[tests] Add deployment test for .dll files of the same size. (#5229)

Context: xamarin/monodroid#1123

There seems to be a bug in the new fast deployment system
where if the `.dll` was modified BUT had exactly the same size
as the existing `.dll` on the device it would not be uploaded.

This commit adds a test to make sure this does work as
expected.

Author: dellis1972

tests/MSBuildDeviceIntegration/Tests/InstallTests.cs

@@ -478,23 +478,25 @@ public void IncrementalFastDeployment ()
 			AssertCommercialBuild ();
 			AssertHasDevices ();
 
+			var class1src = new BuildItem.Source ("Class1.cs") {
+				TextContent = () => "namespace Library1 { public class Class1 { public static int foo = 0; } }"
+			};
 			var lib1 = new XamarinAndroidLibraryProject () {
 				ProjectName = "Library1",
 				Sources = {
-					new BuildItem.Source ("Class1.cs") {
-						TextContent = () => "namespace Library1 { public class Class1 { } }"
-					},
+					class1src,
 				}
 			};
 
+			var class2src = new BuildItem.Source ("Class2.cs") {
+				TextContent = () => "namespace Library2 { public class Class2 { public static int foo = 0; } }"
+			};
 			var lib2 = new DotNetStandard {
 				ProjectName = "Library2",
 				Sdk = "Microsoft.NET.Sdk",
 				TargetFramework = "netstandard2.0",
 				Sources = {
-					new BuildItem.Source ("Class2.cs") {
-						TextContent = () => "namespace Library2 { public class Class2 { } }"
-					},
+					class2src,
 				}
 			};
 
@@ -513,15 +515,22 @@ public void IncrementalFastDeployment ()
 			using (var lb2 = CreateDllBuilder (Path.Combine (rootPath, lib2.ProjectName)))
 				Assert.IsTrue (lb2.Build (lib2), "Second library build should have succeeded.");
 
+			long lib1FirstBuildSize = new FileInfo (Path.Combine (rootPath, lib1.ProjectName, lib1.OutputPath, "Library1.dll")).Length;
+
 			using (var builder = CreateApkBuilder (Path.Combine (rootPath, app.ProjectName))) {
 				builder.ThrowOnBuildFailure = false;
+				builder.BuildLogFile = "install.log";
 				Assert.IsTrue (builder.Install (app), "First install should have succeeded.");
+				var logLines = builder.LastBuildOutput;
+				Assert.IsTrue (logLines.Any (l => l.Contains ("NotifySync CopyFile") && l.Contains ("UnnamedProject.dll")), "UnnamedProject.dll should have been uploaded");
+				Assert.IsTrue (logLines.Any (l => l.Contains ("NotifySync CopyFile") && l.Contains ("Library1.dll")), "Library1.dll should have been uploaded");
+				Assert.IsTrue (logLines.Any (l => l.Contains ("NotifySync CopyFile") && l.Contains ("Library2.dll")), "Library2.dll should have been uploaded");
 				var firstInstallTime = builder.LastBuildTime;
+				builder.BuildLogFile = "install2.log";
 				Assert.IsTrue (builder.Install (app, doNotCleanupOnUpdate: true, saveProject: false), "Second install should have succeeded.");
 				var secondInstallTime = builder.LastBuildTime;
 
 				var filesToTouch = new [] {
-					Path.Combine (rootPath, lib1.ProjectName, "Class1.cs"),
 					Path.Combine (rootPath, lib2.ProjectName, "Class2.cs"),
 					Path.Combine (rootPath, app.ProjectName, "MainPage.xaml"),
 				};
@@ -530,8 +539,22 @@ public void IncrementalFastDeployment ()
 					File.SetLastWriteTimeUtc (file, DateTime.UtcNow);
 				}
 
+				class1src.TextContent = () => "namespace Library1 { public class Class1 { public static int foo = 100; } }";
+				class1src.Timestamp = DateTime.UtcNow.AddSeconds(1);
+				using (var lb1 = CreateDllBuilder (Path.Combine (rootPath, lib1.ProjectName)))
+					Assert.IsTrue (lb1.Build (lib1), "Second library build should have succeeded.");
+
+				long lib1SecondBuildSize = new FileInfo (Path.Combine (rootPath, lib1.ProjectName, lib1.OutputPath, "Library1.dll")).Length;
+				Assert.AreEqual (lib1FirstBuildSize, lib1SecondBuildSize, "Library2.dll was not the same size.");
+
+				builder.BuildLogFile = "install3.log";
 				Assert.IsTrue (builder.Install (app, doNotCleanupOnUpdate: true, saveProject: false), "Third install should have succeeded.");
+				logLines = builder.LastBuildOutput;
+				Assert.IsTrue (logLines.Any (l => l.Contains ("NotifySync CopyFile") && l.Contains ("UnnamedProject.dll")), "UnnamedProject.dll should have been uploaded");
+				Assert.IsTrue (logLines.Any (l => l.Contains ("NotifySync CopyFile") && l.Contains ("Library1.dll")), "Library1.dll should have been uploaded");
+				Assert.IsTrue (logLines.Any (l => l.Contains ("NotifySync SkipCopyFile") && l.Contains ("Library2.dll")), "Library2.dll should not have been uploaded");
 				var thirdInstallTime = builder.LastBuildTime;
+				builder.BuildLogFile = "install4.log";
 				Assert.IsTrue (builder.Install (app, doNotCleanupOnUpdate: true, saveProject: false), "Fourth install should have succeeded.");
 				var fourthInstalTime = builder.LastBuildTime;