Add pretty-printing to unittest and more thoroughly print values.

pkg/unittest/test/pretty_print_test.dart

Index: pkg/unittest/test/pretty_print_test.dart
diff --git a/pkg/unittest/test/pretty_print_test.dart b/pkg/unittest/test/pretty_print_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..8000585ab0795985b6d85e1bf689a2badfda9103
--- /dev/null
+++ b/pkg/unittest/test/pretty_print_test.dart
@@ -0,0 +1,221 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:collection';
+
+import 'package:unittest/src/pretty_print.dart';
+import 'package:unittest/unittest.dart';
+
+class DefaultToString {}
+
+class CustomToString {
+  String toString() => "string representation";
+}
+
+class _PrivateName {
+  String toString() => "string representation";
+}
+
+class _PrivateNameIterable extends IterableMixin {
+  Iterator get iterator => [1, 2, 3].iterator;
+}
+
+void main() {
+  test('with primitive objects', () {
+    expect(prettyPrint(12), equals('<12>'));
+    expect(prettyPrint(12.13), equals('<12.13>'));
+    expect(prettyPrint(true), equals('<true>'));
+    expect(prettyPrint(null), equals('<null>'));
+    expect(prettyPrint(() => 12), equals('<Closure: (dynamic) => dynamic>'));
+  });
+
+  test('with an object with a default [toString]', () {
+    expect(prettyPrint(new DefaultToString()),
+        equals("<Instance of 'DefaultToString'>"));
+  });
+
+  test('with an object with a custom [toString]', () {
+    expect(prettyPrint(new CustomToString()),
+        equals('CustomToString:<string representation>'));
+  });
+
+  test('with an object with a custom [toString] and a private name', () {
+    expect(prettyPrint(new _PrivateName()),
+        equals('Unknown:<string representation>'));
+  });
+
+  group('with a string', () {
+    test('containing simple characters', () {
+      expect(prettyPrint('foo'), equals("'foo'"));
+    });
+
+    test('containing newlines', () {
+      expect(prettyPrint('foo\nbar\nbaz'), equals(
+          "'foo\\n'\n"
+          "  'bar\\n'\n"
+          "  'baz'"));
+    });
+
+    test('containing escapable characters', () {
+      expect(prettyPrint("foo\rbar\tbaz'qux"),
+          equals("'foo\\rbar\\tbaz\\'qux'"));
+    });
+  });
+
+  group('with an iterable', () {
+    test('containing primitive objects', () {
+      expect(prettyPrint([1, true, 'foo']), equals("[1, true, 'foo']"));
+    });
+
+    test('containing a multiline string', () {
+      expect(prettyPrint(['foo', 'bar\nbaz\nbip', 'qux']), equals("[\n"
+          "  'foo',\n"
+          "  'bar\\n'\n"
+          "    'baz\\n'\n"
+          "    'bip',\n"
+          "  'qux'\n"
+          "]"));
+    });
+
+    test("that's under maxLineLength", () {
+      expect(prettyPrint([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], maxLineLength: 30),
+          equals("[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]"));
+    });
+
+    test("that's over maxLineLength", () {
+      expect(prettyPrint([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], maxLineLength: 29),
+          equals("[\n"
+              "  0,\n"
+              "  1,\n"
+              "  2,\n"
+              "  3,\n"
+              "  4,\n"
+              "  5,\n"
+              "  6,\n"
+              "  7,\n"
+              "  8,\n"
+              "  9\n"
+              "]"));
+    });
+
+    test("factors indentation into maxLineLength", () {
+      expect(prettyPrint([
+        "foo\nbar",
+        [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
+      ], maxLineLength: 30), equals("[\n"
+          "  'foo\\n'\n"
+          "    'bar',\n"
+          "  [\n"
+          "    0,\n"
+          "    1,\n"
+          "    2,\n"
+          "    3,\n"
+          "    4,\n"
+          "    5,\n"
+          "    6,\n"
+          "    7,\n"
+          "    8,\n"
+          "    9\n"
+          "  ]\n"
+          "]"));
+    });
+
+    test("that's under maxItems", () {
+      expect(prettyPrint([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], maxItems: 10),
+          equals("[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]"));
+    });
+
+    test("that's over maxItems", () {
+      expect(prettyPrint([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], maxItems: 9),
+          equals("[0, 1, 2, 3, 4, 5, 6, 7, ...]"));
+    });
+
+    test("that's not a list", () {
+      expect(prettyPrint([1, 2, 3, 4].map((n) => n * 2)),
+          equals("MappedListIterable:[2, 4, 6, 8]"));
+    });
+
+    test("that's not a list and has a private name", () {
+      expect(prettyPrint(new _PrivateNameIterable()),
+          equals("Unknown:[1, 2, 3]"));
+    });
+
+    test("that's recursive", () {
+      var list = [1, 2, 3];
+      list.add(list);
+      expect(prettyPrint(list), equals("[1, 2, 3, (recursive)]"));
+    });
+  });
+
+  group("with a map", () {
+    test('containing primitive objects', () {
+      expect(prettyPrint({'foo': 1, 'bar': true}),
+          equals("{'foo': 1, 'bar': true}"));
+    });
+
+    test('containing a multiline string key', () {
+      expect(prettyPrint({'foo\nbar': 1, 'bar': true}), equals("{\n"
+          "  'foo\\n'\n"
+          "    'bar': 1,\n"
+          "  'bar': true\n"
+          "}"));
+    });
+
+    test('containing a multiline string value', () {
+      expect(prettyPrint({'foo': 'bar\nbaz', 'qux': true}), equals("{\n"
+          "  'foo': 'bar\\n'\n"
+          "    'baz',\n"
+          "  'qux': true\n"
+          "}"));
+    });
+
+    test('containing a multiline string key/value pair', () {
+      expect(prettyPrint({'foo\nbar': 'baz\nqux'}), equals("{\n"
+          "  'foo\\n'\n"
+          "    'bar': 'baz\\n'\n"
+          "    'qux'\n"
+          "}"));
+    });
+
+    test("that's under maxLineLength", () {
+      expect(prettyPrint({'0': 1, '2': 3, '4': 5, '6': 7}, maxLineLength: 32),
+          equals("{'0': 1, '2': 3, '4': 5, '6': 7}"));
+    });
+
+    test("that's over maxLineLength", () {
+      expect(prettyPrint({'0': 1, '2': 3, '4': 5, '6': 7}, maxLineLength: 31),
+          equals("{\n"
+              "  '0': 1,\n"
+              "  '2': 3,\n"
+              "  '4': 5,\n"
+              "  '6': 7\n"
+              "}"));
+    });
+
+    test("factors indentation into maxLineLength", () {
+      expect(prettyPrint(["foo\nbar", {'0': 1, '2': 3, '4': 5, '6': 7}],
+              maxLineLength: 32),
+          equals("[\n"
+              "  'foo\\n'\n"
+              "    'bar',\n"
+              "  {\n"
+              "    '0': 1,\n"
+              "    '2': 3,\n"
+              "    '4': 5,\n"
+              "    '6': 7\n"
+              "  }\n"
+              "]"));
+    });
+
+    test("that's under maxItems", () {
+      expect(prettyPrint({'0': 1, '2': 3, '4': 5, '6': 7}, maxItems: 4),
+          equals("{'0': 1, '2': 3, '4': 5, '6': 7}"));
+    });
+
+    test("that's over maxItems", () {
+      expect(prettyPrint({'0': 1, '2': 3, '4': 5, '6': 7}, maxItems: 3),
+          equals("{'0': 1, '2': 3, ...}"));
+    });
+  });
+}