Payment Method Form Hierarchy Tests

StripePaymentSheet/StripePaymentSheetTests/PaymentSheet/FormHierarchyTestHelpers.swift

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+//
+//  FormHierarchyTestHelpers.swift
+//  StripePaymentSheetTests
+//
+//  Test utilities for verifying form hierarchies generated by form specs.
+//
+
+import Foundation
+@testable @_spi(STP) import StripePaymentSheet
+@testable @_spi(STP) import StripeUICore
+import XCTest
+
+// MARK: - FormHierarchyNode
+
+/// A testable, equatable representation of an Element hierarchy.
+/// Use this to verify the structure of forms generated by form specs.
+struct FormHierarchyNode: Equatable, CustomStringConvertible {
+    let type: String
+    let properties: [String: String]
+    let children: [FormHierarchyNode]
+
+    init(type: String, properties: [String: String] = [:], children: [FormHierarchyNode] = []) {
+        self.type = type
+        self.properties = properties
+        self.children = children
+    }
+
+    var description: String {
+        return descriptionWithIndent(0)
+    }
+
+    private func descriptionWithIndent(_ indent: Int) -> String {
+        let indentStr = String(repeating: "  ", count: indent)
+        let propsStr = properties.isEmpty ? "" : "(" + properties.sorted(by: { $0.key < $1.key }).map { "\($0.key): \"\($0.value)\"" }.joined(separator: ", ") + ")"
+        var result = "\(indentStr)\(type)\(propsStr)"
+
+        if !children.isEmpty {
+            result += " {\n"
+            for child in children {
+                result += child.descriptionWithIndent(indent + 1) + "\n"
+            }
+            result += "\(indentStr)}"
+        }
+
+        return result
+    }
+}
+
+// MARK: - Element to Hierarchy Conversion
+
+extension Element {
+    /// Converts this element and its children into a testable hierarchy representation.
+    /// Automatically unwraps PaymentMethodElementWrapper.
+    func toHierarchyNode() -> FormHierarchyNode {
+        // Unwrap PaymentMethodElementWrapper by checking the type name
+        // (We can't check the protocol directly since AnyPaymentMethodElementWrapper is private)
+        if let wrappedElement = unwrappedElement(from: self) {
+            return wrappedElement.toHierarchyNode()
+        }
+
+        let (typeName, props) = extractTypeAndProperties()
+        let childNodes: [FormHierarchyNode]
+
+        if let container = self as? ContainerElement {
+            childNodes = container.elements.map { $0.toHierarchyNode() }
+        } else {
+            childNodes = []
+        }
+
+        return FormHierarchyNode(type: typeName, properties: props, children: childNodes)
+    }
+
+    /// Attempts to unwrap a PaymentMethodElementWrapper to get its underlying element
+    private func unwrappedElement(from element: Element) -> Element? {
+        // Use Mirror to check if this is a PaymentMethodElementWrapper and extract the wrapped element
+        let mirror = Mirror(reflecting: element)
+        let typeName = String(describing: type(of: element))
+
+        if typeName.hasPrefix("PaymentMethodElementWrapper") {
+            for child in mirror.children {
+                if child.label == "element", let unwrapped = child.value as? Element {
+                    return unwrapped
+                }
+            }
+        }
+        return nil
+    }
+
+    /// Extracts the type name and relevant properties for testing
+    private func extractTypeAndProperties() -> (String, [String: String]) {
+        switch self {
+        // Text fields
+        case let textField as TextFieldElement:
+            return ("TextFieldElement", ["label": textField.configuration.label])
+
+        // Dropdowns
+        case let dropdown as DropdownFieldElement:
+            var props: [String: String] = [:]
+            if let label = dropdown.label {
+                props["label"] = label
+            }
+            props["itemCount"] = String(dropdown.items.count)
+            return ("DropdownFieldElement", props)
+
+        // Sections
+        case let section as SectionElement:
+            var props: [String: String] = [:]
+            if let title = section.title {
+                props["title"] = title
+            }
+            return ("SectionElement", props)
+
+        // Form
+        case is FormElement:
+            return ("FormElement", [:])
+
+        // Phone number
+        case is PhoneNumberElement:
+            return ("PhoneNumberElement", [:])
+
+        // Address section
+        case is AddressSectionElement:
+            return ("AddressSectionElement", [:])
+
+        // Checkbox
+        case let checkbox as CheckboxElement:
+            return ("CheckboxElement", ["label": checkbox.label])
+
+        // Static element (for mandates, headers, etc.)
