Adding test for pretty_printer

Author: smotastic

test/printers/pretty_printer_test.dart

@@ -0,0 +1,98 @@
+import 'package:logger/logger.dart';
+import 'package:test/test.dart';
+
+void main() {
+  String _readMessage(List<String> log) {
+    return log.reduce((acc, val) => acc + val);
+  }
+
+  final prettyPrinter = PrettyPrinter(printEmojis: false);
+  test('should print an emoji when option is enabled', () {
+    final expectedMessage = 'some message with an emoji';
+    final emojiPrettyPrinter = PrettyPrinter(printEmojis: true);
+
+    final event = LogEvent(
+      Level.debug,
+      expectedMessage,
+      'some error',
+      StackTrace.current,
+    );
+
+    final actualLog = emojiPrettyPrinter.log(event);
+    final actualLogString = _readMessage(actualLog);
+    expect(actualLogString, contains(PrettyPrinter.levelEmojis[Level.debug]));
+    expect(actualLogString, contains(expectedMessage));
+  });
+
+  test('deal with string type message', () {
+    final expectedMessage = 'normally computed message';
+    final withFunction = LogEvent(
+      Level.debug,
+      expectedMessage,
+      'some error',
+      StackTrace.current,
+    );
+
+    final actualLog = prettyPrinter.log(withFunction);
+    final actualLogString = _readMessage(actualLog);
+
+    expect(
+      actualLogString,
+      contains(expectedMessage),
+    );
+  });
+  test('deal with Map type message', () {
+    final expectedMsgMap = {'foo': 123, 1: 2, true: 'false'};
+    var withMap = LogEvent(
+      Level.debug,
+      expectedMsgMap,
+      'some error',
+      StackTrace.current,
+    );
+
+    final actualLog = prettyPrinter.log(withMap);
+    final actualLogString = _readMessage(actualLog);
+    for (var expectedMsg in expectedMsgMap.entries) {
+      expect(
+        actualLogString,
+        contains('${expectedMsg.key}: ${expectedMsg.value}'),
+      );
+    }
+  });
+
+  test('deal with Iterable type message', () {
+    final expectedMsgItems = ['first', 'second', 'third', 'last'];
+    var withIterable = LogEvent(
+      Level.debug,
+      ['first', 'second', 'third', 'last'],
+      'some error',
+      StackTrace.current,
+    );
+    final actualLog = prettyPrinter.log(withIterable);
+    final actualLogString = _readMessage(actualLog);
+    for (var expectedMsg in expectedMsgItems) {
+      expect(
+        actualLogString,
+        contains(expectedMsg),
+      );
+    }
+  });
+
+  test('deal with Function type message', () {
+    final expectedMessage = 'heavily computed very pretty Message';
+    final withFunction = LogEvent(
+      Level.debug,
+      () => expectedMessage,
+      'some error',
+      StackTrace.current,
+    );
+
+    final actualLog = prettyPrinter.log(withFunction);
+    final actualLogString = _readMessage(actualLog);
+
+    expect(
+      actualLogString,
+      contains(expectedMessage),
+    );
+  });
+}