AsyncAPI Modelina custom property names

modelina-custom-properties-naming.ts

'use strict';

import fs from 'node:fs/promises';
import path from 'node:path';
import { Parser, fromFile } from '@asyncapi/parser';
import { PropertyKeyContext, TypeScriptGenerator } from '@asyncapi/modelina';

/**
 * Modelina by default transforms payload properties' names into `camelCase`. This custom sctript
 * retirns the property names as-is keeping your `snake_case` naming in place.
 */

async function main() {
    // Extract these into the script parameters.
    const src = `${process.cwd()}/src/project.a2s.json`;
    const dest = `${process.cwd()}/destination/models`;

    // 1. Parse the AsyncAPI / A2S document
    const parser = new Parser();
    const { document: asyncapiDoc } = await fromFile(parser, src).parse();
    if (!asyncapiDoc) {
        throw new Error(`Failed to parse document at ${src}`);
    }

    // 2. Create Modelina generator with the settings you want
    const generator = new TypeScriptGenerator({
        modelType: 'interface',

        /**
         * There was solution advised to fix the snake case issue.
         * The solution is not working, at least in "@asyncapi/modelina": "^5.10.1"
         * @see https://github.com/asyncapi/modelina/issues/885
         * 
         * The working solution is below.
         */
        constraints: {
            propertyKey: (context: PropertyKeyContext<any>) => {
                return context.objectPropertyModel.propertyName;
            }
        }
    });

    // 3. Generate models
    const models = await generator.generateCompleteModels(asyncapiDoc, {exportType: 'default'});

    // 4. Write each generated model to the output directory
    await fs.mkdir(dest, { recursive: true });
    await Promise.all(models.map(async model => {
        const filePath = path.join(dest, `${model.modelName}.ts`);
        await fs.writeFile(filePath, model.result, 'utf8');
        console.log(`Generated model: ${filePath}`);
    }));

    console.log('Generation completed successfully.');
}

try {
    await main();
} catch (error) {
    console.error('Error generating models:', error);
    process.exit(1);
}