Add completion for do-stmt, refactor for reuse

pkg/analysis_server/test/services/completion/statement/statement_completion_test.dart

Index: pkg/analysis_server/test/services/completion/statement/statement_completion_test.dart
diff --git a/pkg/analysis_server/test/services/completion/statement/statement_completion_test.dart b/pkg/analysis_server/test/services/completion/statement/statement_completion_test.dart
index 18b8794e4a10061d9b0de3dc9616f5a097bf52fd..1b99cfed2f6992a0819587c184cf7ad930e2e456 100644
--- a/pkg/analysis_server/test/services/completion/statement/statement_completion_test.dart
+++ b/pkg/analysis_server/test/services/completion/statement/statement_completion_test.dart
@@ -24,67 +24,110 @@ class StatementCompletionTest extends AbstractSingleUnitTest {
 
   bool get enableNewAnalysisDriver => true;
 
-  test_completeIfEmptyCondition() async {
+  test_completeDoEmptyCondition() async {
     await _prepareCompletion(
-        'if ()',
+        'while ()',
         '''
 main() {
-  if ()
+  do {
+  } while ()
 }
 ''',
         atEnd: true);
     _assertHasChange(
-        'Complete if-statement',
+        'Complete do-statement',
         '''
 main() {
-  if () {
-    ////
-  }
+  do {
+  } while ();
 }
 ''',
-        (s) => s.indexOf('if (') + 'if ('.length);
+        (s) => s.indexOf('while (') + 'while ('.length);
   }
 
-  test_completeIfKeywordOnly() async {
+  test_completeDoKeywordOnly() async {
     await _prepareCompletion(
-        'if',
+        'do',
         '''
 main() {
-  if ////
+  do ////
 }
 ''',
         atEnd: true);
     _assertHasChange(
-        'Complete if-statement',
+        'Complete do-statement',
         '''
 main() {
-  if () {
+  do {
     ////
-  }
+  } while ();
 }
 ''',
-        (s) => s.indexOf('if (') + 'if ('.length);
+        (s) => s.indexOf('while (') + 'while ('.length);
   }
 
-  test_completeIfWithCondition() async {
+  test_completeDoNoBody() async {
     await _prepareCompletion(
-        'if (tr', // Trigger completion from within expression.
+        'do',
         '''
 main() {
-  if (true)
+  do;
+  while
 }
 ''',
         atEnd: true);
     _assertHasChange(
-        'Complete if-statement',
+        'Complete do-statement',
         '''
 main() {
-  if (true) {
+  do {
     ////
+  } while ();
+}
+''',
+        (s) => s.indexOf('while (') + 'while ('.length);
+  }
+
+  test_completeDoNoCondition() async {
+    await _prepareCompletion(
+        'while',
+        '''
+main() {
+  do {
+  } while
+}
+''',
+        atEnd: true);
+    _assertHasChange(
+        'Complete do-statement',
+        '''
+main() {
+  do {
+  } while ();
+}
+''',
+        (s) => s.indexOf('while (') + 'while ('.length);
+  }
+
+  test_completeDoNoWhile() async {
+    await _prepareCompletion(
+        '}',
+        '''
+main() {
+  do {
   }
 }
 ''',
-        (s) => s.indexOf('    ') + '    '.length);
+        atEnd: true);
+    _assertHasChange(
+        'Complete do-statement',
+        '''
+main() {
+  do {
+  } while ();
+}
+''',
+        (s) => s.indexOf('while (') + 'while ('.length);
   }
 
   test_completeIfAfterCondition_BAD() async {
@@ -113,6 +156,69 @@ main() {
         (s) => s.indexOf('if (true) ') + 'if (true) '.length);
   }
 
+  test_completeIfEmptyCondition() async {
+    await _prepareCompletion(
+        'if ()',
+        '''
+main() {
+  if ()
+}
+''',
+        atEnd: true);
+    _assertHasChange(
+        'Complete if-statement',
+        '''
+main() {
+  if () {
+    ////
+  }
+}
+''',
+        (s) => s.indexOf('if (') + 'if ('.length);
+  }
+
+  test_completeIfKeywordOnly() async {
+    await _prepareCompletion(
+        'if',
+        '''
+main() {
+  if ////
+}
+''',
+        atEnd: true);
+    _assertHasChange(
+        'Complete if-statement',
+        '''
+main() {
+  if () {
+    ////
+  }
+}
+''',
+        (s) => s.indexOf('if (') + 'if ('.length);
+  }
+
+  test_completeIfWithCondition() async {
+    await _prepareCompletion(
+        'if (tr', // Trigger completion from within expression.
+        '''
+main() {
+  if (true)
+}
+''',
+        atEnd: true);
+    _assertHasChange(
+        'Complete if-statement',
+        '''
+main() {
+  if (true) {
+    ////
+  }
+}
+''',
+        (s) => s.indexOf('    ') + '    '.length);
+  }
+
   test_completeIfWithElse_BAD() async {
     await _prepareCompletion(
         'if ()',