Fix false diagnostics showing up on startup

Fixes #132

CHANGELOG.md

@@ -15,6 +15,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Sync to upstream Luau 0.545
 - Inlay hints for variables will no longer show if the type hint string is the same as the variable name (i.e., `local tbl = {}`, the hint `: tbl` will no longer show) ([#137](https://github.com/JohnnyMorganz/luau-lsp/issues/137))
 
+### Fixed
+
+- Fixed false document diagnostics showing up for opened tabs when VSCode is first started ([#132](https://github.com/JohnnyMorganz/luau-lsp/issues/132))
+
 ## [1.9.2] - 2022-09-06
 
 ### Changed

src/Workspace.cpp

@@ -178,6 +178,7 @@ void WorkspaceFolder::initialize()
 
 void WorkspaceFolder::setupWithConfiguration(const ClientConfiguration& configuration)
 {
+    isConfigured = true;
     if (configuration.sourcemap.enabled)
     {
         if (!isNullWorkspace() && !updateSourceMap())

src/include/LSP/Workspace.hpp

@@ -26,6 +26,7 @@ class WorkspaceFolder
     lsp::DocumentUri rootUri;
     WorkspaceFileResolver fileResolver;
     Luau::Frontend frontend;
+    bool isConfigured = false;
 
 public:
     WorkspaceFolder(std::shared_ptr<Client> client, const std::string& name, const lsp::DocumentUri& uri)

src/operations/Diagnostics.cpp

@@ -5,6 +5,12 @@
 
 lsp::DocumentDiagnosticReport WorkspaceFolder::documentDiagnostics(const lsp::DocumentDiagnosticParams& params)
 {
+    if (!isConfigured)
+    {
+        lsp::DiagnosticServerCancellationData cancellationData{/*retriggerRequest: */ true};
+        throw JsonRpcException(lsp::ErrorCode::ServerCancelled, "server not yet received configuration for diagnostics", cancellationData);
+    }
+
     // TODO: should we apply a resultId and return an unchanged report if unchanged?
     lsp::DocumentDiagnosticReport report;
     std::unordered_map<std::string /* lsp::DocumentUri */, std::vector<lsp::Diagnostic>> relatedDiagnostics;