Fix lazy init always "en"

Closes #87 #88

Co-authored-by: yk0n9 <ykonghao@icloud.com>
Co-authored-by: KKRainbow <sijie.sun@smartx.com>

Author: 3 people

crates/macro/src/lib.rs

@@ -324,6 +324,8 @@ fn generate_code(
     quote! {
         use rust_i18n::{BackendExt, CowStr, MinifyKey};
         use std::borrow::Cow;
+        use std::sync::Mutex;
+        use rust_i18n::once_cell::sync::Lazy;
 
         /// I18n backend instance
         ///
@@ -334,11 +336,17 @@ fn generate_code(
             #(#all_translations)*
             #extend_code
 
-            #default_locale
+            if *_RUST_I18N_INITIALIZED_DEFAULT_LOCALE.lock().unwrap() == false {
+                *_RUST_I18N_INITIALIZED_DEFAULT_LOCALE.lock().unwrap() = true;
+                #default_locale
+            }
 
             Box::new(backend)
         });
 
+        /// To mark the default locale has been initialized
+        static _RUST_I18N_INITIALIZED_DEFAULT_LOCALE: Lazy<Mutex<bool>> = Lazy::new(|| Mutex::new(false));
+
         static _RUST_I18N_FALLBACK_LOCALE: Option<&[&'static str]> = #fallback;
         static _RUST_I18N_MINIFY_KEY: bool = #minify_key;
         static _RUST_I18N_MINIFY_KEY_LEN: usize = #minify_key_len;

tests/integration_tests.rs

@@ -33,8 +33,6 @@ rust_i18n::i18n!(
 
 #[cfg(test)]
 mod tests {
-    use std::{thread, time::Duration};
-
     use rust_i18n::t;
     use rust_i18n_support::load_locales;