Commit 3840b83

ExternalOptionFunction,

import type { TransformOptions } from './options/transform-options';

ExternalOptionFunction,

TransformOptions,

The `context` option controls what `this` refers to in the top-level scope of the input modules.

In ES modules, the `this` value is `undefined` by specification. This option allows you to set a different value. For example, if your input modules expects `this` to be `window` like in non-ES module scripts, you can set `context` to `'window'`.

Note that if the input module is detected as CommonJS, Rolldown will use `exports` as the `this` value regardless of this option.

The matched IDs should be either:

1. the name of an external dependency, exactly the way it is written in the import statement. I.e. to mark `import "dependency.js"` as external, use `"dependency.js"` while to mark `import "dependency"` as external, use `"dependency"`.

1. a resolved ID (like an absolute path to a file).

When creating an `iife` or `umd` bundle, you will need to provide global variable names to replace your external imports via the [`output.globals`](/reference/OutputOptions.globals) option.

'components/Foo': 'src/components/Foo.js',

The generated chunk names will follow the [`output.chunkFileNames`](/reference/OutputOptions.chunkFileNames) option. When using the object form, the `[name]` portion of the file name will be the name of the object property while for the array form, it will be the file name of the entry point. Note that it is possible when using the object form to put entry points into different sub-folders by adding a `/` to the name.

The default logLevel of "info" means that info and warnings logs will be processed while debug logs will be swallowed, which means that they are neither passed to plugin `onLog` hooks nor the `onLog` option or printed to the console.

For true, an external import like `import "/Users/Rolldown/project/relative.js"` would be converted to a relative path. When converting an absolute path to a relative path, Rolldown does _not_ take the [`file`](/reference/OutputOptions.file) or [`dir`](/reference/OutputOptions.dir) options into account, because those may not be present e.g. for builds using the JavaScript API. Instead, it assumes that the root of the generated bundle is located at the common shared parent directory of all modules that were included in the bundle. Assuming that the common parent directory of all modules is `"/Users/Rolldown/project"`, the import from above would likely be converted to import `"./relative.js"` in the output. If the output chunk is itself nested in a subdirectory by choosing e.g. `chunkFileNames: "chunks/[name].js"`, the import would be `"../relative.js"`. As stated before, this would also apply to originally relative imports like `import "./relative.js"` that are resolved to an absolute path before they are marked as external by the [`external`](/reference/InputOptions.external) option.

One common problem is that this mechanism will also apply to imports like `import "/absolute.js'"`, resulting in unexpected relative paths in the output. For this case, `"ifRelativeSource"` checks if the original import was a relative import and only then convert it to a relative import in the output.

Choosing `false` will keep all paths as absolute paths in the output.

Note that when a relative path is directly marked as "external" using the [`external`](/reference/InputOptions.external) option, then it will be the same relative path in the output. When it is resolved first via a plugin or Rollup core and then marked as external, the above logic will apply.

This handler will not be invoked if logs are filtered out by the [`logLevel`](/reference/InputOptions.logLevel) option. I.e. by default, `"debug"` logs will be swallowed.

If the default handler is not invoked, the log will not be printed to the console. Moreover, you can change the log level by invoking the default handler with a different level. Using the additional level `"error"` will turn the log into a thrown error that has all properties of the log attached.

To migrate from `onwarn` to `onLog`, check the `level` parameter to filter for warnings:

export default {

onwarn(warning, defaultHandler) {

// Suppress certain warnings

if (warning.code === 'CIRCULAR_DEPENDENCY') return;

// Handle other warnings with default behavior

defaultHandler(warning);

},

};

export default {

onLog(level, log, defaultHandler) {

// Handle only warnings (same behavior as `onwarn`)

if (level === 'warn') {

// Suppress certain warnings

if (log.code === 'CIRCULAR_DEPENDENCY') return;

// Handle other warnings with default behavior

defaultHandler(level, log);

} else {

// Let other log levels pass through

defaultHandler(level, log);

}

},

};