roam_codegen/targets/swift/
mod.rs

1//! Swift code generation for roam services.
2//!
3//! This module generates Swift client and server code from service definitions.
4//! The generated code includes:
5//! - Type definitions for all named types (structs, enums)
6//! - Caller protocol and client implementation for making RPC calls
7//! - Handler protocol for implementing services
8//! - Dispatcher for routing incoming calls
9//! - Encoding/decoding logic for all types
10//! - Runtime schema information for channel binding
11
12pub mod client;
13pub mod decode;
14pub mod encode;
15pub mod schema;
16pub mod server;
17pub mod types;
18pub mod wire;
19
20use roam_types::{MethodDescriptor, ServiceDescriptor};
21
22pub use client::generate_client;
23pub use schema::generate_schemas;
24pub use server::generate_server;
25pub use types::{collect_named_types, generate_named_types};
26
27/// Controls which Swift bindings are generated for a service.
28#[derive(Debug, Clone, Copy, PartialEq, Eq)]
29pub enum SwiftBindings {
30    /// Generate client-side bindings (`*Caller`, `*Client`) and shared support code.
31    Client,
32    /// Generate server-side bindings (`*Handler`, `*ChannelingDispatcher`) and shared support code.
33    Server,
34    /// Generate both client and server bindings (legacy default behavior).
35    ClientAndServer,
36}
37
38/// Generate method IDs as a Swift enum.
39pub fn generate_method_ids(methods: &[&MethodDescriptor]) -> String {
40    use crate::render::{fq_name, hex_u64};
41
42    let mut items = methods
43        .iter()
44        .map(|m| (fq_name(m), m.id.0))
45        .collect::<Vec<_>>();
46    items.sort_by(|a, b| a.0.cmp(&b.0));
47
48    let mut out = String::new();
49    out.push_str("// @generated by roam-codegen\n");
50    out.push_str("// This file defines canonical roam method IDs.\n\n");
51    out.push_str("public enum RoamMethodId {\n");
52    out.push_str("    public static let byName: [String: UInt64] = [\n");
53    for (name, id) in items {
54        out.push_str(&format!("        \"{name}\": {hex},\n", hex = hex_u64(id)));
55    }
56    out.push_str("    ]\n");
57    out.push_str("}\n");
58    out
59}
60
61/// Generate a complete Swift module for a service.
62///
63/// This is the main entry point for Swift code generation.
64pub fn generate_service(service: &ServiceDescriptor) -> String {
65    generate_service_with_bindings(service, SwiftBindings::ClientAndServer)
66}
67
68/// Generate a Swift module for a service with explicit client/server selection.
69///
70/// Shared sections (method IDs, named types, schemas) are always included.
71pub fn generate_service_with_bindings(
72    service: &ServiceDescriptor,
73    bindings: SwiftBindings,
74) -> String {
75    use crate::render::hex_u64;
76    use heck::{ToLowerCamelCase, ToUpperCamelCase};
77
78    let mut out = String::new();
79    out.push_str("// @generated by roam-codegen\n");
80    out.push_str("// DO NOT EDIT - regenerate with `cargo xtask codegen --swift`\n\n");
81    out.push_str("import Foundation\n");
82    out.push_str("import RoamRuntime\n\n");
83
84    let service_name = service.service_name.to_upper_camel_case();
85
86    // Generate method IDs enum
87    out.push_str(&format!("// MARK: - {service_name} Method IDs\n\n"));
88    out.push_str(&format!("public enum {service_name}MethodId {{\n"));
89    for method in service.methods {
90        let method_name = method.method_name.to_lower_camel_case();
91        let id = crate::method_id(method);
92        out.push_str(&format!(
93            "    public static let {method_name}: UInt64 = {hex}\n",
94            hex = hex_u64(id)
95        ));
96    }
97    out.push_str("}\n\n");
98
99    // Generate named types
100    out.push_str(&format!("// MARK: - {service_name} Types\n\n"));
101    let named_types = collect_named_types(service);
102    out.push_str(&generate_named_types(&named_types));
103
104    match bindings {
105        SwiftBindings::Client => {
106            out.push_str(&format!("// MARK: - {service_name} Client\n\n"));
107            out.push_str(&generate_client(service));
108        }
109        SwiftBindings::Server => {
110            out.push_str(&format!("// MARK: - {service_name} Server\n\n"));
111            out.push_str(&generate_server(service));
112        }
113        SwiftBindings::ClientAndServer => {
114            out.push_str(&format!("// MARK: - {service_name} Client\n\n"));
115            out.push_str(&generate_client(service));
116
117            out.push_str(&format!("// MARK: - {service_name} Server\n\n"));
118            out.push_str(&generate_server(service));
119        }
120    }
121
122    // Always generate runtime schema info used for channel binding.
123    out.push_str(&format!("// MARK: - {service_name} Schemas\n\n"));
124    out.push_str(&generate_schemas(service));
125
126    out
127}
128
129#[cfg(test)]
130mod tests {
131    use super::generate_service;
132    use roam::{Rx, Tx};
133    use roam_hash::method_descriptor;
134    use roam_types::ServiceDescriptor;
135
136    #[test]
137    fn generated_swift_preserves_channel_initial_credit() {
138        let subscribe = method_descriptor::<(Tx<u32>, Rx<u32, 32>), ()>(
139            "StreamSvc",
140            "subscribe",
141            &["output", "input"],
142            None,
143        );
144        let methods = Box::leak(vec![subscribe].into_boxed_slice());
145        let service = ServiceDescriptor {
146            service_name: "StreamSvc",
147            methods,
148            doc: None,
149        };
150
151        let generated = generate_service(&service);
152
153        assert!(
154            generated.contains(".tx(initialCredit: 16, element: .u32)"),
155            "generated Swift should preserve default channel credit:\n{generated}"
156        );
157        assert!(
158            generated.contains(".rx(initialCredit: 32, element: .u32)"),
159            "generated Swift should preserve custom channel credit:\n{generated}"
160        );
161    }
162}
roam_codegen/targets/swift/mod.rs

roam_codegen/targets/swift/
mod.rs
