DonHaul opened a new issue, #56953:
URL: https://github.com/apache/airflow/issues/56953
### Apache Airflow version
Other Airflow 2/3 version (please specify below)
### If "Other Airflow 2/3 version" selected, which one?
3.0.6
### What happened?
I have a simple dag where one map task depends on a single task:
when running `airlfow task tests`:
```bash
airflow tasks test problem_dag multiply_by_two --map-index 0 -t
'{"number":2}'
```
I get an error saying that the xcoms for `get_numbers` is not found so its
defaulting to None, even thought I am testing `multiply_by_two` and provide
params for it.
```bash
2025-10-21 13:51:54 [error ] XCom not found
[airflow.sdk.api.client] dag_id=problem_dag detail={'detail': {'reason':
'not_found', 'message': "XCom with key='return_value' map_index=-1 not found
for task 'get_numbers' in DAG run
'__airflow_temporary_run_2025-10-21T13:51:52.789707+00:00__' of
'problem_dag'"}} key=return_value map_index=None
run_id=__airflow_temporary_run_2025-10-21T13:51:52.789707+00:00__
status_code=404 task_id=get_numbers
2025-10-21 13:51:54 [warning ] No XCom value found; defaulting to None.
[task] dag_id=problem_dag key=return_value map_index=None
run_id=__airflow_temporary_run_2025-10-21T13:51:52.789707+00:00__
task_id=get_numbers
```
which than fails
```bash
│
/home/airflow/.local/lib/python3.11/site-packages/airflow/sdk/definitions/xcom_arg.py:596
in _ │
│
│
│ 593 │ if xcom_arg.operator.is_mapped:
│
│ 594 │ │ # TODO: How to tell if all the upstream TIs finished?
│
│ 595 │ │ pass
│
│ ❱ 596 │ return (upstream_map_indexes.get(task_id) or 1) *
len(resolved_val)
```
with
```
TypeError: object of type 'NoneType' has no len()
```
The full logs can be found here:
[log.txt](https://github.com/user-attachments/files/23022615/log.txt)
### What you think should happen instead?
When running
```bash
airflow tasks test problem_dag multiply_by_two --map-index 0 -t
'{"number":2}'
```
Since all the parameters required , it should either:
- not try to fetch the xcoms from `get_numbers()`
- run `get_numbers()` before it fetches its `xcoms`
### How to reproduce
Run
```bash
airflow tasks test problem_dag multiply_by_two --map-index 0 -t
'{"number":2}'
```
for dag
```python
from airflow.decorators import dag, task
@dag
def problem_dag():
@task
def get_numbers(**context):
return [1,2]
@task
def multiply_by_two(number, **context):
return number * 2
numbers = get_numbers()
multiplied_numbers = multiply_by_two.expand(number=numbers)
problem_dag()
```
### Operating System
Debian GNU/Linux 12 (bookworm)
### Versions of Apache Airflow Providers
_No response_
### Deployment
Docker-Compose
### Deployment details
_No response_
### Anything else?
_No response_
### Are you willing to submit PR?
- [ ] Yes I am willing to submit a PR!
### Code of Conduct
- [x] I agree to follow this project's [Code of
Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
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