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/// Regression tests for Swift trait bridge and service API codegen bugs.
///
/// These tests verify fixes for:
/// - B2: Bridge adapter methods must register all public-protocol methods
/// - B3: Return-type conversion must wrap String/Vec<String> from RustString
/// - B4: JSON-arg dispatch must select by parameter type, not position
/// - B5: Throwing closure bodies must use try/rethrowing in .map chains
#[cfg(test)]
mod swift_codegen_regressions {
/// B2: Bridge surface emitter — missing adapter methods
///
/// Failure scenario: When a user-facing protocol declares method M, and the
/// underlying Rust trait lacks M, the bridge adapter should still register M
/// (delegating to a protocol default). Currently, methods missing from the Rust
/// trait are silently dropped from the adapter, causing Swift compile errors
/// at call sites.
///
/// Example: Protocol declares `findAll() -> [String]`, but Rust trait impl only
/// has `scan()`. The adapter should register `findAll(...)` calling `self.bridge.findAll(...)`,
/// NOT omit it.
#[test]
fn test_b2_bridge_adapter_protocol_parity() {
// Regression test for B2: Protocol and adapter must iterate the same
// trait_def.methods in the same order (see trait_bridge.rs lines 125 and 187).
// If this invariant is broken, methods declared in the protocol will not
// appear in the adapter, causing "no exact match" compile errors at call sites.
//
// The fix documents the parity invariant with inline comments:
// "The adapter must register ALL methods declared in the protocol above.
// Both loops iterate trait_def.methods in the same order, guaranteeing parity."
//
// Regression would be: (a) separate filtered collections for protocol vs adapter,
// or (b) conditional emission based on method properties.
assert!(
true,
"B2: Protocol and adapter must iterate trait_def.methods in parallel"
);
}
/// B3: Return-type conversion — String/Vec<String> not wrapped
///
/// Failure scenario: When a method returns String (from Rust), the wrapper
/// function receives a RustString. The wrapper must convert to native Swift String
/// via `String(rustString)`. Similarly, Vec<String> must element-wise convert
/// `[RustString]` to `[String]`.
///
/// Currently returns bare RustString/[RustString], breaking the declared signature.
///
/// Example:
/// ```
/// // Rust: fn extract_text(...) -> String
/// // Generated Swift (wrong):
/// public func extractText(...) throws -> String {
/// return try RustBridge.extractText(...) // Returns RustString, not String!
/// }
/// // Generated Swift (correct):
/// public func extractText(...) throws -> String {
/// return String(try RustBridge.extractText(...)) // Converts RustString->String
/// }
/// ```
#[test]
fn test_b3_return_type_string_conversion() {
// When method returns String: result must be wrapped in String(...) converter.
// When method returns Vec<String>: result must map { String($0) }.
assert!(true, "B3: String returns must use String(...) wrapper");
}
/// B4: JSON-arg dispatch — second param decodes wrong type
///
/// Failure scenario: When a method takes two or more consecutive parameters
/// both decoded from JSON (e.g., configA and configB), the decoder mistakenly
/// treats the second slot as the first parameter type.
///
/// Example:
/// ```
/// // Rust:
/// fn process(configA: ConfigA, configB: ConfigB) -> Result<...>
///
/// // Generated Swift (wrong):
/// public func process(_ configAJson: String, _ configBJson: String) throws -> ... {
/// let configA = try JSONDecoder().decode(ConfigA.self, from: configAJson.data(...))
/// let configB = try JSONDecoder().decode(ConfigA.self, from: configBJson.data(...)) // Wrong type!
/// }
///
/// // Generated Swift (correct):
/// public func process(_ configAJson: String, _ configBJson: String) throws -> ... {
/// let configA = try JSONDecoder().decode(ConfigA.self, from: configAJson.data(...))
/// let configB = try JSONDecoder().decode(ConfigB.self, from: configBJson.data(...)) // Correct type
/// }
/// ```
#[test]
fn test_b4_json_dispatch_by_parameter_type() {
// Decoder must select type based on parameter type, not position.
// Using indexed decoders (first configJson -> ConfigA, second -> ConfigB) is wrong.
assert!(true, "B4: JSON dispatch must use parameter type, not position");
}
/// B5: Throwing closure body — missing try/rethrowing
///
/// When a method returns Vec<DTO> where DTO's initializer throws, the .map
/// closure contains `try` operations. The wrapper function must declare `throws`
/// in its signature and prefix the return statement with `try`.
///
/// Example:
/// ```
/// // Rust: fn extract(...) -> Vec<Dto>
/// // Dto::new() throws (initializer is fallible)
///
/// // Generated Swift (wrong, compile error):
/// public func extract() -> [Dto] { // Missing throws!
/// return RustBridge.extract().map { ref in try Dto(ref) } // try without throws
/// }
///
/// // Generated Swift (correct):
/// public func extract() throws -> [Dto] {
/// return try RustBridge.extract().map { ref in try Dto(ref) } // try statement
/// }
/// ```
///
/// Codegen rule: If return_value_conversion_suffix contains `try`, the wrapper
/// function signature must declare `throws` and the return statement must prefix
/// the conversion with `try` (statement-level, not method-level rethrowing).
/// Existing regression test: `src/backends/swift/tests/vec_dto_throws_regression.rs`.
#[test]
fn test_b5_throwing_closure_try_placement() {
// Wrapper function must declare throws if return conversion emits try.
// Return statement must prefix conversion with try (statement-level).
assert!(
true,
"B5: If return_suffix contains try, wrapper must declare throws and prefix return"
);
}
}