Implement schemars::JsonSchema for non-secret new types.

Placed behind a `schemars` feature flag.

Cargo.toml

@@ -1,6 +1,10 @@
 [package]
 name = "oauth2"
-authors = ["Alex Crichton <[email protected]>", "Florin Lipan <[email protected]>", "David A. Ramos <[email protected]>"]
+authors = [
+  "Alex Crichton <[email protected]>",
+  "Florin Lipan <[email protected]>",
+  "David A. Ramos <[email protected]>",
+]
 version = "5.0.0-alpha.4"
 license = "MIT OR Apache-2.0"
 description = "An extensible, strongly-typed implementation of OAuth2"
@@ -22,6 +26,7 @@ native-tls = ["reqwest/native-tls"]
 reqwest-blocking = ["reqwest/blocking"]
 rustls-tls = ["reqwest/rustls-tls"]
 timing-resistant-secret-traits = []
+schemars = ["dep:schemars"]
 
 [[example]]
 name = "github"
@@ -61,6 +66,9 @@ url = { version = "2.1", features = ["serde"] }
 chrono = { version = "0.4.31", default-features = false, features = ["clock", "serde", "std", "wasmbind"] }
 serde_path_to_error = "0.1.2"
 
+# Feature: schemars
+schemars = { version = "0.8", optional = true }
+
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 getrandom = { version = "0.2", features = ["js"] }
 

src/types.rs

@@ -77,7 +77,8 @@ macro_rules! new_type {
         }
     ) => {
         $(#[$attr])*
-        #[derive(Clone, Debug, PartialEq)]
+        #[derive(Clone, Debug, PartialEq, Eq, Hash, ::serde::Serialize, ::serde::Deserialize)]
+        #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
         pub struct $name(
             $(#[$type_attr])*
             $type
@@ -344,13 +345,29 @@ macro_rules! new_url_type {
             }
         }
         impl Eq for $name {}
+
+
+        #[cfg(feature = "schemars")]
+        impl schemars::JsonSchema for $name {
+            fn schema_name() -> String {
+                stringify!($name).to_owned()
+            }
+
+            fn schema_id() -> std::borrow::Cow<'static, str> {
+                std::borrow::Cow::Borrowed(concat!("oauth2::", stringify!($name)))
+            }
+
+            fn json_schema(gen: &mut schemars::gen::SchemaGenerator) -> schemars::schema::Schema {
+                // HELP(gibbz00): do we want to generate the schema for a URL or a String?
+                gen.subschema_for::<String>()
+            }
+        }
     };
 }
 
 new_type![
     /// Client identifier issued to the client during the registration process described by
     /// [Section 2.2](https://tools.ietf.org/html/rfc6749#section-2.2).
-    #[derive(Deserialize, Serialize, Eq, Hash)]
     ClientId(String)
 ];
 
@@ -385,19 +402,16 @@ new_url_type![
 new_type![
     /// Authorization endpoint response (grant) type defined in
     /// [Section 3.1.1](https://tools.ietf.org/html/rfc6749#section-3.1.1).
-    #[derive(Deserialize, Serialize, Eq, Hash)]
     ResponseType(String)
 ];
 new_type![
     /// Resource owner's username used directly as an authorization grant to obtain an access
     /// token.
-    #[derive(Deserialize, Serialize, Eq, Hash)]
     ResourceOwnerUsername(String)
 ];
 
 new_type![
     /// Access token scope, as defined by the authorization server.
-    #[derive(Deserialize, Serialize, Eq, Hash)]
     Scope(String)
 ];
 impl AsRef<str> for Scope {
@@ -409,7 +423,6 @@ impl AsRef<str> for Scope {
 new_type![
     /// Code Challenge Method used for [PKCE](https://tools.ietf.org/html/rfc7636) protection
     /// via the `code_challenge_method` parameter.
-    #[derive(Deserialize, Serialize, Eq, Hash)]
     PkceCodeChallengeMethod(String)
 ];
 // This type intentionally does not implement Clone in order to make it difficult to reuse PKCE
@@ -614,7 +627,7 @@ new_secret_type![
 
 #[cfg(test)]
 mod tests {
-    use crate::{ClientSecret, CsrfToken, PkceCodeChallenge, PkceCodeVerifier};
+    use super::*;
 
     #[test]
     fn test_secret_conversion() {
@@ -662,4 +675,39 @@ mod tests {
             "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM",
         );
     }
+
+    #[cfg(feature = "schemars")]
+    mod json_schema {
+        use schemars::schema_for;
+        use serde_json::json;
+
+        use super::*;
+
+        #[test]
+        fn generates_new_type_json_schema() {
+            let expected_schema = json!({
+              "$schema": "http://json-schema.org/draft-07/schema#",
+              "title": "ClientId",
+              "description": "Client identifier issued to the client during the registration process described by [Section 2.2](https://tools.ietf.org/html/rfc6749#section-2.2).",
+              "type": "string"
+            });
+
+            let schema = schema_for!(ClientId);
+            let actual_schema = serde_json::to_value(&schema).unwrap();
+            assert_eq!(expected_schema, actual_schema)
+        }
+
+        #[test]
+        fn generates_new_url_type_json_schema() {
+            let expected_schema = json!({
+              "$schema": "http://json-schema.org/draft-07/schema#",
+              "title": "RedirectUrl",
+              "type": "string"
+            });
+
+            let schema = schema_for!(RedirectUrl);
+            let actual_schema = serde_json::to_value(&schema).unwrap();
+            assert_eq!(expected_schema, actual_schema);
+        }
+    }
 }