Change FunctionType to print as "(typeof Foo)" when the type is ass…

…ociated with the definition of an instance type.

This condition corresponds to constructors or interfaces with a known source location and reflects the use of these functions as namespaces. It makes specific distinction between "the Foo constructor" and "some constructor of Foo's". The latter still prints as "function(new:Foo): undefined".

One of the goals is to make the printed types of static methods less verbose and more understandable. Example "function(this:(typeof Foo), string): number".

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=245086325

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

@@ -953,6 +953,16 @@ StringBuilder appendTo(StringBuilder sb, boolean forAnnotations) {
       return sb.append(forAnnotations ? "!Function" : "Function");
     }
 
+    if (hasInstanceType() && getSource() != null) {
+      // Render function types known to be type definitions as "(typeof Foo)". This includes types
+      // defined like "/** @constructor */ function Foo() { }" but not to those defined like "@param
+      // {function(new:Foo)}". Only the former will have a source node.
+      sb.append("(typeof ");
+      getInstanceType().appendTo(sb, forAnnotations);
+      sb.append(")");
+      return sb;
+    }
+
     setPrettyPrint(false);
 
     sb.append("function(");

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

@@ -613,14 +613,14 @@ public void testStaticProperty() {
       + "Bar.a = 0;";
     String output;
 
-    output = ""
-        + "/** @constructor */ function Foo(){}"
-        + "/** @constructor */ function Bar(){}"
-        + "Foo.function_new_Foo___undefined$a = 0;"
-        + "Bar.function_new_Bar___undefined$a = 0;";
+    output =
+        ""
+            + "/** @constructor */ function Foo(){}"
+            + "/** @constructor */ function Bar(){}"
+            + "Foo._typeof_Foo_$a = 0;"
+            + "Bar._typeof_Bar_$a = 0;";
 
-    testSets(js, output, "{a=[[function(new:Bar): undefined]," +
-    " [function(new:Foo): undefined]]}");
+    testSets(js, output, "{a=[[(typeof Bar)]," + " [(typeof Foo)]]}");
   }
 
   @Test
@@ -1629,9 +1629,13 @@ public void testConstructorsWithTypeErrorsAreNotDisambiguated() {
         "",
         "(new Bar()).alias();");
 
-    testSets("", js, js, "{}", TypeValidator.TYPE_MISMATCH_WARNING, "assignment\n"
-            + "found   : function(new:Foo): undefined\n"
-            + "required: function(new:Bar): undefined");
+    testSets(
+        "",
+        js,
+        js,
+        "{}",
+        TypeValidator.TYPE_MISMATCH_WARNING,
+        "assignment\n" + "found   : (typeof Foo)\n" + "required: (typeof Bar)");
   }
 
   @Test
@@ -2968,13 +2972,13 @@ public void testDisambiguateEs6ClassStaticMethods() {
             "Bar.method();"),
         lines(
             "class Foo {",
-            "  function_new_Foo___undefined$method() {}",
+            "  _typeof_Foo_$method() {}",
             "}",
             "class Bar {",
-            "  function_new_Bar___undefined$method() {}",
+            "  _typeof_Bar_$method() {}",
             "}",
-            "Foo.function_new_Foo___undefined$method();",
-            "Bar.function_new_Bar___undefined$method();"));
+            "Foo._typeof_Foo_$method();",
+            "Bar._typeof_Bar_$method();"));
   }
 
   @Test
@@ -2995,17 +2999,17 @@ public void testEs6ClassSideInheritedMethods_areDisambiguated() {
             "Bar.method();"),
         lines(
             "class Foo {",
-            "  function_new_Foo___undefined$method() {}",
+            "  _typeof_Foo_$method() {}",
             "}",
             "class SubFoo extends Foo {",
-            "  static function_new_Foo___undefined$method() {}",
+            "  static _typeof_Foo_$method() {}",
             "}",
             "class Bar {",
-            "  function_new_Bar___undefined$method() {}",
+            "  _typeof_Bar_$method() {}",
             "}",
-            "Foo.function_new_Foo___undefined$method();",
-            "SubFoo.function_new_Foo___undefined$method();",
-            "Bar.function_new_Bar___undefined$method();"));
+            "Foo._typeof_Foo_$method();",
+            "SubFoo._typeof_Foo_$method();",
+            "Bar._typeof_Bar_$method();"));
   }
 
