Issue 27903. Use shared logic for computing new method location.

R=brianwilkerson@google.com
BUG= https://github.com/dart-lang/sdk/issues/27903

Review URL: https://codereview.chromium.org/2538143003 .

pkg/analysis_server/lib/src/services/correction/fix_internal.dart

@@ -2036,23 +2036,17 @@ class FixProcessor {
       MethodInvocation invocation = node.parent as MethodInvocation;
       // prepare environment
       Element targetElement;
-      String prefix;
-      int insertOffset;
-      String sourcePrefix;
-      String sourceSuffix;
       bool staticModifier = false;
+
+      ClassDeclaration targetClassNode;
       Expression target = invocation.realTarget;
       if (target == null) {
         targetElement = unitElement;
         ClassMember enclosingMember =
             node.getAncestor((node) => node is ClassMember);
-        ClassDeclaration enclosingClass = enclosingMember.parent;
-        utils.targetClassElement = enclosingClass.element;
+        targetClassNode = enclosingMember.parent;
+        utils.targetClassElement = targetClassNode.element;
         staticModifier = _inStaticContext();
-        prefix = utils.getNodePrefix(enclosingMember);
-        insertOffset = enclosingMember.end;
-        sourcePrefix = '$eol$eol';
-        sourceSuffix = '';
       } else {
         // prepare target interface type
         DartType targetType = target.bestType;
@@ -2066,32 +2060,24 @@ class FixProcessor {
         if (targetTypeNode is! ClassDeclaration) {
           return;
         }
-        ClassDeclaration targetClassNode = targetTypeNode;
+        targetClassNode = targetTypeNode;
         // maybe static
         if (target is Identifier) {
           staticModifier = target.bestElement.kind == ElementKind.CLASS;
         }
-        // prepare insert offset
-        prefix = '  ';
-        insertOffset = targetClassNode.end - 1;
-        if (targetClassNode.members.isEmpty) {
-          sourcePrefix = '';
-        } else {
-          sourcePrefix = eol;
-        }
-        sourceSuffix = eol;
         // use different utils
         CompilationUnitElement targetUnitElement =
             getCompilationUnitElement(targetClassElement);
         CompilationUnit targetUnit = getParsedUnit(targetUnitElement);
         utils = new CorrectionUtils(targetUnit);
       }
+      ClassMemberLocation targetLocation =
+          utils.prepareNewMethodLocation(targetClassNode);
       String targetFile = targetElement.source.fullName;
       // build method source
-      SourceBuilder sb = new SourceBuilder(targetFile, insertOffset);
+      SourceBuilder sb = new SourceBuilder(targetFile, targetLocation.offset);
       {
-        sb.append(sourcePrefix);
-        sb.append(prefix);
+        sb.append(targetLocation.prefix);
         // maybe "static"
         if (staticModifier) {
           sb.append('static ');
@@ -2108,8 +2094,8 @@ class FixProcessor {
           sb.endPosition();
         }
         _addFix_undefinedMethod_create_parameters(sb, invocation.argumentList);
-        sb.append(') {$eol$prefix}');
-        sb.append(sourceSuffix);
+        sb.append(') {}');
+        sb.append(targetLocation.suffix);
       }
       // insert source
       _insertBuilder(sb, targetElement);

pkg/analysis_server/lib/src/services/correction/util.dart

@@ -1317,6 +1317,16 @@ class CorrectionUtils {
             member is MethodDeclaration && member.isGetter);
   }
 
+  ClassMemberLocation prepareNewMethodLocation(
+      ClassDeclaration classDeclaration) {
+    return prepareNewClassMemberLocation(
+        classDeclaration,
+        (member) =>
+            member is FieldDeclaration ||
+            member is ConstructorDeclaration ||
+            member is MethodDeclaration);
+  }
+
   /**
    * Returns the source with indentation changed from [oldIndent] to
    * [newIndent], keeping indentation of lines relative to each other.

pkg/analysis_server/test/services/correction/fix_test.dart

@@ -4601,8 +4601,7 @@ class A<T> {
 }
 
 class B {
-  void process(Map items) {
-  }
+  void process(Map items) {}
 }
 ''');
   }
@@ -4628,8 +4627,7 @@ class A<T> {
 }
 
 class B {
-  dynamic compute() {
-  }
+  dynamic compute() {}
 }
 ''');
   }
@@ -4644,8 +4642,7 @@ class A {
   }
 }
 
