proc macro for custom #[derive(Deserialize, FromFile)]

Cargo.toml

@@ -38,3 +38,4 @@ tempdir = "0.3.7"
 reqwest = "0.9.2"
 rjs = { path = "rjs-parse" }
 from_file = { path = "from-file" }
+from_file_derive = { path = "from_file_derive" }

from-file/Cargo.toml

@@ -10,6 +10,8 @@ serde_yaml = "0.8"
 serde_derive = "1.0"
 serde_json = "1.0"
 
+from_file_derive = { path = "../from_file_derive" }
+
 [lib]
 name = "from_file"
 path = "src/lib.rs"

from-file/src/lib.rs

@@ -153,11 +153,10 @@ mod tests {
 
     #[test]
     fn test_from_file() {
-        #[derive(Deserialize, Debug, PartialEq)]
+        #[derive(Deserialize, FromFile, Debug, PartialEq)]
         struct Person {
             name: String,
         }
-        impl FromFile for Person {}
 
         let p1 = Person::from_file("test/fixtures/person.json").expect("file->Person");
         assert_eq!(

from_file_derive/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "from_file_derive"
+version = "0.1.0"
+authors = ["Shane Osbourne <[email protected]>"]
+
+[dependencies]
+syn = "0.15.22"
+quote = "0.6.10"
+
+[lib]
+proc-macro = true

from_file_derive/src/lib.rs

@@ -0,0 +1,24 @@
+extern crate proc_macro;
+extern crate syn;
+#[macro_use]
+extern crate quote;
+
+use proc_macro::TokenStream;
+
+#[proc_macro_derive(FromFile)]
+pub fn from_file_macro_derive(input: TokenStream) -> TokenStream {
+    // Construct a representation of Rust code as a syntax tree
+    // that we can manipulate
+    let ast = syn::parse(input).unwrap();
+
+    // Build the trait implementation
+    impl_from_file_macro(&ast)
+}
+
+fn impl_from_file_macro(ast: &syn::DeriveInput) -> TokenStream {
+    let name = &ast.ident;
+    let gen = quote! {
+        impl FromFile for #name {}
+    };
+    gen.into()
+}

rjs-parse/Cargo.toml

@@ -10,6 +10,7 @@ serde_json = "1.0"
 serde_yaml = "0.8"
 ratel = "0.7.0"
 from_file = { path = "../from-file" }
+from_file_derive = { path = "../from_file_derive" }
 
 [lib]
 name = "rjs"

rjs-parse/src/bundle_config.rs

@@ -3,7 +3,7 @@ extern crate serde_yaml;
 
 use from_file::FromFile;
 
-#[derive(Serialize, Deserialize, Debug, PartialEq)]
+#[derive(Serialize, Deserialize, FromFile, Debug, PartialEq)]
 pub struct BundleConfig {
     pub bundles: Vec<ConfigItem>,
     pub module_blacklist: Option<Vec<String>>,
@@ -88,7 +88,6 @@ pub struct ConfigItem {
     pub children: Vec<ConfigItem>,
 }
 
-impl FromFile for BundleConfig {}
 impl Default for BundleConfig {
     fn default() -> BundleConfig {
         BundleConfig {

rjs-parse/src/lib.rs

@@ -1,3 +1,5 @@
+#[macro_use]
+extern crate from_file_derive;
 extern crate from_file;
 extern crate ratel;
 extern crate serde;

src/lib/bs.rs

@@ -4,7 +4,11 @@ extern crate actix_web;
 extern crate base64;
 extern crate bytes;
 extern crate clap;
+
+#[macro_use]
+extern crate from_file_derive;
 extern crate from_file;
+
 extern crate futures;
 extern crate http;
 extern crate mime;

src/lib/config.rs

@@ -8,7 +8,7 @@ use options::ConfigError;
 use serde_json::Value;
 use std;
 
-#[derive(Deserialize, Debug, Clone)]
+#[derive(Deserialize, FromFile, Debug, Clone)]
 pub struct ProgramConfig {
     pub presets: Vec<PresetConfig>,
 }
@@ -19,8 +19,6 @@ impl Default for ProgramConfig {
     }
 }
 
-impl FromFile for ProgramConfig {}
-
 impl ProgramConfig {
     pub fn get_opts(&self, name: &str) -> Option<serde_json::Value> {
         self.presets

src/lib/presets/m2/seed.rs

@@ -2,10 +2,8 @@ use from_file::FromFile;
 use rjs::modules::ModuleData;
 use rjs::RequireJsClientConfig;
 
-#[derive(Serialize, Deserialize, Default)]
+#[derive(Serialize, Deserialize, FromFile, Default)]
 pub struct SeedData {
     pub rjs_client_config: RequireJsClientConfig,
     pub req_log: Vec<ModuleData>,
-}
-
-impl FromFile for SeedData {}
+}