Avoid allocating empty arrays

CA1825: Avoid zero-length array allocations
https://docs.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca1825

Author: decriptor

src/TaglibSharp.Tests/Images/AddImageMetadataTests.cs

@@ -108,7 +108,7 @@ public static void AddXMPTest2 (string sample_file, string tmp_file, bool contai
 			xmp_tag.Comment = null;
 			xmp_tag.Software = test_comment;
 
-			Assert.AreEqual (new string[] { }, xmp_tag.Keywords);
+			Assert.AreEqual (Array.Empty<string> (), xmp_tag.Keywords);
 			Assert.AreEqual (null, xmp_tag.Comment);
 			Assert.AreEqual (test_comment, xmp_tag.Software);
 
@@ -119,7 +119,7 @@ public static void AddXMPTest2 (string sample_file, string tmp_file, bool contai
 			xmp_tag = file.GetTag (TagTypes.XMP, false) as XmpTag;
 			Assert.IsNotNull (xmp_tag, "XMP Tag not read");
 
-			Assert.AreEqual (new string[] { }, xmp_tag.Keywords);
+			Assert.AreEqual (Array.Empty<string> (), xmp_tag.Keywords);
 			Assert.AreEqual (null, xmp_tag.Comment);
 			Assert.AreEqual (test_comment, xmp_tag.Software);
 		}

src/TaglibSharp.Tests/Images/CopyFromTest.cs

@@ -21,8 +21,8 @@ public void TestJPGtoTIFF ()
 			Assert.AreEqual (TagTypes.TiffIFD | TagTypes.XMP, file2.TagTypes);
 			Assert.AreEqual ("%test comment%", file1.ImageTag.Comment);
 			Assert.AreEqual (string.Empty, file2.ImageTag.Comment);
-			Assert.AreEqual (new string[] { }, file1.ImageTag.Keywords);
-			Assert.AreEqual (new string[] { }, file2.ImageTag.Keywords);
+			Assert.AreEqual (Array.Empty<string> (), file1.ImageTag.Keywords);
+			Assert.AreEqual (Array.Empty<string> (), file2.ImageTag.Keywords);
 			Assert.AreEqual (null, file1.ImageTag.Rating);
 			Assert.AreEqual (0, file2.ImageTag.Rating);
 			Assert.AreEqual (new DateTime (2009, 8, 9, 19, 12, 44), (DateTime)file1.ImageTag.DateTime);
@@ -62,8 +62,8 @@ public void TestJPGtoTIFF ()
 			Assert.AreEqual (TagTypes.TiffIFD | TagTypes.XMP, file2.TagTypes);
 			Assert.AreEqual ("%test comment%", file1.ImageTag.Comment);
 			Assert.AreEqual ("%test comment%", file2.ImageTag.Comment);
-			Assert.AreEqual (new string[] { }, file1.ImageTag.Keywords);
-			Assert.AreEqual (new string[] { }, file2.ImageTag.Keywords);
+			Assert.AreEqual (Array.Empty<string> (), file1.ImageTag.Keywords);
+			Assert.AreEqual (Array.Empty<string> (), file2.ImageTag.Keywords);
 			Assert.AreEqual (null, file1.ImageTag.Rating);
 			Assert.AreEqual (null, file2.ImageTag.Rating);
 			Assert.AreEqual (new DateTime (2009, 8, 9, 19, 12, 44), (DateTime)file1.ImageTag.DateTime);

src/TaglibSharp.Tests/Images/GifExiftoolLongCommentTest.cs

@@ -1,3 +1,5 @@
+using System;
+
 using NUnit.Framework;
 using TagLib;
 using TaglibSharp.Tests.Images.Validators;
@@ -20,7 +22,7 @@ public void Test ()
 				true,
 				new GifExiftoolLongCommentTestInvariantValidator (),
 				NoModificationValidator.Instance,
-				new TagKeywordsModificationValidator (new string[] { }, TagTypes.XMP, true),
+				new TagKeywordsModificationValidator (Array.Empty<string> (), TagTypes.XMP, true),
 				new CommentModificationValidator (long_comment_orig),
 				new CommentModificationValidator (long_comment_orig, long_comment_test),
 				new TagCommentModificationValidator (long_comment_orig, TagTypes.GifComment, true),

src/TaglibSharp.Tests/Images/GifExiftoolTangled3Test.cs

@@ -1,3 +1,5 @@
+using System;
+
 using NUnit.Framework;
 using TagLib;
 using TaglibSharp.Tests.Images.Validators;
@@ -19,7 +21,7 @@ public void Test ()
 				true,
 				new GifExiftoolTangled3TestInvariantValidator (),
 				NoModificationValidator.Instance,
-				new TagKeywordsModificationValidator (new string[] { }, TagTypes.XMP, false),
+				new TagKeywordsModificationValidator (Array.Empty<string> (), TagTypes.XMP, false),
 				new CommentModificationValidator ("Created with GIMP"),
 				new TagCommentModificationValidator ("Created with GIMP", TagTypes.GifComment, true),
 				new RemoveMetadataValidator (TagTypes.GifComment)

src/TaglibSharp.Tests/Images/ImageTagTests.cs

@@ -1,3 +1,5 @@
+using System;
+
 using NUnit.Framework;
 using TagLib;
 using TagLib.Image;
@@ -20,7 +22,7 @@ public void TestXMPImageTag ()
 			Assert.IsNotNull (tag);
 
