The code

add
{
    System.Delegate.Combine(value, _OnTemperatureChange);
}

does not modify _OnTemperatureChange field, therefore has no effect.

Return value should be handled:

add
{
    _OnTemperatureChange = System.Delegate.Combine(value, _OnTemperatureChange);
}

Occasionally, listing 9.18 fails with an System.UnauthorizedAccessException. The exception occurs on the last line of the following snippet:

string fileName = @"enumtest.txt";
FileInfo file = new FileInfo(fileName);
file.Open(FileMode.OpenOrCreate).Dispose();

It isn't clear what is different between when it succeeds and doesn't succeed making it exceptionally problematic to figure out.

Below is the error output from the test:

Test Name:	Main_FileAttributes_UseFlagsAttribute 
Test FullName:	Chapter09.Tests.AddisonWesley.Michaelis.EssentialCSharp.Chapter09.Listing09_18.Tests.ProgramTests.Main_FileAttributes_UseFlagsAttribute
Test Source:	C:\Data\EssentialCSharp\YogaX1\1\SCC\src\Chapter09.Tests\Listing09.18.UsingFlagsAttribute.cs : line 11
Test Outcome:	Failed
Test Duration:	0:00:00

Test Name:	Main_FileAttributes_UseFlagsAttribute
Test Outcome:	Failed
Result StackTrace:	
at System.IO.FileStream.ValidateFileHandle(SafeFileHandle fileHandle)
   at System.IO.FileStream.CreateFileOpenHandle(FileMode mode, FileShare share, FileOptions options)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share)
   at System.IO.FileInfo.Open(FileMode mode)
   at AddisonWesley.Michaelis.EssentialCSharp.Chapter09.Listing09_18.Program.Main() in C:\Data\EssentialCSharp\YogaX1\1\SCC\src\Chapter09\Listing09.18.UsingFlagsAttribute.cs:line 13
   at IntelliTect.TestTools.Console.ConsoleAssert.Execute(String givenInput, Action action)
   at IntelliTect.TestTools.Console.ConsoleAssert.Execute(String givenInput, String expectedOutput, Action action, Func`3 areEquivalentOperator, Boolean normalizeLineEndings, String equivalentOperatorErrorMessage)
   at IntelliTect.TestTools.Console.ConsoleAssert.Expect(String expected, Action action, Func`3 comparisonOperator, Boolean normalizeLineEndings, String equivalentOperatorErrorMessage)
   at IntelliTect.TestTools.Console.ConsoleAssert.Expect(String expected, Action action, Boolean normalizeLineEndings)
   at AddisonWesley.Michaelis.EssentialCSharp.Chapter09.Listing09_18.Tests.ProgramTests.Main_FileAttributes_UseFlagsAttribute() in C:\Data\EssentialCSharp\YogaX1\1\SCC\src\Chapter09.Tests\Listing09.18.UsingFlagsAttribute.cs:line 19
Result Message:	
Test method AddisonWesley.Michaelis.EssentialCSharp.Chapter09.Listing09_18.Tests.ProgramTests.Main_FileAttributes_UseFlagsAttribute threw exception: 
System.UnauthorizedAccessException: Access to the path 'C:\Data\EssentialCSharp\YogaX1\1\SCC\src\Chapter09.Tests\bin\Debug\netcoreapp3.0\enumtest.txt' is denied.
``

Thanks to @jaspet, we are compiling and executing the tests on Linux (and almost on Mac), I doubt there are any issues but it would be great if we could run the .NET Portability Analyzer against the entire code base and see what shows up.

Ideally, this task would include adding execution of this analyzer to the build.

In readme it says

Batch Testing
Use one of the following scripts to execute a batch test on all the projects.

/EssentialCSharp/RunTests.ps1 (Windows)
/EssentialCSharp/RunTests.sh (Linux/Mac)
If running on Linux you may need to give the script execution permission. From the /EssentialCSharp/ directory:

$ chmod +x ./RunTests.sh
$ ./RunTests.sh

should we just say run
dotnet test in the essentialCSharp directory on your computer instead?

