superset/docs/docs/contributing/testing-locally.mdx

---
title: Testing
hide_title: true
sidebar_position: 8
version: 1
---

## Testing

### Python Testing

All python tests are carried out in [tox](https://tox.readthedocs.io/en/latest/index.html)
a standardized testing framework.
All python tests can be run with any of the tox [environments](https://tox.readthedocs.io/en/latest/example/basic.html#a-simple-tox-ini-default-environments), via,

```bash
tox -e <environment>
```

For example,

```bash
tox -e py38
```

Alternatively, you can run all tests in a single file via,

```bash
tox -e <environment> -- tests/test_file.py
```

or for a specific test via,

```bash
tox -e <environment> -- tests/test_file.py::TestClassName::test_method_name
```

Note that the test environment uses a temporary directory for defining the
SQLite databases which will be cleared each time before the group of test
commands are invoked.

There is also a utility script included in the Superset codebase to run python integration tests. The [readme can be
found here](https://github.com/apache/superset/tree/master/scripts/tests)

To run all integration tests for example, run this script from the root directory:

```bash
scripts/tests/run.sh
```

You can run unit tests found in './tests/unit_tests' for example with pytest. It is a simple way to run an isolated test that doesn't need any database setup

```bash
pytest ./link_to_test.py
```

#### Testing with local Presto connections

If you happen to change db engine spec for Presto/Trino, you can run a local Presto cluster with Docker:

```bash
docker run -p 15433:15433 starburstdata/presto:350-e.6
```

Then update `SUPERSET__SQLALCHEMY_EXAMPLES_URI` to point to local Presto cluster:

```bash
export SUPERSET__SQLALCHEMY_EXAMPLES_URI=presto://localhost:15433/memory/default
```

### Frontend Testing

We use [Jest](https://jestjs.io/) and [Enzyme](https://airbnb.io/enzyme/) to test TypeScript/JavaScript. Tests can be run with:

```bash
cd superset-frontend
npm run test
```

To run a single test file:

```bash
npm run test -- path/to/file.js
```

### Integration Testing

We use [Cypress](https://www.cypress.io/) for integration tests. Tests can be run by `tox -e cypress`. To open Cypress and explore tests first setup and run test server:

```bash
export SUPERSET_CONFIG=tests.integration_tests.superset_test_config
export SUPERSET_TESTENV=true
export CYPRESS_BASE_URL="http://localhost:8081"
superset db upgrade
superset load_test_users
superset load-examples --load-test-data
superset init
superset run --port 8081
```

Run Cypress tests:

```bash
cd superset-frontend
npm run build-instrumented

cd cypress-base
npm install

# run tests via headless Chrome browser (requires Chrome 64+)
npm run cypress-run-chrome

# run tests from a specific file
npm run cypress-run-chrome -- --spec cypress/integration/explore/link.test.ts

# run specific file with video capture
npm run cypress-run-chrome -- --spec cypress/integration/dashboard/index.test.js --config video=true

# to open the cypress ui
npm run cypress-debug

# to point cypress to a url other than the default (http://localhost:8088) set the environment variable before running the script
# e.g., CYPRESS_BASE_URL="http://localhost:9000"
CYPRESS_BASE_URL=<your url> npm run cypress open
```

See [`superset-frontend/cypress_build.sh`](https://github.com/apache/superset/blob/master/superset-frontend/cypress_build.sh).

As an alternative you can use docker-compose environment for testing:

Make sure you have added below line to your /etc/hosts file:
`127.0.0.1 db`

If you already have launched Docker environment please use the following command to assure a fresh database instance:
`docker-compose down -v`

Launch environment:

`CYPRESS_CONFIG=true docker-compose up`

It will serve backend and frontend on port 8088.

Run Cypress tests:

```bash
cd cypress-base
npm install
npm run cypress open
```

### Debugging Server App

Follow these instructions to debug the Flask app running inside a docker container.

