Add data-URI support class to dart:core (next to Uri).

tests/lib/uri/data_uri_test.dart

+// Copyright (c) 2015, 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:uri";
+import "package:expect/expect.dart";
+import "dart:convert";
+import "dart:typed_data";
+
+main() {
+  testMediaType();
+
+  testRoundTrip("");
+  testRoundTrip("a");
+  testRoundTrip("ab");
+  testRoundTrip("abc");
+  testRoundTrip("abcd");
+  testRoundTrip("Content with special%25 characters: # ? = % # ? = %");
+  testRoundTrip("blåbærgrød", UTF8);
+  testRoundTrip("blåbærgrød", LATIN1);
+
+  testUtf8Encoding("\u1000\uffff");
+  testBytes();
+  testInvalidCharacters();
+  testErrors();
+}
+
+void testMediaType() {
+  for (var mimeType in ["", "text/plain", "text/javascript"]) {
+    for (var charset in ["", ";charset=US-ASCII", ";charset=UTF-8"]) {
+      for (var base64 in ["", ";base64"]) {
+        bool isBase64 = base64.isNotEmpty;
+        var text = "data:$mimeType$charset$base64,";
+        var uri = DataUriHelper.parse(text);
+
+        String expectedCharset =
+            charset.isEmpty ? "US-ASCII" : charset.substring(9);
+        String expectedMimeType =
+            mimeType.isEmpty ? "text/plain" : mimeType;
+
+        Expect.equals(text, "$uri");
+        Expect.equals(expectedMimeType, uri.mimeType);
+        Expect.equals(expectedCharset, uri.charset);
+        Expect.equals(isBase64, uri.isBase64);
+      }
+    }
+  }
+}
+
+void testRoundTrip(String content, [Encoding encoding]) {
+  DataUriHelper dataUri =
+      new DataUriHelper.fromString(content, encoding: encoding);
+  Expect.isFalse(dataUri.isBase64);
+
+  if (encoding != null) {
+    DataUriHelper dataUriParams = new DataUriHelper.fromString(
+        content, parameters: {"charset" : encoding.name});
+    Expect.equals("$dataUri", "$dataUriParams");
+  }
+
+  Expect.equals(encoding ?? ASCII, Encoding.getByName(dataUri.charset));
+
+  Expect.equals(content, dataUri.contentAsString(encoding: encoding));
+  Expect.equals(content, dataUri.contentAsString());
+  Expect.equals(content, (encoding ?? ASCII).decode(dataUri.contentAsBytes()));
+
+  Uri uri = dataUri.toUri();
+  Expect.equals(uri.toString(), dataUri.toString());
+  Expect.equals(dataUri.toString(), new DataUriHelper.fromUri(uri).toString());
+
+  dataUri = new DataUriHelper.fromBytes(content.codeUnits);
+  Expect.listEquals(content.codeUnits, dataUri.contentAsBytes());
+  Expect.equals(content, dataUri.contentAsString(encoding: LATIN1));
+
+  uri = dataUri.toUri();
+  Expect.equals(uri.toString(), dataUri.toString());
+  Expect.equals(dataUri.toString(), new DataUriHelper.fromUri(uri).toString());
+  // Check that the URI is properly normalized.
+  expectUriEquals(uri, Uri.parse("$uri"));
+}
+
+void testUtf8Encoding(String content) {
+  DataUriHelper uri = new DataUriHelper.fromString(content, encoding: UTF8);
+  Expect.equals(content, uri.contentAsString(encoding: UTF8));
+  Expect.listEquals(UTF8.encode(content), uri.contentAsBytes());
+}
+
+void testInvalidCharacters() {
+  // SPACE, CTL and tspecial, plus '%' and '#' (URI gen-delim)
+  // This contains all ASCII character that are not valid in attribute/value
+  // parts.
+  var invalid =
+    '\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x7f'
+    ' ()<>@,;:"/[]?=%#\x80\u{1000}\u{10000}';
+  var invalidNoSlash = invalid.replaceAll('/', '');
+  var dataUri = new DataUriHelper.fromString(
+      invalid,
+      encoding: UTF8,
+      mimeType: "$invalidNoSlash/$invalidNoSlash",
+      parameters: {invalid: invalid});
+
+  Expect.equals(invalid, dataUri.contentAsString());
+  Expect.equals("$invalidNoSlash/$invalidNoSlash", dataUri.mimeType);
+  Expect.equals(invalid, dataUri.parameters[invalid]);
+
+  var uri = dataUri.toUri();
+  Expect.equals("$uri", "$dataUri");
+  expectUriEquals(uri, Uri.parse("$uri"));  // Check that it's canonicalized.
+  Expect.equals("$dataUri", new DataUriHelper.fromUri(uri).toString());
+}
+
+void testBytes() {
+  void testList(List<int> list) {
+    var dataUri = new DataUriHelper.fromBytes(list);
+    Expect.equals("application/octet-stream", dataUri.mimeType);
+    Expect.isTrue(dataUri.isBase64);
+    Expect.listEquals(list, dataUri.contentAsBytes());
+
+    dataUri = new DataUriHelper.fromBytes(list, percentEncoded: true);
+    Expect.equals("application/octet-stream", dataUri.mimeType);
+    Expect.isFalse(dataUri.isBase64);
+    Expect.listEquals(list, dataUri.contentAsBytes());
+
+    var string = new String.fromCharCodes(list);
+
+    dataUri = new DataUriHelper.fromString(string, encoding: LATIN1);
+    Expect.equals("text/plain", dataUri.mimeType);
+    Expect.isFalse(dataUri.isBase64);
+    Expect.listEquals(list, dataUri.contentAsBytes());
+
+    dataUri =
+        new DataUriHelper.fromString(string, encoding: LATIN1, base64: true);
+    Expect.equals("text/plain", dataUri.mimeType);
+    Expect.isTrue(dataUri.isBase64);
+    Expect.listEquals(list, dataUri.contentAsBytes());
+  }
+
+  void testLists(List<int> list) {
+    testList(list);
+    for (int i = 0; i < 27; i++) {
+      testList(list.sublist(i, i + i));  // All lengths from 0 to 27.
