Add an AuthenticationChallenge class.

test/authentication_challenge_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 'package:http_parser/http_parser.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group("parse", () {
+    _singleChallengeTests(
+        (challenge) => new AuthenticationChallenge.parse(challenge));
+  });
+
+  group("parseHeader", () {
+    group("with a single challenge", () {
+      _singleChallengeTests((challenge) {
+        var challenges = AuthenticationChallenge.parseHeader(challenge);
+        expect(challenges, hasLength(1));
+        return challenges.single;
+      });
+    });
+
+    test("parses multiple challenges", () {
+      var challenges = AuthenticationChallenge.parseHeader(
+          "scheme1 realm=fblthp, scheme2 realm=asdfg");
+      expect(challenges, hasLength(2));
+      expect(challenges.first.scheme, equals("scheme1"));
+      expect(challenges.first.parameters, equals({"realm": "fblthp"}));
+      expect(challenges.last.scheme, equals("scheme2"));
+      expect(challenges.last.parameters, equals({"realm": "asdfg"}));
+    });
+
+    test("parses multiple challenges with multiple parameters", () {
+      var challenges = AuthenticationChallenge.parseHeader(
+          "scheme1 realm=fblthp, foo=bar, scheme2 realm=asdfg, baz=bang");
+      expect(challenges, hasLength(2));
+
+      expect(challenges.first.scheme, equals("scheme1"));
+      expect(challenges.first.parameters, equals({
+        "realm": "fblthp",
+        "foo": "bar"
+      }));
+
+      expect(challenges.last.scheme, equals("scheme2"));
+      expect(challenges.last.parameters, equals({
+        "realm": "asdfg",
+        "baz": "bang"
+      }));
+    });
+  });
+}
+
+/// Tests to run for parsing a single challenge.
+///
+/// These are run on both [AuthenticationChallenge.parse] and
+/// [AuthenticationChallenge.parseHeader], since they use almost entirely
+/// separate code paths.
+void _singleChallengeTests(
+    AuthenticationChallenge parseChallenge(String challenge)) {
+  test("parses a simple challenge", () {
+    var challenge = parseChallenge("scheme realm=fblthp");
+    expect(challenge.scheme, equals("scheme"));
+    expect(challenge.parameters, equals({"realm": "fblthp"}));
+  });
+
+  test("parses multiple parameters", () {
+    var challenge = parseChallenge("scheme realm=fblthp, foo=bar, baz=qux");
+    expect(challenge.scheme, equals("scheme"));
+    expect(challenge.parameters, equals({
+      "realm": "fblthp",
+      "foo": "bar",
+      "baz": "qux"
+    }));
+  });
+
+  test("parses quoted string parameters", () {
+    var challenge = parseChallenge('scheme realm="fblthp, foo=bar", baz="qux"');
+    expect(challenge.scheme, equals("scheme"));
+    expect(challenge.parameters, equals({
+      "realm": "fblthp, foo=bar",
+      "baz": "qux"
+    }));
+  });
+
+  test("normalizes the case of the scheme", () {
+    var challenge = parseChallenge("ScHeMe realm=fblthp");
+    expect(challenge.scheme, equals("scheme"));
+    expect(challenge.parameters, equals({"realm": "fblthp"}));
+  });
+
+  test("normalizes the case of the parameter name", () {
+    var challenge = parseChallenge("scheme ReAlM=fblthp");
+    expect(challenge.scheme, equals("scheme"));
+    expect(challenge.parameters, containsPair("realm", "fblthp"));
+  });

[Bob Nystrom, 2015/08/25 21:28:59]

Test that it doesn't normalize the parameter value.

[nweiz, 2015/08/25 22:02:08]

Done.

+
+  test("allows extra whitespace", () {
+    var challenge = parseChallenge(
+        "  scheme\t \trealm\t = \tfblthp\t, \tfoo\t\r\n =\tbar\t");
+    expect(challenge.scheme, equals("scheme"));
+    expect(challenge.parameters, equals({
+      "realm": "fblthp",
+      "foo": "bar"
+    }));
+  });
+
+  test("allows an empty parameter", () {
+    var challenge = parseChallenge(
+        "scheme realm=fblthp, , foo=bar");
+    expect(challenge.scheme, equals("scheme"));
+    expect(challenge.parameters, equals({
+      "realm": "fblthp",
+      "foo": "bar"
+    }));
+  });

[Bob Nystrom, 2015/08/25 21:28:59]

What about a trailing comma?

[nweiz, 2015/08/25 22:02:08]

Done.

+
+  test("disallows only a scheme", () {
+    expect(() => parseChallenge("scheme"),
+        throwsFormatException);
+  });
+
+  test("disallows a valueless parameter", () {
+    expect(() => parseChallenge("scheme realm"),
+        throwsFormatException);
+    expect(() => parseChallenge("scheme realm="),
+        throwsFormatException);
+    expect(() => parseChallenge("scheme realm, foo=bar"),
+        throwsFormatException);
+  });
+
+  test("requires a space after the scheme", () {
+    expect(() => parseChallenge("scheme\trealm"),
+        throwsFormatException);
+    expect(() => parseChallenge("scheme\r\n\trealm="),
+        throwsFormatException);
+  });
+
+  test("disallows junk after the parameters", () {
+    expect(() => parseChallenge("scheme realm=fblthp foo"),
+        throwsFormatException);
+    expect(() => parseChallenge("scheme realm=fblthp, foo=bar baz"),
+        throwsFormatException);
+  });
+}