[erichare]

Summary

Clicking Update on a saved JSON Operations node (the legacy DataOperationsComponent) hides the selected operation's inputs. The node keeps its operation and saved values, but the field disappears, and the graph build skips hidden fields. A Select Keys ['text'] node then returns {} instead of {"text": ...}, with no error.

The cause is the same one #15812 fixed for Data Operations. update_frontend_node rebuilds the template from class defaults, where every operation field has show=False. The generic merge copies back values only, so nothing re-applies visibility.

This adds an update_frontend_node override to DataOperationsComponent, following the #15812 pattern in operations.py:

• Read the selected operation from template["operations"]["value"].
• Show only that operation's fields from actions_data. Hide the rest of ALL_OPERATION_FIELDS. Saved values are not touched.
• Restore data.is_list from ACTION_CONFIG, as update_build_config does.
• For Path Selection, rebuild the selected_key dropdown options from the saved mapped_json_display. Hide selected_key if the saved JSON does not parse.

No operation, more than one, or a removed one such as Filter Values leaves every operation field hidden. That matches what update_build_config produces.

The component index entry for DataOperationsComponent (code and code_hash) is regenerated.

Found by the 1.13.0rc1 smoke test. The bug is also in 1.12.6, so it is not an rc1 regression.

Tests

New class TestUpdateFrontendNodeRestoresVisibility in src/backend/tests/unit/components/processing/test_data_operations_component.py. Each test builds a node the way the canvas saves it, by running the component's own update_build_config for the chosen operation and values. It then puts that node through the Update path: a fresh class-default template plus update_frontend_node.

• For every operation in actions_data: the visible operation fields after Update match that operation's fields and the saved node's flags. data.is_list matches ACTION_CONFIG.
• The saved Select Keys value ['text'] survives Update.
• No operation, or the removed Filter Values operation, keeps all operation fields hidden.
• Path Selection gets its selected_key options back. Invalid saved JSON keeps selected_key hidden.
• Run output is unchanged by Update for Select Keys, Remove Keys, Rename Keys, Append or Update, JQ Expression, and Path Selection. The node is loaded through a real Graph.from_payload, so ParameterHandler drops hidden fields just as it does in a real run.

Verification

# Before the fix (new tests only)
uv run pytest src/backend/tests/unit/components/processing/test_data_operations_component.py -k TestUpdateFrontendNodeRestoresVisibility -q -p no:randomly
# 17 failed, 2 passed. The run test for Select Keys failed with `assert {} == {'text': 'hello'}`, the smoke-test symptom.

# After the fix
uv run pytest src/backend/tests/unit/components/processing/test_data_operations_component.py src/backend/tests/unit/components/processing/test_operations_component.py src/backend/tests/unit/components/processing/test_append_data_payload.py -q -p no:randomly
# 207 passed, 8 skipped (the existing version tests, which have no file mapping)

uv run pytest src/backend/tests/unit/test_code_hash.py src/backend/tests/unit/components/processing/ -q -p no:randomly -n auto
# 499 passed, 37 skipped

# lfx index tests, in an isolated venv because they require langflow not to be installed
cd src/lfx && UV_PROJECT_ENVIRONMENT=<scratch venv> uv sync --group dev && uv run pytest tests/unit/test_component_index.py -q -p no:randomly
# 31 passed

uv run ruff format --check src/lfx/src/lfx/components/processing/data_operations.py src/backend/tests/unit/components/processing/test_data_operations_component.py
uv run ruff check src/lfx/src/lfx/components/processing/data_operations.py src/backend/tests/unit/components/processing/test_data_operations_component.py
# formatted, all checks passed

The index was regenerated with LFX_DEV=1 uv run python scripts/build_component_index.py. The local venv had numpy 2.5.1, while uv.lock pins 2.4.6. That changed three unrelated numpy dependency entries, so I reverted them and recomputed the index sha256 with the script's method. The same method reproduces the committed checksum on release-1.13.0.

Not verified: clicking Update in the browser. The tests call the same two functions the /api/v1/custom_component endpoint calls: build_custom_component_template, then update_frontend_node.

Open questions

• update_build_config (here and in operations.py) sets data["is_list"], but the serialized template key is list, and nothing on the canvas or in ParameterHandler reads is_list. So the Combine-versus-single-input switch may never reach the canvas handle. This PR restores is_list the same way the existing code writes it, to keep the port faithful. Switching to list would change handle behavior and deserves its own PR.

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Reviewing files that changed from the base of the PR and between 753072c and 2c8ce28.

📒 Files selected for processing: 3

• src/backend/tests/unit/components/processing/test_data_operations_component.py
• src/lfx/src/lfx/_assets/component_index.json
• src/lfx/src/lfx/components/processing/data_operations.py

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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 70.85%. Comparing base (a0adbeb) to head (2c8ce28).
⚠️ Report is 16 commits behind head on release-1.13.0.

Additional details and impacted files

@@                Coverage Diff                 @@
##           release-1.13.0   #15833      +/-   ##
==================================================
+ Coverage           69.51%   70.85%   +1.33%     
==================================================
  Files                2788     2798      +10     
  Lines              303015   303080      +65     
  Branches            45155    44246     -909     
==================================================
+ Hits               210644   214750    +4106     
+ Misses              89877    85836    -4041     
  Partials             2494     2494              

see 418 files with indirect coverage changes

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