 			Assert.AreEqual (null, tag.Comment, "Comment");
-			Assert.AreEqual (new string[] { }, tag.Keywords, "Keywords");
+			Assert.AreEqual (Array.Empty<string> (), tag.Keywords, "Keywords");
 			Assert.AreEqual (0, tag.Rating, "Rating");
 			Assert.AreEqual (null, tag.DateTime, "DateTime");
 			Assert.AreEqual (ImageOrientation.None, tag.Orientation, "Orientation");

src/TaglibSharp.Tests/Images/JpegNikon1Bibble5Test.cs

@@ -1,3 +1,5 @@
+using System;
+
 using NUnit.Framework;
 using TagLib;
 using TagLib.IFD;
@@ -20,7 +22,7 @@ public void Test ()
 				new CommentModificationValidator (string.Empty),
 				new TagCommentModificationValidator (null, TagTypes.TiffIFD, true),
 				new TagCommentModificationValidator (null, TagTypes.XMP, true),
-				new TagKeywordsModificationValidator (new string[] { }, TagTypes.XMP, true)
+				new TagKeywordsModificationValidator (Array.Empty<string> (), TagTypes.XMP, true)
 			);
 		}
 	}

src/TaglibSharp.Tests/Images/JpegNikon2Bibble5Test.cs

@@ -1,3 +1,5 @@
+using System;
+
 using NUnit.Framework;
 using TagLib;
 using TagLib.IFD;
@@ -20,7 +22,7 @@ public void Test ()
 				new CommentModificationValidator (string.Empty),
 				new TagCommentModificationValidator (null, TagTypes.TiffIFD, true),
 				new TagCommentModificationValidator (null, TagTypes.XMP, true),
-				new TagKeywordsModificationValidator (new string[] { }, TagTypes.XMP, true)
+				new TagKeywordsModificationValidator (Array.Empty<string> (), TagTypes.XMP, true)
 			);
 		}
 	}

src/TaglibSharp.Tests/Images/JpegOlympus2Test.cs

@@ -165,7 +165,7 @@ public void CheckXMP (File file)
 
 			Assert.IsNotNull (tag, "tag");
 
-			Assert.AreEqual (new string[] { }, tag.Keywords);
+			Assert.AreEqual (Array.Empty<string> (), tag.Keywords);
 			Assert.AreEqual ("OLYMPUS CORPORATION", tag.Make);
 			Assert.AreEqual ("C5060WZ", tag.Model);
 			Assert.AreEqual ("Adobe Photoshop Elements 4.0", tag.Software);

src/TaglibSharp.Tests/Images/PefPentaxKd10Test.cs

@@ -30,7 +30,7 @@ public void ValidateMetadataInvariants (TagLib.Image.File file)
 			var imagetag = file.ImageTag;
 			Assert.IsNotNull (imagetag);
 			Assert.AreEqual (String.Empty, imagetag.Comment, "Comment");
-			Assert.AreEqual (new string[] { }, imagetag.Keywords, "Keywords");
+			Assert.AreEqual (Array.Empty<string> (), imagetag.Keywords, "Keywords");
 			Assert.AreEqual (null, imagetag.Rating, "Rating");
 			Assert.AreEqual (TagLib.Image.ImageOrientation.LeftBottom, imagetag.Orientation, "Orientation");
 			Assert.AreEqual ("K10D Ver 1.31          ", imagetag.Software, "Software");

src/TaglibSharp.Tests/Images/RawLeicaDigilux2Test.cs

@@ -26,7 +26,7 @@ public void ValidateMetadataInvariants (TagLib.Image.File file)
 			var imagetag = file.ImageTag;
 			Assert.IsNotNull (imagetag);
 			Assert.AreEqual (String.Empty, imagetag.Comment, "Comment");
-			Assert.AreEqual (new string[] { }, imagetag.Keywords, "Keywords");
+			Assert.AreEqual (Array.Empty<string> (), imagetag.Keywords, "Keywords");
 			Assert.AreEqual (null, imagetag.Rating, "Rating");
 			Assert.AreEqual (TagLib.Image.ImageOrientation.TopLeft, imagetag.Orientation, "Orientation");
 			Assert.AreEqual (null, imagetag.Software, "Software");