Log a warning when skipping workspace folders without a URI

Restore the per-folder warning that the previous refactor dropped. Silently
discarding malformed workspace folders makes it hard for server operators to
diagnose why a client's folder didn't take effect, and it matches the behavior
the PR description advertises.

Logging each skipped folder requires the explicit loop, so revert the pure
`GetValidWorkspaceFolders` helper (and its dedicated tests); the existing
`AddWorkspaceFoldersIgnoresNullAndUrilessFolders` regression test still covers
null input, URI-less/null folders, and the downstream dereference.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: andyleejordan

src/PowerShellEditorServices/Services/Workspace/WorkspaceService.cs

@@ -118,23 +118,25 @@ public WorkspaceService(ILoggerFactory factory)
         /// </remarks>
         public void AddWorkspaceFolders(IEnumerable<WorkspaceFolder> workspaceFolders)
         {
-            foreach (WorkspaceFolder workspaceFolder in GetValidWorkspaceFolders(workspaceFolders))
+            if (workspaceFolders is null)
             {
+                return;
+            }
+
+            foreach (WorkspaceFolder workspaceFolder in workspaceFolders)
+            {
+                // Some LSP clients send folders without a URI; skip them (and warn) so we never
+                // store a folder whose URI would later be dereferenced and throw.
+                if (workspaceFolder?.Uri is null)
+                {
+                    logger.LogWarning($"Ignoring workspace folder without a URI: {workspaceFolder?.Name}");
+                    continue;
+                }
+
                 WorkspaceFolders.Add(workspaceFolder);
             }
         }
 
-        /// <summary>
-        /// Filters workspace folders down to those usable by the service: non-null folders with a
-        /// non-null URI. The <c>workspaceFolders</c> field is optional in LSP, so the collection
-        /// itself may also be null.
-        /// </summary>
-        /// <param name="workspaceFolders">The workspace folders from the initialize parameters.</param>
-        /// <returns>The folders that have a non-null URI, or an empty sequence.</returns>
-        internal static IEnumerable<WorkspaceFolder> GetValidWorkspaceFolders(IEnumerable<WorkspaceFolder> workspaceFolders)
-            => workspaceFolders?.Where(static folder => folder?.Uri is not null)
-                ?? Enumerable.Empty<WorkspaceFolder>();
-
         /// <summary>
         /// Gets an open file in the workspace. If the file isn't open but exists on the filesystem, load and return it.
         /// <para>IMPORTANT: Not all documents have a backing file e.g. untitled: scheme documents.  Consider using

test/PowerShellEditorServices.Test/Session/WorkspaceTests.cs

@@ -112,31 +112,6 @@ public void AddWorkspaceFoldersIgnoresNullAndUrilessFolders()
             Assert.Equal(s_workspacePath, Assert.Single(workspace.WorkspacePaths));
         }
 
-        [Fact]
-        public void GetValidWorkspaceFoldersReturnsEmptyWhenNull()
-            => Assert.Empty(WorkspaceService.GetValidWorkspaceFolders(null));
-
-        [Fact]
-        public void GetValidWorkspaceFoldersReturnsEmptyWhenEmpty()
-            => Assert.Empty(WorkspaceService.GetValidWorkspaceFolders(new Container<WorkspaceFolder>()));
-
-        [Fact]
-        public void GetValidWorkspaceFoldersSkipsNullFoldersAndNullUris()
-        {
-            WorkspaceFolder valid = new()
-            {
-                Uri = DocumentUri.FromFileSystemPath(s_workspacePath),
-                Name = "valid"
-            };
-
-            Container<WorkspaceFolder> folders = new(
-                null,
-                new WorkspaceFolder { Name = "missing-uri" },
-                valid);
-
-            Assert.Equal(valid, Assert.Single(WorkspaceService.GetValidWorkspaceFolders(folders)));
-        }
-
         [Fact]
         public void HasDefaultForWorkspacePaths()
         {