[BUG] [php] [php-nextgen] Number as first character of Model

[jeroen1602]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When a schema name starts with a number and has an object property, then the class name for that object property starts with a number.
This is not allowed in PHP.

For the example below two model classes are created.

• Model3dPosition
• 3dPositionPosition

The first model gets the Model prefix to fix the name. The second one however doesn't get this prefix.

openapi-generator version

• v7.24.0

OpenAPI declaration file content or url

openapi: 3.0.3
info:
  title: modelWithANumber
  description: Example of a model generated with a number as first character
  version: 1.0.0
paths:
  /:
    get:
      operationId: first
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/3d-position'
          description: This route breaks
components:
  schemas:
    3d-position:
      type: object
      properties:
        position:
          type: object
          properties:
            x:
              type: integer
            y:
              type: integer
            z:
              type: integer

Generation Details

I used the following docker command:

docker run --rm --user "$UID:$(id -g)" \
    -v "$PWD":/local \
    openapitools/openapi-generator-cli:v7.24.0 generate \
    -i "/local/api.yml" \
    -g php-nextgen \
    -c /local/generate-nextgen.json \
    -o /local/nextgen/

Steps to reproduce

• Generate the api as described above.
• Check the model directory (src/Model)
• See error for 3dPositionPosition.php.
• Optionally lint using php -l

Related issues/PRs

I couldn't find anyting.

Suggest a fix

I think the logic that adds Model as a prefix should be expanded to also check the names for sub nested models.

This logic may also be missing for other generators

[jeroen1602]

I've done some debugging.

The following code loops over all the models in the api definition.

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

Lines 1785 to 1801 in 2767397

	for (Map.Entry<String, Schema> definitionsEntry : definitions.entrySet()) {
	String key = definitionsEntry.getKey();
	Schema schema = definitionsEntry.getValue();
	if (schema == null) {
	LOGGER.warn("Schema {} cannot be null in processModels", key);
	continue;
	}
	CodegenModel cm = config.fromModel(key, schema);
	ModelMap mo = new ModelMap();
	mo.setModel(cm);
	mo.put("importPath", config.toModelImport(cm.classname));
	modelMaps.add(mo);
	cm.removeSelfReferenceImport();
	allImports.addAll(cm.imports);
	}

The first time it handles 3dPosition which then goes through

• modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java:1792 -> config.fromModel
• modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java:3426 -> toModelName
• modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPhpCodegen.java:600 -> toGenericName

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

  Lines 577 to 582 in 2767397

  	// model name starts with number
  	if (name.matches("^\\d.*")) {
  	LOGGER.warn("{} (model name starts with number) cannot be used as model name. Renamed to {}", name,
  	camelize("model_" + name));
  	name = "model_" + name; // e.g. 200Response => Model200Response (after camelize)
  	}

Here it will prepend model_ to the model name fixing the first model.

The second time it handels _3d_position_position.

This goes through the same stack. However at the number check it won't pass because the string starts with _.

After that in the toModelName function it will camelize the string. This will then remove the leading _ causing the number to be the first character instead.

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

Lines 613 to 617 in 2767397

	// camelize the model name
	// phone_number => PhoneNumber
	String camelizedName = camelize(name);
	schemaKeyToModelNameCache.put(origName, camelizedName);
	return camelizedName;

Possible fix

I thought a simple fix would be to change the number check from:

// model name starts with number
if (name.matches("^\\d.*")) {
    LOGGER.warn("{} (model name starts with number) cannot be used as model name. Renamed to {}", name,
            camelize("model_" + name));
    name = "model_" + name; // e.g. 200Response => Model200Response (after camelize)
}

to:

// model name starts with number
if (name.matches("^_*\\d.*")) { // <-- changed the regex here.
    LOGGER.warn("{} (model name starts with number) cannot be used as model name. Renamed to {}", name,
            camelize("model_" + name));
    name = "model_" + name; // e.g. 200Response => Model200Response (after camelize)
}

This does lead to an ugly double _ in the name. But the camelize function removes this.

I'm not sure if other characters should also be included in the regex.
This fix would also only fix this issue for PHP based generators and not other generators that may also suffer from this issue.

[wing328]

thanks for reporting the issue

a workaround is to use the modelNameMappings option:

https://github.com/OpenAPITools/openapi-generator/blob/master/docs/customization.md#name-mapping