Add a unit test for reading document information

src/UglyToad.PdfPig.Tests/Integration/DocumentInformationTests.cs

@@ -0,0 +1,38 @@
+namespace UglyToad.PdfPig.Tests.Integration
+{
+    using System;
+    using PdfPig.Tokens;
+    using Xunit;
+
+    public class DocumentInformationTests
+    {
+        [Fact]
+        public void CanReadDocumentInformation()
+        {
+            var path = IntegrationHelpers.GetSpecificTestDocumentPath("custom-properties.pdf");
+
+            using (var document = PdfDocument.Open(path))
+            {
+                var information = document.Information;
+
+                Assert.Equal("Writer", information.Creator);
+                Assert.Equal("MoreKeywords", information.Keywords);
+                Assert.Equal("LibreOffice 6.1", information.Producer);
+                Assert.Equal("TestSubject", information.Subject);
+                Assert.Equal("TestTitle", information.Title);
+
+                var infoDictionary = information.DocumentInformationDictionary;
+
+                var nameToken = NameToken.Create("CustomProperty1");
+                Assert.True(infoDictionary.TryGet(nameToken, out var valueToken), "first custom property must be present");
+                Assert.IsType<StringToken>(valueToken);
+                Assert.Equal("Property Value", ((StringToken)valueToken).Data);
+
+                nameToken = NameToken.Create("CustomProperty2");
+                Assert.True(infoDictionary.TryGet(nameToken, out var valueToken2), "second custom property must be present");
+                Assert.IsType<StringToken>(valueToken2);
+                Assert.Equal("Another Property Value", ((StringToken)valueToken2).Data);
+            }
+        }
+    }
+}