#1728: add pass_row as configurable parameter for field_update (#1729)

# Description

As described in #1728, pass_row parameter is now added as an editable
parameter for the field_update step. This allows us to use row data
inside custom python function.

The default value of the parameter remains False so that any existing
uses of this functionality will not be affected.

# Tests

Ensured the newly added unit test `test_step_field_update_with_function_and_pass_row_true` runs without
fail and also that all the previous test cases run and pass too.

- fixes #1728

---------

Co-authored-by: Pierre Camilleri <[email protected]>

frictionless/steps/field/__spec__/test_field_update.py

@@ -144,3 +144,31 @@ def test_step_field_update_referenced_as_foreign_key():
             "reference": {"fields": ["pkey"], "resource": "resource1"},
         }
     ]
+
+
+def test_step_field_update_with_function_and_pass_row_true():
+    source = TableResource(path="data/transform.csv")
+
+    def add_country_to_id(value, row):
+        return str(value) + " " + row["name"]
+
+    pipeline = Pipeline(
+        steps=[
+            steps.field_update(
+                name="id", function=add_country_to_id,
+                descriptor={"type": "string"}, pass_row=True)
+        ],
+    )
+    target = source.transform(pipeline)
+    assert target.schema.to_descriptor() == {
+        "fields": [
+            {"name": "id", "type": "string"},
+            {"name": "name", "type": "string"},
+            {"name": "population", "type": "integer"},
+        ]
+    }
+    assert target.read_rows() == [
+        {"id": "1 germany", "name": "germany", "population": 83},
+        {"id": "2 france", "name": "france", "population": 66},
+        {"id": "3 spain", "name": "spain", "population": 47},
+    ]

frictionless/steps/field/field_update.py

@@ -50,11 +50,17 @@ class field_update(Step):
     A descriptor for the field to set the metadata.
     """
 
+    pass_row: bool = False
+    """
+    Pass the entire row as a second parameter for the transformation function if set to True.
+    The first parameter (the value) remains unchanged.
+    """
+
     # Transform
 
     def transform_resource(self, resource: Resource):
         function = self.function
-        pass_row = False
+        pass_row = self.pass_row
         table = resource.to_petl()  # type: ignore
         descriptor = deepcopy(self.descriptor) or {}
         new_name = descriptor.get("name")
@@ -106,5 +112,6 @@ def transform_resource(self, resource: Resource):
             "value": {},
             "formula": {"type": "string"},
             "descriptor": {"type": "object"},
+            "pass_row": {"type": "boolean"},
         },
     }