satay_codegen/render/
mod.rs

1use proc_macro2::{Span, TokenStream};
2use quote::quote;
3use syn::{Ident, LitStr, parse_quote};
4use tracing::info;
5
6use crate::model::{Api, Field, IntegerType, Operation, ParseAs, RangeScalar, TypeRef};
7use crate::{GenerateOptions, RootModule};
8
9const PREAMBLE: &str = "\
10//! @generated by satay. Do not edit by hand.
11#![allow(
12    clippy::doc_markdown,
13    clippy::missing_errors_doc,
14    clippy::must_use_candidate,
15    clippy::needless_pass_by_value,
16    clippy::return_self_not_must_use,
17    clippy::single_match_else
18)]
19
20";
21
22#[derive(Debug)]
23pub struct GeneratedFile {
24    pub relative_path: String,
25    pub contents: String,
26}
27
28pub(crate) fn render_api(api: &Api, options: GenerateOptions) -> Vec<GeneratedFile> {
29    info!(
30        components = api.components.len(),
31        operations = api.operations.len(),
32        "rendering API"
33    );
34    let mut files = vec![];
35
36    let root_module = match options.root_module {
37        RootModule::ModRs => "mod.rs",
38        RootModule::LibRs => "lib.rs",
39    };
40    let top_mod = render_top_mod(api);
41    files.push(GeneratedFile {
42        relative_path: root_module.to_owned(),
43        contents: format_file(top_mod),
44    });
45
46    if !api.components.is_empty() || !api.constrained_types.is_empty() {
47        let types_file = types::render_types_file(api);
48        files.push(GeneratedFile {
49            relative_path: "types.rs".to_owned(),
50            contents: format_file(types_file),
51        });
52    }
53
54    let api_file = api::render_api_file(api);
55    files.push(GeneratedFile {
56        relative_path: "api.rs".to_owned(),
57        contents: format_file(api_file),
58    });
59
60    for operation in &api.operations {
61        let dir = &operation.fn_name;
62        let endpoint_mod = endpoint::render_endpoint_mod(operation);
63        files.push(GeneratedFile {
64            relative_path: format!("{dir}/mod.rs"),
65            contents: format_file(endpoint_mod),
66        });
67
68        let parts_file = endpoint::render_endpoint_parts_file(api, operation);
69        files.push(GeneratedFile {
70            relative_path: format!("{dir}/parts.rs"),
71            contents: format_file(parts_file),
72        });
73
74        let json_file = endpoint::render_endpoint_json_file(api, operation);
75        files.push(GeneratedFile {
76            relative_path: format!("{dir}/json.rs"),
77            contents: format_file(json_file),
78        });
79    }
80
81    info!(files = files.len(), "rendered API");
82    files
83}
84
85fn format_file(file: syn::File) -> String {
86    let code = prettyplease::unparse(&file);
87    let mut formatted = String::with_capacity(PREAMBLE.len() + code.len());
88    formatted.push_str(PREAMBLE);
89    formatted.push_str(&code);
90    formatted
91}
92
93fn render_top_mod(api: &Api) -> syn::File {
94    let mut items: Vec<syn::Item> = vec![];
95    let server_url = lit_str(&api.server_url);
96    items.push(parse_quote!(pub const SERVER_URL: &str = #server_url;));
97
98    let has_types = !api.components.is_empty() || !api.constrained_types.is_empty();
99    if has_types {
100        items.push(parse_quote!(
101            pub mod types;
102        ));
103        items.push(parse_quote!(
104            pub use types::*;
105        ));
106    }
107
108    items.push(parse_quote!(
109        #[cfg(feature = "json")]
110        mod api;
111    ));
112    items.push(parse_quote!(
113        #[cfg(feature = "json")]
114        pub use api::*;
115    ));
116
117    for operation in &api.operations {
118        let module = ident(&operation.fn_name);
119        items.push(parse_quote!(pub mod #module;));
120        items.push(parse_quote!(pub use #module::*;));
121    }
122
123    syn::File {
124        shebang: None,
125        attrs: vec![],
126        items,
127    }
128}
129
130pub fn ident(value: &str) -> Ident {
131    if let Some(raw) = value.strip_prefix("r#") {
132        Ident::new_raw(raw, Span::call_site())
133    } else {
134        Ident::new(value, Span::call_site())
135    }
136}
137
138pub fn lit_str(value: &str) -> LitStr {
139    LitStr::new(value, Span::call_site())
140}
141
