ruma_macros/api/
request.rs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
use cfg_if::cfg_if;
use proc_macro2::TokenStream;
use quote::{quote, ToTokens};
use syn::{
    parse::{Parse, ParseStream},
    punctuated::Punctuated,
    Field, Generics, Ident, ItemStruct, Token, Type,
};

use super::{
    attribute::{DeriveRequestMeta, RequestMeta},
    ensure_feature_presence,
};
use crate::util::{field_has_serde_flatten_attribute, import_ruma_common, PrivateField};

mod incoming;
mod outgoing;

pub fn expand_request(attr: RequestAttr, item: ItemStruct) -> TokenStream {
    let ruma_common = import_ruma_common();
    let ruma_macros = quote! { #ruma_common::exports::ruma_macros };

    let maybe_feature_error = ensure_feature_presence().map(syn::Error::to_compile_error);

    let error_ty = attr.0.first().map_or_else(
        || quote! { #ruma_common::api::error::MatrixError },
        |DeriveRequestMeta::Error(ty)| quote! { #ty },
    );

    cfg_if! {
        if #[cfg(feature = "__internal_macro_expand")] {
            use syn::parse_quote;

            let mut derive_input = item.clone();
            derive_input.attrs.push(parse_quote! { #[ruma_api(error = #error_ty)] });
            crate::util::cfg_expand_struct(&mut derive_input);

            let extra_derive = quote! { #ruma_macros::_FakeDeriveRumaApi };
            let ruma_api_attribute = quote! {};
            let request_impls =
                expand_derive_request(derive_input).unwrap_or_else(syn::Error::into_compile_error);
        } else {
            let extra_derive = quote! { #ruma_macros::Request };
            let ruma_api_attribute = quote! { #[ruma_api(error = #error_ty)] };
            let request_impls = quote! {};
        }
    }

    quote! {
        #maybe_feature_error

        #[derive(Clone, Debug, #ruma_common::serde::_FakeDeriveSerde, #extra_derive)]
        #[cfg_attr(not(ruma_unstable_exhaustive_types), non_exhaustive)]
        #ruma_api_attribute
        #item

        #request_impls
    }
}

pub struct RequestAttr(Punctuated<DeriveRequestMeta, Token![,]>);

impl Parse for RequestAttr {
    fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
        Punctuated::<DeriveRequestMeta, Token![,]>::parse_terminated(input).map(Self)
    }
}

pub fn expand_derive_request(input: ItemStruct) -> syn::Result<TokenStream> {
    let fields =
        input.fields.into_iter().map(RequestField::try_from).collect::<syn::Result<_>>()?;

    let mut error_ty = None;

    for attr in input.attrs {
        if !attr.path().is_ident("ruma_api") {
            continue;
        }

        let metas =
            attr.parse_args_with(Punctuated::<DeriveRequestMeta, Token![,]>::parse_terminated)?;
        for meta in metas {
            match meta {
                DeriveRequestMeta::Error(t) => error_ty = Some(t),
            }
        }
    }

    let request = Request {
        ident: input.ident,
        generics: input.generics,
        fields,
        error_ty: error_ty.expect("missing error_ty attribute"),
    };

    let ruma_common = import_ruma_common();
    let test = request.check(&ruma_common)?;
    let types_impls = request.expand_all(&ruma_common);

    Ok(quote! {
        #types_impls

        #[allow(deprecated)]
        #[cfg(test)]
        mod __request {
            #test
        }
    })
}

struct Request {
    ident: Ident,
    generics: Generics,
    fields: Vec<RequestField>,

    error_ty: Type,
}

impl Request {
    fn body_fields(&self) -> impl Iterator<Item = &Field> {
        self.fields.iter().filter_map(RequestField::as_body_field)
    }

    fn has_body_fields(&self) -> bool {
        self.fields
            .iter()
            .any(|f| matches!(&f.kind, RequestFieldKind::Body | RequestFieldKind::NewtypeBody))
    }

    fn has_newtype_body(&self) -> bool {
        self.fields.iter().any(|f| matches!(&f.kind, RequestFieldKind::NewtypeBody))
    }

    fn has_header_fields(&self) -> bool {
        self.fields.iter().any(|f| matches!(&f.kind, RequestFieldKind::Header(_)))
    }

    fn has_path_fields(&self) -> bool {
        self.fields.iter().any(|f| matches!(&f.kind, RequestFieldKind::Path))
    }

    fn has_query_fields(&self) -> bool {
        self.fields.iter().any(|f| matches!(&f.kind, RequestFieldKind::Query))
    }

    fn header_fields(&self) -> impl Iterator<Item = (&Field, &Ident)> {
        self.fields.iter().filter_map(RequestField::as_header_field)
    }

