Thanks to visit codestin.com
Credit goes to docs.rs

sqlm-postgres-macros 0.1.0

macros for `sqlm-postgres`
Documentation
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
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
use std::collections::hash_map::Entry;
use std::collections::HashMap;
use std::fmt::Write;
use std::str::FromStr;
use std::sync::Arc;

use postgres::config::SslMode;
use postgres::Config;
use proc_macro::TokenStream;
use quote::{format_ident, quote, ToTokens};
use syn::parse::{Parse, ParseStream};
use syn::punctuated::Punctuated;
use syn::spanned::Spanned;
use syn::token::Comma;
use syn::{parse_macro_input, parse_quote, Expr, LitStr, Type};

use crate::const_name;
use crate::parser::{self, Argument, Token};

pub fn sql(item: TokenStream) -> TokenStream {
    let input = parse_macro_input!(item as Input);
    // dbg!(&input);

    let mut unnamed_arguments = Vec::new();
    let mut named_arguments = HashMap::new();
    let mut variable_arguments = HashMap::new();
    if let Some(arguments) = input.arguments {
        for expr in arguments.arguments {
            if let Expr::Assign(expr_assign) = expr {
                named_arguments.insert(
                    expr_assign.left.into_token_stream().to_string(),
                    Parameter {
                        expr: expr_assign.right,
                        index: None,
                    },
                );
            } else {
                if !named_arguments.is_empty() {
                    return syn::Error::new(
                        expr.span(),
                        "positional arguments cannot follow named arguments",
                    )
                    .into_compile_error()
                    .into();
                }

                unnamed_arguments.push(Parameter {
                    expr: Box::new(expr),
                    index: None,
                });
            }
        }
    }

    let mut next_arg = 0;
    let query = input.query.value();
    let mut result = String::with_capacity(query.len());
    let mut parameters = Vec::new();

    let tokens = match parser::parse(&query) {
        Ok(tokens) => tokens,
        Err(err) => {
            return syn::Error::new(input.query.span(), err)
                .into_compile_error()
                .into();
        }
    };

    for token in tokens {
        let index = match token {
            Token::EscapedCurlyStart => {
                result.push('{');
                continue;
            }
            Token::EscapedCurlyEnd => {
                result.push('}');
                continue;
            }
            Token::Text(text) => {
                result.push_str(text);
                continue;
            }
            Token::Argument(Argument::Next) => {
                let Some(param) = unnamed_arguments.get_mut(next_arg) else {
                    return syn::Error::new(
                        input.query.span(),
                        format!("missing argument for position {next_arg}"),
                    )
                    .into_compile_error()
                    .into();
                };
                next_arg += 1;
                if let Some(index) = param.index {
                    index
                } else {
                    parameters.push(param.expr.to_token_stream());
                    let index = parameters.len();
                    param.index = Some(index);
                    index
                }
            }
            Token::Argument(Argument::Positional(ix)) => {
                let Some(param) = unnamed_arguments.get_mut(ix) else {
                    return syn::Error::new(
                        input.query.span(),
                        format!("missing argument for index {ix}"),
                    )
                    .into_compile_error()
                    .into();
                };
                if let Some(index) = param.index {
                    index
                } else {
                    parameters.push(param.expr.to_token_stream());
                    let index = parameters.len();
                    param.index = Some(index);
                    index
                }
            }
            Token::Argument(Argument::Named(ident)) => {
                if let Some(param) = named_arguments.get_mut(ident) {
                    if let Some(index) = param.index {
                        index
                    } else {
                        parameters.push(param.expr.to_token_stream());
                        let index = parameters.len();
                        param.index = Some(index);
                        index
                    }
                } else {
                    match variable_arguments.entry(ident) {
                        Entry::Occupied(e) => *e.get(),
                        Entry::Vacant(e) => {
                            let ident = format_ident!("{}", ident);
                            parameters.push(ident.to_token_stream());
                            let index = parameters.len();
                            e.insert(index);
                            index
                        }
                    }
                }
            }
        };

        write!(result, "${}", index).unwrap();
    }

    for arg in unnamed_arguments
        .into_iter()
        .chain(named_arguments.into_values())
    {
        if arg.index.is_none() {
            return syn::Error::new(arg.expr.span(), "argument never used")
                .into_compile_error()
                .into();
        }
    }

    let Ok(database_url) = dotenvy::var("DATABASE_URL") else {
        return syn::Error::new(
            input.query.span(),
            "compile-time query checks require DATABASE_URL environment variable to be defined",
        )
        .into_compile_error()
        .into();
    };
    let config = match Config::from_str(&database_url) {
        Ok(config) => config,
        Err(err) => {
            return syn::Error::new(
                input.query.span(),
                format!("failed to parse connection config from DATABASE_URL: {err}"),
            )
            .into_compile_error()
            .into();
        }
    };

