pkg/matcher: cleanup, updates, deprecations, fixes

pkg/matcher/lib/src/pretty_print.dart

 // 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.
 
 library matcher.pretty_print;
 
 import 'description.dart';
 import 'interfaces.dart';
-import 'utils.dart';
 
-/**
- * Returns a pretty-printed representation of [object].
- *
- * If [maxLineLength] is passed, this will attempt to ensure that each line is
- * no longer than [maxLineLength] characters long. This isn't guaranteed, since
- * individual objects may have string representations that are too long, but
- * most lines will be less than [maxLineLength] long.
- *
- * If [maxItems] is passed, [Iterable]s and [Map]s will only print their first
- * [maxItems] members or key/value pairs, respectively.
- */
+/// Returns a pretty-printed representation of [object].
+///
+/// If [maxLineLength] is passed, this will attempt to ensure that each line is
+/// no longer than [maxLineLength] characters long. This isn't guaranteed, since
+/// individual objects may have string representations that are too long, but
+/// most lines will be less than [maxLineLength] long.
+///
+/// If [maxItems] is passed, [Iterable]s and [Map]s will only print their first
+/// [maxItems] members or key/value pairs, respectively.
 String prettyPrint(object, {int maxLineLength, int maxItems}) {
   String _prettyPrint(object, int indent, Set seen, bool top) {
     // If the object is a matcher, use its description.
     if (object is Matcher) {
       var description = new StringDescription();
       object.describe(description);
       return "<$description>";
     }
 
     // Avoid looping infinitely on recursively-nested data structures.
     if (seen.contains(object)) return "(recursive)";
     seen = seen.union(new Set.from([object]));
     String pp(child) => _prettyPrint(child, indent + 2, seen, false);
 
     if (object is Iterable) {
       // Print the type name for non-List iterables.
-      var type = object is List ? "" : typeName(object) + ":";
+      var type = object is List ? "" : _typeName(object) + ":";
 
       // Truncate the list of strings if it's longer than [maxItems].
       var strings = object.map(pp).toList();
       if (maxItems != null && strings.length > maxItems) {
         strings.replaceRange(maxItems - 1, strings.length, ['...']);
       }
 
       // If the printed string is short and doesn't contain a newline, print it
       // as a single line.
       var singleLine = "$type[${strings.join(', ')}]";
@@ skipping 27 matching lines @@
         return singleLine;
       }
 
       // Otherwise, print each key/value pair on its own line.
       return "{\n" + strings.map((string) {
         return _indent(indent + 2) + string;
       }).join(",\n") + "\n" + _indent(indent) + "}";
     } else if (object is String) {
       // Escape strings and print each line on its own line.
       var lines = object.split("\n");
-      return "'" + lines.map(escapeString)
+      return "'" + lines.map(_escapeString)
           .join("\\n'\n${_indent(indent + 2)}'") + "'";
     } else {
       var value = object.toString().replaceAll("\n", _indent(indent) + "\n");
       var defaultToString = value.startsWith("Instance of ");
 
       // If this is the top-level call to [prettyPrint], wrap the value on angle
       // brackets to set it apart visually.
       if (top) value = "<$value>";
 
       // Print the type of objects with custom [toString] methods. Primitive
       // objects and objects that don't implement a custom [toString] don't need
       // to have their types printed.
       if (object is num || object is bool || object is Function ||
           object == null || defaultToString) {
         return value;
       } else {
-        return "${typeName(object)}:$value";
+        return "${_typeName(object)}:$value";
       }
     }
   }
 
   return _prettyPrint(object, 0, new Set(), true);
 }
 
 String _indent(int length) => new List.filled(length, ' ').join('');
+
+/// Returns the name of the type of [x], or "Unknown" if the type name can't be
+/// determined.
+String _typeName(x) {
+  // dart2js blows up on some objects (e.g. window.navigator).
+  // So we play safe here.
+  try {
+    if (x == null) return "null";
+    var type = x.runtimeType.toString();
+    // TODO(nweiz): if the object's type is private, find a public superclass to
+    // display once there's a portable API to do that.
+    return type.startsWith("_") ? "?" : type;
+  } catch (e) {
+    return "?";
+  }
+}
+
+/// Returns [source] with any control characters replaced by their escape
+/// sequences.
+///
+/// This doesn't add quotes to the string, but it does escape single quote
+/// characters so that single quotes can be applied externally.
+String _escapeString(String source) =>
+  source.split("").map(_escapeChar).join("");
+
+/// Return the escaped form of a character [ch].
+String _escapeChar(String ch) {
+  if (ch == "'")
+    return "\\'";
+  else if (ch == '\n')
+    return '\\n';
+  else if (ch == '\r')
+    return '\\r';
+  else if (ch == '\t')
+    return '\\t';
+  else
+    return ch;
+}
+