142pub fn doc_attrs(description: Option<&str>) -> Vec<syn::Attribute> {
143    let Some(description) = description.filter(|description| !description.trim().is_empty()) else {
144        return vec![];
145    };
146
147    description
148        .lines()
149        .map(|line| {
150            let doc_line = if line.is_empty() {
151                String::new()
152            } else {
153                format!(" {line}")
154            };
155            let doc_line = lit_str(&doc_line);
156            parse_quote!(#[doc = #doc_line])
157        })
158        .collect()
159}
160
161pub fn rust_type(ty: &TypeRef) -> syn::Type {
162    match ty {
163        TypeRef::String => parse_quote!(String),
164        TypeRef::ParsedString(parse_as) | TypeRef::ParsedInteger(parse_as) => {
165            parse_as_rust_type(*parse_as)
166        }
167        TypeRef::Integer(integer_type) => integer_rust_type(*integer_type),
168        TypeRef::F32 => parse_quote!(f32),
169        TypeRef::F64 => parse_quote!(f64),
170        TypeRef::Bool => parse_quote!(bool),
171        TypeRef::Array(item) => {
172            let item = rust_type(item);
173            parse_quote!(Vec<#item>)
174        }
175        TypeRef::Map(value) => {
176            let value = rust_type(value);
177            parse_quote!(BTreeMap<String, #value>)
178        }
179        TypeRef::JsonValue => parse_quote!(satay_runtime::JsonValue),
180        TypeRef::Range(range_type) => {
181            let name = ident(&range_type.rust_name);
182            parse_quote!(#name)
183        }
184        TypeRef::Named(name)
185        | TypeRef::Constrained {
186            rust_name: name, ..
187        } => {
188            let name = ident(name);
189            parse_quote!(#name)
190        }
191        TypeRef::Option(inner) => {
192            let inner = rust_type(inner);
193            parse_quote!(Option<#inner>)
194        }
195    }
196}
197
198pub fn range_scalar_rust_type(scalar: RangeScalar) -> syn::Type {
199    match scalar {
200        RangeScalar::Integer(integer_type) => integer_rust_type(integer_type),
201        RangeScalar::F32 => parse_quote!(f32),
202        RangeScalar::F64 => parse_quote!(f64),
203    }
204}
205
206pub fn integer_rust_type(integer_type: IntegerType) -> syn::Type {
207    match integer_type {
208        IntegerType::U8 => parse_quote!(u8),
209        IntegerType::U16 => parse_quote!(u16),
210        IntegerType::U32 => parse_quote!(u32),
211        IntegerType::U64 => parse_quote!(u64),
212        IntegerType::I8 => parse_quote!(i8),
213        IntegerType::I16 => parse_quote!(i16),
214        IntegerType::I32 => parse_quote!(i32),
215        IntegerType::I64 => parse_quote!(i64),
216    }
217}
218
219pub fn parse_as_rust_type(parse_as: ParseAs) -> syn::Type {
220    match parse_as {
221        ParseAs::U8 => parse_quote!(u8),
222        ParseAs::U16 => parse_quote!(u16),
223        ParseAs::U32 => parse_quote!(u32),
224        ParseAs::U64 => parse_quote!(u64),
225        ParseAs::I8 => parse_quote!(i8),
226        ParseAs::I16 => parse_quote!(i16),
227        ParseAs::I32 => parse_quote!(i32),
228        ParseAs::I64 => parse_quote!(i64),
229        ParseAs::F32 => parse_quote!(f32),
230        ParseAs::F64 => parse_quote!(f64),
231        ParseAs::Bool => parse_quote!(bool),
232        ParseAs::Date => parse_quote!(satay_runtime::Date),
233        ParseAs::NaiveDateTime => parse_quote!(satay_runtime::PrimitiveDateTime),
234        ParseAs::OffsetDateTime => parse_quote!(satay_runtime::OffsetDateTime),
235        ParseAs::UnixTime => parse_quote!(satay_runtime::OffsetDateTime),
236        ParseAs::Time => parse_quote!(satay_runtime::Time),
237        ParseAs::IntegerRange | ParseAs::NumberRange => {
238            unreachable!("range parse-as uses generated range types")
239        }
240    }
241}
242
243pub fn parse_as_string_serde_module(parse_as: ParseAs) -> &'static str {
244    match parse_as {
245        ParseAs::U8 => "satay_runtime::serde_string::as_u8",
246        ParseAs::U16 => "satay_runtime::serde_string::as_u16",
247        ParseAs::U32 => "satay_runtime::serde_string::as_u32",
248        ParseAs::U64 => "satay_runtime::serde_string::as_u64",
