Instruct users with JsonFormatter errors to attach messages

Additionally, for users that haven't enabled messages, one is generated
anyway in the users temporary location. This will hopefully shed some
light onto a previously reported and hard-to-reproduce issue [1].

I would ideally have liked to use error cause for this, but Cypress will
swallow this [2].

[1] #1161
[2] cypress-io/cypress#30265

CHANGELOG.md

@@ -18,6 +18,8 @@ Other changees:
 
 - Re-introduce support for Node v18, fixes [#1230](https://github.com/badeball/cypress-cucumber-preprocessor/discussions/1230).
 
+- Generate a temporary messages report in case of `JsonFormatter` errors, relates to [#1161](https://github.com/badeball/cypress-cucumber-preprocessor/issues/1161).
+
 ## v20.1.2
 
 - Updated all dependencies, including esbuild, relates to [#1068](https://github.com/badeball/cypress-cucumber-preprocessor/issues/1068).

lib/plugin-event-handlers.ts

@@ -375,8 +375,35 @@ export async function afterRunHandler(config: Cypress.PluginConfigOptions) {
       },
     );
 
-    for (const message of state.messages.accumulation) {
-      eventBroadcaster.emit("envelope", message);
+    try {
+      for (const message of state.messages.accumulation) {
+        eventBroadcaster.emit("envelope", message);
+      }
+    } catch (e) {
+      const message = (messagesOutput: string) =>
+        `JsonFormatter failed with an error shown below. This might be a bug, please report at ${homepage} and make sure to attach the messages report in your ticket (${messagesOutput}).\n`;
+
+      if (preprocessor.messages.enabled) {
+        console.warn(chalk.yellow(message(preprocessor.messages.output)));
+      } else {
+        const temporaryMessagesOutput = path.join(
+          await fs.mkdtemp(
+            path.join(os.tmpdir(), "cypress-cucumber-preprocessor-"),
+          ),
+          "cucumber-messages.ndjson",
+        );
+
+        await fs.writeFile(
+          temporaryMessagesOutput,
+          state.messages.accumulation
+            .map((message) => JSON.stringify(message))
+            .join("\n") + "\n",
+        );
+
+        console.warn(chalk.yellow(message(temporaryMessagesOutput)));
+      }
+
+      throw e;
     }
 
     assertIsString(