From b71bf8bd74b36380356be3445495b5f7aed52490 Mon Sep 17 00:00:00 2001
From: kanarus <kanarus786@gmail.com>
Date: Sat, 14 Sep 2024 07:13:26 +0900
Subject: [PATCH] feat: support `#[serdev(crate = "path::to::serdev")]` (#21)

* support `#[serdev(crate = "path::to::serdev")]`

* fix workflows
---
 .github/workflows/auto_approve.yml      |  2 +-
 .gitignore                              |  4 +-
 README.md                               | 10 ++--
 Taskfile.yml                            |  1 +
 examples/.gitignore                     |  2 -
 examples/Cargo.toml                     |  7 ++-
 examples/reexport/Cargo.toml            | 12 +++++
 examples/reexport/reexporter/Cargo.toml |  7 +++
 examples/reexport/reexporter/src/lib.rs |  3 ++
 examples/reexport/src/main.rs           | 34 +++++++++++++
 serdev/Cargo.toml                       |  4 +-
 serdev_derive/Cargo.toml                |  2 +-
 serdev_derive/src/internal.rs           | 64 +++++++++++++++++--------
 serdev_derive/src/internal/reexport.rs  | 60 +++++++++++++++++++++++
 serdev_derive/src/internal/validate.rs  |  6 +--
 serdev_derive/src/lib.rs                |  4 +-
 16 files changed, 184 insertions(+), 38 deletions(-)
 delete mode 100644 examples/.gitignore
 create mode 100644 examples/reexport/Cargo.toml
 create mode 100644 examples/reexport/reexporter/Cargo.toml
 create mode 100644 examples/reexport/reexporter/src/lib.rs
 create mode 100644 examples/reexport/src/main.rs
 create mode 100644 serdev_derive/src/internal/reexport.rs

diff --git a/.github/workflows/auto_approve.yml b/.github/workflows/auto_approve.yml
index f2e7891..f6a4ca6 100644
--- a/.github/workflows/auto_approve.yml
+++ b/.github/workflows/auto_approve.yml
@@ -12,7 +12,7 @@ on:
 jobs:
   auto_approve:
     if: |
-      github.event.pull_request.user.login == 'kana-rus' &&
+      github.event.pull_request.user.login == 'kanarus' &&
       !github.event.pull_request.draft
     permissions:
       pull-requests: write
diff --git a/.gitignore b/.gitignore
index 2ebc5ea..2a6fee4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
-/target
-/Cargo.lock
\ No newline at end of file
+**/target
+**/Cargo.lock
\ No newline at end of file
diff --git a/README.md b/README.md
index ca55b98..fb9af25 100644
--- a/README.md
+++ b/README.md
@@ -5,8 +5,8 @@
 
 <br>
 
-- Just a wrapper of <a href="https://github.com/serde-rs/serde" target="_blank">Serde</a> and 100% compatible.
-- Automatic validation in deserialization by `#[serde(validate = "...")]`, no boilerplate.
+- Just a wrapper of <a href="https://github.com/serde-rs/serde" target="_blank">Serde</a> and 100% compatible
+- Declarative validation in deserialization by `#[serde(validate = "...")]`
 
 <div align="right">
     <a href="https://github.com/ohkami-rs/serdev/blob/main/LICENSE" target="_blank">
@@ -25,7 +25,7 @@
 
 ```toml
 [dependencies]
-serdev     = "0.1"
+serdev     = "0.2"
 serde_json = "1.0"
 ```
 
@@ -81,7 +81,9 @@ Of course, you can use it in combination with some validation tools like <a href
   This may be preferred when you need better performance _even in error cases_.\
   For **no-std** use, this is the only way supported.
 
-Both `"function"` and `"Type"` accept path like `"crate::utils::validate"`.
+Both `"function"` and `"Type"` accept path like `"crate::util::validate"`.
+
+Additionally, `#[serdev(crate = "path::to::serdev")]` is supported for reexport from another crate.
 
