feat: add special message for bad indentation (#53744)

tools/client-plugins/browser-scripts/python-test-evaluator.ts

@@ -1,7 +1,7 @@
 // We have to specify pyodide.js because we need to import that file (not .mjs)
 // and 'import' defaults to .mjs
 import { loadPyodide, type PyodideInterface } from 'pyodide/pyodide.js';
-import type { PyProxy } from 'pyodide/ffi';
+import type { PyProxy, PythonError } from 'pyodide/ffi';
 import pkg from 'pyodide/package.json';
 import * as helpers from '@freecodecamp/curriculum-helpers';
 import chai from 'chai';
@@ -135,17 +135,22 @@ input = __inputGen(${JSON.stringify(input ?? [])})
     // available to the test.
     try {
       runPython(code);
-    } catch (err) {
-      // We don't, yet, want user code to raise exceptions. When they do, we
-      // count this as a failing test.
-      ctx.postMessage({
+    } catch (e) {
+      const err = e as PythonError;
+
+      // Quite a lot of lessons can easily lead users to write code that has
+      // indentation errors. In these cases we want to provide a more helpful
+      // error message. For other errors, we can just provide the standard
+      // message.
+      const errorType =
+        err.type === 'IndentationError' ? 'indentation' : 'other';
+      return ctx.postMessage({
         err: {
-          message: (err as Error).message,
-          stack: (err as Error).stack,
-          syntaxError: true
+          message: err.message,
+          stack: err.stack,
+          errorType
         }
       });
-      return;
     }
     // TODO: remove the next line, creating __locals, once all the tests access
     // variables directly.