Track locales files in proc macro

README.md

@@ -595,6 +595,7 @@ The `cookie` feature enable to set a cookie when a locale is chosen by the user,
 The `serde` feature implement `serde::Serialize` and `serde::Deserialize` for the locale enum.
 
 The `nightly` feature enable to do `i18n()` to get the locale instead of `i18n.get_locale()` and `i18n(new_locale)` instead of `i18n.set_locale(new_locale)`.
+It also allow macros to use unstable APIs for better warnings.
 
 The `debug_interpolations` feature enable the macros to generate code to emit a warning if a key is supplied twice in interpolations and a better compilation error when a key is missing.
 Better compilation errors are generated for interpolations with 4 keys or less.
@@ -607,6 +608,12 @@ The `json_files` feature tell the macro to expect JSON files for the locales, en
 
 The `yaml_files` feature tell the macro to expect YAML files for the locales
 
+The `track_locale_files` feature is to track files for rebuilds. The `load_locales!()` macro using external dependencies the build system is not aware that the macro should be rerun when those files changes,
+you may have noticed that if you use `cargo-leptos` with `watch-additional-files = ["locales"]` and running `cargo leptos watch`, even if the file changes and cargo-leptos triggers a rebuild nothing changes.
+This feature use a "trick" by using `include_bytes!()` to declare the use of a file, but I'm a bit sceptical of the impact on build time using this.
+I've already checked and it does not include the bytes in the final binary, even in debug, but it may slow down compilation time.
+If you use the `nighly` feature it use the [path tracking API](https://github.com/rust-lang/rust/issues/99515) so no trick using `include_bytes!` and the possible slowdown in compile times coming with it.
+
 ## Contributing
 
 Errors are a bit clunky or obscure for now, there is a lot of edge cases and I did not had time to track every failing scenario, feel free to open an issue on github so I can improve those.

docs/book/src/06_features.md

@@ -44,4 +44,14 @@ Set a cookie to remember the last chosen locale.
 
 #### `nightly`
 
-Enable the use of some nighly features, like directly calling the context to get/set the current locale, also allow the `load_locale!` macro to emit better warnings.
+- Enable the use of some nighly features, like directly calling the context to get/set the current locale.
+- Allow the `load_locale!` macro to emit better warnings.
+
+#### `track_locale_files`
+
+Allow tracking of locale files as dependencies for rebuilds in stable.
+The `load_locales!()` macro using external dependencies the build system is not aware that the macro should be rerun when those files changes,
+you may have noticed that if you use `cargo-leptos` with `watch-additional-files = ["locales"]` and running `cargo leptos watch`, even if the file changes and cargo-leptos triggers a rebuild nothing changes.
+This feature use a "trick" by using `include_bytes!()` to declare the use of a file, but I'm a bit sceptical of the impact on build time using this.
+I've already checked and it does not include the bytes in the final binary, even in debug, but it may slow down compilation time.
+If you use the `nighly` feature it use the [path tracking API](https://github.com/rust-lang/rust/issues/99515) so no trick using `include_bytes!` and the possible slowdown in compile times coming with it.

examples/hello_world_actix/Cargo.toml

@@ -16,6 +16,7 @@ leptos_meta = "0.6"
 leptos_actix = { version = "0.6.0", optional = true }
 leptos_i18n = { path = "../../leptos_i18n", features = [
     "debug_interpolations",
+    "track_locale_files",
 ] }
 serde = { version = "1", features = ["derive"] }
 console_error_panic_hook = { version = "0.1", optional = true }
@@ -87,5 +88,11 @@ lib-features = ["hydrate"]
 # Optional. Defaults to false.
 lib-default-features = false
 
