[Bug]: x-modelgen-inferred-name extension ignored for inline enums in payloads preset

[jonaslagoni]

Description

The payloads preset generates files named AnonymousSchema_X.ts for inline enum properties even when the x-modelgen-inferred-name extension is provided. The extension is present in the AsyncAPI document but is completely ignored by the generator.

This may be related to the previously closed #137, but that fix did not address the x-modelgen-inferred-name extension case.

Environment

• CLI Version: 0.64.2 (latest)
• Node Version: 22+
• OS: Windows 11 (MINGW64)

Minimal Reproduction

codegen.ts

import { TheCodegenConfiguration } from '@the-codegen-project/cli'

const config: TheCodegenConfiguration = {
  inputType: 'asyncapi',
  inputPath: './input.asyncapi.json',
  language: 'typescript',
  generators: [
    {
      preset: 'payloads',
      outputPath: './output',
      serializationType: 'json',
      language: 'typescript',
      enum: 'enum',
    },
  ],
}

export default config

input.asyncapi.json

{
  "asyncapi": "3.0.0",
  "info": {
    "title": "Test x-modelgen-inferred-name",
    "version": "1.0.0"
  },
  "channels": {
    "test": {
      "messages": {
        "testMsg": {
          "payload": {
            "type": "object",
            "properties": {
              "status": {
                "x-modelgen-inferred-name": "Status",
                "type": "string",
                "enum": ["active", "inactive"]
              }
            }
          }
        }
      }
    }
  }
}

Command

pnpm codegen generate ./codegen.ts

Expected Output

• File: Status.ts
• Content:

enum Status {
  ACTIVE = "active",
  INACTIVE = "inactive",
}
export { Status };

Actual Output

• File: AnonymousSchema_1StatusEnum.ts
• Content:

enum AnonymousSchema_1StatusEnum {
  ACTIVE = "active",
  INACTIVE = "inactive",
}
export { AnonymousSchema_1StatusEnum };

Additional Context

The x-modelgen-inferred-name extension is documented in Modelina and should be respected when present. Looking at Modelina's JsonSchemaInputProcessor.ts, it explicitly checks for existing values:

} else if (
  name &&
  !(schema as any)[this.MODELGEN_INFFERED_NAME] &&
  schema.$ref === undefined
)

This suggests the extension should NOT be overwritten if already present. The issue seems to be in how the CLI processes/transforms schemas before passing them to Modelina - the extension may be stripped or not properly forwarded.

[jonaslagoni]

Root Cause Analysis Complete

After investigating, this is a bug in @asyncapi/modelina, not The Codegen Project.

Summary

The AsyncAPIInputProcessor.determineSchemaName() function in Modelina does not check for an existing x-modelgen-inferred-name extension when determining schema names. For inline enums, it uses context-based naming (ParentPropertyEnum) instead of respecting the user-provided extension.

Interestingly, JsonSchemaInputProcessor.reflectSchemaNames() already has this check:

else if (name && !schema[this.MODELINA_INFERRED_NAME] && schema.$ref === undefined) {
    // Only set name if x-modelgen-inferred-name is NOT already present
}

But AsyncAPIInputProcessor does not have an equivalent check.

Upstream Issue Filed

I've filed the bug with Modelina: asyncapi/modelina#2448

Workaround

Until this is fixed in Modelina, users can use the title property instead of x-modelgen-inferred-name:

{
  "status": {
    "title": "Status",
    "type": "string",
    "enum": ["active", "inactive"]
  }
}

The title property is checked by Modelina's determineSchemaName() before context-based inference (Priority 2), so it should work as a workaround.