    // TODO: take all possible SSL variants into account, see e.g.
    // https://github.com/jbg/tokio-postgres-rustls/issues/11
    let client = match config.get_ssl_mode() {
        SslMode::Disable => config.connect(postgres::NoTls),
        _ => {
            let client_config = rustls::ClientConfig::builder()
                .dangerous()
                .with_custom_certificate_verifier(Arc::new(NoServerCertVerify::default()))
                .with_no_client_auth();
            config.connect(tokio_postgres_rustls::MakeRustlsConnect::new(client_config))
        }
    };
    let mut client = match client {
        Ok(client) => client,
        Err(err) => {
            return syn::Error::new(
                input.query.span(),
                format!("failed to connect to postgres (using DATABASE_URL): {err}"),
            )
            .into_compile_error()
            .into();
        }
    };

    let stmt = match client.prepare(&result) {
        Ok(stmt) => stmt,
        Err(err) => {
            return syn::Error::new(input.query.span(), format!("query failed: {err}"))
                .into_compile_error()
                .into();
        }
    };

    let mut typed_parameters = Vec::with_capacity(parameters.len());
    for (ty, param) in stmt.params().iter().zip(parameters) {
        if let Some((is_array, variants)) = enum_type(ty) {
            let mut enum_variants: Vec<Type> = Vec::with_capacity(variants.len());
            for variant in variants {
                let name = const_name(&variant);
                enum_variants.push(parse_quote!(::sqlm_postgres::types::EnumVariant<#name>));
            }

            let enum_struct = quote! { ::sqlm_postgres::types::Enum<(#(#enum_variants,)*)> };
            let type_check = if is_array {
                quote! {
                    {
                        const fn assert_type<T: ::sqlm_postgres::internal::AsSqlType<SqlType = #enum_struct>>(_: &[T]) {}
                        assert_type(&(#param));
                    }
                }
            } else {
                quote! {
                    {
                        const fn assert_type<T: ::sqlm_postgres::internal::AsSqlType<SqlType = #enum_struct>>(_: &T) {}
                        assert_type(&(#param));
                    }
                }
            };

            typed_parameters.push(quote! {
                {
                    #type_check
                    &(#param)
                }
            });
            continue;
        }

        let Some((ty_owned, ty_borrowed, _)) = postgres_to_rust_type(ty) else {
            return syn::Error::new(
                input.query.span(),
                format!("unsupporte postgres type: {ty:?}"),
            )
            .into_compile_error()
            .into();
        };

        // `Option::from` is used to allow parameters to be an Option
        typed_parameters.push(quote! {
            {
                {
                    const fn assert_type<T, S>(_: &T)
                    where
                        T: ::sqlm_postgres::internal::AsSqlType<SqlType = S>,
                        for<'a> ::sqlm_postgres::internal::Valid<'a, #ty_borrowed, #ty_owned>: From<S>
                    {}
                    assert_type(&(#param));
                }
                &(#param)
            }
        });
    }

    let col_count = stmt.columns().len();
    if col_count == 0 {
        return quote! {
            {
                ::sqlm_postgres::Sql::<'_, (), ()> {
                    query: #result,
                    parameters: &[#(&(#typed_parameters),)*],
                    transaction: None,
                    connection: None,
                    marker: ::std::marker::PhantomData,
                }
            }
        }
        .into();
    } else if col_count == 1 {
        // Consider the result to be a literal
        let ty = stmt.columns()[0].type_();
        if let Some((is_array, variants)) = enum_type(ty) {
            let mut enum_variants: Vec<Type> = Vec::with_capacity(variants.len());
            for variant in variants {
                let name = const_name(&variant);
                enum_variants.push(parse_quote!(::sqlm_postgres::types::EnumVariant<#name>));
            }

