Method tail_operations

assert-struct-macros/src/pattern/field.rs:239–277

Get operations after the root field access (tail operations) For NamedField/UnnamedField alone, returns None (no additional operations) For Chained, returns all operations except the first non-Deref field access Examples: - Chained([Deref, NamedField("x")]) → Some(Deref) - Chained([NamedField("x"), Method("len")]) → Some(Method("len")) - Chained([Deref, NamedField("x"), Method("len")]) → Some(Cha

(&self)

    /// - Chained([NamedField("x"), Method("len")]) → Some(Method("len"))
    /// - Chained([Deref, NamedField("x"), Method("len")]) → Some(Chained([Deref, Method("len")]))
    pub(crate) fn tail_operations(&self) -> Option<Self> {
        match self {
            FieldOperation::NamedField { .. } | FieldOperation::UnnamedField { .. } => {
                // Just a field access, no additional operations
                None
            }
            FieldOperation::Chained { operations, span } => {
                // Find the index of the first non-Deref field access
                let field_access_idx = operations
                    .iter()
                    .position(|op| {
                        matches!(
                            op,
                            FieldOperation::NamedField { .. } | FieldOperation::UnnamedField { .. }
                        )
                    })
                    .expect("Chained operation must have at least one field access");

                // Collect all operations except the field access itself
                let mut tail_ops: Vec<_> = operations[..field_access_idx].to_vec();
                tail_ops.extend_from_slice(&operations[field_access_idx + 1..]);

                if tail_ops.is_empty() {
                    None
                } else if tail_ops.len() == 1 {
                    Some(tail_ops.into_iter().next().unwrap())
                } else {
                    Some(FieldOperation::Chained {
                        operations: tail_ops,
                        span: *span,
                    })
                }
            }
            // For other operation types (Method, Await, Index, Deref), they don't have a root field to strip
            // These should not appear at the root level of a FieldAssertion, but if they do,
            // return None to indicate no tail
            _ => None,
        }
    }
}

impl FieldOperation {