---
name: e2e-testing
description: Guide for running end-to-end tests of the Qwen Code CLI, including
  headless mode, MCP server testing, and API traffic inspection. Use this skill
  whenever you need to verify CLI behavior with real model calls, reproduce
  user-reported bugs end-to-end, test MCP tool integrations, or inspect raw API
  request/response payloads. Trigger on mentions of E2E testing, headless
  testing, MCP tool testing, or reproducing issues.
---

# E2E Testing Guide

How to run the Qwen Code CLI end-to-end, from building the bundle to inspecting
raw API traffic. Use when unit tests are not enough and you need to verify
behavior through the full pipeline (model API → tool validation → tool
execution).

## Which binary to use

- **Reproducing bugs**: use the globally installed `qwen` command — this
  matches what the user ran when they filed the issue.
- **Verifying fixes**: build first (`npm run build && npm run bundle`), then
  run `node dist/cli.js` — this tests your local changes.

## Headless Mode

Run the CLI non-interactively with JSON output (`<qwen>` = `qwen` or `node
dist/cli.js` per above):

```bash
<qwen> "your prompt here" \
  --approval-mode yolo \
  --output-format json \
  2>/dev/null
```

The JSON output is a stream of objects. Key types:

- `type: "system"` — init: `tools`, `mcp_servers`, `model`, `permission_mode`
- `type: "assistant"` — model output: `content[].type` is `text`, `tool_use`,
  or `thinking`
- `type: "user"` — tool results: `content[].type` is `tool_result` with
  `is_error`
- `type: "result"` — final output with `result` text and `usage` stats

Pipe through `jq` to filter the verbose stream, e.g. extract tool-result errors:
`... 2>/dev/null | jq 'select(.type=="user") | .message.content[] |
select(.is_error)'`

## Inspecting Raw API Traffic

When debugging model behavior (wrong tool arguments, schema issues), enable API
logging to see the exact request/response payloads:

```bash
<qwen> "prompt" \
  --approval-mode yolo \
  --output-format json \
  --openai-logging \
  --openai-logging-dir /tmp/api-logs
```

Each API call produces a JSON file (can be 80KB+ due to full message history).
The bulk is in `request.messages` (conversation history). Trimmed structure:

```json
{
  "request": {
    "model": "coder-model",
    "messages": [
      {
        "role": "system|user|assistant",
        "content": "...",
        "tool_calls?": []
      }
    ],
    "tools": [
      {
        "type": "function",
        "function": {
          "name": "tool_name",
          "description": "...",
          "parameters": { ... }      // schema sent to the model
        }
      }
    ]
  },
  "response": {
    "choices": [
      {
        "message": {
          "role": "assistant",
          "content": "...",          // text response (may be null)
          "tool_calls": [
            {
              "id": "call_...",
              "function": {
                "name": "tool_name",
                "arguments": "..."   // raw JSON string from the model
              }
            }
          ]
        }
      }
    ]
  }
}
```

## Interactive Mode (tmux)

Use when you need to verify TUI rendering, test keyboard interactions, or see
what the user sees. Headless mode is simpler when you only need structured
output.

### Launching

```bash
tmux new-session -d -s test -x 200 -y 50 \
  "cd /tmp/test-dir && <qwen> --approval-mode yolo"
sleep 3  # wait for TUI to initialize
```

### Sending prompts

Split text and Enter with a short delay — sending them together can cause the
TUI to swallow the submit:

```bash
tmux send-keys -t test "your prompt here"
sleep 0.5
tmux send-keys -t test Enter
```

### Waiting for completion

Poll for the input prompt to reappear instead of blind sleeping:

```bash
for i in $(seq 1 60); do
  sleep 2
  tmux capture-pane -t test -p | grep -q "Type your message" && break
done
```

### Capturing output

```bash
tmux capture-pane -t test -p -S -100   # -S -100 = 100 lines of scrollback
```

### Limitations

- **Key combos**: `tmux send-keys` cannot reliably send all key combinations.
  `C-?`, `C-Shift-*`, and function keys with modifiers are unsupported or
  unreliable. For these, use the `InteractiveSession` harness in
  `integration-tests/interactive/` or test manually.
- **Visual artifacts**: `capture-pane` captures the final rendered frame, not
  intermediate states. Flicker, tearing, or brief blank frames cannot be
  detected this way.

### Cleanup

```bash
tmux kill-session -t test
```

## MCP Server Testing

For testing MCP tool behavior end-to-end, read `references/mcp-testing.md`. It
covers the setup gotchas (config location, git repo requirement) and includes a
reusable zero-dependency test server template in `scripts/mcp-test-server.js`.

## Token Usage Stats

Use `scripts/token-stats.py` to summarize token usage across recent API logs:

```bash
python3 .qwen/skills/e2e-testing/scripts/token-stats.py 20  # last 20 requests
```

Shows input, cached, and output tokens per request with cache hit rates. Useful
for verifying prompt caching behavior or investigating unexpected token counts.

## Tips

- Use interactive (tmux) mode when the bug involves permission prompts, slash
  commands, or keyboard interactions. Headless mode has no TUI — these don't
  exist there.
- Use interactive (tmux) mode for hang-related issues. Headless mode produces
  no output when the process stalls, giving you nothing to work with.
- Use `--approval-mode default` when testing permission rules. `yolo` bypasses
  rule evaluation entirely — it can't test whether a rule matches.