[OCaml] Introduce support for oneOf/anyOf, fix default value for non-required maps (OpenAPITools#21798)

* Add OCaml fake-petstore to test corner cases

* Prefix List functions with Stdlib as the fake petstore generates a List module

* Handle decimal and any types

* Indent to_json.mustache for easier maintenance

* Indent api-impl.mustache a bit more for readability before fix

* Fix: do not call `to_json` for free forms and byte arrays

Fixes OpenAPITools#21312

* Fix compilation for binary types

The implementation may not be correct, but at least it compiles. To be checked
if someday someone actually uses it/complains.

* Indent to_string.mustache

* Add support for exploded form-style object query params

Fixes OpenAPITools#21307

* Add ocaml-fake-petstore to CI

* Fix free-form body params

* Cohttp_lwt.Response is deprecated, use Cohttp.Response instead

* Safe Java code cleanup

* Split into model-record.mustache

* Add some support for oneOf/anyOf

* Re-generate all OCaml samples

* Fix: correctly mark non-required maps with default empty list

* Fix: Correctly encode/decode maps

* Refresh documentation

* Refresh after merging master

Author: sir4ur0n

.github/workflows/samples-ocaml.yaml

@@ -4,9 +4,13 @@ on:
   push:
     paths:
       - 'samples/client/petstore/ocaml/**'
+      - 'samples/client/petstore/ocaml-fake-petstore/**'
+      - 'samples/client/petstore/ocaml-oneOf/**'
   pull_request:
     paths:
       - 'samples/client/petstore/ocaml/**'
+      - 'samples/client/petstore/ocaml-fake-petstore/**'
+      - 'samples/client/petstore/ocaml-oneOf/**'
 
 jobs:
   build:
@@ -17,6 +21,8 @@ jobs:
       matrix:
         sample:
           - 'samples/client/petstore/ocaml/'
+          - 'samples/client/petstore/ocaml-fake-petstore/'
+          - 'samples/client/petstore/ocaml-oneOf/'
     steps:
       - uses: actions/checkout@v5
       - name: Set-up OCaml

.gitignore

@@ -296,6 +296,8 @@ samples/openapi3/client/petstore/go/privatekey.pem
 
 ## OCaml
 samples/client/petstore/ocaml/_build/
+samples/client/petstore/ocaml-fake-petstore/_build/
+samples/client/petstore/ocaml-oneOf/_build/
 
 # jetbrain http client
 samples/client/jetbrains/adyen/checkout71/http/client/Apis/http-client.private.env.json

bin/configs/ocaml-fake-petstore.yaml

@@ -0,0 +1,6 @@
+generatorName: ocaml
+outputDir: samples/client/petstore/ocaml-fake-petstore
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+templateDir: modules/openapi-generator/src/main/resources/ocaml
+additionalProperties:
+  packageName: petstore_client

bin/configs/ocaml-oneOf.yaml

@@ -0,0 +1,6 @@
+generatorName: ocaml
+outputDir: samples/client/petstore/ocaml-oneOf
+inputSpec: modules/openapi-generator/src/test/resources/3_0/oneOf_primitive.yaml
+templateDir: modules/openapi-generator/src/main/resources/ocaml
+additionalProperties:
+  packageName: petstore_client

docs/generators/ocaml.md

@@ -209,8 +209,8 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |Polymorphism|✗|OAS2,OAS3
 |Union|✗|OAS3
 |allOf|✗|OAS2,OAS3
-|anyOf|✗|OAS3
-|oneOf|✗|OAS3
+|anyOf|✓|OAS3
+|oneOf|✓|OAS3
 |not|✗|OAS3
 
 ### Security Feature

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

@@ -51,8 +51,6 @@ public class OCamlClientCodegen extends DefaultCodegen implements CodegenConfig
 
     static final String X_MODEL_MODULE = "x-model-module";
 
-    public static final String CO_HTTP = "cohttp";
-
     @Setter protected String packageName = "openapi";
     @Setter protected String packageVersion = "1.0.0";
     protected String apiDocPath = "docs/";
@@ -97,12 +95,15 @@ public OCamlClientCodegen() {
                 .excludeSchemaSupportFeatures(
                         SchemaSupportFeature.Polymorphism
                 )
+                .includeSchemaSupportFeatures(
+                        SchemaSupportFeature.oneOf,
+                        SchemaSupportFeature.anyOf
+                )
                 .includeClientModificationFeatures(
                         ClientModificationFeature.BasePath
                 )
         );
 
