fix(cli-repl): improve debuggability of mongosh not initialized yet errors

These errors have historically been very hard to debug, so adding stack
traces unconditionally will hopefully improve this situation in the long term.

Author: addaleax

packages/cli-repl/src/mongosh-repl.ts

@@ -126,6 +126,7 @@ type Mutable<T> = {
  */
 class MongoshNodeRepl implements EvaluationListener {
   _runtimeState: MongoshRuntimeState | null;
+  closeTrace?: string;
   input: Readable;
   lineByLineInput: LineByLineInput;
   output: Writable;
@@ -1028,7 +1029,13 @@ class MongoshNodeRepl implements EvaluationListener {
    */
   runtimeState(): MongoshRuntimeState {
     if (this._runtimeState === null) {
-      throw new MongoshInternalError('Mongosh not initialized yet');
+      // This error can be really hard to debug, so we always attach stack traces
+      // from both when .close() was called and when
+      throw new MongoshInternalError(
+        `mongosh not initialized yet\nCurrentTrace: ${
+          new Error().stack
+        }\nClose trace: ${this.closeTrace}\n`
+      );
     }
     return this._runtimeState;
   }
@@ -1043,6 +1050,7 @@ class MongoshNodeRepl implements EvaluationListener {
     const rs = this._runtimeState;
     if (rs) {
       this._runtimeState = null;
+      this.closeTrace = new Error().stack;
       rs.repl?.close();
       await rs.instanceState.close(true);
       await new Promise((resolve) => this.output.write('', resolve));