   @Test
@@ -3051,18 +3055,18 @@ public void testEs6ClassSideInheritedMethods_referencedWithSuper_areDisambiguate
             "Bar.method();"),
         lines(
             "class Foo {",
-            "  static function_new_Foo___undefined$method() {}",
+            "  static _typeof_Foo_$method() {}",
             "}",
             "class SubFoo extends Foo {",
             "  static method2() {",
-            "    super.function_new_Foo___undefined$method();",
+            "    super._typeof_Foo_$method();",
             "  }",
             "}",
             "class Bar {",
-            "  static function_new_Bar___undefined$method() {}",
+            "  static _typeof_Bar_$method() {}",
             "}",
-            "Foo.function_new_Foo___undefined$method();",
-            "Bar.function_new_Bar___undefined$method();"));
+            "Foo._typeof_Foo_$method();",
+            "Bar._typeof_Bar_$method();"));
   }
 
   @Test
@@ -3228,9 +3232,9 @@ public void testDisambiguatePropertyReference_objectPattern_stringKey_inDeclarat
             "  }",
             "}",
             "/** @type {string} */",
-            "Foo.function_new_Foo___undefined$prop = 'static property!';",
+            "Foo._typeof_Foo_$prop = 'static property!';",
             "const {Foo$prop: prop} = (new Foo());"),
-        "{prop=[[Foo], [function(new:Foo): undefined]]}");
+        "{prop=[[(typeof Foo)], [Foo]]}");
   }
 
   @Test
@@ -3254,10 +3258,10 @@ public void testDontDisambiguatePropertyReference_objectPattern_withQuotedString
             "  }",
             "}",
             "/** @type {string} */",
-            "Foo.function_new_Foo___undefined$prop = 'static property!';",
+            "Foo._typeof_Foo_$prop = 'static property!';",
             // we still rewrite the other 'prop' references, but ignore the quoted 'prop'
             "const {'prop': prop} = {'prop': 3};"),
-        "{prop=[[Foo], [function(new:Foo): undefined]]}");
+        "{prop=[[(typeof Foo)], [Foo]]}");
   }
 
   @Test
@@ -3281,9 +3285,9 @@ public void testDisambiguateCtorPropertyReference_objectPattern_stringKey_inDecl
             "  }",
             "}",
             "/** @type {string} */",
-            "Foo.function_new_Foo___undefined$prop = 'static property!';",
-            "const {function_new_Foo___undefined$prop: prop} = Foo;"),
-        "{prop=[[Foo], [function(new:Foo): undefined]]}");
+            "Foo._typeof_Foo_$prop = 'static property!';",
+            "const {_typeof_Foo_$prop: prop} = Foo;"),
+        "{prop=[[(typeof Foo)], [Foo]]}");
   }
 
   @Test
@@ -3307,9 +3311,9 @@ public void testDisambiguatePropertyReference_objectPattern_stringKey_withDefaul
             "  }",
             "}",
             "/** @type {string} */",
-            "Foo.function_new_Foo___undefined$prop = 'static property!';",
+            "Foo._typeof_Foo_$prop = 'static property!';",
             "const {Foo$prop: prop = 0} = (new Foo());"),
-        "{prop=[[Foo], [function(new:Foo): undefined]]}");
+        "{prop=[[(typeof Foo)], [Foo]]}");
   }
 
   @Test
@@ -3333,9 +3337,9 @@ public void testDisambiguatePropertyReference_objectPattern_stringKey_inParamete
             "  }",
             "}",
             "/** @type {string} */",
-            "Foo.function_new_Foo___undefined$prop = 'static property!';",
+            "Foo._typeof_Foo_$prop = 'static property!';",
             "const fn = (/** !Foo */ {Foo$prop: prop}) => prop;"),
-        "{prop=[[Foo], [function(new:Foo): undefined]]}");
+        "{prop=[[(typeof Foo)], [Foo]]}");
   }
 