-
         outputFolder = "generated-code/ocaml";
         modelTemplateFiles.put("model.mustache", ".ml");
 
@@ -171,6 +172,7 @@ public OCamlClientCodegen() {
         typeMapping.put("short", "int");
         typeMapping.put("char", "char");
         typeMapping.put("float", "float");
+        typeMapping.put("decimal", "string");
         typeMapping.put("double", "float");
         typeMapping.put("integer", "int32");
         typeMapping.put("number", "float");
@@ -179,36 +181,27 @@ public OCamlClientCodegen() {
         typeMapping.put("any", "Yojson.Safe.t");
         typeMapping.put("file", "string");
         typeMapping.put("ByteArray", "string");
+        typeMapping.put("AnyType", "Yojson.Safe.t");
         // lib
         typeMapping.put("string", "string");
         typeMapping.put("UUID", "string");
         typeMapping.put("URI", "string");
         typeMapping.put("set", "`Set");
         typeMapping.put("password", "string");
         typeMapping.put("DateTime", "string");
-
-//        supportedLibraries.put(CO_HTTP, "HTTP client: CoHttp.");
-//
-//        CliOption libraryOption = new CliOption(CodegenConstants.LIBRARY, "library template (sub-template) to use.");
-//        libraryOption.setEnum(supportedLibraries);
-//        // set hyper as the default
-//        libraryOption.setDefault(CO_HTTP);
-//        cliOptions.add(libraryOption);
-//        setLibrary(CO_HTTP);
     }
 
     @Override
     public Map<String, ModelsMap> postProcessAllModels(Map<String, ModelsMap> superobjs) {
         List<String> toRemove = new ArrayList<>();
 
         for (Map.Entry<String, ModelsMap> modelEntry : superobjs.entrySet()) {
-            // process enum in models
             List<ModelMap> models = modelEntry.getValue().getModels();
             for (ModelMap mo : models) {
                 CodegenModel cm = mo.getModel();
 
                 // for enum model
-                if (Boolean.TRUE.equals(cm.isEnum) && cm.allowableValues != null) {
+                if (cm.isEnum && cm.allowableValues != null) {
                     toRemove.add(modelEntry.getKey());
                 } else {
                     enrichPropertiesWithEnumDefaultValues(cm.getAllVars());
@@ -219,6 +212,15 @@ public Map<String, ModelsMap> postProcessAllModels(Map<String, ModelsMap> supero
                     enrichPropertiesWithEnumDefaultValues(cm.getVars());
                     enrichPropertiesWithEnumDefaultValues(cm.getParentVars());
                 }
+
+                if (!cm.oneOf.isEmpty()) {
+                    // Add a boolean if it is a `oneOf`, because Mustache does not let us check if a list is non-empty
+                    cm.getVendorExtensions().put("x-ocaml-isOneOf", true);
+                }
+                if (!cm.anyOf.isEmpty()) {
+                    // Add a boolean if it is a `anyOf`, because Mustache does not let us check if a list is non-empty
+                    cm.getVendorExtensions().put("x-ocaml-isAnyOf", true);
+                }
             }
         }
 
@@ -242,8 +244,7 @@ private void enrichPropertiesWithEnumDefaultValues(List<CodegenProperty> propert
     @Override
     protected void updateDataTypeWithEnumForMap(CodegenProperty property) {
         CodegenProperty baseItem = property.items;
-        while (baseItem != null && (Boolean.TRUE.equals(baseItem.isMap)
-                || Boolean.TRUE.equals(baseItem.isArray))) {
+        while (baseItem != null && (baseItem.isMap || baseItem.isArray)) {
             baseItem = baseItem.items;
         }
 
@@ -260,8 +261,7 @@ protected void updateDataTypeWithEnumForMap(CodegenProperty property) {
     @Override
     protected void updateDataTypeWithEnumForArray(CodegenProperty property) {
         CodegenProperty baseItem = property.items;
-        while (baseItem != null && (Boolean.TRUE.equals(baseItem.isMap)
-                || Boolean.TRUE.equals(baseItem.isArray))) {
+        while (baseItem != null && (baseItem.isMap || baseItem.isArray)) {
             baseItem = baseItem.items;
         }
         if (baseItem != null) {
@@ -312,19 +312,17 @@ private void collectEnumSchemas(String parentName, Map<String, Schema> schemas)
 
             collectEnumSchemas(parentName, sName, schema);
 
