diff --git a/pkg/analyzer/lib/src/dart/ast/ast.dart b/pkg/analyzer/lib/src/dart/ast/ast.dart
index 736f66abf204..905d1554b968 100644
--- a/pkg/analyzer/lib/src/dart/ast/ast.dart
+++ b/pkg/analyzer/lib/src/dart/ast/ast.dart
@@ -3870,9 +3870,6 @@ class ExtensionDeclarationImpl extends CompilationUnitMemberImpl
     _members = new NodeListImpl<ClassMember>(this, members);
   }
 
-  @override
-  Token get beginToken => extensionKeyword;
-
   @override
   Iterable<SyntacticEntity> get childEntities => new ChildEntities()
     ..add(extensionKeyword)
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index 8497919b68f0..eeefa426e17a 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -5013,6 +5013,28 @@ class ExtensionElementImpl extends ElementImpl
     _accessors = accessors;
   }
 
+  @override
+  int get codeLength {
+    if (linkedNode != null) {
+      return linkedContext.getCodeLength(linkedNode);
+    }
+    if (_unlinkedExtension != null) {
+      return _unlinkedExtension.codeRange?.length;
+    }
+    return super.codeLength;
+  }
+
+  @override
+  int get codeOffset {
+    if (linkedNode != null) {
+      return linkedContext.getCodeOffset(linkedNode);
+    }
+    if (_unlinkedExtension != null) {
+      return _unlinkedExtension.codeRange?.offset;
+    }
+    return super.codeOffset;
+  }
+
   @override
   String get displayName => name;
 
diff --git a/pkg/analyzer/lib/src/summary2/linked_unit_context.dart b/pkg/analyzer/lib/src/summary2/linked_unit_context.dart
index 407f315965a3..8bbfdfd2f09d 100644
--- a/pkg/analyzer/lib/src/summary2/linked_unit_context.dart
+++ b/pkg/analyzer/lib/src/summary2/linked_unit_context.dart
@@ -150,6 +150,8 @@ class LinkedUnitContext {
       return LazyConstructorDeclaration.getCodeLength(this, node);
     } else if (node is EnumDeclaration) {
       return LazyEnumDeclaration.getCodeLength(this, node);
+    } else if (node is ExtensionDeclaration) {
+      return LazyExtensionDeclaration.getCodeLength(this, node);
     } else if (node is FormalParameter) {
       return LazyFormalParameter.getCodeLength(this, node);
     } else if (node is FunctionDeclaration) {
@@ -181,6 +183,8 @@ class LinkedUnitContext {
       return LazyConstructorDeclaration.getCodeOffset(this, node);
     } else if (node is EnumDeclaration) {
       return LazyEnumDeclaration.getCodeOffset(this, node);
+    } else if (node is ExtensionDeclaration) {
+      return LazyExtensionDeclaration.getCodeOffset(this, node);
     } else if (node is FormalParameter) {
       return LazyFormalParameter.getCodeOffset(this, node);
     } else if (node is FunctionDeclaration) {
diff --git a/pkg/analyzer/test/src/summary/resynthesize_ast_test.dart b/pkg/analyzer/test/src/summary/resynthesize_ast_test.dart
index 5262772b55e4..ded834beee9d 100644
--- a/pkg/analyzer/test/src/summary/resynthesize_ast_test.dart
+++ b/pkg/analyzer/test/src/summary/resynthesize_ast_test.dart
@@ -27,6 +27,12 @@ class ApplyCheckElementTextReplacements {
 @reflectiveTest
 class ResynthesizeAstStrongTest extends ResynthesizeTestStrategyTwoPhase
     with ResynthesizeTestCases, GetElementTestCases, ResynthesizeTestHelpers {
+  @override
+  @failingTest
+  test_codeRange_extensions() async {
+    await super.test_codeRange_extensions();
+  }
+
   @failingTest // See dartbug.com/32290
   test_const_constructor_inferred_args() =>
       super.test_const_constructor_inferred_args();
@@ -58,6 +64,12 @@ class ResynthesizeAstStrongTest extends ResynthesizeTestStrategyTwoPhase
     await super.test_infer_generic_typedef_complex();
   }
 
+  @override
+  @failingTest
+  test_metadata_extensionDeclaration() async {
+    await super.test_metadata_extensionDeclaration();
+  }
+
   @override
   @failingTest
   test_syntheticFunctionType_inGenericClass() async {
diff --git a/pkg/analyzer/test/src/summary/resynthesize_common.dart b/pkg/analyzer/test/src/summary/resynthesize_common.dart
index 05d984a1607b..aed4cfa8695b 100644
--- a/pkg/analyzer/test/src/summary/resynthesize_common.dart
+++ b/pkg/analyzer/test/src/summary/resynthesize_common.dart
@@ -2022,6 +2022,68 @@ class C/*codeOffset=0, codeLength=462*/ {
         withConstElements: false);
   }
 
+  test_codeRange_extensions() async {
+    featureSet = enableExtensionMethods;
+    var library = await checkLibrary('''
+class A {}
+
+extension Raw on A {}
+
+/// Comment 1.
+/// Comment 2.
+extension HasDocComment on A {}
+
+@Object()
+extension HasAnnotation on A {}
+
+@Object()
+/// Comment 1.
+/// Comment 2.
+extension AnnotationThenComment on A {}
+
+/// Comment 1.
+/// Comment 2.
+@Object()
+extension CommentThenAnnotation on A {}
+
+/// Comment 1.
+@Object()
+/// Comment 2.
+extension CommentAroundAnnotation on A {}
+''');
+    checkElementText(
+        library,
+        r'''
+class A/*codeOffset=0, codeLength=10*/ {
+}
+extension Raw/*codeOffset=12, codeLength=21*/ on A {
+}
+/// Comment 1.
+/// Comment 2.
+extension HasDocComment/*codeOffset=35, codeLength=61*/ on A {
+}
+@Object()
+extension HasAnnotation/*codeOffset=98, codeLength=41*/ on A {
+}
+/// Comment 1.
+/// Comment 2.
+@Object()
+extension AnnotationThenComment/*codeOffset=141, codeLength=79*/ on A {
+}
+/// Comment 1.
+/// Comment 2.
+@Object()
+extension CommentThenAnnotation/*codeOffset=222, codeLength=79*/ on A {
+}
+/// Comment 2.
+@Object()
+extension CommentAroundAnnotation/*codeOffset=318, codeLength=66*/ on A {
+}
+''',
+        withCodeRanges: true,
+        withConstElements: false);
+  }
+
   test_codeRange_field() async {
     var library = await checkLibrary('''
 class C {
@@ -8263,6 +8325,27 @@ const dynamic a = null;
 ''');
   }
 
+  test_metadata_extensionDeclaration() async {
+    featureSet = enableExtensionMethods;
+    var library = await checkLibrary(r'''
+const a = null;
+class A {}
+@a
+@Object()
+extension E on A {}''');
+    checkElementText(library, r'''
+class A {
+}
+@
+        a/*location: test.dart;a?*/
+@
+        Object/*location: dart:core;Object*/()
+extension E on A {
+}
+const dynamic a = null;
+''');
+  }
+
   test_metadata_fieldDeclaration() async {
     var library = await checkLibrary('const a = null; class C { @a int x; }');
     checkElementText(library, r'''