+# Additional files your application could depends on.
+# A change to any file in those directories will trigger a rebuild.
+#
+# Optional.
+watch-additional-files = ["locales"]
+
 [package.metadata.cargo-all-features]
 skip_feature_sets = [["hydrate", "ssr"]]

examples/hello_world_axum/Cargo.toml

@@ -15,6 +15,7 @@ leptos_meta = "0.6"
 leptos_axum = { version = "0.6", optional = true }
 leptos_i18n = { path = "../../leptos_i18n", features = [
     "debug_interpolations",
+    "track_locale_files",
 ] }
 serde = { version = "1", features = ["derive"] }
 console_error_panic_hook = { version = "0.1", optional = true }
@@ -93,5 +94,11 @@ lib-features = ["hydrate"]
 # Optional. Defaults to false.
 lib-default-features = false
 
+# Additional files your application could depends on.
+# A change to any file in those directories will trigger a rebuild.
+#
+# Optional.
+watch-additional-files = ["locales"]
+
 [package.metadata.cargo-all-features]
 skip_feature_sets = [["hydrate", "ssr"]]

leptos_i18n/Cargo.toml

@@ -37,6 +37,7 @@ suppress_key_warnings = ["leptos_i18n_macro/suppress_key_warnings"]
 json_files = ["leptos_i18n_macro/json_files"]
 yaml_files = ["leptos_i18n_macro/yaml_files"]
 interpolate_display = ["leptos_i18n_macro/interpolate_display"]
+track_locale_files = ["leptos_i18n_macro/track_locale_files"]
 
 
 [package.metadata.cargo-all-features]
@@ -50,6 +51,7 @@ denylist = [
     "serde",
     "debug_interpolations",
     "suppress_key_warnings",
+    "track_locale_files",
 ]
 skip_feature_sets = [
     # Axum and Actix features are incompatible with each other - see `./src/server/mod.rs`, always exclude:

leptos_i18n/src/lib.rs

@@ -45,6 +45,7 @@
 //! - `suppress_key_warnings`: Disable the warning emission of the `load_locales!()` macro when some keys are missing or ignored.
 //! - `yaml_files`: Enable this feature if you use YAML files for declaring your locales (can't be used with `json_files`).
 //! - `nightly`: On `nightly` Rust, enables the function-call syntax on the i18n context to get/set the locale.
+//! - `track_locale_files`: Enable the tracking of locale files as dependencies, usefull if you use some watcher. See the README for more infos.
 //!
 //! # A Simple Counter
 //!

leptos_i18n_macro/Cargo.toml

@@ -31,6 +31,7 @@ suppress_key_warnings = []
 json_files = ["serde_json"]
 yaml_files = ["serde_yaml"]
 interpolate_display = []
+track_locale_files = []
 
 [package.metadata.cargo-all-features]
 # cargo-all-features don't provide a way to always include one feature in a set, so CI will just do json...

leptos_i18n_macro/src/lib.rs

@@ -1,7 +1,7 @@
 #![deny(missing_docs)]
 #![forbid(unsafe_code)]
 #![deny(warnings)]
-#![cfg_attr(feature = "nightly", feature(proc_macro_diagnostic))]
+#![cfg_attr(feature = "nightly", feature(proc_macro_diagnostic, track_path))]
 //! # About Leptos i18n macro
 //!
 //! This crate expose the utility macro for `leptos_i18n`

leptos_i18n_macro/src/load_locales/locale.rs

@@ -10,6 +10,7 @@ use super::{
     error::{Error, Result},
     key::{Key, KeyPath},
     parsed_value::{InterpolateKey, ParsedValue, ParsedValueSeed},
+    tracking::track_file,
     warning::{emit_warning, Warning},
 };
 
@@ -190,6 +191,8 @@ impl Locale {
         locale: Rc<Key>,
         namespace: Option<Rc<Key>>,
     ) -> Result<Self> {
+        track_file(&locale, namespace.as_ref(), path);
+
         let seed = LocaleSeed {
             name: Rc::clone(&locale),
             top_locale_name: locale,

leptos_i18n_macro/src/load_locales/mod.rs

@@ -12,6 +12,7 @@ pub mod key;
 pub mod locale;
 pub mod parsed_value;
 pub mod plural;
+pub mod tracking;
 pub mod warning;
 
 use cfg_file::ConfigFile;
@@ -67,8 +68,12 @@ pub fn load_locales() -> Result<TokenStream> {
         )
     };
 