   @Test
@@ -3359,9 +3363,9 @@ public void testDisambiguatePropertyReference_objectPattern_stringKey_inNestedPa
             "  }",
             "}",
             "/** @type {string} */",
-            "Foo.function_new_Foo___undefined$prop = 'static property!';",
+            "Foo._typeof_Foo_$prop = 'static property!';",
             "const {f: {Foo$prop: prop}} = {f: new Foo()};"),
-        "{prop=[[Foo], [function(new:Foo): undefined]]}");
+        "{prop=[[(typeof Foo)], [Foo]]}");
   }
 
   @Test

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

@@ -72,8 +72,8 @@ public void testBuiltInTypeDifferentReturnType() {
         warning(FunctionTypeBuilder.TYPE_REDEFINITION)
             .withMessage(
                 "attempted re-definition of type String\n"
-                    + "found   : function(new:String, *=): number\n"
-                    + "expected: function(new:String, *=): string"));
+                    + "found   : (typeof String)\n"
+                    + "expected: (typeof String)"));
   }
 
   @Test
@@ -89,8 +89,8 @@ public void testBuiltInTypeDifferentNumParams() {
         warning(FunctionTypeBuilder.TYPE_REDEFINITION)
             .withMessage(
                 "attempted re-definition of type String\n"
-                    + "found   : function(new:String): string\n"
-                    + "expected: function(new:String, *=): string"));
+                    + "found   : (typeof String)\n"
+                    + "expected: (typeof String)"));
   }
 
   @Test
@@ -106,8 +106,8 @@ public void testBuiltInTypeDifferentNumParams2() {
         warning(FunctionTypeBuilder.TYPE_REDEFINITION)
             .withMessage(
                 "attempted re-definition of type String\n"
-                    + "found   : function(new:String, ?=, ?=): string\n"
-                    + "expected: function(new:String, *=): string"));
+                    + "found   : (typeof String)\n"
+                    + "expected: (typeof String)"));
   }
 
   @Test
@@ -123,8 +123,8 @@ public void testBuiltInTypeDifferentParamType() {
         warning(FunctionTypeBuilder.TYPE_REDEFINITION)
             .withMessage(
                 "attempted re-definition of type String\n"
-                    + "found   : function(new:String, ?=): string\n"
-                    + "expected: function(new:String, *=): string"));
+                    + "found   : (typeof String)\n"
+                    + "expected: (typeof String)"));
   }
 
   @Test
@@ -135,8 +135,8 @@ public void testBadFunctionTypeDefinition() {
         warning(FunctionTypeBuilder.TYPE_REDEFINITION)
             .withMessage(
                 "attempted re-definition of type Function\n"
-                    + "found   : function(new:Function, ?=): ?\n"
-                    + "expected: function(new:Function, ...*): ?"));
+                    + "found   : (typeof Function)\n"
+                    + "expected: (typeof Function)"));
   }
 
   @Test

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

@@ -354,7 +354,7 @@ public void testJSDocIsPropagatedToCtors() {
                 )));
 
     JSType xType = inferredTypeOfName("x");
-    assertThat(xType.toString()).isEqualTo("function(new:Foo): undefined");
+    assertThat(xType.toString()).isEqualTo("(typeof Foo)");
 
     // Then
     assertThat(xType.getJSDocInfo().getBlockDescription()).isEqualTo("I'm a user class.");
@@ -919,7 +919,7 @@ public void testJSDocIsPropagatedToStaticProperties_Es5() {
                 )));
 
     ObjectType xType = (ObjectType) inferredTypeOfName("x");
-    assertThat(xType.toString()).isEqualTo("function(new:Foo): undefined");
+    assertThat(xType.toString()).isEqualTo("(typeof Foo)");
 
     // Then
     assertThat(xType.getPropertyJSDocInfo("static").getBlockDescription())
@@ -944,7 +944,7 @@ public void testJSDocIsPropagatedToStaticProperties_Es6Class() {
                 )));
 
     ObjectType xType = (ObjectType) inferredTypeOfName("x");
-    assertThat(xType.toString()).isEqualTo("function(new:Foo): undefined");
+    assertThat(xType.toString()).isEqualTo("(typeof Foo)");
 
     // Then
     assertThat(xType.getPropertyJSDocInfo("static").getBlockDescription())