-class B {
-}
+class B {}
 ''');
     await assertHasFix(
         DartFixKind.CREATE_METHOD,
@@ -4659,8 +4656,7 @@ class A {
 }
 
 class B {
-  void process(List<int> items) {
-  }
+  void process(List<int> items) {}
 }
 ''');
   }
@@ -4683,8 +4679,26 @@ class A<T> {
     process(items);
   }
 
-  void process(List<T> items) {
+  void process(List<T> items) {}
+}
+''');
   }
+
+  test_undefinedMethod_createQualified_emptyClassBody() async {
+    resolveTestUnit('''
+class A {}
+main() {
+  A.myUndefinedMethod();
+}
+''');
+    await assertHasFix(
+        DartFixKind.CREATE_METHOD,
+        '''
+class A {
+  static void myUndefinedMethod() {}
+}
+main() {
+  A.myUndefinedMethod();
 }
 ''');
   }
@@ -4701,8 +4715,7 @@ main() {
         DartFixKind.CREATE_METHOD,
         '''
 class A {
-  static void myUndefinedMethod() {
-  }
+  static void myUndefinedMethod() {}
 }
 main() {
   A.myUndefinedMethod();
@@ -4725,8 +4738,7 @@ main() {
 class A {
   foo() {}
 
-  static void myUndefinedMethod() {
-  }
+  static void myUndefinedMethod() {}
 }
 main() {
   A.myUndefinedMethod();
@@ -4746,8 +4758,7 @@ main(A a) {
         DartFixKind.CREATE_METHOD,
         '''
 class A {
-  void myUndefinedMethod() {
-  }
+  void myUndefinedMethod() {}
 }
 main(A a) {
   a.myUndefinedMethod();
@@ -4797,8 +4808,7 @@ class D {
     bar(c1.x, c2.x);
   }
 
-  void bar(int x, int x2) {
-  }
+  void bar(int x, int x2) {}
 }''');
   }
 
@@ -4818,8 +4828,7 @@ class A {
     myUndefinedMethod(0, 1.0, '3');
   }
 
-  void myUndefinedMethod(int i, double d, String s) {
-  }
+  void myUndefinedMethod(int i, double d, String s) {}
 }
 ''');
     // linked positions
@@ -4864,8 +4873,7 @@ class A {
     myUndefinedMethod(0, bbb: 1.0, ccc: '2');
   }
 
-  void myUndefinedMethod(int i, {double bbb, String ccc}) {
-  }
+  void myUndefinedMethod(int i, {double bbb, String ccc}) {}
 }
 ''');
     // linked positions
@@ -4908,8 +4916,7 @@ class A {
     int v = myUndefinedMethod();
   }
 
-  int myUndefinedMethod() {
-  }
+  int myUndefinedMethod() {}
 }
 ''');
     // linked positions
@@ -4930,8 +4937,7 @@ class A {
 class A {
   static var f = myUndefinedMethod();
 
-  static myUndefinedMethod() {
-  }
+  static myUndefinedMethod() {}
 }
 ''');
   }
@@ -4952,8 +4958,7 @@ class A {
     myUndefinedMethod();
   }
 
-  static void myUndefinedMethod() {
-  }
+  static void myUndefinedMethod() {}
 }
 ''');
   }
@@ -4971,8 +4976,7 @@ main() {
         DartFixKind.CREATE_METHOD,
         '''
 class A {
-  void myUndefinedMethod() {
-  }
+  void myUndefinedMethod() {}
 }
 main() {
   var a = new A();
@@ -5018,8 +5022,7 @@ library test2;
 import 'test3.dart' as bbb;
 export 'test3.dart';
 class D {
-  void foo(bbb.E e) {
-  }
+  void foo(bbb.E e) {}
 }
 ''');
   }
@@ -5052,8 +5055,7 @@ main(test2.D d, test2.E e) {
         r'''
 library test2;
 class D {
-  void foo(E e) {
-  }
+  void foo(E e) {}
 }
 class E {}
 ''');