 
 ## License
diff --git a/Taskfile.yml b/Taskfile.yml
index b0f305b..a0a9b30 100644
--- a/Taskfile.yml
+++ b/Taskfile.yml
@@ -47,6 +47,7 @@ tasks:
       - cargo run --example readme
       - cargo run --example validator
       - cargo run --example various_users
+      - cd reexport && cargo run
 
   ##### check #####
 
diff --git a/examples/.gitignore b/examples/.gitignore
deleted file mode 100644
index 2ebc5ea..0000000
--- a/examples/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-/target
-/Cargo.lock
\ No newline at end of file
diff --git a/examples/Cargo.toml b/examples/Cargo.toml
index d9f080c..d81ef43 100644
--- a/examples/Cargo.toml
+++ b/examples/Cargo.toml
@@ -1,6 +1,11 @@
+[workspace]
+resolver = "2"
+members  = ["."]
+exclude  = ["reexport"]
+
 [package]
 name    = "examples"
-version = "0.1.0"
+version = "0.0.0"
 edition = "2021"
 
 [dev-dependencies]
diff --git a/examples/reexport/Cargo.toml b/examples/reexport/Cargo.toml
new file mode 100644
index 0000000..285bac2
--- /dev/null
+++ b/examples/reexport/Cargo.toml
@@ -0,0 +1,12 @@
+[workspace]
+resolver = "2"
+members  = ["reexporter", "."]
+
+[package]
+name    = "user"
+version = "0.0.0"
+edition = "2021"
+
+[dependencies]
+reexporter = { path = "./reexporter" }
+serde_json = { version = "1.0" }
\ No newline at end of file
diff --git a/examples/reexport/reexporter/Cargo.toml b/examples/reexport/reexporter/Cargo.toml
new file mode 100644
index 0000000..777fcfd
--- /dev/null
+++ b/examples/reexport/reexporter/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name    = "reexporter"
+version = "0.0.0"
+edition = "2021"
+
+[dependencies]
+serdev = { path = "../../../serdev" }
\ No newline at end of file
diff --git a/examples/reexport/reexporter/src/lib.rs b/examples/reexport/reexporter/src/lib.rs
new file mode 100644
index 0000000..d17e395
--- /dev/null
+++ b/examples/reexport/reexporter/src/lib.rs
@@ -0,0 +1,3 @@
+pub mod private {
+    pub use ::serdev;
+}
diff --git a/examples/reexport/src/main.rs b/examples/reexport/src/main.rs
new file mode 100644
index 0000000..6735294
--- /dev/null
+++ b/examples/reexport/src/main.rs
@@ -0,0 +1,34 @@
+use reexporter::private::serdev::{Serialize, Deserialize};
+
+#[derive(Serialize, Deserialize, Debug)]
+#[serdev(crate = "reexporter::private::serdev")]
+#[serde(validate = "Self::validate")]
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+impl Point {
+    fn validate(&self) -> Result<(), impl std::fmt::Display> {
+        if self.x * self.y > 100 {
+            return Err("x * y must not exceed 100")
+        }
+        Ok(())
+    }
+}
+
+fn main() {
+    let point = serde_json::from_str::<Point>(r#"
+        { "x" : 1, "y" : 2 }
+    "#).unwrap();
+
+    // Prints point = Point { x: 1, y: 2 }
+    println!("point = {point:?}");
+
+    let error = serde_json::from_str::<Point>(r#"
+        { "x" : 10, "y" : 20 }
+    "#).unwrap_err();
+
+    // Prints error = x * y must not exceed 100
+    println!("error = {error}");
+}
diff --git a/serdev/Cargo.toml b/serdev/Cargo.toml
index c134f67..e2df8d7 100644
--- a/serdev/Cargo.toml
+++ b/serdev/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name          = "serdev"
-version       = "0.1.0"
+version       = "0.2.0"
 edition       = "2021"
 authors       = ["kanarus <kanarus786@gmail.com>"]
 documentation = "https://docs.rs/serdev"
@@ -13,7 +13,7 @@ keywords      = ["serde", "validation", "serialization"]
 categories    = ["encoding", "rust-patterns", "no-std", "no-std::no-alloc"]
 
 [dependencies]
-serdev_derive = { version = "=0.1.0", path = "../serdev_derive" }
+serdev_derive = { version = "=0.2.0", path = "../serdev_derive" }
 serde         = { version = "1", features = ["derive"] }
 
