> ## Documentation Index
> Fetch the complete documentation index at: https://www.testmuai.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Console Assertions

> Verify browser console output: errors, warnings, log messages, and JavaScript exceptions captured during test execution.

***

<Note>
  **Using Claude Code, Cursor, or another coding agent?** Paste this into your prompt to run cross-browser and real-device tests, debug sessions, and wire up CI on the TestMu AI cloud:

  ```
  Read https://www.testmuai.com/support/docs/SKILL.md to set up TestMu AI (formerly LambdaTest) cloud testing.
  ```
</Note>

Console assertions let you verify browser console output: error messages, warnings, log messages, and uncaught JavaScript exceptions.

## How Capture Works

KaneAI captures all browser console output automatically during each test step:

* **Continuous capture**: Every `console.log()`, `console.warn()`, `console.error()`, and uncaught JS exception is recorded
* **Per-step scope**: Each test step starts with a fresh capture. Console messages from previous steps are not carried over
* **Limits**: Up to 50,000 messages are stored per step. When the limit is reached, the oldest 10% are dropped
* **No truncation**: Message text is stored in full. Unlike network response bodies, console messages are never truncated
* **Object resolution**: When JavaScript logs an object (`console.log({status: "ok"})`), KaneAI resolves it to the actual value instead of storing "JSHandle\@object"
* **Multi-tab support**: Console messages from new tabs and popups are also captured
* **Top-frame only**: Messages from embedded iframes (payment widgets, third-party components) are not captured

### Planning for Multi-Step Tests

Because console data resets each step, plan accordingly:

* If you need to verify a console message **later**, extract and store it in the same step it appears
* Console output from step 1 won't be visible in step 3's console log

### Level Normalization

Console message levels are normalized to 5 values:

| Level     | What triggers it                                                                |
| --------- | ------------------------------------------------------------------------------- |
| `log`     | `console.log()`, `console.dir()`, `console.table()`, and other info-level calls |
| `warning` | `console.warn()`                                                                |
| `error`   | `console.error()` and uncaught exceptions                                       |
| `info`    | `console.info()`                                                                |
| `debug`   | `console.debug()`                                                               |

## What You Can Query

| Field          | Type   | Description                                               |
| -------------- | ------ | --------------------------------------------------------- |
| `level`        | string | Message level: "log", "warning", "error", "info", "debug" |
| `text`         | string | Full message text (not truncated)                         |
| `url`          | string | Source file URL                                           |
| `line_number`  | int    | Source line number                                        |
| `is_exception` | bool   | True for uncaught JS exceptions (pageerror events)        |
| `stack_trace`  | string | Stack trace (exceptions only)                             |

### Errors vs Exceptions

* **`errors`** includes ALL error-level messages: both `console.error()` calls AND uncaught exceptions
* **`exceptions`** is a subset of errors: only uncaught JavaScript exceptions
* To check for app-level errors without exceptions: query errors where `is_exception` is false

## Example Assertions

```
Assert: no console errors on the page
Assert: no uncaught JavaScript exceptions
Assert: console contains "Amplitude SDK triggered"
Assert: no console warnings
Assert: no JS errors after clicking Submit
```

## Example Extractions

```
Store all console error messages
Extract the first console error text
Store all console log output
```

## Example If/Else

```
If console contains "feature_flag_enabled" then use new flow, else use legacy flow
```