This concerns the "other" renames, the renames which we currently ignore and treat as neither simple nor complex. This is the following cases:

• a: $b.c.d - when the right hand side has more than 2 components (2 components is "complex rename")

• a.b: $c - when the left hand side has more than 1 component

These are not reported by the ExpressionFieldPath.

We can implement describeTransformation for FieldPathExpression (SERVER-119380) to report all renames and use that describeTransformation for describeComputedPath in dependency_analysis/document_transformation_helpers.cpp.

This will require some of the graph tests to update, since these other renames are currently reported as computed paths.