 [dev-dependencies]
diff --git a/serdev_derive/Cargo.toml b/serdev_derive/Cargo.toml
index 041da46..f316e87 100644
--- a/serdev_derive/Cargo.toml
+++ b/serdev_derive/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name          = "serdev_derive"
-version       = "0.1.0"
+version       = "0.2.0"
 edition       = "2021"
 authors       = ["kanarus <kanarus786@gmail.com>"]
 documentation = "https://docs.rs/serdev_derive"
diff --git a/serdev_derive/src/internal.rs b/serdev_derive/src/internal.rs
index bd50355..a05ef0e 100644
--- a/serdev_derive/src/internal.rs
+++ b/serdev_derive/src/internal.rs
@@ -1,22 +1,36 @@
 mod target;
 mod validate;
+mod reexport;
 
 use self::target::Target;
 use self::validate::Validate;
+use self::reexport::Reexport;
 
 use proc_macro2::{Span, TokenStream};
-use quote::{format_ident, quote};
+use quote::{format_ident, quote, ToTokens};
 use syn::{Error, LitStr};
 
 
 pub(super) fn Serialize(input: TokenStream) -> Result<TokenStream, Error> {
     let mut target = syn::parse2::<Target>(input.clone())?;
-    Validate::take(target.attrs_mut())?;
+
+    let _ = Validate::take(target.attrs_mut())?;
+
+    let (serdev, serde) = match Reexport::take(target.attrs_mut())? {
+        None => (
+            quote! {::serdev},
+            litstr("::serdev::__private__::serde")
+        ),
+        Some(r) => (
+            r.path()?.into_token_stream(),
+            litstr(&format!("{}::__private__::serde", r.path_str()))
+        )
+    };
 
     Ok(quote! {
-        #[derive(::serdev::__private__::serde::Serialize)]
-        #[serde(crate = "::serdev::__private__::serde")]
-        #[::serdev::__private__::consume]
+        #[derive(#serdev::__private__::serde::Serialize)]
+        #[serde(crate = #serde)]
+        #[#serdev::__private__::consume]
         #target
     })
 }
@@ -27,6 +41,17 @@ pub(super) fn Deserialize(input: TokenStream) -> Result<TokenStream, Error> {
     let generics = target.generics().clone();
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
 
+    let (serdev, serde) = match Reexport::take(target.attrs_mut())? {
+        None => (
+            quote! {::serdev},
+            litstr("::serdev::__private__::serde")
+        ),
+        Some(r) => (
+            r.path()?.into_token_stream(),
+            litstr(&format!("{}::__private__::serde", r.path_str()))
+        )
+    };
+
     Ok(match Validate::take(target.attrs_mut())? {
         Some(validate) => {
             let proxy = target.create_proxy(format_ident!("serdev_proxy_{}", target.ident()));
@@ -36,10 +61,7 @@ pub(super) fn Deserialize(input: TokenStream) -> Result<TokenStream, Error> {
 
             let transmute_from_proxy = proxy.transmute_expr("proxy", target_ident);
 
-            let proxy_type_lit = LitStr::new(
-                &quote!(#proxy_ident #ty_generics).to_string(),
-                Span::call_site()
-            );
+            let proxy_type_lit = litstr(&quote!(#proxy_ident #ty_generics).to_string());
 
             let validate_fn = validate.function()?;
             let (error_ty, e_as_error_ty) = match validate.error()? {
@@ -48,15 +70,15 @@ pub(super) fn Deserialize(input: TokenStream) -> Result<TokenStream, Error> {
                     quote! {e}
                 ),
                 None => (
-                    quote! {::serdev::__private__::DefaultError},
-                    quote! {::serdev::__private__::default_error(e)}
+                    quote! {#serdev::__private__::DefaultError},
+                    quote! {#serdev::__private__::default_error(e)}
                 )
             };
 
             quote! {
                 const _: () = {
-                    #[derive(::serdev::__private__::serde::Deserialize)]
-                    #[serde(crate = "::serdev::__private__::serde")]
+                    #[derive(#serdev::__private__::serde::Deserialize)]
+                    #[serde(crate = #serde)]
                     #[allow(non_camel_case_types)]
                     #proxy
 
@@ -73,10 +95,10 @@ pub(super) fn Deserialize(input: TokenStream) -> Result<TokenStream, Error> {
                         }
                     }
 
-                    #[derive(::serdev::__private__::serde::Deserialize)]
-                    #[serde(crate = "::serdev::__private__::serde")]
+                    #[derive(#serdev::__private__::serde::Deserialize)]
+                    #[serde(crate = #serde)]
                     #[serde(try_from = #proxy_type_lit)]
-                    #[::serdev::__private__::consume]
+                    #[#serdev::__private__::consume]
                     #target
                 };
             }
@@ -84,11 +106,15 @@ pub(super) fn Deserialize(input: TokenStream) -> Result<TokenStream, Error> {
 