            let enum_struct = if is_array {
                quote! { ::sqlm_postgres::types::Array<Vec<::sqlm_postgres::types::Enum<(#(#enum_variants,)*)>>> }
            } else {
                quote! { ::sqlm_postgres::types::Primitive<::sqlm_postgres::types::Enum<(#(#enum_variants,)*)>> }
            };
            return quote! {
                {
                    ::sqlm_postgres::Sql::<'_, #enum_struct, _> {
                        query: #result,
                        parameters: &[#(&(#typed_parameters),)*],
                        transaction: None,
                        connection: None,
                        marker: ::std::marker::PhantomData,
                    }
                }
            }
            .into();
        } else if let Some((ty, _, is_array)) = postgres_to_rust_type(ty) {
            if is_array {
                return quote! {
                    {
                        ::sqlm_postgres::Sql::<'_, ::sqlm_postgres::types::Array<#ty>, _> {
                            query: #result,
                            parameters: &[#(&(#typed_parameters),)*],
                            transaction: None,
                            connection: None,
                            marker: ::std::marker::PhantomData,
                        }
                    }
                }
                .into();
            } else {
                return quote! {
                    {
                        ::sqlm_postgres::Sql::<'_, ::sqlm_postgres::types::Primitive<#ty>, _> {
                            query: #result,
                            parameters: &[#(&(#typed_parameters),)*],
                            transaction: None,
                            connection: None,
                            marker: ::std::marker::PhantomData,
                        }
                    }
                }
                .into();
            }
        } else {
            return syn::Error::new(
                input.query.span(),
                format!("unsupported postgres type: {ty:?}"),
            )
            .into_compile_error()
            .into();
        }
    }

    let mut columns = stmt.columns().iter().collect::<Vec<_>>();
    columns.sort_by_key(|c| c.name());

    let mut struct_columns: Vec<Type> = Vec::with_capacity(columns.len());
    for column in columns {
        let ty = column.type_();
        let name = const_name(column.name());
        if let Some((is_array, variants)) = enum_type(ty) {
            let mut enum_variants: Vec<Type> = Vec::with_capacity(variants.len());
            for variant in variants {
                let name = const_name(&variant);
                enum_variants.push(parse_quote!(::sqlm_postgres::types::EnumVariant<#name>));
            }

            if is_array {
                struct_columns.push(parse_quote!(::sqlm_postgres::types::StructColumn<Vec<::sqlm_postgres::types::Enum<(#(#enum_variants,)*)>>, #name>));
            } else {
                struct_columns.push(parse_quote!(::sqlm_postgres::types::StructColumn<::sqlm_postgres::types::Enum<(#(#enum_variants,)*)>, #name>));
            }
        } else if let Some((ty, _, _)) = postgres_to_rust_type(ty) {
            struct_columns.push(parse_quote!(::sqlm_postgres::types::StructColumn<#ty, #name>));
        } else {
            return syn::Error::new(
                input.query.span(),
                format!("unsupported postgres type: {ty:?}"),
            )
            .into_compile_error()
            .into();
        };
    }

    let type_struct = quote! { ::sqlm_postgres::types::Struct<(#(#struct_columns,)*)> };
    quote! {
        {
            ::sqlm_postgres::Sql::<'_, #type_struct, _> {
                query: #result,
                parameters: &[#(&(#typed_parameters),)*],
                transaction: None,
                connection: None,
                marker: ::std::marker::PhantomData,
            }
        }
    }
    .into()
}

fn postgres_to_rust_type(
    ty: &postgres::types::Type,
) -> Option<(proc_macro2::TokenStream, proc_macro2::TokenStream, bool)> {
    use postgres::types::{FromSql, Kind};

    if let Kind::Array(ty) = ty.kind() {
        // reject nested array
        if matches!(ty.kind(), Kind::Array(_)) {
            return None;
        }

        return postgres_to_rust_type(ty).map(|(ty, _, _)| (quote!(Vec<#ty>), quote!([#ty]), true));
    }

    match ty {
        ty if <String as FromSql>::accepts(ty) => Some((quote!(String), quote!(str), false)),
        ty if <i64 as FromSql>::accepts(ty) => Some((quote!(i64), quote!(i64), false)),
        ty if <i32 as FromSql>::accepts(ty) => Some((quote!(i32), quote!(i32), false)),
        ty if <f64 as FromSql>::accepts(ty) => Some((quote!(f64), quote!(f64), false)),
        ty if <f32 as FromSql>::accepts(ty) => Some((quote!(f32), quote!(f32), false)),
        ty if <bool as FromSql>::accepts(ty) => Some((quote!(bool), quote!(bool), false)),
        ty if <Vec<u8> as FromSql>::accepts(ty) => Some((
            quote!(::sqlm_postgres::types::Bytea),
            quote!(::sqlm_postgres::types::Bytea),
            false,
        )),

