PluginBuilder.onBeforeParse

interface PluginConstraints

• filter: RegExp

  Only apply the plugin when the import specifier matches this regular expression

  // Only apply the plugin when the import specifier matches the regex
  Bun.plugin({
   setup(builder) {
      builder.onLoad({ filter: /node_modules/underscore/ }, (args) => {
       return { contents: "throw new Error('Please use lodash instead of underscore.')" };
      });
   }
  })
  
• namespace?: string

  Only apply the plugin when the import specifier has a namespace matching this string

  Namespaces are prefixes in import specifiers. For example, "bun:ffi" has the namespace "bun".

  The default namespace is "file" and it can be omitted from import specifiers.