         None => {
             quote! {
-                #[derive(::serdev::__private__::serde::Deserialize)]
-                #[serde(crate = "::serdev::__private__::serde")]
-                #[::serdev::__private__::consume]
+                #[derive(#serdev::__private__::serde::Deserialize)]
+                #[serde(crate = #serde)]
+                #[#serdev::__private__::consume]
                 #target
             }
         }
     })
 }
+
+fn litstr(value: &str) -> LitStr {
+    LitStr::new(value, Span::call_site())
+}
diff --git a/serdev_derive/src/internal/reexport.rs b/serdev_derive/src/internal/reexport.rs
new file mode 100644
index 0000000..2e4ab93
--- /dev/null
+++ b/serdev_derive/src/internal/reexport.rs
@@ -0,0 +1,60 @@
+use proc_macro2::TokenStream;
+use syn::{parse::Parse, punctuated::Punctuated, token, Attribute, Error, LitStr, MacroDelimiter, Meta, MetaList, Path};
+
+
+pub(crate) struct Reexport {
+    path: LitStr,
+}
+
+impl Parse for Reexport {
+    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
+        let _path: token::Crate = input.parse()?;
+
+        let _eq: token::Eq = input.parse()?;
+
+        let path: LitStr = input.parse()?;
+
+        Ok(Self { path })
+    }
+}
+
+impl Reexport {
+    pub(crate) fn take(attrs: &mut Vec<Attribute>) -> Result<Option<Self>, Error> {
+        for attr in attrs {
+            if attr.path().get_ident().is_some_and(|i| i == "serdev") {
+                let directives = attr.parse_args_with(
+                    Punctuated::<TokenStream, token::Comma>::parse_terminated
+                )?;
+                for (i, directive) in directives.iter().enumerate() {
+                    if directive.to_string().starts_with("crate") {
+                        attr.meta = Meta::List(MetaList {
+                            path:      syn::parse_str("serdev")?,
+                            delimiter: MacroDelimiter::Paren(Default::default()),
+                            tokens:    syn::parse_str(&{
+                                let mut others = String::new();
+                                for (j, directive) in directives.iter().enumerate() {
+                                    if j != i {
+                                        others.push_str(&directive.to_string());
+                                        others.push(',')
+                                    }
+                                }; others.pop();
+                                others
+                            })?
+                        });
+                        return syn::parse2(directive.clone()).map(Some)
+                    }
+                }
+            }
+        }; Ok(None)
+    }
+}
+
+impl Reexport {
+    pub(crate) fn path(&self) -> Result<Path, Error> {
+        syn::parse_str(&self.path.value())
+    }
+
+    pub(crate) fn path_str(&self) -> String {
+        self.path.value()
+    }
+}
diff --git a/serdev_derive/src/internal/validate.rs b/serdev_derive/src/internal/validate.rs
index 604acad..b492f88 100644
--- a/serdev_derive/src/internal/validate.rs
+++ b/serdev_derive/src/internal/validate.rs
@@ -76,8 +76,7 @@ impl Validate {
                                         others.push_str(&directive.to_string());
                                         others.push(',')
                                     }
-                                }
-                                others.pop();
+                                }; others.pop();
                                 others
                             })?
                         });
@@ -85,8 +84,7 @@ impl Validate {
                     }
                 }
             }
-        }
-        Ok(None)
+        }; Ok(None)
     }
 
     pub(crate) fn function(&self) -> Result<Path, Error> {
diff --git a/serdev_derive/src/lib.rs b/serdev_derive/src/lib.rs
index 95db011..d6805cc 100644
--- a/serdev_derive/src/lib.rs
+++ b/serdev_derive/src/lib.rs
@@ -2,14 +2,14 @@
 
 mod internal;
 
-#[proc_macro_derive(Serialize, attributes(serde))]
+#[proc_macro_derive(Serialize, attributes(serde, serdev))]
 pub fn Serialize(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     internal::Serialize(input.into())
         .unwrap_or_else(syn::Error::into_compile_error)
         .into()
 }
 
-#[proc_macro_derive(Deserialize, attributes(serde))]
+#[proc_macro_derive(Deserialize, attributes(serde, serdev))]
 pub fn Deserialize(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     internal::Deserialize(input.into())
         .unwrap_or_else(syn::Error::into_compile_error)