@netlify/build/lib/plugins/manifest/path.js

Netlify build module

import { locatePath } from 'locate-path';
import { addErrorInfo } from '../../error/info.js';
// Retrieve "manifest.yml" path for a specific plugin
export const getManifestPath = async function ({ pluginDir, packageDir, packageName }) {
    const dirs = [pluginDir, packageDir]
        .filter(Boolean)
        .flatMap((dir) => MANIFEST_FILENAMES.map((filename) => `${dir}/${filename}`));
    const manifestPath = await locatePath(dirs);
    validateManifestExists(manifestPath, packageName);
    return manifestPath;
};
const validateManifestExists = function (manifestPath, packageName) {
    if (manifestPath !== undefined) {
        return;
    }
    const error = new Error(`The plugin "${packageName}" is missing a "manifest.yml".
This might mean:
  - The plugin "package" name is misspelled
  - The plugin "package" points to a Node module that is not a Netlify Build plugin
  - If you're developing a plugin, please see the documentation at https://docs.netlify.com/configure-builds/build-plugins/create-plugins/#anatomy-of-a-plugin`);
    addErrorInfo(error, { type: 'resolveConfig' });
    throw error;
};
const MANIFEST_FILENAMES = ['manifest.yml', 'manifest.yaml'];