[Rust-Axum][Breaking Change] Improve the oneOf model generator (#20336)

* Improve the implementation of oneOf

* Fixed 2.0 schemas; possible freeze present

* Fix generate-samples.sh freezing

* Fix validation of primitive types

* Move oneOf handling to its own method

* Fix formatting and add comments

* Remove allOf based discriminator handling

* Implement a test for v3 oneOf

* Implement oneOf tests for rust axum

* Fix circle CI

* Fix pom path, ensure cargo is present

* Implement untagged test

* Add final and fix double underscore typo

Author: Victoria-Casasampere-BeeTheData

CI/circle_parallel.sh

@@ -15,12 +15,22 @@ if [ "$NODE_INDEX" = "1" ]; then
 
   sudo apt-get -y install cpanminus
 
+  # install rust
+  curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+  source "$HOME/.cargo/env"
+
+  echo "Testing perl"
   (cd samples/client/petstore/perl && /bin/bash ./test.bash)
+
+  echo "Testing ruby"
   (cd samples/client/petstore/ruby && mvn integration-test)
   (cd samples/client/petstore/ruby-faraday && mvn integration-test)
   (cd samples/client/petstore/ruby-httpx && mvn integration-test)
   (cd samples/client/petstore/ruby-autoload && mvn integration-test)
 
+  echo "Testing rust"
+  (cd samples/server/petstore/rust-axum && mvn integration-test)
+
 elif [ "$NODE_INDEX" = "2" ]; then
   echo "Running node $NODE_INDEX to test Go"
   # install haskell

bin/configs/manual/rust-axum-oneof-v3.yaml

@@ -0,0 +1,11 @@
+generatorName: rust-axum
+outputDir: samples/server/petstore/rust-axum/output/rust-axum-oneof
+inputSpec: modules/openapi-generator/src/test/resources/3_0/rust-axum/rust-axum-oneof.yaml
+templateDir: modules/openapi-generator/src/main/resources/rust-axum
+generateAliasAsModel: true
+additionalProperties:
+  hideGenerationTimestamp: "true"
+  packageName: rust-axum-oneof
+globalProperties:
+  skipFormModel: "false"
+enablePostProcessFile: true

bin/utils/test_file_list.yaml

@@ -49,3 +49,8 @@
   sha256: 67a9e63e13ebddac21cb236aa015edce30f5d3bd8d6adcf50044cad00d48c45e
 - filename: "samples/openapi3/client/petstore/java/jersey2-java8/src/test/java/org/openapitools/client/model/ZebraTest.java"
   sha256: 15eeb6d8a9a79d0f1930b861540d9c5780d6c49ea4fdb68269ac3e7ec481e142
+# rust axum test files
+- filename: "samples/server/petstore/rust-axum/output/rust-axum-oneof/src/tests.rs"
+  sha256: 3d4198174018cc7fd9d4bcffd950609a5bd306cf03b2fa780516f4e22a566e8c
+- filename: "samples/server/petstore/rust-axum/output/openapi-v3/src/tests.rs"
+  sha256: 356ac684b1fce91b153c63caefc1fe7472ea600ac436a19631e16bc00e986c50

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java

@@ -1083,8 +1083,8 @@ public String toString() {
         sb.append(", items='").append(items).append('\'');
         sb.append(", additionalProperties='").append(additionalProperties).append('\'');
         sb.append(", isModel='").append(isModel).append('\'');
-        sb.append(", isNull='").append(isNull);
-        sb.append(", hasValidation='").append(hasValidation);
+        sb.append(", isNull='").append(isNull).append('\'');
+        sb.append(", hasValidation='").append(hasValidation).append('\'');
         sb.append(", getAdditionalPropertiesIsAnyType=").append(getAdditionalPropertiesIsAnyType());
         sb.append(", getHasDiscriminatorWithNonEmptyMapping=").append(hasDiscriminatorWithNonEmptyMapping);
         sb.append(", getIsAnyType=").append(getIsAnyType());

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustAxumServerCodegen.java

@@ -236,8 +236,9 @@ public RustAxumServerCodegen() {
         supportingFiles.add(new SupportingFile("header.mustache", "src", "header.rs"));
         supportingFiles.add(new SupportingFile("server-mod.mustache", "src/server", "mod.rs"));
         supportingFiles.add(new SupportingFile("apis-mod.mustache", apiPackage().replace('.', File.separatorChar), "mod.rs"));
-        supportingFiles.add(new SupportingFile("README.mustache", "", "README.md")
-                .doNotOverwrite());
+        // The file gets overwritten regardless
+        supportingFiles.add(new SupportingFile("tests.mustache", "src", "tests.rs").doNotOverwrite());
+        supportingFiles.add(new SupportingFile("README.mustache", "", "README.md").doNotOverwrite());
     }
 