249        ParseAs::I8 => "satay_runtime::serde_string::as_i8",
250        ParseAs::I16 => "satay_runtime::serde_string::as_i16",
251        ParseAs::I32 => "satay_runtime::serde_string::as_i32",
252        ParseAs::I64 => "satay_runtime::serde_string::as_i64",
253        ParseAs::F32 => "satay_runtime::serde_string::as_f32",
254        ParseAs::F64 => "satay_runtime::serde_string::as_f64",
255        ParseAs::Bool => "satay_runtime::serde_string::as_bool",
256        ParseAs::Date => "satay_runtime::serde_string::as_date",
257        ParseAs::NaiveDateTime => "satay_runtime::serde_string::as_naive_datetime",
258        ParseAs::OffsetDateTime => "satay_runtime::serde_string::as_offset_datetime",
259        ParseAs::UnixTime => "satay_runtime::serde_string::as_unix_time",
260        ParseAs::Time => "satay_runtime::serde_string::as_time",
261        ParseAs::IntegerRange | ParseAs::NumberRange => {
262            unreachable!("range parse-as uses generated range types")
263        }
264    }
265}
266
267pub fn parse_as_integer_serde_module(parse_as: ParseAs) -> &'static str {
268    match parse_as {
269        ParseAs::Bool => "satay_runtime::serde_integer::as_bool",
270        ParseAs::UnixTime => "satay_runtime::serde_integer::as_unix_time",
271        ParseAs::U8
272        | ParseAs::U16
273        | ParseAs::U32
274        | ParseAs::U64
275        | ParseAs::I8
276        | ParseAs::I16
277        | ParseAs::I32
278        | ParseAs::I64
279        | ParseAs::F32
280        | ParseAs::F64
281        | ParseAs::Date
282        | ParseAs::NaiveDateTime
283        | ParseAs::OffsetDateTime
284        | ParseAs::Time
285        | ParseAs::IntegerRange
286        | ParseAs::NumberRange => unreachable!("only bool and unixtime can parse from integer"),
287    }
288}
289
290pub fn rust_field_type(ty: &TypeRef, required: bool, treat_error_as_none: bool) -> syn::Type {
291    if (required && !treat_error_as_none) || ty.is_option() {
292        rust_type(ty)
293    } else {
294        let ty = rust_type(ty);
295        parse_quote!(Option<#ty>)
296    }
297}
298
299pub fn input_fields(operation: &Operation) -> Vec<Field> {
300    let mut input_fields = Vec::with_capacity(
301        operation.parameters.len() + usize::from(operation.request_body.is_some()),
302    );
303    input_fields.extend(operation.parameters.iter().map(|parameter| Field {
304        wire_name: parameter.wire_name.clone(),
305        rust_name: parameter.rust_name.clone(),
306        description: parameter.description.clone(),
307        ty: parameter.ty.clone(),
308        required: parameter.required,
309        treat_error_as_none: false,
310    }));
311    if let Some(body) = &operation.request_body {
312        input_fields.push(Field {
313            wire_name: body.field_name.clone(),
314            rust_name: body.field_name.clone(),
315            description: body.description.clone(),
316            ty: body.ty.clone(),
317            required: body.required,
318            treat_error_as_none: false,
319        });
320    }
321
322    input_fields
323}
324
325pub fn input_setter_name(field: &Field) -> Ident {
326    if field.rust_name == "new" {
327        ident("with_new")
328    } else {
329        ident(&field.rust_name)
330    }
331}
332
333pub fn input_builder_arg_type(ty: &TypeRef) -> TokenStream {
334    if ty == &TypeRef::String {
335        quote!(impl Into<String>)
336    } else {
337        let ty = rust_type(ty);
338        quote!(#ty)
339    }
340}
341
342pub fn input_builder_value(value: TokenStream, ty: &TypeRef) -> TokenStream {
343    if ty == &TypeRef::String {
344        quote!(#value.into())
345    } else {
346        value
347    }
348}
349
350pub fn request_from_parts_expr(operation: &Operation) -> syn::Expr {
351    match &operation.request_body {
352        Some(body) if body.required => parse_quote!(satay_runtime::into_json_request(parts)),
353        Some(_) => parse_quote!(satay_runtime::into_optional_json_request(parts)),
354        None => parse_quote!(satay_runtime::into_empty_request(parts)),
355    }
356}
357
358pub fn input_field(field: &str) -> syn::Expr {
359    let field = ident(field);
360    parse_quote!(input.#field)
361}
362
363mod api;
364mod endpoint;
365mod types;
366
367#[cfg(test)]
