Support TildeSlash expand (#8589)

Author: William Lee

src/Microsoft.DotNet.Cli.Utils/EnvironmentProvider.cs

@@ -14,6 +14,7 @@ public class EnvironmentProvider : IEnvironmentProvider
         private static char[] s_pathSeparator = new char[] { Path.PathSeparator };
         private static char[] s_quote = new char[] { '"' };
         private IEnumerable<string> _searchPaths;
+        private readonly Lazy<string> _userHomeDirectory = new Lazy<string>(() => Environment.GetEnvironmentVariable("HOME") ?? string.Empty);
         private IEnumerable<string> _executableExtensions;
 
         public IEnumerable<string> ExecutableExtensions
@@ -45,7 +46,8 @@ private IEnumerable<string> SearchPaths
                     searchPaths.AddRange(Environment
                         .GetEnvironmentVariable("PATH")
                         .Split(s_pathSeparator)
-                        .Select(p => p.Trim(s_quote)));
+                        .Select(p => p.Trim(s_quote))
+                        .Select(p => ExpandTildeSlash(p)));
 
                     _searchPaths = searchPaths;
                 }
@@ -54,6 +56,19 @@ private IEnumerable<string> SearchPaths
             }
         }
 
+        private string ExpandTildeSlash(string path)
+        {
+            const string tildeSlash = "~/";
+            if (path.StartsWith(tildeSlash, StringComparison.Ordinal) && !string.IsNullOrEmpty(_userHomeDirectory.Value))
+            {
+                return Path.Combine(_userHomeDirectory.Value, path.Substring(tildeSlash.Length));
+            }
+            else
+            {
+                return path;
+            }
+        }
+
         public EnvironmentProvider(
             IEnumerable<string> extensionsOverride = null,
             IEnumerable<string> searchPathsOverride = null)