+            String pName = parentName != null ? parentName + "_" + sName : sName;
             if (schema.getProperties() != null) {
-                String pName = parentName != null ? parentName + "_" + sName : sName;
                 collectEnumSchemas(pName, schema.getProperties());
             }
 
             if (schema.getAdditionalProperties() != null && schema.getAdditionalProperties() instanceof Schema) {
-                String pName = parentName != null ? parentName + "_" + sName : sName;
                 collectEnumSchemas(pName, (Schema) schema.getAdditionalProperties());
             }
 
             if (ModelUtils.isArraySchema(schema)) {
                 if (ModelUtils.getSchemaItems(schema) != null) {
-                    String pName = parentName != null ? parentName + "_" + sName : sName;
                     collectEnumSchemas(pName, ModelUtils.getSchemaItems(schema));
                 }
             }
@@ -677,7 +675,7 @@ private List<Map<String, Object>> buildEnumValues(String valueString) {
     public String toEnumValueName(String name) {
         if (reservedWords.contains(name)) {
             return escapeReservedWord(name);
-        } else if (((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.keySet().contains(String.valueOf((char) character)))) {
+        } else if (name.chars().anyMatch(character -> specialCharReplacements.containsKey(String.valueOf((char) character)))) {
             return escape(name, specialCharReplacements, Collections.singletonList("_"), null);
         } else {
             return name;
@@ -723,8 +721,6 @@ public OperationsMap postProcessOperationsWithModels(OperationsMap objs, List<Mo
         List<CodegenOperation> operations = objectMap.getOperation();
 
         for (CodegenOperation operation : operations) {
-            // http method verb conversion, depending on client library (e.g. Hyper: PUT => Put, Reqwest: PUT => put)
-            //if (CO_HTTP.equals(getLibrary())) {
             for (CodegenParameter param : operation.bodyParams) {
                 if (param.isModel && param.dataType.endsWith(".t")) {
                     param.vendorExtensions.put(X_MODEL_MODULE, param.dataType.substring(0, param.dataType.lastIndexOf('.')));

modules/openapi-generator/src/main/resources/ocaml/api-impl.mustache

@@ -30,7 +30,7 @@ let {{{operationId}}} {{^hasParams}}(){{/hasParams}}{{#allParams}}{{> to_param}}
     let uri = Request.{{> to_optional_prefix}}replace_path_param uri "{{{baseName}}}" {{> to_string}} {{{paramName}}} in
 {{/pathParams}}
 {{#queryParams}}
-    let uri = Request.{{> to_optional_prefix}}add_query_param{{#isArray}}_list{{/isArray}} uri "{{{baseName}}}" {{> to_string}} {{{paramName}}} in
+    let uri = Request.{{> to_optional_prefix}}add_query_param{{#isArray}}_list{{/isArray}}{{#isExplode}}{{#isFormStyle}}{{#isMap}}_exploded_form_object{{/isMap}}{{/isFormStyle}}{{/isExplode}} uri "{{{baseName}}}" {{> to_string}} {{{paramName}}} in
 {{/queryParams}}
 {{#hasAuthMethods}}
     {{#authMethods}}
@@ -42,7 +42,10 @@ let {{{operationId}}} {{^hasParams}}(){{/hasParams}}{{#allParams}}{{> to_param}}
     {{/authMethods}}
 {{/hasAuthMethods}}
 {{#bodyParams}}
-    let body = Request.{{#isFreeFormObject}}write_json_body{{/isFreeFormObject}}{{#isByteArray}}write_string_body{{/isByteArray}}{{^isFreeFormObject}}{{^isByteArray}}write_as_json_body{{/isByteArray}}{{/isFreeFormObject}} {{> to_json}} {{{paramName}}} in
+    let body = Request.
+        {{#isByteArray}}write_string_body {{{paramName}}}{{/isByteArray}}
+        {{^isByteArray}}write_as_json_body {{> to_json}} {{{paramName}}}{{/isByteArray}}
+    in
 {{/bodyParams}}
 {{^hasBodyParam}}
     {{#hasFormParams}}

modules/openapi-generator/src/main/resources/ocaml/json.mustache

@@ -50,6 +50,19 @@ let of_int32 x = `Intlit (Int32.to_string x)
 
 let of_int64 x = `Intlit (Int64.to_string x)
 
