local-testing-bug-fix

name	local-testing-bug-fix
description	Fix a GitHub Local Testing issue

Fix GitHub issue $ARGUMENTS (provide a GitHub issue URL or number) following our coding standards.

Prerequisites

Before using this skill, ensure the following are set up:

1. gh CLI — must be installed and authenticated (gh auth status) to fetch issue details

2. tests/parameters.py — must exist (gitignored, create it manually) with your Snowflake credentials:

   CONNECTION_PARAMETERS = {
       "account": "your_account",
       "user": "your_user",
       "password": "your_password",
       "database": "your_db",
       "schema": "public",
   }
   

   Required only for running live integ tests. Mock-only tests (tests/mock/) do not need credentials.

3. Fetch and read the issue description (use gh issue view <number> or the URL)

4. Understand the requirements and reproduce the problem mentally

5. Determine if the fix is feasible (see Known Limitations below)

6. Find the relevant code in src/snowflake/snowpark/_internal/mock/

7. Implement the fix

8. Write or update tests (see Test approach below)

9. Update CHANGELOG.md (see Changelog below)

10. Create a commit with message format: SNOW-XXXXXXX: <description>

Codebase layout

• Local testing implementation: src/snowflake/snowpark/_internal/mock/
• Mock-only tests (local testing exclusive): tests/mock/
• Shared integ tests (run against both live and local): tests/integ/
  • Tests unsupported in local testing are explicitly skipped with the marker below

Skipping a test for local testing

When a test in tests/integ/ cannot run in local testing mode, mark it:

@pytest.mark.skipif(
    "config.getoption('local_testing_mode', default=False)",
    reason="<explain why it is not supported>",
)
def test_something(session):
    ...

Test approach

Validate by comparing live session output to local testing session output:

from snowflake.snowpark import Session

# live session — tries ~/.snowflake/connections.toml first, falls back to tests/parameters.py
try:
    session = Session.builder.getOrCreate()
except Exception:
    from tests.parameters import CONNECTION_PARAMETERS
    session = Session.builder.configs(CONNECTION_PARAMETERS).create()

# local testing session
local_session = Session.builder.config("local_testing", True).create()

df = session...              # DF operation
local_df = local_session...  # same DF operation

df.print_schema()
df.show()

local_df.print_schema()
local_df.show()

# compare the output, fix

Run integ tests in local testing mode:

pytest tests/integ/<test_file>.py --local_testing_mode

Run mock-only tests:

pytest tests/mock/<test_file>.py

Changelog

Add an entry under the top-most unreleased version in CHANGELOG.md, in the ### Snowpark Local Testing Updates > #### Bug Fixes section:

## x.y.z (TBD)

### Snowpark Local Testing Updates

#### Bug Fixes

- Fixed a bug where <description of the fix>.

If the ### Snowpark Local Testing Updates section doesn't exist yet in the TBD block, add it after ### Snowpark Python API Updates.

Known Limitations

1. Local Testing does not support raw SQL
2. If the issue requires a feature that is fundamentally server-side (e.g., raw SQL execution, file stages), it may not be feasible — explain this to the user instead of partially implementing