        // serde_json::Value
        #[cfg(feature = "json")]
        ty if <::serde_json::Value as FromSql>::accepts(ty) => Some((
            quote!(::serde_json::Value),
            quote!(::serde_json::Value),
            false,
        )),

        // time::Date
        #[cfg(feature = "time")]
        ty if <::time::Date as FromSql>::accepts(ty) => {
            Some((quote!(::time::Date), quote!(::time::Date), false))
        }

        // time::OffsetDateTime
        #[cfg(feature = "time")]
        ty if <::time::OffsetDateTime as FromSql>::accepts(ty) => Some((
            quote!(::time::OffsetDateTime),
            quote!(::time::OffsetDateTime),
            false,
        )),

        // uuid::Uuid
        #[cfg(feature = "uuid")]
        ty if <::uuid::Uuid as FromSql>::accepts(ty) => {
            Some((quote!(::uuid::Uuid), quote!(::uuid::Uuid), false))
        }

        // pgvector::Vector
        #[cfg(feature = "pgvector")]
        ty if <::pgvector::Vector as FromSql>::accepts(ty) => Some((
            quote!(::pgvector::Vector),
            quote!(::pgvector::Vector),
            false,
        )),

        // Unsupported
        _ => None,
    }
}

fn enum_type(ty: &postgres::types::Type) -> Option<(bool, Vec<String>)> {
    use postgres::types::Kind;
    let mut data = match ty.kind() {
        Kind::Enum(variants) => Some((false, variants.clone())),
        Kind::Array(ty) => {
            if let Kind::Enum(variants) = ty.kind() {
                Some((true, variants.clone()))
            } else {
                None
            }
        }
        _ => None,
    };
    if let Some((_, variants)) = &mut data {
        variants.sort();
    }
    data
}

struct Parameter {
    expr: Box<Expr>,
    index: Option<usize>,
}

#[derive(Debug)]
struct Input {
    query: LitStr,
    arguments: Option<Arguments>,
}

#[derive(Debug)]
struct Arguments {
    #[allow(unused)]
    comma: Comma,
    arguments: Punctuated<Expr, Comma>,
}

impl Parse for Input {
    fn parse(input: ParseStream) -> syn::Result<Self> {
        Ok(Input {
            query: input.parse()?,
            arguments: input
                .peek(Comma)
                .then(|| {
                    Ok::<_, syn::Error>(Arguments {
                        comma: Comma::parse(input)?,
                        // TODO: no unnamed after named
                        arguments: Punctuated::<Expr, Comma>::parse_terminated(input)?,
                    })
                })
                .transpose()?,
        })
    }
}

#[derive(Debug)]
struct NoServerCertVerify {
    crypto_provider: Arc<rustls::crypto::CryptoProvider>,
}

impl Default for NoServerCertVerify {
    fn default() -> Self {
        Self {
            crypto_provider: Arc::clone(
                rustls::crypto::CryptoProvider::get_default()
                    .expect("no default provider for rustls installed"),
            ),
        }
    }
}

impl rustls::client::danger::ServerCertVerifier for NoServerCertVerify {
    fn verify_server_cert(
        &self,
        _end_entity: &rustls::pki_types::CertificateDer<'_>,
        _intermediates: &[rustls::pki_types::CertificateDer<'_>],
        _server_name: &rustls::pki_types::ServerName<'_>,
        _ocsp_response: &[u8],
        _now: rustls::pki_types::UnixTime,
    ) -> Result<rustls::client::danger::ServerCertVerified, rustls::Error> {
        Ok(rustls::client::danger::ServerCertVerified::assertion())
    }

    fn verify_tls12_signature(
        &self,
        message: &[u8],
        cert: &rustls::pki_types::CertificateDer<'_>,
        dss: &rustls::DigitallySignedStruct,
    ) -> Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error> {
        rustls::crypto::verify_tls12_signature(
            message,
            cert,
            dss,
            &self.crypto_provider.signature_verification_algorithms,
        )
    }

    fn verify_tls13_signature(
        &self,
        message: &[u8],
        cert: &rustls::pki_types::CertificateDer<'_>,
        dss: &rustls::DigitallySignedStruct,
    ) -> Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error> {
        rustls::crypto::verify_tls13_signature(
            message,
            cert,
            dss,
            &self.crypto_provider.signature_verification_algorithms,
        )
    }

    fn supported_verify_schemes(&self) -> Vec<rustls::SignatureScheme> {
        self.crypto_provider
            .signature_verification_algorithms
            .supported_schemes()
    }
}