How to mock object value in python using unittest library?

Question

The sample API -

@admin_blueprint.route("/test", methods=["GET"])
def test(kwargs):
    """
    test API
    """

    # Check if cache purge is required
    if redisconn.exists("url_prefix"):
        # Purge user roles
        pipeline.delete("url_prefix")
        cache_purge = pipeline.execute()
        if cache_purge == [1]:
            log.info("Hash table url_prefix was purged in the test API")
        else:
            log.error("Unable to purge cache in the test API")
            return (
                cacheRoles500Schema().dump(
                    {"message": "Unable to purge cache"}
                ),
                500,
            )

I want to write a pytests case to meet the else block, so here is the sample that I wrote but couldn't meet the else block, appreciate your help.

@patch('parentmodule.module.views.test.cache_purge', return_value=[0])
def test_cacheRoles_mock_failure(mock_data, fetch_eid, client):

    data = {
        "eid": fetch_eid["eid"]
    }
    resp = client.get(
        "admin/cacheRoles", query_string=data, headers=fetch_eid["headers"]
    )
    assert resp.status_code == 500

Answer 1

It seems you have to patch pipeline.execute(), probably something like this

@patch('parentmodule.module.pipeline.execute', return_value=[0])
def test_cacheRoles_mock_failure(mock_data, fetch_eid, client):

    data = {
        "eid": fetch_eid["eid"]
    }
    resp = client.get(
        "admin/cacheRoles", query_string=data, headers=fetch_eid["headers"]
    )
    assert resp.status_code == 500