+    let file_tracking = tracking::generate_file_tracking();
+
     Ok(quote! {
         pub mod i18n {
+            #file_tracking
+
             #locale_enum
 
             #locale_type

leptos_i18n_macro/src/load_locales/tracking.rs

@@ -0,0 +1,56 @@
+use std::{path::PathBuf, rc::Rc};
+
+use super::key::Key;
+
+#[cfg(feature = "track_locale_files")]
+mod inner {
+    use super::*;
+
+    #[cfg(not(feature = "nightly"))]
+    thread_local! {
+        pub static LOCALES_PATH: std::cell::RefCell<Vec<String>>  = const { std::cell::RefCell::new(Vec::new()) };
+    }
+
+    #[cfg(not(feature = "nightly"))]
+    pub fn generate_file_tracking() -> proc_macro2::TokenStream {
+        LOCALES_PATH.with_borrow(
+            |paths| quote::quote!(#(const _: &'static [u8] = include_bytes!(#paths);)*),
+        )
+    }
+
+    #[cfg(feature = "nightly")]
+    pub fn generate_file_tracking() -> proc_macro2::TokenStream {
+        proc_macro2::TokenStream::new()
+    }
+
+    pub fn track_file(locale: &Rc<Key>, namespace: Option<&Rc<Key>>, path: &PathBuf) {
+        use crate::load_locales::warning::{emit_warning, Warning};
+        if let Some(path) = path.as_os_str().to_str() {
+            #[cfg(not(feature = "nightly"))]
+            LOCALES_PATH.with_borrow_mut(|paths| paths.push(path.to_owned()));
+            #[cfg(feature = "nightly")]
+            proc_macro::tracked_path::path(path);
+        } else {
+            emit_warning(Warning::NonUnicodePath {
+                locale: locale.clone(),
+                namespace: namespace.cloned(),
+                path: path.clone(),
+            });
+        }
+    }
+}
+
+#[cfg(not(feature = "track_locale_files"))]
+mod inner {
+    use super::*;
+
+    pub fn generate_file_tracking() -> proc_macro2::TokenStream {
+        proc_macro2::TokenStream::new()
+    }
+
+    pub fn track_file(locale: &Rc<Key>, namespace: Option<&Rc<Key>>, path: &PathBuf) {
+        let _ = (locale, namespace, path);
+    }
+}
+
+pub use inner::*;

leptos_i18n_macro/src/load_locales/warning.rs

@@ -7,8 +7,20 @@ use std::{cell::RefCell, fmt::Display, rc::Rc};
 
 #[derive(Debug)]
 pub enum Warning {
-    MissingKey { locale: Rc<Key>, key_path: KeyPath },
-    SurplusKey { locale: Rc<Key>, key_path: KeyPath },
+    MissingKey {
+        locale: Rc<Key>,
+        key_path: KeyPath,
+    },
+    SurplusKey {
+        locale: Rc<Key>,
+        key_path: KeyPath,
+    },
+    #[cfg(feature = "track_locale_files")]
+    NonUnicodePath {
+        locale: Rc<Key>,
+        namespace: Option<Rc<Key>>,
+        path: std::path::PathBuf,
+    },
 }
 
 thread_local! {
@@ -32,6 +44,10 @@ impl Display for Warning {
                 "Key {} is present in locale {:?} but not in default locale, it is ignored",
                 key_path, locale
             ),
+            #[cfg(feature = "track_locale_files")]
+            Warning::NonUnicodePath { locale, namespace: None, path } => write!(f, "File path for locale {:?} is not valid Unicode, can't add it to proc macro depedencies. Path: {:?}", locale, path),
+            #[cfg(feature = "track_locale_files")]
+            Warning::NonUnicodePath { locale, namespace: Some(ns), path } => write!(f, "File path for locale {:?} in namespace {:?} is not valid Unicode, can't add it to proc macro depedencies. Path: {:?}", locale, ns, path),
         }
     }
 }