Note: The loaders API is being redesigned. This hook may disappear or its signature may change. Do not rely on the API described below.

    • url {string}
    • context {Object}
      • format {string}
    • defaultGetSource {Function}
    • Returns: {Object}
      • source {string|SharedArrayBuffer|Uint8Array}

    The getSource hook provides a way to define a custom method for retrieving the source code of an ES module specifier. This would allow a loader to potentially avoid reading files from disk.

    1. /**
    2.  * @param {string} url
    3.  * @param {{ format: string }} context
    4.  * @param {Function} defaultGetSource
    5.  * @returns {Promise<{ source: !(string | SharedArrayBuffer | Uint8Array) }>}
    6.  */
    7. export async function getSource(url, context, defaultGetSource) {
    8.   const { format } = context;
    9.   if (Math.random() > 0.5) { // Some condition.
    10.     // For some or all URLs, do some custom logic for retrieving the source.
    11.     // Always return an object of the form {source: <string|buffer>}.
    12.     return {
    13.       source: '...',
    14.     };
    15.   }
    16.   // Defer to Node.js for all other URLs.
    17.   return defaultGetSource(url, context, defaultGetSource);
    18. }