    fn path_fields(&self) -> impl Iterator<Item = &Field> {
        self.fields.iter().filter_map(RequestField::as_path_field)
    }

    fn raw_body_field(&self) -> Option<&Field> {
        self.fields.iter().find_map(RequestField::as_raw_body_field)
    }

    fn query_all_field(&self) -> Option<&Field> {
        self.fields.iter().find_map(RequestField::as_query_all_field)
    }

    fn expand_all(&self, ruma_common: &TokenStream) -> TokenStream {
        let ruma_macros = quote! { #ruma_common::exports::ruma_macros };
        let serde = quote! { #ruma_common::exports::serde };

        let request_body_struct = self.has_body_fields().then(|| {
            let serde_attr = self.has_newtype_body().then(|| quote! { #[serde(transparent)] });
            let fields =
                self.fields.iter().filter_map(RequestField::as_body_field).map(PrivateField);

            quote! {
                /// Data in the request body.
                #[cfg(any(feature = "client", feature = "server"))]
                #[derive(Debug, #ruma_macros::_FakeDeriveRumaApi, #ruma_macros::_FakeDeriveSerde)]
                #[cfg_attr(feature = "client", derive(#serde::Serialize))]
                #[cfg_attr(feature = "server", derive(#serde::Deserialize))]
                #serde_attr
                struct RequestBody { #(#fields),* }
            }
        });

        let request_query_def = if let Some(f) = self.query_all_field() {
            let field = Field { ident: None, colon_token: None, ..f.clone() };
            let field = PrivateField(&field);
            Some(quote! { (#field); })
        } else if self.has_query_fields() {
            let fields =
                self.fields.iter().filter_map(RequestField::as_query_field).map(PrivateField);
            Some(quote! { { #(#fields),* } })
        } else {
            None
        };

        let request_query_struct = request_query_def.map(|def| {
            quote! {
                /// Data in the request's query string.
                #[cfg(any(feature = "client", feature = "server"))]
                #[derive(Debug, #ruma_macros::_FakeDeriveRumaApi, #ruma_macros::_FakeDeriveSerde)]
                #[cfg_attr(feature = "client", derive(#serde::Serialize))]
                #[cfg_attr(feature = "server", derive(#serde::Deserialize))]
                struct RequestQuery #def
            }
        });

        let outgoing_request_impl = self.expand_outgoing(ruma_common);
        let incoming_request_impl = self.expand_incoming(ruma_common);

        quote! {
            #request_body_struct
            #request_query_struct

            #[allow(deprecated)]
            mod __request_impls {
                use super::*;
                #outgoing_request_impl
                #incoming_request_impl
            }
        }
    }

    pub(super) fn check(&self, ruma_common: &TokenStream) -> syn::Result<TokenStream> {
        let http = quote! { #ruma_common::exports::http };

        // TODO: highlight problematic fields

        let newtype_body_fields = self.fields.iter().filter(|f| {
            matches!(&f.kind, RequestFieldKind::NewtypeBody | RequestFieldKind::RawBody)
        });

        let has_newtype_body_field = match newtype_body_fields.count() {
            0 => false,
            1 => true,
            _ => {
                return Err(syn::Error::new_spanned(
                    &self.ident,
                    "Can't have more than one newtype body field",
                ))
            }
        };

        let query_all_fields =
            self.fields.iter().filter(|f| matches!(&f.kind, RequestFieldKind::QueryAll));
        let has_query_all_field = match query_all_fields.count() {
            0 => false,
            1 => true,
            _ => {
                return Err(syn::Error::new_spanned(
                    &self.ident,
                    "Can't have more than one query_all field",
                ))
            }
        };

        let mut body_fields =
            self.fields.iter().filter(|f| matches!(f.kind, RequestFieldKind::Body));
        let first_body_field = body_fields.next();
        let has_body_fields = first_body_field.is_some();

        if has_newtype_body_field && has_body_fields {
            return Err(syn::Error::new_spanned(
                &self.ident,
                "Can't have both a newtype body field and regular body fields",
            ));
        }

        if let Some(first_body_field) = first_body_field {
            let is_single_body_field = body_fields.next().is_none();

            if is_single_body_field && field_has_serde_flatten_attribute(&first_body_field.inner) {
                return Err(syn::Error::new_spanned(
                    first_body_field,
                    "Use `#[ruma_api(body)]` to represent the JSON body as a single field",
                ));
            }
        }

        let has_query_fields = self.has_query_fields();
        if has_query_all_field && has_query_fields {
            return Err(syn::Error::new_spanned(
                &self.ident,
                "Can't have both a query_all field and regular query fields",
            ));
        }

