Add an mssql Persister for SQL Server and Azure SQL

cspell.json

@@ -101,6 +101,7 @@
     "hashchange",
     "havings",
     "hidedevtools",
+    "HOLDLOCK",
     "hrana",
     "hypot",
     "importmap",
@@ -155,6 +156,7 @@
     "nkzw",
     "nocheck",
     "Noll",
+    "nvarchar",
     "nwse",
     "oddr",
     "ogawa",
@@ -169,6 +171,7 @@
     "partyserver",
     "partysocket",
     "parvovirus",
+    "passwordless",
     "Patryk",
     "Pearce",
     "Persistable",
@@ -182,6 +185,7 @@
     "prettierrc",
     "primodiumxyz",
     "reconnections",
+    "recordset",
     "relationshipinhtmltable",
     "requiredness",
     "resultsortablegrid",
@@ -191,6 +195,7 @@
     "Riedl",
     "Romniyi",
     "Rosso",
+    "rowversion",
     "sandboxed",
     "savepoints",
     "schematizer",

gulpfile.mjs

@@ -34,6 +34,7 @@ const ALL_MODULES = [
   'persisters/persister-file',
   'persisters/persister-indexed-db',
   'persisters/persister-libsql',
+  'persisters/persister-mssql',
   'persisters/persister-partykit-client',
   'persisters/persister-partykit-server',
   'persisters/persister-pg',
@@ -241,10 +242,12 @@ const copyPackageFiles = async (forProd = false) => {
   await promises.copyFile('agents.md', join(DIST_DIR, 'agents.md'));
 };
 
-let labelBlocks;
-const getLabelBlocks = async () => {
-  if (labelBlocks == null) {
-    labelBlocks = new Map();
+// The promise is memoized rather than the Map, since callers run concurrently
+// and would otherwise be handed the Map before it has been filled.
+let labelBlocksPromise;
+const getLabelBlocks = () =>
+  (labelBlocksPromise ??= (async () => {
+    const labelBlocks = new Map();
     await allModules(async (module) => {
       [
         ...(
@@ -257,9 +260,8 @@ const getLabelBlocks = async () => {
         labelBlocks.set(label, block);
       });
     });
-  }
-  return labelBlocks;
-};
+    return labelBlocks;
+  })());
 
 const copyDefinition = async (dir, module) => {
   const labelBlocks = await getLabelBlocks();