Merge pull request #232 from Wulf/wulf/custom-crate-path

Allow users to specify a custom path to the rust_embed crate in generated code

Author: pyrossh

.github/workflows/test.yml

@@ -37,6 +37,8 @@ jobs:
           cargo test --test mime_guess --features "mime-guess" --release
           cargo test --test interpolated_path --features "interpolate-folder-path"
           cargo test --test interpolated_path --features "interpolate-folder-path" --release
+          cargo test --test custom_crate_path
+          cargo test --test custom_crate_path --release
           cargo build --example basic
           cargo build --example rocket --features rocket
           cargo build --example actix --features actix

impl/src/lib.rs

@@ -17,7 +17,7 @@ use syn::{parse_macro_input, Data, DeriveInput, Expr, ExprLit, Fields, Lit, Meta
 
 fn embedded(
   ident: &syn::Ident, relative_folder_path: Option<&str>, absolute_folder_path: String, prefix: Option<&str>, includes: &[String], excludes: &[String],
-  metadata_only: bool,
+  metadata_only: bool, crate_path: &syn::Path,
 ) -> syn::Result<TokenStream2> {
   extern crate rust_embed_utils;
 
@@ -30,7 +30,7 @@ fn embedded(
   for rust_embed_utils::FileEntry { rel_path, full_canonical_path } in rust_embed_utils::get_files(absolute_folder_path.clone(), matcher) {
     match_values.insert(
       rel_path.clone(),
-      embed_file(relative_folder_path, ident, &rel_path, &full_canonical_path, metadata_only)?,
+      embed_file(relative_folder_path, ident, &rel_path, &full_canonical_path, metadata_only, crate_path)?,
     );
 
     list_values.push(if let Some(prefix) = prefix {
@@ -63,9 +63,9 @@ fn embedded(
     }
   });
   let value_type = if cfg!(feature = "compression") {
-    quote! { fn() -> rust_embed::EmbeddedFile }
+    quote! { fn() -> #crate_path::EmbeddedFile }
   } else {
-    quote! { rust_embed::EmbeddedFile }
+    quote! { #crate_path::EmbeddedFile }
   };
   let get_value = if cfg!(feature = "compression") {
     quote! {|idx| (ENTRIES[idx].1)()}
@@ -76,7 +76,7 @@ fn embedded(
       #not_debug_attr
       impl #ident {
           /// Get an embedded file and its metadata.
-          pub fn get(file_path: &str) -> ::std::option::Option<rust_embed::EmbeddedFile> {
+          pub fn get(file_path: &str) -> ::std::option::Option<#crate_path::EmbeddedFile> {
             #handle_prefix
             let key = file_path.replace("\\", "/");
             const ENTRIES: &'static [(&'static str, #value_type)] = &[
@@ -98,18 +98,20 @@ fn embedded(
       }
 
       #not_debug_attr
-      impl rust_embed::RustEmbed for #ident {
-        fn get(file_path: &str) -> ::std::option::Option<rust_embed::EmbeddedFile> {
+      impl #crate_path::RustEmbed for #ident {
+        fn get(file_path: &str) -> ::std::option::Option<#crate_path::EmbeddedFile> {
           #ident::get(file_path)
         }
-        fn iter() -> rust_embed::Filenames {
-          rust_embed::Filenames::Embedded(#ident::names())
+        fn iter() -> #crate_path::Filenames {
+          #crate_path::Filenames::Embedded(#ident::names())
         }
       }
   })
 }
 
-fn dynamic(ident: &syn::Ident, folder_path: String, prefix: Option<&str>, includes: &[String], excludes: &[String], metadata_only: bool) -> TokenStream2 {
+fn dynamic(
+  ident: &syn::Ident, folder_path: String, prefix: Option<&str>, includes: &[String], excludes: &[String], metadata_only: bool, crate_path: &syn::Path,
+) -> TokenStream2 {
   let (handle_prefix, map_iter) = if let ::std::option::Option::Some(prefix) = prefix {
     (
       quote! { let file_path = file_path.strip_prefix(#prefix)?; },
@@ -141,14 +143,14 @@ fn dynamic(ident: &syn::Ident, folder_path: String, prefix: Option<&str>, includ
       impl #ident {
 