     @Override
@@ -594,8 +595,105 @@ public CodegenOperation fromOperation(String path, String httpMethod, Operation
         return op;
     }
 
+    private void postProcessOneOfModels(List<ModelMap> allModels) {
+        final HashMap<String, List<String>> oneOfMapDiscriminator = new HashMap<>();
+
+        for (ModelMap mo : allModels) {
+            final CodegenModel cm = mo.getModel();
+
+            final CodegenComposedSchemas cs = cm.getComposedSchemas();
+            if (cs != null) {
+                final List<CodegenProperty> csOneOf = cs.getOneOf();
+
+                if (csOneOf != null) {
+                    for (CodegenProperty model : csOneOf) {
+                        // Generate a valid name for the enum variant.
+                        // Mainly needed for primitive types.
+                        String[] modelParts = model.dataType.replace("<", "Of").replace(">", "").split("::");
+                        model.datatypeWithEnum = camelize(modelParts[modelParts.length - 1]);
+
+                        // Primitive type is not properly set, this overrides it to guarantee adequate model generation.
+                        if (!model.getDataType().matches(String.format(Locale.ROOT, ".*::%s", model.getDatatypeWithEnum()))) {
+                            model.isPrimitiveType = true;
+                        }
+                    }
+
+                    cs.setOneOf(csOneOf);
+                    cm.setComposedSchemas(cs);
+                }
+            }
+
+            if (cm.discriminator != null) {
+                for (String model : cm.oneOf) {
+                    List<String> discriminators = oneOfMapDiscriminator.getOrDefault(model, new ArrayList<>());
+                    discriminators.add(cm.discriminator.getPropertyName());
+                    oneOfMapDiscriminator.put(model, discriminators);
+                }
+            }
+        }
+
+        for (ModelMap mo : allModels) {
+            final CodegenModel cm = mo.getModel();
+
+            for (CodegenProperty var : cm.vars) {
+                var.isDiscriminator = false;
+            }
+
+            final List<String> discriminatorsForModel = oneOfMapDiscriminator.get(cm.getSchemaName());
+
+            if (discriminatorsForModel != null) {
+                for (String discriminator : discriminatorsForModel) {
+                    boolean hasDiscriminatorDefined = false;
+
+                    for (CodegenProperty var : cm.vars) {
+                        if (var.baseName.equals(discriminator)) {
+                            var.isDiscriminator = true;
+                            hasDiscriminatorDefined = true;
+                            break;
+                        }
+                    }
+
+                    // If the discriminator field is not a defined attribute in the variant structure, create it.
+                    if (!hasDiscriminatorDefined) {
+                        CodegenProperty property = new CodegenProperty();
+
+                        // Static attributes
+                        // Only strings are supported by serde for tag field types, so it's the only one we'll deal with
+                        property.openApiType = "string";
+                        property.complexType = "string";
+                        property.dataType = "String";
+                        property.datatypeWithEnum = "String";
+                        property.baseType = "string";
+                        property.required = true;
+                        property.isPrimitiveType = true;
+                        property.isString = true;
+                        property.isDiscriminator = true;
+
+                        // Attributes based on the discriminator value
+                        property.baseName = discriminator;
+                        property.name = discriminator;
+                        property.nameInCamelCase = camelize(discriminator);
+                        property.nameInPascalCase = property.nameInCamelCase.substring(0, 1).toUpperCase(Locale.ROOT) + property.nameInCamelCase.substring(1);
+                        property.nameInSnakeCase = underscore(discriminator).toUpperCase(Locale.ROOT);
+                        property.getter = String.format(Locale.ROOT, "get%s", property.nameInPascalCase);
+                        property.setter = String.format(Locale.ROOT, "set%s", property.nameInPascalCase);
+                        property.defaultValueWithParam = String.format(Locale.ROOT, " = data.%s;", property.name);
+
+                        // Attributes based on the model name
+                        property.defaultValue = String.format(Locale.ROOT, "r#\"%s\"#.to_string()", cm.getSchemaName());
+                        property.jsonSchema = String.format(Locale.ROOT, "{ \"default\":\"%s\"; \"type\":\"string\" }", cm.getSchemaName());
+
+                        cm.vars.add(property);
+                    }
+                }
+            }
+        }
+    }
+
     @Override
     public OperationsMap postProcessOperationsWithModels(final OperationsMap operationsMap, List<ModelMap> allModels) {
+        postProcessOneOfModels(allModels);
+
         final OperationMap operations = operationsMap.getOperations();
         operations.put("classnamePascalCase", camelize(operations.getClassname()));
 

modules/openapi-generator/src/main/resources/rust-axum/lib.mustache

@@ -28,3 +28,6 @@ pub mod apis;
 
