Allow analyzer to distinguish unresolved types from dynamic.

pkg/analyzer/test/generated/resolver_test.dart

Index: pkg/analyzer/test/generated/resolver_test.dart
diff --git a/pkg/analyzer/test/generated/resolver_test.dart b/pkg/analyzer/test/generated/resolver_test.dart
index f10dc5634d5670362cff740f42e46943775eb2b3..6c7e93cfdbdecb2a9faed619ecdb4de646faa5b1 100644
--- a/pkg/analyzer/test/generated/resolver_test.dart
+++ b/pkg/analyzer/test/generated/resolver_test.dart
@@ -437,6 +437,21 @@ class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
     verify([source]);
   }
 
+  void test_fieldFormalParameterAssignableToField_fieldType_unresolved_null() {
+    // Null always passes runtime type checks, even when the type is
+    // unresolved.
+    Source source = addSource(EngineTestCase.createSource([
+        "class A {",
+        "  final Unresolved x;",
+        "  const A(String this.x);",
+        "}",
+        "var v = const A(null);"]));
+    resolve(source);
+    assertErrors(source, [
+        StaticWarningCode.UNDEFINED_CLASS]);
+    verify([source]);
+  }
+
   void test_fieldFormalParameterAssignableToField_implements() {
     // According to checked-mode type checking rules, a value of type B is
     // assignable to a field of type A, because B implements A (and hence is a
@@ -604,6 +619,20 @@ class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
     verify([source]);
   }
 
+  void test_fieldFormalParameterNotAssignableToField_fieldType_unresolved() {
+    Source source = addSource(EngineTestCase.createSource([
+        "class A {",
+        "  final Unresolved x;",
+        "  const A(String this.x);",
+        "}",
+        "var v = const A('foo');"]));
+    resolve(source);
+    assertErrors(source, [
+        CheckedModeCompileTimeErrorCode.CONST_CONSTRUCTOR_PARAM_TYPE_MISMATCH,
+        StaticWarningCode.UNDEFINED_CLASS]);
+    verify([source]);
+  }
+
   void test_fieldFormalParameterNotAssignableToField_extends() {
     // According to checked-mode type checking rules, a value of type A is not
     // assignable to a field of type B, because B extends A (the subtyping
@@ -745,6 +774,20 @@ class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
     verify([source]);
   }
 
+  void test_fieldTypeMismatch_unresolved() {
+    Source source = addSource(EngineTestCase.createSource([
+        "class A {",
+        "  const A(x) : y = x;",
+        "  final Unresolved y;",
+        "}",
+        "var v = const A('foo');"]));
+    resolve(source);
+    assertErrors(source, [
+        CheckedModeCompileTimeErrorCode.CONST_CONSTRUCTOR_FIELD_TYPE_MISMATCH,
+        StaticWarningCode.UNDEFINED_CLASS]);
+    verify([source]);
+  }
+
   void test_fieldTypeOk_null() {
     Source source = addSource(EngineTestCase.createSource([
         "class A {",
@@ -757,6 +800,21 @@ class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
     verify([source]);
   }
 
+  void test_fieldTypeOk_unresolved_null() {
+    // Null always passes runtime type checks, even when the type is
+    // unresolved.
+    Source source = addSource(EngineTestCase.createSource([
+        "class A {",
+        "  const A(x) : y = x;",
+        "  final Unresolved y;",
+        "}",
+        "var v = const A(null);"]));
+    resolve(source);
+    assertErrors(source, [
+        StaticWarningCode.UNDEFINED_CLASS]);
+    verify([source]);
+  }
+
   void test_listElementTypeNotAssignable() {
     Source source = addSource(EngineTestCase.createSource(["var v = const <String> [42];"]));
     resolve(source);
@@ -796,6 +854,20 @@ class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
     verify([source]);
   }
 
