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IfCondition evaluates the expressions of the branch not taken (case-sensitive "activities" check)

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
84/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Active
Tech stack
python
Domain
devtools, testing-qa

Research direction

Start in src/data_factory_testing_framework/models/activities/_activity.py at the expression walker around lines 89 and 101, then reproduce the provided IfCondition example. Ensure nested activity-list keys are skipped regardless of case, and verify that only Set_Today is evaluated when the condition is true without evaluating the false branch expression.

Written by the indexing model from the issue text.

Description

When an IfCondition activity is evaluated, the expressions of both branches are evaluated, not only the branch that is taken. An expression that is only valid on one branch then makes the evaluation fail.

Environment: data-factory-testing-framework 1.4.2 (also present on main at 11b9f27), Python 3.12.13, .NET 10.0.12, Linux.

Repro

A pipeline uses today's date when the date parameter is empty, and formats the given date otherwise:

import json, tempfile
from pathlib import Path

from data_factory_testing_framework import TestFramework, TestFrameworkType
from data_factory_testing_framework.state import RunParameter, RunParameterType

pipeline = {
    "name": "if_branch",
    "properties": {
        "parameters": {"date": {"type": "string"}},
        "variables": {"day": {"type": "String"}},
        "activities": [
            {
                "name": "Has_Date",
                "type": "IfCondition",
                "dependsOn": [],
                "typeProperties": {
                    "expression": {"value": "@empty(pipeline().parameters.date)", "type": "Expression"},
                    "ifTrueActivities": [
                        {
                            "name": "Set_Today",
                            "type": "SetVariable",
                            "dependsOn": [],
                            "typeProperties": {
                                "variableName": "day",
                                "value": {"value": "@formatDateTime(utcNow(), 'yyyy-MM-dd')", "type": "Expression"},
                            },
                        }
                    ],
                    "ifFalseActivities": [
                        {
                            "name": "Set_Given_Date",
                            "type": "SetVariable",
                            "dependsOn": [],
                            "typeProperties": {
                                "variableName": "day",
                                "value": {
                                    "value": "@formatDateTime(pipeline().parameters.date, 'yyyy-MM-dd')",
                                    "type": "Expression",
                                },
                            },
                        }
                    ],
                },
            }
        ],
    },
}

root = Path(tempfile.mkdtemp())
(root / "pipeline").mkdir()
(root / "pipeline" / "if_branch.json").write_text(json.dumps(pipeline))

framework = TestFramework(framework_type=TestFrameworkType.DataFactory, root_folder_path=str(root))
activities = framework.evaluate_pipeline(
    framework.get_pipeline_by_name("if_branch"), [RunParameter(RunParameterType.Pipeline, "date", "")]
)
print(next(activities).name)  # expected: Set_Today

Expected: Set_Today (the condition is true, the false branch never runs, as in Data Factory).

Actual:

DataFactoryElementEvaluationError: Error evaluating expression: @formatDateTime(pipeline().parameters.date, 'yyyy-MM-dd')
  (In function 'formatDateTime', the value provided for date time string '' was not valid.)

Cause

IfConditionActivity.evaluate calls Activity._evaluate_expressions, which walks type_properties. The nested activities are still there as raw JSON (type_properties["ifFalseActivities"] holds dicts, not the deserialized activities). The walker is meant to skip them, but the check is case-sensitive (_activity.py#L89, #L101):

if "activities" in key:
    continue

activities (ForEach, Switch cases) is skipped, but ifTrueActivities, ifFalseActivities and defaultActivities (Switch) are not, so their expressions are evaluated eagerly, in the scope of the container.

Suggested fix: if "activities" in key.lower(): (and the same for attribute_name), or drop the raw nested activity lists from type_properties once they are deserialized.

Dominant language
Python
Stars
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Forks
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Avg merge
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Merged PRs (30d)
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