368mod tests {
369    use super::*;
370    use crate::model::PathSegment;
371    use crate::model::{Component, ComponentKind, HttpMethod, RequestBody, ResponseCase};
372    use quote::{ToTokens, quote};
373    use syn::{Fields, GenericArgument, Item, PathArguments, Type};
374
375    #[test]
376    fn render_file_exposes_struct_ast_without_source_comparison() {
377        let api = Api::new(
378            String::new(),
379            vec![],
380            vec![Component {
381                rust_name: "Pet".to_owned(),
382                description: None,
383                kind: ComponentKind::Struct(vec![
384                    Field {
385                        wire_name: "id".to_owned(),
386                        rust_name: "id".to_owned(),
387                        description: None,
388                        ty: TypeRef::String,
389                        required: true,
390                        treat_error_as_none: false,
391                    },
392                    Field {
393                        wire_name: "tag_count".to_owned(),
394                        rust_name: "tag_count".to_owned(),
395                        description: None,
396                        ty: TypeRef::Integer(IntegerType::I32),
397                        required: false,
398                        treat_error_as_none: false,
399                    },
400                ]),
401            }],
402            vec![],
403            vec![],
404        );
405
406        let file = types::render_types_file(&api);
407        assert_eq!(file.items.len(), 1);
408        let Item::Struct(item) = &file.items[0] else {
409            panic!("expected struct item");
410        };
411        assert_eq!(item.ident, "Pet");
412        let Fields::Named(fields) = &item.fields else {
413            panic!("expected named fields");
414        };
415        assert_eq!(fields.named.len(), 2);
416
417        let mut fields = fields.named.iter();
418        let id = fields.next().expect("id field");
419        assert_eq!(id.ident.as_ref().expect("field ident"), "id");
420        assert!(type_path_is(&id.ty, "String"));
421
422        let tag_count = fields.next().expect("tag_count field");
423        assert_eq!(tag_count.ident.as_ref().expect("field ident"), "tag_count");
424        let Some(inner) = option_inner(&tag_count.ty) else {
425            panic!("optional field should render as Option<T>");
426        };
427        assert!(type_path_is(inner, "i32"));
428    }
429
430    #[test]
431    fn render_file_exposes_operation_items_without_source_comparison() {
432        let api = Api::new(
433            String::new(),
434            vec![],
435            vec![],
436            vec![],
437            vec![Operation {
438                fn_name: "create_pet".to_owned(),
439                description: None,
440                input_name: "CreatePetInput".to_owned(),
441                response_name: "CreatePetResponse".to_owned(),
442                method: HttpMethod::Post,
443                path: "/pets".to_owned(),
444                path_segments: vec![PathSegment::Literal("/pets".to_owned())],
445                parameters: vec![],
446                request_body: Some(RequestBody {
447                    field_name: "body".to_owned(),
448                    description: None,
449                    content_type: "application/json".to_owned(),
450                    ty: TypeRef::Named("Pet".to_owned()),
451                    required: true,
452                }),
453                responses: vec![ResponseCase {
454                    status: 201,
455                    variant_name: "Created".to_owned(),
456                    description: None,
457                    body: Some(TypeRef::Named("Pet".to_owned())),
458                }],
459            }],
460        );
461
462        let files = render_api(&api, GenerateOptions::default());
463        assert!(files.iter().any(|f| f.relative_path == "mod.rs"));
464        assert!(files.iter().any(|f| f.relative_path == "create_pet/mod.rs"));
465        assert!(
466            files
467                .iter()
468                .any(|f| f.relative_path == "create_pet/parts.rs")
469        );
470        assert!(
471            files
472                .iter()