+  void test_parameterAssignable_undefined_null() {
+    // Null always passes runtime type checks, even when the type is
+    // unresolved.
+    Source source = addSource(EngineTestCase.createSource([
+        "class A {",
+        "  const A(Unresolved x);",
+        "}",
+        "var v = const A(null);"]));
+    resolve(source);
+    assertErrors(source, [
+        StaticWarningCode.UNDEFINED_CLASS]);
+    verify([source]);
+  }
+
   void test_parameterAssignable_typeSubstitution() {
     Source source = addSource(EngineTestCase.createSource([
         "class A<T> {",
@@ -820,6 +892,19 @@ class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
     verify([source]);
   }
 
+  void test_parameterNotAssignable_undefined() {
+    Source source = addSource(EngineTestCase.createSource([
+        "class A {",
+        "  const A(Unresolved x);",
+        "}",
+        "var v = const A('foo');"]));
+    resolve(source);
+    assertErrors(source, [
+        CheckedModeCompileTimeErrorCode.CONST_CONSTRUCTOR_PARAM_TYPE_MISMATCH,
+        StaticWarningCode.UNDEFINED_CLASS]);
+    verify([source]);
+  }
+
   void test_parameterNotAssignable_typeSubstitution() {
     Source source = addSource(EngineTestCase.createSource([
         "class A<T> {",
@@ -841,6 +926,17 @@ class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
     verify([source]);
   }
 
+  void test_topLevelVarAssignable_undefined_null() {
+    // Null always passes runtime type checks, even when the type is
+    // unresolved.
+    Source source = addSource(EngineTestCase.createSource([
+        "const Unresolved x = null;"]));
+    resolve(source);
+    assertErrors(source, [
+        StaticWarningCode.UNDEFINED_CLASS]);
+    verify([source]);
+  }
+
   void test_topLevelVarNotAssignable() {
     Source source = addSource(EngineTestCase.createSource([
         "const int x = 'foo';"]));
@@ -850,6 +946,16 @@ class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
         StaticTypeWarningCode.INVALID_ASSIGNMENT]);
     verify([source]);
   }
+
+  void test_topLevelVarNotAssignable_undefined() {
+    Source source = addSource(EngineTestCase.createSource([
+        "const Unresolved x = 'foo';"]));
+    resolve(source);
+    assertErrors(source, [
+        CheckedModeCompileTimeErrorCode.VARIABLE_TYPE_MISMATCH,
+        StaticWarningCode.UNDEFINED_CLASS]);
+    verify([source]);
+  }
 }
 
 class DeclarationMatcherTest extends ResolverTestCase {
@@ -8445,7 +8551,7 @@ class StaticTypeVerifier extends GeneralizingAstVisitor<Object> {
   Object visitPrefixedIdentifier(PrefixedIdentifier node) {
     // In cases where we have a prefixed identifier where the prefix is dynamic, we don't want to
     // assert that the node will have a type.
-    if (node.staticType == null && identical(node.prefix.staticType, DynamicTypeImpl.instance)) {
+    if (node.staticType == null && node.prefix.staticType.isDynamic) {
       return null;
     }
     return super.visitPrefixedIdentifier(node);
@@ -8838,6 +8944,11 @@ class TestTypeProvider implements TypeProvider {
    */
   InterfaceType _typeType;
 
+  /**
+   * The type representing typenames that can't be resolved.
+   */
+  DartType _undefinedType;
+
   @override
   InterfaceType get boolType {
     if (_boolType == null) {
@@ -9046,6 +9157,14 @@ class TestTypeProvider implements TypeProvider {
     return _typeType;
   }
 
+  @override
+  DartType get undefinedType {
+    if (_undefinedType == null) {
+      _undefinedType = UndefinedTypeImpl.instance;
+    }
+    return _undefinedType;
+  }
+
   /**
    * Initialize the numeric types. They are created as a group so that we can (a) create the right
    * hierarchy and (b) add members to them.