 
-        fn matcher() -> ::rust_embed::utils::PathMatcher {
+        fn matcher() -> #crate_path::utils::PathMatcher {
             #declare_includes
             #declare_excludes
-            static PATH_MATCHER: ::std::sync::OnceLock<::rust_embed::utils::PathMatcher> = ::std::sync::OnceLock::new();
-            PATH_MATCHER.get_or_init(|| rust_embed::utils::PathMatcher::new(INCLUDES, EXCLUDES)).clone()
+            static PATH_MATCHER: ::std::sync::OnceLock<#crate_path::utils::PathMatcher> = ::std::sync::OnceLock::new();
+            PATH_MATCHER.get_or_init(|| #crate_path::utils::PathMatcher::new(INCLUDES, EXCLUDES)).clone()
         }
           /// Get an embedded file and its metadata.
-          pub fn get(file_path: &str) -> ::std::option::Option<rust_embed::EmbeddedFile> {
+          pub fn get(file_path: &str) -> ::std::option::Option<#crate_path::EmbeddedFile> {
               #handle_prefix
 
               let rel_file_path = file_path.replace("\\", "/");
@@ -171,7 +173,7 @@ fn dynamic(ident: &syn::Ident, folder_path: String, prefix: Option<&str>, includ
               }
               let path_matcher = Self::matcher();
               if path_matcher.is_path_included(&rel_file_path) {
-                rust_embed::utils::read_file_from_fs(&canonical_file_path).ok() #strip_contents
+                #crate_path::utils::read_file_from_fs(&canonical_file_path).ok() #strip_contents
               } else {
                 ::std::option::Option::None
               }
@@ -182,27 +184,27 @@ fn dynamic(ident: &syn::Ident, folder_path: String, prefix: Option<&str>, includ
               use ::std::path::Path;
 
 
-              rust_embed::utils::get_files(::std::string::String::from(#folder_path), Self::matcher())
+              #crate_path::utils::get_files(::std::string::String::from(#folder_path), Self::matcher())
                   .map(|e| #map_iter)
           }
       }
 
       #[cfg(debug_assertions)]
-      impl rust_embed::RustEmbed for #ident {
-        fn get(file_path: &str) -> ::std::option::Option<rust_embed::EmbeddedFile> {
+      impl #crate_path::RustEmbed for #ident {
+        fn get(file_path: &str) -> ::std::option::Option<#crate_path::EmbeddedFile> {
           #ident::get(file_path)
         }
-        fn iter() -> rust_embed::Filenames {
+        fn iter() -> #crate_path::Filenames {
           // the return type of iter() is unnamable, so we have to box it
-          rust_embed::Filenames::Dynamic(::std::boxed::Box::new(#ident::iter()))
+          #crate_path::Filenames::Dynamic(::std::boxed::Box::new(#ident::iter()))
         }
       }
   }
 }
 
 fn generate_assets(
   ident: &syn::Ident, relative_folder_path: Option<&str>, absolute_folder_path: String, prefix: Option<String>, includes: Vec<String>, excludes: Vec<String>,
-  metadata_only: bool,
+  metadata_only: bool, crate_path: &syn::Path,
 ) -> syn::Result<TokenStream2> {
   let embedded_impl = embedded(
     ident,
@@ -212,20 +214,23 @@ fn generate_assets(
     &includes,
     &excludes,
     metadata_only,
+    crate_path,
   );
   if cfg!(feature = "debug-embed") {
     return embedded_impl;
   }
   let embedded_impl = embedded_impl?;
-  let dynamic_impl = dynamic(ident, absolute_folder_path, prefix.as_deref(), &includes, &excludes, metadata_only);
+  let dynamic_impl = dynamic(ident, absolute_folder_path, prefix.as_deref(), &includes, &excludes, metadata_only, crate_path);
 