473                .any(|f| f.relative_path == "create_pet/json.rs")
474        );
475    }
476
477    #[test]
478    fn rust_field_type_wraps_optional_and_treat_error_as_none_fields() {
479        assert_eq!(
480            rust_field_type(&TypeRef::String, true, false)
481                .to_token_stream()
482                .to_string(),
483            "String"
484        );
485        assert_eq!(
486            rust_field_type(&TypeRef::String, false, false)
487                .to_token_stream()
488                .to_string(),
489            "Option < String >"
490        );
491        assert_eq!(
492            rust_field_type(&TypeRef::String, true, true)
493                .to_token_stream()
494                .to_string(),
495            "Option < String >"
496        );
497        assert_eq!(
498            rust_field_type(&TypeRef::Option(Box::new(TypeRef::String)), true, false)
499                .to_token_stream()
500                .to_string(),
501            "Option < String >"
502        );
503    }
504
505    #[test]
506    fn input_builder_arguments_convert_strings_only() {
507        assert_eq!(
508            input_builder_arg_type(&TypeRef::String).to_string(),
509            "impl Into < String >"
510        );
511        assert_eq!(
512            input_builder_arg_type(&TypeRef::Integer(IntegerType::I32)).to_string(),
513            "i32"
514        );
515        assert_eq!(
516            input_builder_value(quote!(value), &TypeRef::String).to_string(),
517            "value . into ()"
518        );
519        assert_eq!(
520            input_builder_value(quote!(value), &TypeRef::Integer(IntegerType::I32)).to_string(),
521            "value"
522        );
523    }
524
525    #[test]
526    fn request_conversion_mode_matches_body_requirement() {
527        assert_eq!(
528            request_from_parts_expr(&operation_with_body(None))
529                .to_token_stream()
530                .to_string(),
531            "satay_runtime :: into_empty_request (parts)"
532        );
533        assert_eq!(
534            request_from_parts_expr(&operation_with_body(Some(true)))
535                .to_token_stream()
536                .to_string(),
537            "satay_runtime :: into_json_request (parts)"
538        );
539        assert_eq!(
540            request_from_parts_expr(&operation_with_body(Some(false)))
541                .to_token_stream()
542                .to_string(),
543            "satay_runtime :: into_optional_json_request (parts)"
544        );
545    }
546
547    fn operation_with_body(required: Option<bool>) -> Operation {
548        Operation {
549            fn_name: "create_pet".to_owned(),
550            description: None,
551            input_name: "CreatePetInput".to_owned(),
552            response_name: "CreatePetResponse".to_owned(),
553            method: HttpMethod::Post,
554            path: "/pets".to_owned(),
555            path_segments: vec![PathSegment::Literal("/pets".to_owned())],
556            parameters: vec![],
557            request_body: required.map(|required| RequestBody {
558                field_name: "body".to_owned(),
559                description: None,
560                content_type: "application/json".to_owned(),
561                ty: TypeRef::Named("Pet".to_owned()),
562                required,
563            }),
564            responses: vec![],
565        }
566    }
567
568    fn type_path_is(ty: &syn::Type, expected: &str) -> bool {
569        let Type::Path(path) = ty else {
570            return false;
571        };
572        path.path.is_ident(expected)
573    }
574
575    fn option_inner(ty: &syn::Type) -> Option<&syn::Type> {
576        let Type::Path(path) = ty else {
577            return None;
578        };
579        let segment = path.path.segments.first()?;
580        if segment.ident != "Option" {
581            return None;
582        }
583        let PathArguments::AngleBracketed(arguments) = &segment.arguments else {
584            return None;
585        };
586        let GenericArgument::Type(inner) = arguments.args.first()? else {
587            return None;
588        };
589        Some(inner)
590    }
591}
satay_codegen/render/mod.rs

satay_codegen/render/
mod.rs