-let of_list_of of_f l = `List (List.map of_f l)
+let of_list_of of_f l = `List (Stdlib.List.map of_f l)
 
-let of_map_of of_f l = `Assoc (List.map (fun (k, v) -> (k, of_f v)) l)
+let of_map_of of_f l = `Assoc (Stdlib.List.map (fun (k, v) -> (k, of_f v)) l)
+
+let to_map_of of_f json =
+  match json with
+  | `Assoc l ->
+    Stdlib.List.fold_right
+      (fun (k, json) acc ->
+        match (of_f json, acc) with
+        | Stdlib.Result.Ok parsed_v, Stdlib.Result.Ok tl ->
+          Stdlib.Result.Ok ((k, parsed_v) :: tl)
+        | Stdlib.Result.Error e, _ -> Stdlib.Result.Error e
+        | _, Stdlib.Result.Error e -> Stdlib.Result.Error e)
+      l (Stdlib.Result.Ok [])
+  | _ -> Stdlib.Result.Error "Expected"

modules/openapi-generator/src/main/resources/ocaml/model-any-of.mustache

@@ -0,0 +1,25 @@
+type t =
+{{#composedSchemas.anyOf}}
+    | {{{nameInPascalCase}}} of {{{dataType}}}
+{{/composedSchemas.anyOf}}
+[@@deriving show, eq];;
+
+let to_yojson = function
+{{#composedSchemas.anyOf}}
+    | {{{nameInPascalCase}}} v -> [%to_yojson: {{{ datatypeWithEnum }}}] v
+{{/composedSchemas.anyOf}}
+
+(* Manual implementations because the derived one encodes into a tuple list where the first element is the constructor name. *)
+
+let of_yojson json =
+  [
+{{#composedSchemas.anyOf}}
+    [%of_yojson: {{{ datatypeWithEnum }}}] json
+      |> Stdlib.Result.to_option
+      |> Stdlib.Option.map (fun v -> {{{nameInPascalCase}}} v);
+{{/composedSchemas.anyOf}}
+                ]
+  |> Stdlib.List.filter_map (Fun.id)
+  |> function
+     | t :: _ -> Ok t (* Return the first successful parsing. *)
+     | [] -> Error ("Failed to parse JSON " ^ Yojson.Safe.show json ^ " into a value of type {{{ classname }}}")

modules/openapi-generator/src/main/resources/ocaml/model-one-of.mustache

@@ -0,0 +1,29 @@
+type t =
+{{#composedSchemas.oneOf}}
+    | {{{nameInPascalCase}}} of {{{dataType}}}
+{{/composedSchemas.oneOf}}
+[@@deriving show, eq];;
+
+let to_yojson = function
+{{#composedSchemas.oneOf}}
+    | {{{nameInPascalCase}}} v -> [%to_yojson: {{{ datatypeWithEnum }}}] v
+{{/composedSchemas.oneOf}}
+
+(* Manual implementations because the derived one encodes into a tuple list where the first element is the constructor name. *)
+
+let of_yojson json =
+  [
+{{#composedSchemas.oneOf}}
+    [%of_yojson: {{{ datatypeWithEnum }}}] json
+      |> Stdlib.Result.to_option
+      |> Stdlib.Option.map (fun v -> {{{nameInPascalCase}}} v);
+{{/composedSchemas.oneOf}}
+                ]
+  |> Stdlib.List.filter_map (Fun.id)
+  |> function
+     | [t] -> Ok t
+     | [] -> Error ("Failed to parse JSON " ^ Yojson.Safe.show json ^ " into a value of type {{{ classname }}}")
+     | ts -> let parsed_ts = ts
+                 |> Stdlib.List.map show
+                 |> Stdlib.String.concat " | "
+             in Error ("Failed to parse JSON " ^ Yojson.Safe.show json ^ " into a value of type {{{ classname }}}: oneOf should only succeed on one parser, but the JSON was parsed into [" ^ parsed_ts ^ "]")