DirectoryCountLines(subdirectory) called the DirectoryCountLines(string directory),this method will counting lines with ".cs" extension,but if i called DirectoryCountLines(string directory, string extension) ,it's mean i want to counting lines with the string "extension" rather than "*.cs"

Listing 9.16 uses a FileAttributes.Hidden enum which doesn't work on Linux. Update the sample to work on Linux.

Proposals on what change to make are welcome.

Unfortunately, Listing 20.20 only works on Windows. It would be great to have the equivalent code on Linux and Mac.

I have marked it as "High Priority" in the hopes that we can have an implementation before we publish the book so that I still have time to modify the text.

If you take this on, create an issue for the platform you are implementing and modify this issue to refer to the remaining one.

Hello,

In Essential C# 6.0, page 321 : "... programmers can override one or more of the three virtual methods. Chapter 9...."

It seems, there is four virtual methods for Object, like in table 6.2.

Have a nice day.

It appears that some CSPROJ files are getting detected as binary files so they fail to work with git diff. All files should be changed to text files - preferably without adding a CSPROJ extension attribute.

Once conversion to C# 8 nullable is complete, remove the #nullable declarative from Program.cs

P.75 "The result is that the number variable is available from both the true and false consequence of the if statement but not outside the if statement."

In fact, the variable is still in scope outside of the if block.

            // double number;
            string input;
            System.Console.Write("Enter a number: ");
            input = System.Console.ReadLine();
            if (double.TryParse(input, out double number))
            {
                System.Console.WriteLine($"input was parsed successfully to {number}.");
            }
            else
            {
                // Note: number scope is here too (although not assigned)
                System.Console.WriteLine("The text entered was not a valid number.");
            }

            System.Console.Write($"the value of number is {number}.");

How do I modify the statement of the text?

Here is my screenshot.

After downloading the source code zip from github (not using a clone), the project fails to build with the following error:
C:\Program Files\dotnet\sdk\2.1.202\NuGet.targets(239,5): error MSB3202: not found project file“C:\Users\...\Documents\EC\submodules\TestTools\IntelliTect.TestTools.Console\IntelliTect.TestTools.Console.csproj”。 [C:\Users\...\Documents\EC\EssentialCSharp.sln]

Hi,

At page 121, there's the following statement:

if ((hourOfTheDay > 23) || (hourOfTheDay < 0))

[...]
Note that the parentheses are not necessary here; the logical operators are of higher precedence than the relational operators

Actually logical operators have a lower precedence than relational operators, because otherwise hourOfTheDay > 23 || hourOfTheDay < 0 would be equivalent to hourOfTheDay > (23 || hourOfTheDay) < 0, which obviously results in a compile error.

• Create all pipelines for all branches between devops and github for coverage
• Create github actions for v8.0 and v9.0
• Schedule builds as well as on push/PRs
• Check collectors and report generators
• update readme status badges

When running Shared\Program.cs from any project (the launcher that calls each source file, the invocation doesn't wait for an async method to complete.

Line Shared\Program.cs (93) checks for an STAThreadAttribute but neglects to check for the System.Runtime.CompilerServices.AsyncStateMachineAttribute. When this attribute exists, the InvokeMethodUsingReflection() method needs to wait for the result (handling Task, Task<T>, ValueTask<T>, and IAsyncEnumerable<T> returns. See line 67

We are missing quite a few tests and it would be great to get the remainder in place. Rather than one person take this issue, please create a new issue titled something like "Tests missing in Chapter X' and then assign it to yourself so we know which chapters are being investigated.

If there are chapters where there are no missing tests, please still create the issue but mark it as done. :)

In addition, remove listings:
Listing02.01-2.06.SpecifyingLiteralValues.cs
Listing02.08-2.10.ComparingStringsEscapeSequencesAndUnicode.cs

Listing 19.17: AsyncVoidReturnTest failed.