        let path_fields = self.path_fields().map(|f| f.ident.as_ref().unwrap().to_string());
        let mut tests = quote! {
            #[::std::prelude::v1::test]
            fn path_parameters() {
                let path_params = super::METADATA._path_parameters();
                let request_path_fields: &[&::std::primitive::str] = &[#(#path_fields),*];
                ::std::assert_eq!(
                    path_params, request_path_fields,
                    "Path parameters must match the `Request`'s `#[ruma_api(path)]` fields"
                );
            }
        };

        if has_body_fields || has_newtype_body_field {
            tests.extend(quote! {
                #[::std::prelude::v1::test]
                fn request_is_not_get() {
                    ::std::assert_ne!(
                        super::METADATA.method, #http::Method::GET,
                        "GET endpoints can't have body fields",
                    );
                }
            });
        }

        Ok(tests)
    }
}

/// A field of the request struct.
pub(super) struct RequestField {
    pub(super) inner: Field,
    pub(super) kind: RequestFieldKind,
}

/// The kind of a request field.
pub(super) enum RequestFieldKind {
    /// JSON data in the body of the request.
    Body,

    /// Data in an HTTP header.
    Header(Ident),

    /// A specific data type in the body of the request.
    NewtypeBody,

    /// Arbitrary bytes in the body of the request.
    RawBody,

    /// Data that appears in the URL path.
    Path,

    /// Data that appears in the query string.
    Query,

    /// Data that represents all the query string as a single type.
    QueryAll,
}

impl RequestField {
    /// Creates a new `RequestField`.
    fn new(inner: Field, kind_attr: Option<RequestMeta>) -> Self {
        let kind = match kind_attr {
            Some(RequestMeta::NewtypeBody) => RequestFieldKind::NewtypeBody,
            Some(RequestMeta::RawBody) => RequestFieldKind::RawBody,
            Some(RequestMeta::Path) => RequestFieldKind::Path,
            Some(RequestMeta::Query) => RequestFieldKind::Query,
            Some(RequestMeta::QueryAll) => RequestFieldKind::QueryAll,
            Some(RequestMeta::Header(header)) => RequestFieldKind::Header(header),
            None => RequestFieldKind::Body,
        };

        Self { inner, kind }
    }

    /// Return the contained field if this request field is a body kind.
    pub fn as_body_field(&self) -> Option<&Field> {
        match &self.kind {
            RequestFieldKind::Body | RequestFieldKind::NewtypeBody => Some(&self.inner),
            _ => None,
        }
    }

    /// Return the contained field if this request field is a raw body kind.
    pub fn as_raw_body_field(&self) -> Option<&Field> {
        match &self.kind {
            RequestFieldKind::RawBody => Some(&self.inner),
            _ => None,
        }
    }

    /// Return the contained field if this request field is a path kind.
    pub fn as_path_field(&self) -> Option<&Field> {
        match &self.kind {
            RequestFieldKind::Path => Some(&self.inner),
            _ => None,
        }
    }

    /// Return the contained field if this request field is a query kind.
    pub fn as_query_field(&self) -> Option<&Field> {
        match &self.kind {
            RequestFieldKind::Query => Some(&self.inner),
            _ => None,
        }
    }

    /// Return the contained field if this request field is a query all kind.
    pub fn as_query_all_field(&self) -> Option<&Field> {
        match &self.kind {
            RequestFieldKind::QueryAll => Some(&self.inner),
            _ => None,
        }
    }

    /// Return the contained field and header ident if this request field is a header kind.
    pub fn as_header_field(&self) -> Option<(&Field, &Ident)> {
        match &self.kind {
            RequestFieldKind::Header(header_name) => Some((&self.inner, header_name)),
            _ => None,
        }
    }
}

impl TryFrom<Field> for RequestField {
    type Error = syn::Error;

    fn try_from(mut field: Field) -> syn::Result<Self> {
        let (mut api_attrs, attrs) =
            field.attrs.into_iter().partition::<Vec<_>, _>(|attr| attr.path().is_ident("ruma_api"));
        field.attrs = attrs;

        let kind_attr = match api_attrs.as_slice() {
            [] => None,
            [_] => Some(api_attrs.pop().unwrap().parse_args::<RequestMeta>()?),
            _ => {
                return Err(syn::Error::new_spanned(
                    &api_attrs[1],
                    "multiple field kind attribute found, there can only be one",
                ));
            }
        };

        Ok(RequestField::new(field, kind_attr))
    }
}

impl Parse for RequestField {
    fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
        input.call(Field::parse_named)?.try_into()
    }
}

impl ToTokens for RequestField {
    fn to_tokens(&self, tokens: &mut TokenStream) {
        self.inner.to_tokens(tokens);
    }
}