something is working

node_modules/mongodb/src/explain.ts

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+import { MongoInvalidArgumentError } from './error';
+
+/** @public */
+export const ExplainVerbosity = Object.freeze({
+  queryPlanner: 'queryPlanner',
+  queryPlannerExtended: 'queryPlannerExtended',
+  executionStats: 'executionStats',
+  allPlansExecution: 'allPlansExecution'
+} as const);
+
+/** @public */
+export type ExplainVerbosity = string;
+
+/**
+ * For backwards compatibility, true is interpreted as "allPlansExecution"
+ * and false as "queryPlanner". Prior to server version 3.6, aggregate()
+ * ignores the verbosity parameter and executes in "queryPlanner".
+ * @public
+ */
+export type ExplainVerbosityLike = ExplainVerbosity | boolean;
+
+/** @public */
+export interface ExplainOptions {
+  /** Specifies the verbosity mode for the explain output. */
+  explain?: ExplainVerbosityLike;
+}
+
+/** @internal */
+export class Explain {
+  verbosity: ExplainVerbosity;
+
+  constructor(verbosity: ExplainVerbosityLike) {
+    if (typeof verbosity === 'boolean') {
+      this.verbosity = verbosity
+        ? ExplainVerbosity.allPlansExecution
+        : ExplainVerbosity.queryPlanner;
+    } else {
+      this.verbosity = verbosity;
+    }
+  }
+
+  static fromOptions(options?: ExplainOptions): Explain | undefined {
+    if (options?.explain == null) return;
+
+    const explain = options.explain;
+    if (typeof explain === 'boolean' || typeof explain === 'string') {
+      return new Explain(explain);
+    }
+
+    throw new MongoInvalidArgumentError('Field "explain" must be a string or a boolean');
+  }
+}