rust: Update codegen templates to support struct enums

rust/templates/component_type.rs.jinja

@@ -9,6 +9,8 @@
     {% include "types/string_enum.rs.jinja" -%}
 {% elif type.kind == "integer_enum" -%}
     {% include "types/integer_enum.rs.jinja" -%}
+{% elif type.kind == "struct_enum" -%}
+    {% include "types/struct_enum.rs.jinja" -%}
 {% else -%}
     compile_error!("{{ type.kind }} types are not supported by this codegen template");
 {% endif %}

rust/templates/types/struct.rs.jinja

@@ -12,53 +12,7 @@ use super::{
 {{ doc_comment }}
 #[derive(Clone, Debug, Default, PartialEq, Deserialize, Serialize)]
 pub struct {{ type.name | to_upper_camel_case }} {
-    {% for field in type.fields %}
-        {% if field.description is defined -%}
-            {{ field.description | to_doc_comment(style="rust") }}
-            {# we currently use String for date-time params, for backwards compat -#}
-            {# document the format so it's not _that_ awkward -#}
-            {% if field.type.is_datetime() -%}
-            ///
-            /// RFC3339 date string.
-            {% endif -%}
-        {% endif -%}
-
-        {% if field.deprecated -%}
-            #[deprecated]
-        {% endif -%}
-
-        {% if field.name != field.name | to_snake_case -%}
-            #[serde(rename = "{{ field.name }}")]
-        {% endif -%}
-
-        {#
-            we only have defaults on optional fields now, and the old codegen
-            was not doing anything with them, so leave them alone here as well,
-            at least for now
-        -#}
-        {# {% if field.default is defined and field.default is not none -%}
-        #[serde(default = "{{ field.name | to_snake_case }}_default")]
-        {% endif -%} -#}
-        {% if field.type.is_datetime() -%}
-            {% set field_ty = "String" -%}
-        {% else -%}
-            {% set field_ty = field.type.to_rust() -%}
-        {% endif -%}
-
-        {% if not field.required or field.nullable -%}
-            {# only for patch requests, if the field is both non-required
-               and nullable, use JsOption -#}
-            {% if type.name is endingwith "Patch" and field.nullable -%}
-                {% set field_ty %}JsOption<{{ field_ty }}>{% endset -%}
-                #[serde(default, skip_serializing_if = "JsOption::is_undefined")]
-            {% else -%}
-                {% set field_ty %}Option<{{ field_ty }}>{% endset -%}
-                #[serde(skip_serializing_if = "Option::is_none")]
-            {% endif -%}
-        {% endif -%}
-
-        pub {{ field.name | to_snake_case }}: {{ field_ty }},
-    {% endfor %}
+    {% include "types/struct_fields.rs.jinja" -%}
 }
 
 impl {{ type.name | to_upper_camel_case }} {

rust/templates/types/struct_enum.rs.jinja

@@ -0,0 +1,38 @@
+use serde::{Deserialize, Serialize};
+
+use super::{
+    {% for c in referenced_components -%}
+        {{ c | to_snake_case }}::{{ c | to_upper_camel_case }},
+    {% endfor -%}
+};
+
+{% set type_name = type.name | to_upper_camel_case -%}
+{% if type.fields | length > 0 -%}
+    {% set enum_type_name %}{{ type_name }}{{ type.content_field | to_upper_camel_case }}{% endset -%}
+
+    {{ doc_comment }}
+    #[derive(Clone, Debug, Deserialize, Serialize)]
+    pub struct {{ type_name }} {
+        {% include "types/struct_fields.rs.jinja" %}
+
+        #[serde(flatten)]
+        {% set enum_field_name = type.content_field | to_snake_case %}
+        {% if type.content_field != enum_field_name -%}
+            #[serde(rename = "{{ type.content_field }}")]
+        {% endif -%}
+        pub {{ enum_field_name }}: {{ enum_type_name }},
+    }
+{% else -%}
+    {% set enum_type_name = type_name %}
+{% endif %}
+
+#[derive(Clone, Debug, Deserialize, Serialize)]
+#[serde(tag = "{{ type.discriminator_field }}", content = "{{ type.content_field }}")]
+pub enum {{ enum_type_name }} {
+    {% for variant in type.variants -%}
+        {{ variant.name | to_upper_camel_case -}}
+        {% if variant.schema_ref is defined -%}
+            ({{ variant.schema_ref | to_upper_camel_case }})
+        {%- endif %},
+    {% endfor -%}
+}

rust/templates/types/struct_fields.rs.jinja

@@ -0,0 +1,47 @@
+{% for field in type.fields %}
+    {% if field.description is defined -%}
+        {{ field.description | to_doc_comment(style="rust") }}
+        {# we currently use String for date-time params, for backwards compat -#}
+        {# document the format so it's not _that_ awkward -#}
+        {% if field.type.is_datetime() -%}
+        ///
+        /// RFC3339 date string.
+        {% endif -%}
+    {% endif -%}
+
+    {% if field.deprecated -%}
+        #[deprecated]
+    {% endif -%}
+
+    {% if field.name != field.name | to_snake_case -%}
+        #[serde(rename = "{{ field.name }}")]
+    {% endif -%}
+
+    {#
+        we only have defaults on optional fields now, and the old codegen
+        was not doing anything with them, so leave them alone here as well,
+        at least for now
+    -#}
+    {# {% if field.default is defined and field.default is not none -%}
+    #[serde(default = "{{ field.name | to_snake_case }}_default")]
+    {% endif -%} -#}
+    {% if field.type.is_datetime() -%}
+        {% set field_ty = "String" -%}
+    {% else -%}
+        {% set field_ty = field.type.to_rust() -%}
+    {% endif -%}
+
+    {% if not field.required or field.nullable -%}
+        {# only for patch requests, if the field is both non-required
+            and nullable, use JsOption -#}
+        {% if type.name is endingwith "Patch" and field.nullable -%}
+            {% set field_ty %}JsOption<{{ field_ty }}>{% endset -%}
+            #[serde(default, skip_serializing_if = "JsOption::is_undefined")]
+        {% else -%}
+            {% set field_ty %}Option<{{ field_ty }}>{% endset -%}
+            #[serde(skip_serializing_if = "Option::is_none")]
+        {% endif -%}
+    {% endif -%}
+
+    pub {{ field.name | to_snake_case }}: {{ field_ty }},
+{% endfor %}