[learn_dart] Create Stream: async*

notes/learn_dart/test/dart_lang!sdk!io/process.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-for i in {1..3} ; do echo $i;sleep 1; done;
+for i in {1..3} ; do echo "Hong文的最此打算"$i;sleep 1; done;

notes/learn_dart/test/dart_lang!sdk!io/process.dart → notes/learn_dart/test/dart_lang!sdk!io/process_test.dart

@@ -5,7 +5,7 @@ import 'dart:io';
 import 'package:path/path.dart' as path;
 
 main() async {
-  var cmd = path.join(path.current, "test/dart_lang!sdk!io/process.sh");
+  var cmd = path.join(path.current, "test/dart_lang!sdk!io/process.sh1");
   await runProcess(cmd, []);
 }
 
@@ -14,19 +14,26 @@ Future<void> runProcess(
   List<String> args, {
   String? cwd,
 }) async {
-  print('\n$command ${args.join(' ')}');
+  print('\n cmd:$command args:${args.join(' ')}');
 
-  var process = await Process.start(command, args, workingDirectory: cwd);
+  var process = await Process.start(command, args, workingDirectory: cwd,runInShell: true);
 
-  process.stdout.transform(utf8.decoder).transform(LineSplitter()).listen((line) {
-    print('  $line');
-  });
-  process.stderr.transform(utf8.decoder).transform(LineSplitter()).listen((line) {
-    print('  $line');
-  });
+  printStream(process.stdout);
+  printStream(process.stderr);
 
   var exitCode = await process.exitCode;
   if (exitCode != 0) {
     throw '$command exited with $exitCode';
   }
 }
+Future<void> printStream(Stream<List<int>> stream) async {
+  var s = stream.transform(utf8.decoder).transform(LineSplitter());
+  await for (final line in s) {
+    print('  $line');
+  }
+
+  // stream.transform(utf8.decoder).transform(LineSplitter()).listen((line) {
+  //   print('  $line');
+  // });
+
+}

notes/learn_dart/test/dart_lang!sdk!io/stream_test.dart

@@ -0,0 +1,22 @@
+// ignore_for_file: avoid_print
+
+import 'package:checks/checks.dart';
+import 'package:test/test.dart';
+
+
+main() async {
+  group('Create Stream: async*', () {
+    test('create', () async {
+      Stream<int> range(int to) async* {
+        for (int i = 1; i <= to; i++) {
+          yield i;
+        }
+      }
+      List<int> collect = [];
+      await for (int i in range(3)) {
+        collect.add(i);
+      }
+      check(collect).deepEquals([1, 2, 3]);
+    });
+  });
+}