 #[cfg(feature = "server")]
 pub(crate) mod header;
+
+#[cfg(test)]
+mod tests;

modules/openapi-generator/src/main/resources/rust-axum/models.mustache

@@ -573,21 +573,70 @@ impl PartialEq for {{{classname}}} {
         self.0.get() == other.0.get()
     }
 }
+
 {{/anyOf.size}}
 {{#oneOf.size}}
-/// One of:
-{{#oneOf}}
-/// - {{{.}}}
-{{/oneOf}}
-#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
-pub struct {{{classname}}}(Box<serde_json::value::RawValue>);
+{{#discriminator}}
+#[derive(Debug, Clone, PartialEq, serde::Deserialize)]
+#[serde(tag = "{{{propertyBaseName}}}")]
+{{/discriminator}}
+{{^discriminator}}
+#[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+#[serde(untagged)]
+{{/discriminator}}
+#[allow(non_camel_case_types)]
+pub enum {{{classname}}} {
+    {{#composedSchemas}}
+    {{#oneOf}}
+    {{{datatypeWithEnum}}}(Box<{{{dataType}}}>),
+    {{/oneOf}}
+    {{/composedSchemas}}
+}
 
 impl validator::Validate for {{{classname}}}
 {
     fn validate(&self) -> std::result::Result<(), validator::ValidationErrors> {
-        std::result::Result::Ok(())
+        match self {
+            {{#composedSchemas}}
+            {{#oneOf}}
+            {{#isPrimitiveType}}
+            Self::{{{datatypeWithEnum}}}(_) => std::result::Result::Ok(()),
+            {{/isPrimitiveType}}
+            {{^isPrimitiveType}}
+            Self::{{{datatypeWithEnum}}}(x) => x.validate(),
+            {{/isPrimitiveType}}
+            {{/oneOf}}
+            {{/composedSchemas}}
+        }
+    }
+}
+
+{{#discriminator}}
+impl serde::Serialize for {{{classname}}} {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where S: serde::Serializer {
+            match self {
+                {{#composedSchemas}}
+                {{#oneOf}}
+                Self::{{{datatypeWithEnum}}}(x) => x.serialize(serializer),
+                {{/oneOf}}
+                {{/composedSchemas}}
+            }
     }
 }
+{{/discriminator}}
+
+
+
+{{#composedSchemas}}
+{{#oneOf}}
+impl From<{{{dataType}}}> for {{{classname}}} {
+    fn from(value: {{{dataType}}}) -> Self {
+        Self::{{{datatypeWithEnum}}}(Box::new(value))
+    }
+}
+{{/oneOf}}
+{{/composedSchemas}}
 
 /// Converts Query Parameters representation (style=form, explode=false) to a {{{classname}}} value
 /// as specified in https://swagger.io/docs/specification/serialization/
@@ -600,11 +649,6 @@ impl std::str::FromStr for {{{classname}}} {
     }
 }
 
-impl PartialEq for {{{classname}}} {
-    fn eq(&self, other: &Self) -> bool {
-        self.0.get() == other.0.get()
-    }
-}
 {{/oneOf.size}}
 {{^anyOf.size}}
 {{^oneOf.size}}
@@ -613,11 +657,15 @@ impl PartialEq for {{{classname}}} {
 pub struct {{{classname}}} {
 {{#vars}}
 {{#description}}    
-/// {{{.}}}
+    /// {{{.}}}
 {{/description}}
 {{#isEnum}}
-/// Note: inline enums are not fully supported by openapi-generator
+    /// Note: inline enums are not fully supported by openapi-generator
 {{/isEnum}}
+{{#isDiscriminator}}
+    #[serde(default = "{{{classname}}}::_name_for_{{{name}}}")]
+    #[serde(serialize_with = "{{{classname}}}::_serialize_{{{name}}}")]
+{{/isDiscriminator}}
     #[serde(rename = "{{{baseName}}}")]
 {{#hasValidation}}
     #[validate(
@@ -685,6 +733,25 @@ pub struct {{{classname}}} {
 {{/vars}}
 }
 
+
+{{#vars}}
+{{#isDiscriminator}}
+impl {{{classname}}} {
+    fn _name_for_{{{name}}}() -> String {
+        String::from("{{{classname}}}")
+    }
+
+    fn _serialize_{{{name}}}<S>(_: &String, s: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        s.serialize_str(&Self::_name_for_{{{name}}}())
+    }
+}
+{{/isDiscriminator}}
+{{/vars}}
+
+
 {{#vars}}
 {{#hasValidation}}
 {{#pattern}}

modules/openapi-generator/src/main/resources/rust-axum/tests.mustache

@@ -0,0 +1,9 @@
+#[test]
+fn std_test() {
+    assert!(true);
+}
+
+#[tokio::test]
+async fn tokio_test() {
+    assert!(true);
+}