -361,10 +360,9 @@ public List<Symbol> getAllSymbolsForType(JSType type) {
       return ImmutableList.of();
     }
 
-    UnionType unionType = type.toMaybeUnionType();
-    if (unionType != null) {
+    if (type.isUnionType()) {
       ImmutableList.Builder<Symbol> result = ImmutableList.builder();
-      for (JSType alt : unionType.getAlternates()) {
+      for (JSType alt : type.toMaybeUnionType().getAlternates()) {
         // Our type system never has nested unions.
         Symbol altSym = getSymbolForTypeHelper(alt, true);
         if (altSym != null) {
@@ -831,7 +829,7 @@ void fillNamespaceReferences() {
           if (namespace == null && root.scope.isGlobalScope()) {
             // Originally UNKNOWN_TYPE has been always used for namespace symbols even though
             // compiler does have type information attached to a node. Unclear why. Changing code to
-            // propery type mostly works. It only fails on Foo.prototype cases for some reason.
+            // property type mostly works. It only fails on Foo.prototype cases for some reason.
             // It's pretty rare case when Foo.prototype defined in global scope though so for now
             // just carve it out.
             JSType nodeType = currentNode.getJSType();
@@ -1890,9 +1888,25 @@ public void process(Node externs, Node root) {
     }
 
     private boolean maybeDefineReference(Node n, String propName, Symbol ownerSymbol) {
-      // getPropertyScope() will be null in some rare cases where there
-      // are no extern declarations for built-in types (like Function).
-      if (ownerSymbol != null && ownerSymbol.getPropertyScope() != null) {
+      if (ownerSymbol == null) {
+        return false;
+      }
+      // If current symbol is ObjectType - try using ObjectType.getPropertyNode to find a node.
+      // That function searches for property in all extended classes and interfaces, which supports
+      // multiple extended interfaces.
+      JSType owner = ownerSymbol.getType();
+      if (owner != null && owner.isObjectType()) {
+        Node propNode = owner.toObjectType().getPropertyNode(propName);
+        Symbol propSymbol = symbols.get(propNode, propName);
+        if (propSymbol != null) {
+          propSymbol.defineReferenceAt(n);
+          return true;
+        }
+      }
+      // Use PropertyScope to find property. PropertyScope doesn't support multiple parents so all
+      // cases where multiple parents can occur (e.g. class implementing 2+ interfaces) must be
+      // handled above.
+      if (ownerSymbol.getPropertyScope() != null) {
         Symbol prop = ownerSymbol.getPropertyScope().getSlot(propName);
         if (prop != null) {
           prop.defineReferenceAt(n);

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

@@ -750,6 +750,100 @@ public void testMethodReferences() {
     assertThat(table.getReferences(method)).hasSize(3);
   }
 
+  @Test
+  public void testMethodReferencesNullableClass() {
+    SymbolTable table =
+        createSymbolTable(
+            lines(
+                "class DomHelper { method() {} }",
+                "let /** ?DomHelper */ helper;",
+                "helper.method();"));
+
+    Symbol method = getGlobalVar(table, "DomHelper.prototype.method");
+    assertThat(table.getReferences(method)).hasSize(2);
+  }
+
+  @Test
+  public void testMethodReferencesNullableInterface() {
+    SymbolTable table =
+        createSymbolTable(
+            lines(
+                "/** @interface */ class DomHelper { method() {} }",
+                "let /** ?DomHelper */ helper;",
+                "helper.method();"));
+
+    Symbol method = getGlobalVar(table, "DomHelper.prototype.method");
+    assertThat(table.getReferences(method)).hasSize(2);
+  }
+
+  @Test
+  public void testMethodReferencesNullableRecord() {
+    SymbolTable table =
+        createSymbolTable(
+            lines(
+                "/** @record */ function DomHelper() {}",
+                "DomHelper.prototype.method = function() {};",
+                "let /** ?DomHelper */ helper;",
+                "helper.method();"));
+
+    Symbol method = getGlobalVar(table, "DomHelper.prototype.method");
+    assertThat(table.getReferences(method)).hasSize(2);
+  }
+
+  @Test
+  public void testRecordInheritance() {
+    SymbolTable table =
+        createSymbolTable(
+            lines(
+                "/** @record */ function DomHelper() {}",
+                "DomHelper.prototype.method = function() {};",
+                "",
+                "/** @record @extends {DomHelper} */ function DomHelper2() {}",
+                "DomHelper2.prototype.method2 = function() {};",
+                "",
+                "let /** ?DomHelper2 */ helper;",
+                "helper.method();"));
+
+    Symbol method = getGlobalVar(table, "DomHelper.prototype.method");
+    assertThat(table.getReferences(method)).hasSize(2);
+  }
+
+  @Test
+  public void testUnionType() {
+    SymbolTable table =
+        createSymbolTable(
+            lines(
+                "class First { method() {} }",
+                "class Second { method() {} }",
+                "let /** !Second|!First */ obj;",
+                "obj.method();"));
+
+    assertThat(table.getReferences(getGlobalVar(table, "First.prototype.method"))).hasSize(2);
+    assertThat(table.getReferences(getGlobalVar(table, "Second.prototype.method"))).hasSize(2);
+  }
+
+  @Test
+  public void testMultipleInterfaceInheritance() {
+    SymbolTable table =
+        createSymbolTable(
+            lines(
+                "/** @interface */",
+                "class First { doFirst() {} }",
+                "",
+                "/** @interface */",
+                "class Second { doSecond() {} }",
+                "",
+                "/** @interface @extends {First} @extends {Second} */",
+                "class Third {}",
+                "",
+                "let /** !Third */ obj;",
+                "obj.doFirst();",
+                "obj.doSecond();"));
+
+    assertThat(table.getReferences(getGlobalVar(table, "First.prototype.doFirst"))).hasSize(2);
+    assertThat(table.getReferences(getGlobalVar(table, "Second.prototype.doSecond"))).hasSize(2);
+  }
+
   @Test
   public void testSuperClassMethodReferences() {
     SymbolTable table =
@@ -1737,7 +1831,7 @@ public void testDuplicatedWindowExternsMergedWithWindowPrototype() {
     }
     assertThat(refsPerFile).containsExactly("in1", 2, "externs1", 1);
   }
-
+  
   private void assertSymmetricOrdering(Ordering<Symbol> ordering, Symbol first, Symbol second) {
     assertThat(ordering.compare(first, first)).isEqualTo(0);
     assertThat(ordering.compare(second, second)).isEqualTo(0);