From 91636ae2bb926a33d9e689e53d5b95d464cf024c Mon Sep 17 00:00:00 2001
From: Juha Kukkonen <juha7kukkonen@gmail.com>
Date: Tue, 15 Oct 2024 21:06:04 +0300
Subject: [PATCH] Add `identifier` for `Info`

This commit adds `identifier` field to `Info` what was missing since
upgrading to OpenAPI 3.1.

Fixes #1139
---
 utoipa-gen/src/openapi/info.rs     | 13 +++++++++++++
 utoipa-gen/tests/openapi_derive.rs | 20 ++++++++++++++++++++
 utoipa/src/openapi/info.rs         | 15 +++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/utoipa-gen/src/openapi/info.rs b/utoipa-gen/src/openapi/info.rs
index 6973fb4e..76729550 100644
--- a/utoipa-gen/src/openapi/info.rs
+++ b/utoipa-gen/src/openapi/info.rs
@@ -179,6 +179,7 @@ impl ToTokens for Info<'_> {
 pub(super) struct License<'l> {
     name: Cow<'l, str>,
     url: Option<Cow<'l, str>>,
+    identifier: Cow<'l, str>,
 }
 
 impl Parse for License<'_> {
@@ -200,6 +201,11 @@ impl Parse for License<'_> {
                         parse_utils::parse_next(input, || input.parse::<LitStr>())?.value(),
                     ))
                 }
+                "identifier" => {
+                    license.identifier = Cow::Owned(
+                        parse_utils::parse_next(input, || input.parse::<LitStr>())?.value(),
+                    )
+                }
                 _ => {
                     return Err(Error::new(
                         ident.span(),
@@ -222,11 +228,18 @@ impl ToTokens for License<'_> {
     fn to_tokens(&self, tokens: &mut TokenStream2) {
         let name = &self.name;
         let url = self.url.as_ref().map(|url| quote! { .url(Some(#url))});
+        let identifier = if !self.identifier.is_empty() {
+            let identifier = self.identifier.as_ref();
+            quote! { .identifier(Some(#identifier))}
+        } else {
+            TokenStream2::new()
+        };
 
         tokens.extend(quote! {
             utoipa::openapi::info::LicenseBuilder::new()
                 .name(#name)
                 #url
+                #identifier
                 .build()
         })
     }
diff --git a/utoipa-gen/tests/openapi_derive.rs b/utoipa-gen/tests/openapi_derive.rs
index 2f0d7cf7..f411a5f4 100644
--- a/utoipa-gen/tests/openapi_derive.rs
+++ b/utoipa-gen/tests/openapi_derive.rs
@@ -251,6 +251,26 @@ fn derive_openapi_with_servers() {
     )
 }
 
+#[test]
+fn derive_openapi_with_licence() {
+    #[derive(OpenApi)]
+    #[openapi(info(license(name = "licence_name", identifier = "MIT"), version = "1.0.0",))]
+    struct ApiDoc;
+
+    let value = serde_json::to_value(ApiDoc::openapi()).unwrap();
+    let info = value.pointer("/info/license");
+    dbg!(&info);
+
+    assert_json_include!(
+        actual: info,
+        expected:
+            json!({
+                "name": "licence_name",
+                "identifier": "MIT",
+            })
+    )
+}
+
 #[test]
 fn derive_openapi_with_custom_info() {
     #[derive(OpenApi)]
diff --git a/utoipa/src/openapi/info.rs b/utoipa/src/openapi/info.rs
index d6e64207..0df2bf35 100644
--- a/utoipa/src/openapi/info.rs
+++ b/utoipa/src/openapi/info.rs
@@ -212,6 +212,13 @@ builder! {
         #[serde(skip_serializing_if = "Option::is_none")]
         pub url: Option<String>,
 
+        /// An [SPDX-Licenses][spdx_licence] expression for the API. The _`identifier`_ field
+        /// is mutually exclusive of the _`url`_ field. E.g. Apache-2.0
+        ///
+        /// [spdx_licence]: <https://spdx.org/licenses/>
+        #[serde(skip_serializing_if = "Option::is_none")]
+        pub identifier: Option<String>,
+
         /// Optional extensions "x-something".
         #[serde(skip_serializing_if = "Option::is_none", flatten)]
         pub extensions: Option<Extensions>,
@@ -245,6 +252,14 @@ impl LicenseBuilder {
     pub fn extensions(mut self, extensions: Option<Extensions>) -> Self {
         set_value!(self extensions extensions)
     }
+
+    /// Set identifier of the licence as [SPDX-Licenses][spdx_licence] expression for the API.
+    /// The _`identifier`_ field is mutually exclusive of the _`url`_ field. E.g. Apache-2.0
+    ///
+    /// [spdx_licence]: <https://spdx.org/licenses/>
+    pub fn identifier<S: Into<String>>(mut self, identifier: Option<S>) -> Self {
+        set_value!(self identifier identifier.map(|identifier| identifier.into()))
+    }
 }
 
 #[cfg(test)]