+        case let staticElement as StaticElement:
+            // Try to identify the type of view for more specific matching
+            let viewType = String(describing: type(of: staticElement.view))
+            return ("StaticElement", ["viewType": viewType])
+
+        // Subtitle element (for headers like Affirm, Klarna)
+        case is SubtitleElement:
+            return ("SubtitleElement", [:])
+
+        // SimpleMandateElement
+        case let mandate as SimpleMandateElement:
+            let mandateText = mandate.mandateTextView.attributedText?.string ?? ""
+            // Truncate mandate text for readability
+            let truncated = mandateText.count > 50 ? String(mandateText.prefix(50)) + "..." : mandateText
+            return ("SimpleMandateElement", ["text": truncated])
+
+        // Hidden element wrapper
+        case is SectionElement.HiddenElement:
+            return ("HiddenElement", [:])
+
+        // CardSectionElement
+        case is CardSectionElement:
+            return ("CardSectionElement", [:])
+
+        // USBankAccountPaymentMethodElement
+        case is USBankAccountPaymentMethodElement:
+            return ("USBankAccountPaymentMethodElement", [:])
+
+        // InstantDebitsPaymentMethodElement
+        case is InstantDebitsPaymentMethodElement:
+            return ("InstantDebitsPaymentMethodElement", [:])
+
+        // MultiElementRow (horizontal row of elements, e.g., MM/YY + CVC)
+        case is SectionElement.MultiElementRow:
+            return ("MultiElementRow", [:])
+
+        // DummyAddressLine (placeholder for autocomplete address line)
+        case is AddressSectionElement.DummyAddressLine:
+            return ("DummyAddressLine", [:])
+
+        // Unknown element type - this will cause test failure with a clear message
+        // Add a new case above when you encounter this
+        default:
+            let typeName = String(describing: type(of: self))
+            return ("UNHANDLED_ELEMENT_TYPE<\(typeName)>", [:])
+        }
+    }
+}
+
+// MARK: - Helper to print hierarchy (for debugging / generating expected values)
+
+extension Element {
+    /// Prints the hierarchy in a format that can be copy-pasted into test code.
+    /// Call this when writing new tests to generate the expected hierarchy.
+    func printHierarchyForTests() {
+        print(toHierarchyNode().asSwiftCode())
+    }
+}
+
+extension FormHierarchyNode {
+    /// Returns Swift code that constructs this node, useful for generating test expectations.
+    func asSwiftCode(indent: Int = 0) -> String {
+        let indentStr = String(repeating: "    ", count: indent)
+        let nextIndent = String(repeating: "    ", count: indent + 1)
+
+        var propsCode = ""
+        if !properties.isEmpty {
+            let sortedProps = properties.sorted(by: { $0.key < $1.key })
+            propsCode = sortedProps.map { "\"\($0.key)\": \"\($0.value)\"" }.joined(separator: ", ")
+            propsCode = "properties: [\(propsCode)]"
+        }
+
+        if children.isEmpty {
+            if properties.isEmpty {
+                return "\(indentStr)FormHierarchyNode(type: \"\(type)\")"
+            } else {
+                return "\(indentStr)FormHierarchyNode(type: \"\(type)\", \(propsCode))"
+            }
+        } else {
+            var result = "\(indentStr)FormHierarchyNode(type: \"\(type)\""
+            if !properties.isEmpty {
+                result += ", \(propsCode)"
+            }
+            result += ", children: [\n"
+            for (index, child) in children.enumerated() {
+                result += child.asSwiftCode(indent: indent + 1)
+                if index < children.count - 1 {
+                    result += ","
+                }
+                result += "\n"
+            }
+            result += "\(nextIndent)])"
+            return result
+        }
+    }
+}