Test Name:	AsyncVoidReturnTest
Test FullName:	AddisonWesley.Michaelis.EssentialCSharp.Chapter19.Listing19_17.Tests.ProgramTests.AsyncVoidReturnTest
Test Source:	C:\Dropbox\EssentialCSharp\1\SCC\src\Chapter19.Tests\Listing19.17.Tests.cs : line 21
Test Outcome:	Failed
Test Duration:	0:00:00.2601871

Result StackTrace:	
at IntelliTect.TestTools.Console.ConsoleAssert.AssertExpectation(String expectedOutput, String output, Func`3 areEquivalentOperator) in C:\Dropbox\EssentialCSharp\1\SCC\submodules\TestTools\IntelliTect.TestTools.Console\ConsoleAssert.cs:line 164
   at IntelliTect.TestTools.Console.ConsoleAssert.Execute(String givenInput, String expectedOutput, Action action, Func`3 areEquivalentOperator, Boolean replaceCRLF) in C:\Dropbox\EssentialCSharp\1\SCC\submodules\TestTools\IntelliTect.TestTools.Console\ConsoleAssert.cs:line 148
   at IntelliTect.TestTools.Console.ConsoleAssert.Expect(String expected, Action action, Func`3 comparisonOperator, Boolean replaceCRLF) in C:\Dropbox\EssentialCSharp\1\SCC\submodules\TestTools\IntelliTect.TestTools.Console\ConsoleAssert.cs:line 77
   at IntelliTect.TestTools.Console.ConsoleAssert.ExpectLike(String expected, Action action) in C:\Dropbox\EssentialCSharp\1\SCC\submodules\TestTools\IntelliTect.TestTools.Console\ConsoleAssert.cs:line 94
   at AddisonWesley.Michaelis.EssentialCSharp.Chapter19.Listing19_17.Tests.ProgramTests.AsyncVoidReturnTest() in C:\Dropbox\EssentialCSharp\1\SCC\src\Chapter19.Tests\Listing19.17.Tests.cs:line 31
Result Message:	
Test method AddisonWesley.Michaelis.EssentialCSharp.Chapter19.Listing19_17.Tests.ProgramTests.AsyncVoidReturnTest threw exception: 
System.Exception: expected: 4241
actual: 5541
NOTE: The expected string contains wildcard charaters: [,],?,*,#
AreEqual failed:

Expected:
-----------------------------------
Invoking Task.Run...(Thread ID: *)
Running task... (Thread ID: *)
Post notification invoked...(Thread ID: *)
Post notification invoked...(Thread ID: *)
Throwing expected exception....(Thread ID: *)
System.Exception: Expected Exception
   *(Thread ID: *)
-----------------------------------
Actual: 
-----------------------------------
Invoking Task.Run...(Thread ID: 7)
Running task... (Thread ID: 8)
Post notification invoked...(Thread ID: 7)
Throwing expected exception....(Thread ID: 7)
System.Exception: Expected Exception
   at AddisonWesley.Michaelis.EssentialCSharp.Chapter19.Listing19_17.Program.<>c.<OnEvent>b__6_0() in C:\Dropbox\EssentialCSharp\1\SCC\src\Chapter19\Listing19.17.AsyncVoidReturn.cs:line 94
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at AddisonWesley.Michaelis.EssentialCSharp.Chapter19.Listing19_17.Program.<OnEvent>d__6.MoveNext() in C:\Dropbox\EssentialCSharp\1\SCC\src\Chapter19\Listing19.17.AsyncVoidReturn.cs:line 90
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at AddisonWesley.Michaelis.EssentialCSharp.Chapter19.Listing19_17.AsyncSynchronizationContext.Post(SendOrPostCallback callback, Object state) in C:\Dropbox\EssentialCSharp\1\SCC\src\Chapter19\Listing19.17.AsyncVoidReturn.cs:line 36
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at AddisonWesley.Michaelis.EssentialCSharp.Chapter19.Listing19_17.Program.Main() in C:\Dropbox\EssentialCSharp\1\SCC\src\Chapter19\Listing19.17.AsyncVoidReturn.cs:line 75 thrown as expected.(Thread ID: 7)
-----------------------------------
The expected length of 259 does not match the output length of 1821.

(Page numbers are obtained from the kindle edition.)