First add the following to the ./docker-compose.yaml file

```diff
superset:
    env_file: docker/.env
    image: *superset-image
    container_name: superset_app
    command: ["/app/docker/docker-bootstrap.sh", "app"]
    restart: unless-stopped
+   cap_add:
+     - SYS_PTRACE
    ports:
      - 8088:8088
+     - 5678:5678
    user: "root"
    depends_on: *superset-depends-on
    volumes: *superset-volumes
    environment:
      CYPRESS_CONFIG: "${CYPRESS_CONFIG}"
```

Start Superset as usual

```bash
docker-compose up
```

Install the required libraries and packages to the docker container

Enter the superset_app container

```bash
docker exec -it superset_app /bin/bash
root@39ce8cf9d6ab:/app#
```

Run the following commands inside the container

```bash
apt update
apt install -y gdb
apt install -y net-tools
pip install debugpy
```

Find the PID for the Flask process. Make sure to use the first PID. The Flask app will re-spawn a sub-process every time you change any of the python code. So it's important to use the first PID.

```bash
ps -ef

UID        PID  PPID  C STIME TTY          TIME CMD
root         1     0  0 14:09 ?        00:00:00 bash /app/docker/docker-bootstrap.sh app
root         6     1  4 14:09 ?        00:00:04 /usr/local/bin/python /usr/bin/flask run -p 8088 --with-threads --reload --debugger --host=0.0.0.0
root        10     6  7 14:09 ?        00:00:07 /usr/local/bin/python /usr/bin/flask run -p 8088 --with-threads --reload --debugger --host=0.0.0.0
```

Inject debugpy into the running Flask process. In this case PID 6.

```bash
python3 -m debugpy --listen 0.0.0.0:5678 --pid 6
```

Verify that debugpy is listening on port 5678

```bash
netstat -tunap

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:5678            0.0.0.0:*               LISTEN      462/python
tcp        0      0 0.0.0.0:8088            0.0.0.0:*               LISTEN      6/python
```

You are now ready to attach a debugger to the process. Using VSCode you can configure a launch configuration file .vscode/launch.json like so.

```
{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Attach to Superset App in Docker Container",
            "type": "python",
            "request": "attach",
            "connect": {
                "host": "127.0.0.1",
                "port": 5678
            },
            "pathMappings": [
                {
                    "localRoot": "${workspaceFolder}",
                    "remoteRoot": "/app"
                }
            ]
        },
    ]
}
```

VSCode will not stop on breakpoints right away. We've attached to PID 6 however it does not yet know of any sub-processes. In order to "wakeup" the debugger you need to modify a python file. This will trigger Flask to reload the code and create a new sub-process. This new sub-process will be detected by VSCode and breakpoints will be activated.

### Debugging Server App in Kubernetes Environment

To debug Flask running in POD inside kubernetes cluster. You'll need to make sure the pod runs as root and is granted the SYS_TRACE capability.These settings should not be used in production environments.

```
  securityContext:
    capabilities:
      add: ["SYS_PTRACE"]
```

See (set capabilities for a container)[https://kubernetes.io/docs/tasks/configure-pod-container/security-context/#set-capabilities-for-a-container] for more details.

Once the pod is running as root and has the SYS_PTRACE capability it will be able to debug the Flask app.

You can follow the same instructions as in the docker-compose. Enter the pod and install the required library and packages; gdb, netstat and debugpy.

Often in a Kubernetes environment nodes are not addressable from outside the cluster. VSCode will thus be unable to remotely connect to port 5678 on a Kubernetes node. In order to do this you need to create a tunnel that port forwards 5678 to your local machine.

```
kubectl port-forward  pod/superset-<some random id> 5678:5678
```

You can now launch your VSCode debugger with the same config as above. VSCode will connect to to 127.0.0.1:5678 which is forwarded by kubectl to your remote kubernetes POD.

### Storybook

Superset includes a [Storybook](https://storybook.js.org/) to preview the layout/styling of various Superset components, and variations thereof. To open and view the Storybook:

```bash
cd superset-frontend
npm run storybook
```

When contributing new React components to Superset, please try to add a Story alongside the component's `jsx/tsx` file.