Let iOS flutter run auto-sign default to first profile (#10181)

* Let run default to first profile

* fix

* review notes

packages/flutter_tools/lib/src/base/terminal.dart

@@ -90,16 +90,29 @@ class AnsiTerminal {
   /// Prompts the user to input a chraracter within the accepted list.
   /// Reprompts if inputted character is not in the list.
   ///
+  /// `prompt` is the text displayed prior to waiting for user input each time.
+  /// `defaultChoiceIndex`, if given, will be the character in `acceptedCharacters`
+  ///     in the index given if the user presses enter without any key input.
+  /// `displayAcceptedCharacters` prints also the accepted keys next to the `prompt` if true.
+  ///
   /// Throws a [TimeoutException] if a `timeout` is provided and its duration
   /// expired without user input. Duration resets per key press.
   Future<String> promptForCharInput(
     List<String> acceptedCharacters, {
     String prompt,
+    int defaultChoiceIndex,
     bool displayAcceptedCharacters: true,
     Duration timeout,
   }) async {
     assert(acceptedCharacters != null);
     assert(acceptedCharacters.isNotEmpty);
+    List<String> charactersToDisplay = acceptedCharacters;
+    if (defaultChoiceIndex != null) {
+      assert(defaultChoiceIndex >= 0 && defaultChoiceIndex < acceptedCharacters.length);
+      charactersToDisplay = new List<String>.from(charactersToDisplay);
+      charactersToDisplay[defaultChoiceIndex] = bolden(charactersToDisplay[defaultChoiceIndex]);
+      acceptedCharacters.add('\n');
+    }
     String choice;
     singleCharMode = true;
     while(
@@ -110,7 +123,7 @@ class AnsiTerminal {
       if (isNotEmpty(prompt)) {
         printStatus(prompt, emphasis: true, newline: false);
         if (displayAcceptedCharacters)
-          printStatus(' [${acceptedCharacters.join("|")}]', newline: false);
+          printStatus(' [${charactersToDisplay.join("|")}]', newline: false);
         printStatus(': ', emphasis: true, newline: false);
       }
       Future<String> inputFuture = onCharInput.first;
@@ -120,6 +133,8 @@ class AnsiTerminal {
       printStatus(choice);
     }
     singleCharMode = false;
+    if (defaultChoiceIndex != null && choice == '\n')
+      choice = acceptedCharacters[defaultChoiceIndex];
     return choice;
   }
 }

packages/flutter_tools/lib/src/ios/code_signing.dart

@@ -153,6 +153,7 @@ Future<String> _chooseSigningIdentity(List<String> validCodeSigningIdentities) a
           ..add('a'),
       prompt: 'Please select a certificate for code signing',
       displayAcceptedCharacters: true,
+      defaultChoiceIndex: 0, // Just pressing enter chooses the first one.
     );
 
     if (choice == 'a')

packages/flutter_tools/test/src/base/terminal_test.dart

@@ -21,6 +21,7 @@ void main() {
     testUsingContext('character prompt', () async {
       mockStdInStream = new Stream<String>.fromFutures(<Future<String>>[
         new Future<String>.value('d'), // Not in accepted list.
+        new Future<String>.value('\n'), // Not in accepted list
         new Future<String>.value('b'),
       ]).asBroadcastStream();
       final String choice =
@@ -29,10 +30,32 @@ void main() {
             prompt: 'Please choose something',
           );
       expect(choice, 'b');
-      expect(testLogger.statusText, '''
-Please choose something [a|b|c]: d
-Please choose something [a|b|c]: b
-''');
+      expect(
+        testLogger.statusText,
+        'Please choose something [a|b|c]: d\n'
+        'Please choose something [a|b|c]: \n'
+        '\n'
+        'Please choose something [a|b|c]: b\n'
+      );
+    });
+
+    testUsingContext('default character choice without displayAcceptedCharacters', () async {
+      mockStdInStream = new Stream<String>.fromFutures(<Future<String>>[
+        new Future<String>.value('\n'), // Not in accepted list
+      ]).asBroadcastStream();
+      final String choice =
+          await terminalUnderTest.promptForCharInput(
+            <String>['a', 'b', 'c'],
+            prompt: 'Please choose something',
+            displayAcceptedCharacters: false,
+            defaultChoiceIndex: 1, // which is b.
+          );
+      expect(choice, 'b');
+      expect(
+        testLogger.statusText,
+        'Please choose something: \n'
+        '\n'
+      );
     });
   });
 }

packages/flutter_tools/test/src/ios/code_signing_test.dart

@@ -189,7 +189,7 @@ void main() {
 
       expect(
         testLogger.statusText,
-        contains('Please select a certificate for code signing [1|2|3|a]: 3')
+        contains('Please select a certificate for code signing [<bold>1</bold>|2|3|a]: 3')
       );
       expect(
         testLogger.statusText,
@@ -228,6 +228,9 @@ class MockStdIn extends Mock implements IOSink {}
 Stream<String> mockTerminalStdInStream;
 
 class TestTerminal extends AnsiTerminal {
+  @override
+  String bolden(String message) => '<bold>$message</bold>';
+
   @override
   Stream<String> get onCharInput {
     return mockTerminalStdInStream;