add tests for array token

src/UglyToad.PdfPig.Tests/Tokenization/Tokens/ArrayTokenTests.cs

@@ -0,0 +1,54 @@
+namespace UglyToad.PdfPig.Tests.Tokenization.Tokens
+{
+    using System;
+    using PdfPig.Tokenization.Tokens;
+    using Xunit;
+
+    public class ArrayTokenTests
+    {
+        [Fact]
+        public void SetsData()
+        {
+            var token = new ArrayToken(new[]
+            {
+                OperatorToken.StartStream,
+                OperatorToken.EndStream
+            });
+
+            Assert.Equal(2, token.Data.Count);
+
+            Assert.Equal(OperatorToken.StartStream, token.Data[0]);
+            Assert.Equal(OperatorToken.EndStream, token.Data[1]);
+        }
+
+        [Fact]
+        public void SetsDataEmpty()
+        {
+            var token = new ArrayToken(new IToken[0]);
+
+            Assert.Empty(token.Data);
+        }
+
+        [Fact]
+        public void SetsDataNullThrows()
+        {
+            // ReSharper disable once ObjectCreationAsStatement
+            Action action = () => new ArrayToken(null);
+
+            Assert.Throws<ArgumentNullException>(action);
+        }
+
+        [Fact]
+        public void ToStringCorrect()
+        {
+            var token = new ArrayToken(new IToken[]
+            {
+                new StringToken("hedgehog"),
+                new NumericToken(7),
+                OperatorToken.StartObject
+            });
+
+            Assert.Equal("[ (hedgehog), 7, obj ]", token.ToString());
+        }
+    }
+}

src/UglyToad.PdfPig/Tokenization/Tokens/ArrayToken.cs

@@ -1,5 +1,6 @@
 namespace UglyToad.PdfPig.Tokenization.Tokens
 {
+    using System;
     using System.Collections.Generic;
     using System.Text;
 
@@ -9,16 +10,25 @@
 
         public ArrayToken(IReadOnlyList<IToken> data)
         {
-            Data = data;
+            Data = data ?? throw new ArgumentNullException(nameof(data));
         }
 
         public override string ToString()
         {
             var builder = new StringBuilder("[ ");
 
-            foreach (var token in Data)
+            for (var i = 0; i < Data.Count; i++)
             {
-                builder.Append(token).Append(' ');
+                var token = Data[i];
+
+                builder.Append(token);
+
+                if (i < Data.Count - 1)
+                {
+                    builder.Append(',');
+                }
+
+                builder.Append(' ');
             }
 
             builder.Append(']');

src/UglyToad.PdfPig/Tokenization/Tokens/StringToken.cs

@@ -11,7 +11,7 @@ namespace UglyToad.PdfPig.Tokenization.Tokens
 
         public override string ToString()
         {
-            return $"\"{Data}\"";
+            return $"({Data})";
         }
     }
 }