Add fwe excerpt projects to examples workspace and fix lints (#13290)

Contributes to #13028

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: parlough

examples/fwe/birdle/.gitignore

@@ -1,3 +1,4 @@
-# birdle
+# Birdle app
 
-A new Flutter project.
+Code excerpts for the Birdle example app built in
+the [Flutter tutorial](https://docs.flutter.dev/learn/pathway/tutorial).

examples/fwe/birdle/.metadata

@@ -8,28 +8,28 @@ enum HitType { none, hit, partial, miss, removed }
 
 typedef Letter = ({String char, HitType type});
 
-const legalWords = <String>["aback", "abase", "abate", "abbey", "abbot"];
+const legalWords = <String>['aback', 'abase', 'abate', 'abbey', 'abbot'];
 
 /// Legal guesses minus legal wordles
 const legalGuesses = <String>[
-  "aback",
-  "abase",
-  "abate",
-  "abbey",
-  "abbot",
-  "abhor",
-  "abide",
-  "abled",
-  "abode",
-  "abort",
+  'aback',
+  'abase',
+  'abate',
+  'abbey',
+  'abbot',
+  'abhor',
+  'abide',
+  'abled',
+  'abode',
+  'abort',
 ];
 
 /// This class holds game state for a single round of Bulls and Cows,
 /// and exposes methods that a UI would need to manage the game state.
 ///
-/// On it's own, this class won't manage a game. For example, it won't
-/// call [startGame] on it's own. It assumes that a client will use it's
-/// methods to progress through a game.
+/// On its own, this class won't manage a game.
+/// For example, it won't call [resetGame] on its own.
+/// It assumes that a client will use its methods to progress through a game.
 class Game {
   Game({this.numAllowedGuesses = defaultNumGuesses, this.seed}) {
     _wordToGuess = seed == null ? Word.random() : Word.fromSeed(seed!);
@@ -76,7 +76,7 @@ class Game {
   bool get didWin {
     if (_guesses.first.isEmpty) return false;
 
-    for (var letter in previousGuess) {
+    for (final letter in previousGuess) {
       if (letter.type != HitType.hit) return false;
     }
 
@@ -94,7 +94,7 @@ class Game {
   // Doesn't move the game forward, only executes match logic.
   Word matchGuessOnly(String guess) {
     // The hidden word will be used by subsequent guesses.
-    var hiddenCopy = Word.fromString(_wordToGuess.toString());
+    final hiddenCopy = Word.fromString(_wordToGuess.toString());
     return Word.fromString(guess).evaluateGuess(hiddenCopy);
   }
 
@@ -112,16 +112,16 @@ class Word with IterableMixin<Letter> {
   }
 
   factory Word.fromString(String guess) {
-    var list = guess.toLowerCase().split('');
-    var letters = list
-        .map((String char) => (char: char, type: HitType.none))
+    final list = guess.toLowerCase().split('');
+    final letters = list
+        .map((char) => (char: char, type: HitType.none))
         .toList();
     return Word(letters);
   }
 
   factory Word.random() {
-    var rand = Random();
-    var nextWord = legalWords[rand.nextInt(legalWords.length)];
+    final rand = Random();
+    final nextWord = legalWords[rand.nextInt(legalWords.length)];
     return Word.fromString(nextWord);
   }
 
@@ -148,7 +148,7 @@ class Word with IterableMixin<Letter> {
 
   @override
   String toString() {
-    return _letters.map((Letter c) => c.char).join().trim();
+    return _letters.map((c) => c.char).join().trim();
   }
 
   // Used to play game in the CLI implementation
@@ -168,7 +168,7 @@ extension WordUtils on Word {
   }
 
   /// Compares two [Word] objects and returns a new [Word] that
-  /// has the same letters as the [this], but each [Letter]
+  /// has the same letters as this word, but each [Letter]
   /// has new a [HitType] of either [HitType.hit],
   /// [HitType.partial], or [HitType.miss].
   Word evaluateGuess(Word other) {
@@ -188,12 +188,12 @@ extension WordUtils on Word {
     for (var i = 0; i < other.length; i++) {
       // If a letter in the hidden word is already marked as "removed",
       // then it's already an exact match, so skip it
-      Letter targetLetter = other[i];
+      final targetLetter = other[i];
       if (targetLetter.type != HitType.none) continue;
 
       // loop through the guessed word onces for each letter in the hidden word
       for (var j = 0; j < length; j++) {
-        Letter guessedLetter = this[j];
+        final guessedLetter = this[j];
         // skip letters that have already been marked as exact matches
         if (guessedLetter.type != HitType.none) continue;
         // If this letter, which must not be in the same position, is the same,

examples/fwe/birdle/README.md

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+
 import 'game.dart';
 
 void main() {
@@ -14,9 +15,12 @@ class MainApp extends StatelessWidget {
     return MaterialApp(
       home: Scaffold(
         appBar: AppBar(
-          title: Align(alignment: Alignment.centerLeft, child: Text('Birdle')),
+          title: const Align(
+            alignment: Alignment.centerLeft,
+            child: Text('Birdle'),
+          ),
         ),
-        body: Center(child: GamePage()),
+        body: const Center(child: GamePage()),
       ),
     );
   }
@@ -42,16 +46,16 @@ class _GamePageState extends State<GamePage> {
         spacing: 5.0,
         mainAxisAlignment: MainAxisAlignment.center,
         children: [
-          for (var guess in _game.guesses)
+          for (final guess in _game.guesses)
             Row(
               spacing: 5.0,
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
-                for (var letter in guess) Tile(letter.char, letter.type),
+                for (final letter in guess) Tile(letter.char, letter.type),
               ],
             ),
           GuessInput(
-            onSubmitGuess: (String guess) {
+            onSubmitGuess: (guess) {
               setState(() {
                 _game.guess(guess);
               });
@@ -98,7 +102,7 @@ class GuessInput extends StatelessWidget {
               controller: _textEditingController,
               autofocus: true,
               focusNode: _focusNode,
-              onSubmitted: (String input) {
+              onSubmitted: (input) {
                 _onSubmit();
               },
             ),

examples/fwe/birdle/analysis_options.yaml

@@ -1,4 +1,3 @@
-// ignore_for_file: unused_import, unused_field, unused_local_variable, avoid_print, prefer_const_constructors_in_immutables, use_key_in_widget_constructors, sized_box_for_whitespace
 import 'package:flutter/material.dart';
 
 // #docregion main

examples/fwe/birdle/lib/game.dart

@@ -1,5 +1,7 @@
-// ignore_for_file: unused_import, unused_field, unused_local_variable, avoid_print, prefer_const_constructors_in_immutables, use_key_in_widget_constructors, sized_box_for_whitespace
+// ignore_for_file: prefer_const_constructors
+
 import 'package:flutter/material.dart';
+
 import 'game.dart';
 
 void main() {

examples/fwe/birdle/lib/main.dart

@@ -1,5 +1,5 @@
-// ignore_for_file: unused_import, unused_field, unused_local_variable, avoid_print, prefer_const_constructors_in_immutables, use_key_in_widget_constructors, sized_box_for_whitespace
 import 'package:flutter/material.dart';
+
 import 'game.dart';
 
 // #docregion Tile

examples/fwe/birdle/lib/step1_main.dart

@@ -1,5 +1,5 @@
-// ignore_for_file: unused_import, unused_field, unused_local_variable, avoid_print, prefer_const_constructors_in_immutables, use_key_in_widget_constructors, sized_box_for_whitespace
 import 'package:flutter/material.dart';
+
 import 'game.dart';
 
 // #docregion Tile