+    }
+  }
+
+  var bytes = new Uint8List(512);
+  for (int i = 0; i < bytes.length; i++) {
+    bytes[i] = i;
+  }
+  testLists(bytes);
+  testLists(new List.from(bytes));
+  testLists(new List.unmodifiable(bytes));
+}
+
+bool badArgument(e) => e is ArgumentError;
+bool badFormat(e) => e is FormatException;
+
+void testErrors() {
+  // Invalid constructor parameters.
+  Expect.throws(() { new DataUriHelper.fromBytes([], mimeType: "noslash"); },
+                badArgument);
+  Expect.throws(() { new DataUriHelper.fromBytes([257]); },
+                badArgument);
+  Expect.throws(() { new DataUriHelper.fromBytes([-1]); },
+                badArgument);
+  Expect.throws(() { new DataUriHelper.fromBytes([0x100000000]); },
+                badArgument);
+  Expect.throws(() { new DataUriHelper.fromString("", mimeType: "noslash"); },
+                badArgument);
+
+  // Empty parameters allowed, not an error.
+  var uri = new DataUriHelper.fromString("", mimeType: "", parameters: {});
+  Expect.equals("data:,", "$uri");
+  // Empty parameter key or value is an error.
+  Expect.throws(() =>  new DataUriHelper.fromString("", parameters: {"": "X"}),
+                badArgument);
+  Expect.throws(() =>  new DataUriHelper.fromString("", parameters: {"X": ""}),
+                badArgument);
+
+  // Not recognizing charset is an error.
+  uri = DataUriHelper.parse("data:;charset=arglebargle,X");
+  Expect.throws(() {
+    uri.contentAsString();
+  });
+  // Doesn't throw if we specify the encoding.
+  Expect.equals("X", uri.contentAsString(encoding: ASCII));
+
+  // Parse format.
+  Expect.throws(() { DataUriHelper.parse("notdata:,");}, badFormat);
+  Expect.throws(() { DataUriHelper.parse("text/plain,noscheme");}, badFormat);
+  Expect.throws(() { DataUriHelper.parse("data:noseparator");}, badFormat);
+  Expect.throws(() { DataUriHelper.parse("data:noslash,text");}, badFormat);
+  Expect.throws(() { DataUriHelper.parse("data:type/sub;noequals,text");},
+                badFormat);
+  Expect.throws(() { DataUriHelper.parse("data:type/sub;knocomma=");},
+                badFormat);
+  Expect.throws(() { DataUriHelper.parse("data:type/sub;k=v;nocomma");},
+                badFormat);
+  Expect.throws(() { DataUriHelper.parse("data:type/sub;k=nocomma");},
+                badFormat);
+  Expect.throws(() { DataUriHelper.parse("data:type/sub;k=v;base64");},
+                badFormat);
+
+  // Invalid base64 format (only detected when decodeing).
+  for (var a = 0; a <= 4; a++) {
+    for (var p = 0; p <= 4; p++) {
+      // Base-64 encoding must have length divisible by four and no more
+      // than two padding characters at the end.
+      if (p < 3 && (a + p) % 4 == 0) continue;
+      uri = DataUriHelper.parse("data:;base64," + "A" * a + "=" * p);
+      Expect.throws(uri.contentAsBytes, badFormat);
+    }
+  }
+  // Invalid base64 encoding: padding not at end.
+  uri = DataUriHelper.parse("data:;base64,AA=A");
+  Expect.throws(uri.contentAsBytes, badFormat);
+  uri = DataUriHelper.parse("data:;base64,A=AA");
+  Expect.throws(uri.contentAsBytes, badFormat);
+  uri = DataUriHelper.parse("data:;base64,=AAA");
+  Expect.throws(uri.contentAsBytes, badFormat);
+  uri = DataUriHelper.parse("data:;base64,A==A");
+  Expect.throws(uri.contentAsBytes, badFormat);
+  uri = DataUriHelper.parse("data:;base64,==AA");
+  Expect.throws(uri.contentAsBytes, badFormat);
+  uri = DataUriHelper.parse("data:;base64,===A");
+  Expect.throws(uri.contentAsBytes, badFormat);
+}
+
+/// Checks that two [Uri]s are exactly the same.
+expectUriEquals(Uri expect, Uri actual) {
+  Expect.equals(expect.scheme, actual.scheme, "scheme");
+  Expect.equals(expect.hasAuthority, actual.hasAuthority, "hasAuthority");
+  Expect.equals(expect.userInfo, actual.userInfo, "userInfo");
+  Expect.equals(expect.host, actual.host, "host");
+  Expect.equals(expect.hasPort, actual.hasPort, "hasPort");
+  Expect.equals(expect.port, actual.port, "port");
+  Expect.equals(expect.port, actual.port, "port");
+  Expect.equals(expect.hasQuery, actual.hasQuery, "hasQuery");
+  Expect.equals(expect.query, actual.query, "query");
+  Expect.equals(expect.hasFragment, actual.hasFragment, "hasFragment");
+  Expect.equals(expect.fragment, actual.fragment, "fragment");
+}