Optional request bodies

The idea is to identify args for the CLI that can be omitted since the
entire body is technically optional.

Author: svix-onelson

src/api.rs

@@ -28,7 +28,11 @@ pub(crate) struct Api {
 }
 
 impl Api {
-    pub(crate) fn new(paths: openapi::Paths, with_deprecated: bool) -> anyhow::Result<Self> {
+    pub(crate) fn new(
+        paths: openapi::Paths,
+        with_deprecated: bool,
+        component_schemas: &IndexMap<String, openapi::SchemaObject>,
+    ) -> anyhow::Result<Self> {
         let mut resources = BTreeMap::new();
 
         for (path, pi) in paths {
@@ -46,7 +50,9 @@ impl Api {
                     continue;
                 }
 
-                if let Some((res_path, op)) = Operation::from_openapi(&path, method, op) {
+                if let Some((res_path, op)) =
+                    Operation::from_openapi(&path, method, op, &component_schemas)
+                {
                     let resource = get_or_insert_resource(&mut resources, res_path);
                     if op.method == "post" {
                         resource.has_post_operation = true;
@@ -223,6 +229,10 @@ struct Operation {
     /// Name of the request body type, if any.
     #[serde(skip_serializing_if = "Option::is_none")]
     request_body_schema_name: Option<String>,
+    /// Some request bodies are required, but all the fields are optional (i.e. the CLI can omit
+    /// this from the argument list).
+    /// Only useful when `request_body_schema_name` is `Some`.
+    request_body_all_optional: bool,
     /// Name of the response body type, if any.
     #[serde(skip_serializing_if = "Option::is_none")]
     response_body_schema_name: Option<String>,
@@ -234,6 +244,7 @@ impl Operation {
         path: &str,
         method: &str,
         op: openapi::Operation,
+        component_schemas: &IndexMap<String, aide::openapi::SchemaObject>,
     ) -> Option<(Vec<String>, Self)> {
         let Some(op_id) = op.operation_id else {
             // ignore operations without an operationId
@@ -343,6 +354,51 @@ impl Operation {
             }
         }
 
+        let request_body_all_optional = op
+            .request_body
+            .as_ref()
+            .map(|r| {
+                match r {
+                    ReferenceOr::Reference { .. } => {
+                        unimplemented!("reference")
+                    }
+                    ReferenceOr::Item(body) => {
+                        if let Some(mt) = body.content.get("application/json") {
+                            match mt.schema.as_ref().map(|so| &so.json_schema) {
+                                Some(Schema::Object(schemars::schema::SchemaObject {
+                                    object: Some(ov),
+                                    ..
+                                })) => {
+                                    return ov.required.is_empty();
+                                }
+                                Some(Schema::Object(schemars::schema::SchemaObject {
+                                    reference: Some(s),
+                                    ..
+                                })) => {
+                                    match component_schemas
+                                        .get(
+                                            &get_schema_name(Some(s)).expect("schema should exist"),
+                                        )
+                                        .map(|so| &so.json_schema)
+                                    {
+                                        Some(Schema::Object(schemars::schema::SchemaObject {
+                                            object: Some(ov),
+                                            ..
+                                        })) => {
+                                            return ov.required.is_empty();
+                                        }
+                                        _ => unimplemented!("double ref not supported"),
+                                    }
+                                }
+                                _ => {}
+                            }
+                        }
+                    }
+                }
+                false
+            })
+            .unwrap_or_default();
+
         let request_body_schema_name = op.request_body.and_then(|b| match b {
             ReferenceOr::Item(mut req_body) => {
                 assert!(req_body.required);
@@ -362,7 +418,7 @@ impl Operation {
                         if !obj.is_ref() {
                             tracing::error!(?obj, "unexpected non-$ref json body schema");
                         }
-                        get_schema_name(obj.reference)
+                        get_schema_name(obj.reference.as_deref())
                     }
                 }
             }
@@ -415,6 +471,7 @@ impl Operation {
             header_params,
             query_params,
             request_body_schema_name,
+            request_body_all_optional,
             response_body_schema_name,
         };
         Some((res_path, op))
@@ -458,7 +515,7 @@ fn response_body_schema_name(resp: ReferenceOr<openapi::Response>) -> Option<Str
                     if !obj.is_ref() {
                         tracing::error!(?obj, "unexpected non-$ref json body schema");
                     }
-                    get_schema_name(obj.reference)
+                    get_schema_name(obj.reference.as_deref())
                 }
             }
         }

src/main.rs

@@ -60,7 +60,7 @@ fn main() -> anyhow::Result<()> {
     let mut components = spec.components.unwrap_or_default();
 
     if let Some(paths) = spec.paths {
-        let api = Api::new(paths, with_deprecated).unwrap();
+        let api = Api::new(paths, with_deprecated, &components.schemas).unwrap();
         {
             let mut api_file = BufWriter::new(File::create("api.ron")?);
             writeln!(api_file, "{api:#?}")?;

src/types.rs

@@ -72,7 +72,7 @@ impl FieldType {
             Some(SingleOrVec::Vec(types)) => {
                 bail!("unsupported multi-typed parameter: `{types:?}`")
             }
-            None => match get_schema_name(obj.reference) {
+            None => match get_schema_name(obj.reference.as_deref()) {
                 Some(name) => Self::SchemaRef(name),
                 None => bail!("unsupported type-less parameter"),
             },

src/util.rs

@@ -2,7 +2,7 @@ use std::{collections::BTreeSet, io, process::Command, sync::Mutex};
 
 use camino::Utf8Path;
 
-pub(crate) fn get_schema_name(maybe_ref: Option<String>) -> Option<String> {
+pub(crate) fn get_schema_name(maybe_ref: Option<&str>) -> Option<String> {
     let r = maybe_ref?;
     let schema_name = r.strip_prefix("#/components/schemas/");
     if schema_name.is_none() {

templates/svix_cli_resource.rs.jinja

@@ -86,7 +86,12 @@ pub enum {{ resource_type_name }}Commands {
             {# body parameter struct -#}
             {% if op.request_body_schema_name is defined -%}
                 {{ op.request_body_schema_name | to_snake_case }}:
-                    JsonOf<{{ op.request_body_schema_name }}>,
+                {% if op.request_body_all_optional %}
+                Option<JsonOf<{{ op.request_body_schema_name }}>>
+                {% else %}
+                JsonOf<{{ op.request_body_schema_name }}>
+                {% endif %}
+                ,
             {% endif -%}
 
             {# query parameters -#}
@@ -151,7 +156,13 @@ impl {{ resource_type_name }}Commands {
 
                             {# body parameter struct -#}
                             {% if op.request_body_schema_name is defined -%}
-                                {{ op.request_body_schema_name | to_snake_case }}.into_inner(),
+                                {{ op.request_body_schema_name | to_snake_case }}
+                                {% if op.request_body_all_optional -%}
+                                    .map(|x| x.into_inner()).unwrap_or_default()
+                                {% else -%}
+                                    .into_inner()
+                                {% endif -%}
+                                ,
                             {% endif -%}
 
                             {# query parameters -#}