release: WRNexusJS 0.8.0

packages/db/src/performance.ts

@@ -28,6 +28,24 @@ export interface QueryPolicy {
   onIssue?: (issue: QueryIssue) => void | Promise<void>;
 }
 
+const recentQueries: QueryRecord[] = [];
+const recentQueryIssues: QueryIssue[] = [];
+const TELEMETRY_LIMIT = 200;
+
+export function getDbPerformanceSnapshot(): { queries: QueryRecord[]; issues: QueryIssue[] } {
+  return { queries: structuredClone(recentQueries), issues: structuredClone(recentQueryIssues) };
+}
+
+export function resetDbPerformanceSnapshot(): void {
+  recentQueries.length = 0;
+  recentQueryIssues.length = 0;
+}
+
+function remember<T>(items: T[], value: T): void {
+  items.push(structuredClone(value));
+  if (items.length > TELEMETRY_LIMIT) items.splice(0, items.length - TELEMETRY_LIMIT);
+}
+
 function normalizedSql(sql: string): string {
   return sql
     .replace(/--.*$/gm, " ")
@@ -70,12 +88,14 @@ export function instrumentDb(db: Db, policy: QueryPolicy = {}): Db {
   const inspect = async (sql: string): Promise<void> => {
     const normalized = normalizedSql(sql);
     if (policy.warnSelectStar !== false && /^SELECT\s+\*/i.test(normalized)) {
-      await policy.onIssue?.({
+      const issue: QueryIssue = {
         code: "WRN-DB-SELECT-STAR",
         severity: "warning",
         message: "Avoid SELECT * in production queries.",
         sql,
-      });
+      };
+      remember(recentQueryIssues, issue);
+      await policy.onIssue?.(issue);
     }
     if (
       policy.warnUnboundedSelect !== false &&
@@ -83,12 +103,14 @@ export function instrumentDb(db: Db, policy: QueryPolicy = {}): Db {
       !/\bLIMIT\b/i.test(normalized) &&
       !/\bCOUNT\s*\(/i.test(normalized)
     ) {
-      await policy.onIssue?.({
+      const issue: QueryIssue = {
         code: "WRN-DB-UNBOUNDED-SELECT",
         severity: "warning",
         message: "SELECT query has no LIMIT. Prefer cursor pagination for large datasets.",
         sql,
-      });
+      };
+      remember(recentQueryIssues, issue);
+      await policy.onIssue?.(issue);
     }
   };
 
@@ -110,22 +132,27 @@ export function instrumentDb(db: Db, policy: QueryPolicy = {}): Db {
       operation,
       duplicateCount,
     };
+    remember(recentQueries, queryRecord);
     await policy.onQuery?.(queryRecord);
     if (durationMs >= slowQueryMs) {
-      await policy.onIssue?.({
+      const issue: QueryIssue = {
         code: "WRN-DB-SLOW-QUERY",
         severity: durationMs >= slowQueryMs * 5 ? "error" : "warning",
         message: `Query took ${durationMs.toFixed(2)} ms.`,
         sql,
-      });
+      };
+      remember(recentQueryIssues, issue);
+      await policy.onIssue?.(issue);
     }
     if (duplicateCount === duplicateWarningCount) {
-      await policy.onIssue?.({
+      const issue: QueryIssue = {
         code: "WRN-DB-DUPLICATE-QUERY",
         severity: "warning",
         message: `The same query ran ${duplicateCount} times in one request scope (possible N+1).`,
         sql,
-      });
+      };
+      remember(recentQueryIssues, issue);
+      await policy.onIssue?.(issue);
     }
   };