fix(cli-repl): handle thrown primitives MONGOSH-739

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

@@ -531,6 +531,24 @@ describe('MongoshNodeRepl', () => {
       await tick();
       expect(stripAnsi(output)).to.equal('\n> ');
     });
+
+    context('thrown non-Errors', () => {
+      it('allows `throw null`', async() => {
+        output = '';
+        input.write('throw null;\n');
+        await waitEval(bus);
+        // We do verify that both `Error` and `null` are syntax-highlighted here.
+        expect(output).to.match(/\x1b\[\d+mError\x1b\[\d+m: \x1b\[\d+mnull\x1b\[\d+m/);
+      });
+
+      it('allows `throw number`', async() => {
+        output = '';
+        input.write('throw 123;\n');
+        await waitEval(bus);
+        // We do verify that both `Error` and `123` are syntax-highlighted here.
+        expect(output).to.match(/\x1b\[\d+mError\x1b\[\d+m: \x1b\[\d+m123\x1b\[\d+m/);
+      });
+    });
   });
 
   context('with fake TTY', () => {

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

@@ -343,6 +343,13 @@ class MongoshNodeRepl implements EvaluationListener {
       // topology, server version, etc., so for those, we do not autocomplete
       // at all and instead leave that to the @mongosh/autocomplete package.
       return shellResult.type !== null ? null : shellResult.rawValue;
+    } catch (err) {
+      if (!isErrorLike(err)) {
+        throw new Error(this.formatOutput({
+          value: err
+        }));
+      }
+      throw err;
     } finally {
       if (!this.insideAutoCompleteOrGetPrompt) {
         repl.setPrompt(await this.getShellPrompt());
@@ -379,10 +386,7 @@ class MongoshNodeRepl implements EvaluationListener {
     // This checks for error instances.
     // The writer gets called immediately by the internal `repl.eval`
     // in case of errors.
-    if (result && (
-      (result.message !== undefined && typeof result.stack === 'string') ||
-      (result.code !== undefined && result.errmsg !== undefined)
-    )) {
+    if (isErrorLike(result)) {
       // eslint-disable-next-line chai-friendly/no-unused-expressions
       this._runtimeState?.shellEvaluator.revertState();
 
@@ -415,7 +419,7 @@ class MongoshNodeRepl implements EvaluationListener {
     return (await passwordPromise).toString();
   }
 
-  formatOutput(value: any): string {
+  formatOutput(value: { value: any, type?: string }): string {
     return formatOutput(value, this.getFormatOptions());
   }
 
@@ -519,4 +523,15 @@ class MongoshNodeRepl implements EvaluationListener {
   }
 }
 
+function isErrorLike(value: any): boolean {
+  try {
+    return value && (
+      (value.message !== undefined && typeof value.stack === 'string') ||
+      (value.code !== undefined && value.errmsg !== undefined)
+    );
+  } catch (err) {
+    throw new MongoshInternalError(err?.message || String(err));
+  }
+}
+
 export default MongoshNodeRepl;