Page 467:
"One important characteristic of the argument exception types (including ArgumentNullException, ArgumentNullException, and ArgumentOutOfRangeException) is that..."

The issue is that "ArgumentNullException" is listed twice.

Page 472:
"With the ExeptionDispatchInfo.Throw() method..."

The class "ExceptionDispatchInfo" is missing a c. It is spelled correctly many times earlier in the chapter.

Page 473:
"C# requires that any object that code throws must derive from System.Exception. However, this requirement is not universal to all languages. C and C++, for example, allow any object type to be thrown, including managed exceptions that don’t derive from System.Exception."

Although C++ supports exception handling and throwing, C has no standardized support or special syntax for either of them. The closest things to exception throwing in C that I can think of are setting function pointers, jumping, and dealing with errno.

Just for reference since I finally got one of the Linux builds to fail again on devops and this is to save the logs since they disappear after 10 days.

Build:
https://intellitect.visualstudio.com/EssentialCSharp/_build/results?buildId=12706&view=results

Log Files:
LinuxBuildLogs.zip

It seems that in the conversion we lost code analysis. It would be great to get this back up and running but it is not the highest priority by any means.

After running a build from the command line ('dotnet build'), if you try run 'dotnet test' it reports errors because it tries to run tests against the non-test assemblies (the ones being tested).

page 93: The assignment syntax shown in Listing 3.6 is available only if you declare and assign the value within one statement.
should be Listing 3.7

Although 'dotnet.exe build' works correctly, it appears that running 'msbuild.exe' fails to build the project. Ideally, this should work (or at least we should understand why it doesn't). :)

It seems, that both book site and this code support only previous edition of the book.
Also, not sure it is the right place, but some supplemental on Span and Memory would be nice.

Once TestTools.ConsoleAssert appropriately normalizes \r\n, remove the following line from the AddisonWesley.Michaelis.EssentialCSharp.Chapter16.Listing16_14.Tests.ProgramTests.SelectingAnonymousTypeFollowingGroupClause method:

expected = IntelliTect.TestTools.Console.ConsoleAssert.ReplaceCRLF(expected);

NOTE: Make the change in v7.0, merge to master, and then merge to v8.0.

page xxvi: The formatting is as follows. • Comments are shown in italics.
This is not true.

Create unit tests for Listing 18.15B (to become 18.16) and add a Main() method that calls the Compress/Uncompress methods (given a file name for args.).

In 2018 off a chapter split from 18, chapter 19 code got moved, but is off by .02 and also needs to be updated to match the book for v08 since it is out of date.

Write about the above and put it here: IntelliTect.com/AsyncUsing.

If time allows, add it to Chapter 19.

Somewhere in the conversion, each listing was changed so that:

• the listing files used ChapterMain rather than Main
• Referenced a new project Called SharedCode rather than just linking to the necessary files in the Shared folder when required

At the time this was done (during project.json), I suspect it wasnt possible to have two static Mainmethods and be able to disambiguate which ones to use as the entry point via theStartupObject` property element. Going forward, this is not a satisfactory solution, however.

I would like to request a restructuring as follows:

• - Remove the reference to the "SharedCode" project
• - Delete the SharedCode project
• - Add "linked" files that point to the Program.cs file in the Shared directory
• - Add "liked" files that point to the other files in the Shared directory as needed (i.e. PI Calculator in the threading listings.
• - Add the following to CSProj tiles to disambiguate which Main to use in startup.
  <PropertyGroup> <StartupObject>AddisonWesley.Michaelis.EssentialCSharp.Shared.Program</StartupObject> </PropertyGroup>
• - Rename all ChapterMain methods to Main (consider doing this via a mass search and replace.
• - Verify dotnet build and dotnet test work from the command line
• - Verify dotnet test works from the command line.
• - Verify build/test works from VS2017
• - If a mass/automated search and replace is performed, please verify that all files stay recognizable to Git as UTF8 files.

It is acceptable if this is done one project at a time rather than with a PowerShell/batch file just as long as it is clearly recorded which projects are done and which need work.

Thoughts? Questions? Volunteers? :)