   Ok(quote! {
       #embedded_impl
       #dynamic_impl
   })
 }
 
-fn embed_file(folder_path: Option<&str>, ident: &syn::Ident, rel_path: &str, full_canonical_path: &str, metadata_only: bool) -> syn::Result<TokenStream2> {
+fn embed_file(
+  folder_path: Option<&str>, ident: &syn::Ident, rel_path: &str, full_canonical_path: &str, metadata_only: bool, crate_path: &syn::Path,
+) -> syn::Result<TokenStream2> {
   let file = rust_embed_utils::read_file_from_fs(Path::new(full_canonical_path)).expect("File should be readable");
   let hash = file.metadata.sha256_hash();
   let last_modified = match file.metadata.last_modified() {
@@ -254,7 +259,7 @@ fn embed_file(folder_path: Option<&str>, ident: &syn::Ident, rel_path: &str, ful
     let full_relative_path = PathBuf::from_iter([folder_path, rel_path]);
     let full_relative_path = full_relative_path.to_string_lossy();
     quote! {
-      rust_embed::flate!(static BYTES: [u8] from #full_relative_path);
+      #crate_path::flate!(static BYTES: [u8] from #full_relative_path);
     }
   } else {
     quote! {
@@ -270,9 +275,9 @@ fn embed_file(folder_path: Option<&str>, ident: &syn::Ident, rel_path: &str, ful
        #closure_args {
         #embedding_code
 
-        rust_embed::EmbeddedFile {
+        #crate_path::EmbeddedFile {
             data: ::std::borrow::Cow::Borrowed(&BYTES),
-            metadata: rust_embed::Metadata::__rust_embed_new([#(#hash),*], #last_modified, #created #mimetype_tokens)
+            metadata: #crate_path::Metadata::__rust_embed_new([#(#hash),*], #last_modified, #created #mimetype_tokens)
         }
       }
   })
@@ -317,6 +322,11 @@ fn impl_rust_embed(ast: &syn::DeriveInput) -> syn::Result<TokenStream2> {
     _ => return Err(syn::Error::new_spanned(ast, "RustEmbed can only be derived for unit structs")),
   };
 
+  let crate_path: syn::Path = find_attribute_values(ast, "crate_path")
+    .last()
+    .map(|v| syn::parse_str(&v).unwrap())
+    .unwrap_or_else(|| syn::parse_str("rust_embed").unwrap());
+
   let mut folder_paths = find_attribute_values(ast, "folder");
   if folder_paths.len() != 1 {
     return Err(syn::Error::new_spanned(
@@ -384,10 +394,11 @@ fn impl_rust_embed(ast: &syn::DeriveInput) -> syn::Result<TokenStream2> {
     includes,
     excludes,
     metadata_only,
+    &crate_path,
   )
 }
 
-#[proc_macro_derive(RustEmbed, attributes(folder, prefix, include, exclude, metadata_only))]
+#[proc_macro_derive(RustEmbed, attributes(folder, prefix, include, exclude, metadata_only, crate_path))]
 pub fn derive_input_object(input: TokenStream) -> TokenStream {
   let ast = parse_macro_input!(input as DeriveInput);
   match impl_rust_embed(&ast) {

tests/custom_crate_path.rs

@@ -0,0 +1,20 @@
+/// This test checks that the `crate_path` attribute can be used
+/// to specify a custom path to the `rust_embed` crate.
+
+mod custom {
+  pub mod path {
+    pub use rust_embed;
+  }
+}
+
+// We introduce a 'rust_embed' module here to break compilation in case
+// the `rust_embed` crate is not loaded correctly.
+//
+// To test this, try commenting out the attribute which specifies the
+// the custom crate path -- you should find that the test fails to compile.
+mod rust_embed {}
+
+#[derive(custom::path::rust_embed::RustEmbed)]
+#[crate_path = "custom::path::rust_embed"]
+#[folder = "examples/public/"]
+struct Asset;