PreprocessResult Class — svelte Architecture

Source Code

packages/svelte/src/compiler/preprocess/index.js lines 19–99

class PreprocessResult {
	/** @type {string} */
	source;

	/** @type {string | undefined} The filename passed as-is to preprocess */
	filename;

	// sourcemap_list is sorted in reverse order from last map (index 0) to first map (index -1)
	// so we use sourcemap_list.unshift() to add new maps
	// https://github.com/jridgewell/sourcemaps/tree/main/packages/remapping#multiple-transformations-of-a-file

	/**
	 * @default []
	 * @type {Array<DecodedSourceMap | RawSourceMap>}
	 */
	sourcemap_list = [];

	/**
	 * @default []
	 * @type {string[]}
	 */
	dependencies = [];

	/**
	 * @type {string | null} last part of the filename, as used for `sources` in sourcemaps
	 */
	file_basename = /** @type {any} */ (undefined);

	/**
	 * @type {ReturnType<typeof getLocator>}
	 */
	get_location = /** @type {any} */ (undefined);

	/**
	 * @param {string} source
	 * @param {string} [filename]
	 */
	constructor(source, filename) {
		this.source = source;
		this.filename = filename;
		this.update_source({ string: source });
		// preprocess source must be relative to itself or equal null
		this.file_basename = filename == null ? null : get_basename(filename);
	}

	/**
	 * @param {SourceUpdate} opts
	 */
	update_source({ string: source, map, dependencies }) {
		if (source != null) {
			this.source = source;
			this.get_location = getLocator(source);
		}
		if (map) {
			this.sourcemap_list.unshift(map);
		}
		if (dependencies) {
			this.dependencies.push(...dependencies);
		}
	}

	/**
	 * @returns {Processed}
	 */
	to_processed() {
		// Combine all the source maps for each preprocessor function into one
		// @ts-expect-error TODO there might be a bug in hiding here
		const map = combine_sourcemaps(this.file_basename, this.sourcemap_list);
		return {
			// TODO return separated output, in future version where svelte.compile supports it:
			// style: { code: styleCode, map: styleMap },
			// script { code: scriptCode, map: scriptMap },
			// markup { code: markupCode, map: markupMap },
			code: this.source,
			dependencies: [...new Set(this.dependencies)],
			// @ts-expect-error TODO there might be a bug in hiding here
			map,
			toString: () => this.source
		};
	}
}