Avoid elm-test-rs command failing on many environments

Remove the dependency on the additional setup of the environment before running `elm-test-rs`: Remove the dependency on node.

For discussion around this functionality, see:

+ mpizenberg/elm-test-rs#37
+ mpizenberg/elm-test-rs#92

Author: Viir

implement/elm-fullstack/ElmTestRs.cs

@@ -1,6 +1,8 @@
-using Pine;
+using Mono.Unix;
+using Pine;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
 
@@ -29,11 +31,25 @@ public class ElmTestRs
             ("98708c4ecd1a34b61545f0faca7ac3c46b5bb3d0bf6b4719b16eb4cffe0a82ac",
             @"https://github.com/mpizenberg/elm-test-rs/releases/download/v1.2.2/elm-test-rs_windows.zip"));
 
-    static public byte[] LoadElmTestRsExecutableFileForCurrentOs()
+    static public IReadOnlyDictionary<OSPlatform, (string hash, string remoteSource)> DenoExecutableFileByOs =
+        ImmutableDictionary<OSPlatform, (string hash, string remoteSource)>.Empty
+        .Add(
+            OSPlatform.Linux,
+            ("34374d77515b093028df6605b6e74985aa6cd7a022c5e8310a14d65daecbd91d",
+            @"https://github.com/denoland/deno/releases/download/v1.16.2/deno-x86_64-unknown-linux-gnu.zip"))
+        .Add(
+            OSPlatform.Windows,
+            ("3a1611329306d24b24fd6b98418ddec9ee79c044623e712093db24eba6a573df",
+            @"https://github.com/denoland/deno/releases/download/v1.16.2/deno-x86_64-pc-windows-msvc.zip"));
+
+    static public byte[] ElmTestRsExecutableFileForCurrentOs() => LoadFileForCurrentOs(ElmTestRsExecutableFileByOs);
+
+    static public byte[] DenoExecutableFileForCurrentOs() => LoadFileForCurrentOs(DenoExecutableFileByOs);
+
+    static public byte[] LoadFileForCurrentOs(IReadOnlyDictionary<OSPlatform, (string hash, string remoteSource)> dict)
     {
         var hashAndRemoteSource =
-            ElmTestRsExecutableFileByOs
-            .FirstOrDefault(c => RuntimeInformation.IsOSPlatform(c.Key)).Value;
+            dict.FirstOrDefault(c => RuntimeInformation.IsOSPlatform(c.Key)).Value;
 
         if (hashAndRemoteSource.hash == null)
             throw new System.Exception("Unknown OS: " + RuntimeInformation.OSDescription);
@@ -48,22 +64,61 @@ static public byte[] LoadElmTestRsExecutableFileForCurrentOs()
     static public (string stdout, string stderr, IReadOnlyList<(string rawLine, ElmTestRsReportJsonEntry parsedLine)> stdoutLines) Run(
         IImmutableDictionary<IImmutableList<string>, IReadOnlyList<byte>> elmProjectFiles)
     {
-        var elmTestExecutableFile = LoadElmTestRsExecutableFileForCurrentOs();
+        var elmTestExecutableFile = ElmTestRsExecutableFileForCurrentOs();
 
         var elmExecutableFileName = "elm.exe";
 
+        string elmTestEnvironmentPath = null;
+
+        {
+            /*
+             * We found no way yet to point elm-test-rs to the deno executable file.
+             * As a temporary solution, adapt the file path and environment variables to help elm-test-rs find it.
+             * */
+
+            var (denoExecutableFileName, pathEnvironmentVarSeparator) =
+                RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? ("deno.exe", ";") : ("deno", ":");
+
+            var denoExecutableFileContent = DenoExecutableFileForCurrentOs();
+
+            var denoExecutableFileDirectory =
+                Path.Combine(Filesystem.CacheDirectory,
+                "bin-by-sha256",
+                CommonConversion.StringBase16FromByteArray(CommonConversion.HashSHA256(denoExecutableFileContent)));
+
+            var denoExecutableFilePath = Path.Combine(denoExecutableFileDirectory, denoExecutableFileName);
+
+            Directory.CreateDirectory(denoExecutableFileDirectory);
+
+            File.WriteAllBytes(denoExecutableFilePath, denoExecutableFileContent);
+
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+            {
+                var unixFileInfo = new UnixFileInfo(denoExecutableFilePath);
+
+                unixFileInfo.FileAccessPermissions |=
+                    FileAccessPermissions.GroupExecute | FileAccessPermissions.UserExecute | FileAccessPermissions.OtherExecute |
+                    FileAccessPermissions.GroupRead | FileAccessPermissions.UserRead | FileAccessPermissions.OtherRead;
+            }
+
+            var environmentPath =
+                System.Environment.GetEnvironmentVariable("PATH") ?? System.Environment.GetEnvironmentVariable("path");
+
+            elmTestEnvironmentPath = environmentPath + pathEnvironmentVarSeparator + denoExecutableFileDirectory;
+        }
+
         var environmentFilesExecutable =
-            ImmutableDictionary.Create<IImmutableList<string>, IReadOnlyList<byte>>().SetItem(
-                ImmutableList.Create(elmExecutableFileName), ElmFullstack.ProcessFromElm019Code.GetElmExecutableFile);
+            ImmutableDictionary.Create<IImmutableList<string>, IReadOnlyList<byte>>()
+            .SetItem(ImmutableList.Create(elmExecutableFileName), ElmFullstack.ProcessFromElm019Code.GetElmExecutableFile);
 
         var executeElmTestResult =
             ExecutableFile.ExecuteFileWithArguments(
             environmentFilesNotExecutable: elmProjectFiles,
             executableFile: elmTestExecutableFile,
-            arguments: "--compiler=./" + elmExecutableFileName + " --report=json",
-            environmentStrings: null,
+            arguments: "--compiler=./" + elmExecutableFileName + "  --deno  --report=json",
+            environmentStrings: ImmutableDictionary<string, string>.Empty.SetItem("PATH", elmTestEnvironmentPath),
             workingDirectory: null,
-            environmentFilesExecutable: environmentFilesExecutable);
+            environmentFilesExecutable: environmentFilesExecutable); ;
 
         var stdoutLines =
             executeElmTestResult.processOutput.StandardOutput