fixed issue #35: Agency_id is required if multiple agencies in agency…

….txt

GTFS.Test/GTFS.Test.csproj

@@ -80,6 +80,7 @@
     <Compile Include="GTFSFeedTests.cs" />
     <Compile Include="FileNotDisposedTest.cs" />
     <Compile Include="ParseFeedTests.cs" />
+    <Compile Include="ParseAgenciesTests.cs" />
     <Compile Include="ParseRoutesTests.cs" />
     <Compile Include="ParseEntitiesTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
@@ -183,6 +184,26 @@
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </None>
   </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="other-feed\agency_with_id.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </EmbeddedResource>
+  </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="other-feed\agency_no_id.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </EmbeddedResource>
+  </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="other-feed\agencies_no_id.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </EmbeddedResource>
+  </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="other-feed\agencies_with_id.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </EmbeddedResource>
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.

GTFS.Test/ParseAgenciesTests.cs

@@ -0,0 +1,141 @@
+// The MIT License (MIT)
+
+// Copyright (c) 2014 Ben Abelshausen
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using GTFS.IO;
+using GTFS.IO.CSV;
+using NUnit.Framework;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using GTFS.Exceptions;
+
+namespace GTFS.Test
+{
+    /// <summary>
+    /// Contains additional parsing tests for agencies.
+    /// </summary>
+    [TestFixture]
+    public class ParseAgenciesTests
+    {
+        private static Assembly _executingAssembly;
+
+        /// <summary>
+        /// Setup the test environment.
+        /// </summary>
+        [OneTimeSetUp]
+        public static void Setup()
+        {
+            _executingAssembly = Assembly.GetExecutingAssembly();
+        }
+
+        /// <summary>
+        /// Tests parsing single agency without agency_id.
+        /// </summary>
+        [Test]
+        public void ParseSingleAgencyWithoutAgencyId()
+        {
+            var reader = new GTFSReader<GTFSFeed>();
+            var source = new List<IGTFSSourceFile>
+            {
+                new GTFSSourceFileStream(_executingAssembly.GetManifestResourceStream("GTFS.Test.other_feed.agency_no_id.txt"),"agency")
+            };
+
+
+            var feed = reader.Read(source, source.First(x => x.Name.Equals("agency")));
+
+
+            var agencies = feed.Agencies;
+            Assert.IsNotNull(agencies);
+
+            var agency = agencies.SingleOrDefault();
+            Assert.IsNotNull(agency);
+            Assert.IsNull(agency.Id);
+        }
+
+        /// <summary>
+        /// Tests parsing single agency with agency_id.
+        /// </summary>
+        [Test]
+        public void ParseSingleAgencyWithAgencyId()
+        {
+            var reader = new GTFSReader<GTFSFeed>();
+            var source = new List<IGTFSSourceFile>
+            {
+                new GTFSSourceFileStream(_executingAssembly.GetManifestResourceStream("GTFS.Test.other_feed.agency_with_id.txt"),"agency")
+            };
+
+
+            var feed = reader.Read(source, source.First(x => x.Name.Equals("agency")));
+
+
+            var agencies = feed.Agencies;
+            Assert.IsNotNull(agencies);
+
+            var agency = agencies.SingleOrDefault();
+            Assert.IsNotNull(agency);
+            Assert.IsNotNull(agency.Id);
+        }
+
+        /// <summary>
+        /// Tests parsing multiple agencies with agency_id.
+        /// </summary>
+        [Test]
+        public void ParseAgenciesWithAgencyId()
+        {
+            var reader = new GTFSReader<GTFSFeed>();
+            var source = new List<IGTFSSourceFile>
+            {
+                new GTFSSourceFileStream(_executingAssembly.GetManifestResourceStream("GTFS.Test.other_feed.agencies_with_id.txt"),"agency")
+            };
+
+
+            var feed = reader.Read(source, source.First(x => x.Name.Equals("agency")));
+
+
+            var agencies = feed.Agencies;
+            Assert.IsNotNull(agencies);
+            Assert.IsNotNull(agencies.SingleOrDefault(x => x.Id == "DTA"));
+            Assert.IsNotNull(agencies.SingleOrDefault(x => x.Id == "OTA"));
+        }
+
+        /// <summary>
+        /// Tests parsing multiple agencies with agency_id.
+        /// </summary>
+        [Test]
+        public void ParseAgenciesWithoutAgencyId()
+        {
+            const string Agency = "agency";
+            var reader = new GTFSReader<GTFSFeed>();
+            var source = new List<IGTFSSourceFile>
+            {
+                new GTFSSourceFileStream(_executingAssembly.GetManifestResourceStream("GTFS.Test.other_feed.agencies_no_id.txt"),Agency)
+            };
+
+
+            Assert.Throws<GTFSRequiredFieldMissingException>(() =>
+            {
+                reader.Read(source, source.First(x => x.Name.Equals(Agency)));
+            },
+            GTFSRequiredFieldMissingException.MessageFormat, "agency_id", Agency);
+        }
+    }
+}

GTFS.Test/other-feed/agencies_no_id.txt

@@ -0,0 +1,3 @@
+agency_name,agency_url,agency_timezone
+Demo Transit Authority,http://google.com,America/Los_Angeles
+Other Transit Authority,http://somewhere.com,Europe/Brussels

GTFS.Test/other-feed/agencies_with_id.txt

@@ -0,0 +1,3 @@
+agency_id,agency_name,agency_url,agency_timezone
+DTA,Demo Transit Authority,http://google.com,America/Los_Angeles
+OTA,Other Transit Authority,http://somewhere.com,Europe/Brussels

GTFS.Test/other-feed/agency_no_id.txt

@@ -0,0 +1,2 @@
+agency_name,agency_url,agency_timezone
+Demo Transit Authority,http://google.com,America/Los_Angeles

GTFS.Test/other-feed/agency_with_id.txt

@@ -0,0 +1,2 @@
+agency_id,agency_name,agency_url,agency_timezone
+DTA,Demo Transit Authority,http://google.com,America/Los_Angeles

GTFS/Exceptions/GTFSRequiredFieldMissingException.cs

@@ -27,13 +27,18 @@ namespace GTFS.Exceptions
     /// </summary>
     public class GTFSRequiredFieldMissingException : GTFSExceptionBase
     {
+        /// <summary>
+        /// Message format used for formatting the exception.
+        /// </summary>
+        public static readonly string MessageFormat = "Required field {0} not found in {1}.";
+
         /// <summary>
         /// Creates a new field missing exception.
         /// </summary>
         /// <param name="name"></param>
         /// <param name="fieldName"></param>
         public GTFSRequiredFieldMissingException(string name, string fieldName)
-            : base(string.Format("Required field {0} not found in {1}.", fieldName, name))
+            : base(string.Format(MessageFormat, fieldName, name))
         {
             this.Name = name;
             this.FieldName = fieldName;

GTFS/GTFSReader.cs

@@ -508,6 +508,12 @@ protected virtual Agency ParseAgency(T feed, GTFSSourceFileHeader header, string
             this.CheckRequiredField(header, header.Name, this.AgencyMap, "agency_url");
             this.CheckRequiredField(header, header.Name, this.AgencyMap, "agency_timezone");
 
+            // if we already have another agency, then the agency_id is required
+            if (feed.Agencies.Any())
+            {
+                CheckRequiredField(header, header.Name, AgencyMap, "agency_id");
+            }
+
             // parse/set all fields.
             Agency agency = new Agency();
             for(int idx = 0; idx < data.Length; idx++)