firefish/packages/client/vite.json5.ts

// Original: https://github.com/rollup/plugins/tree/8835dd2aed92f408d7dc72d7cc25a9728e16face/packages/json

import JSON5 from "json5";
import { Plugin } from "rollup";
import { createFilter, dataToEsm } from "@rollup/pluginutils";
import { RollupJsonOptions } from "@rollup/plugin-json";

interface Json5SyntaxError extends SyntaxError {
	lineNumber: number;
	columnNumber: number;
}

export default function json5(options: RollupJsonOptions = {}): Plugin {
	const filter = createFilter(options.include, options.exclude);
	const indent = "indent" in options ? options.indent : "\t";

	return {
		name: "json5",

		transform(json, id) {
			if (id.slice(-6) !== ".json5" || !filter(id)) return null;

			try {
				const parsed = JSON5.parse(json);
				return {
					code: dataToEsm(parsed, {
						preferConst: options.preferConst,
						compact: options.compact,
						namedExports: options.namedExports,
						indent,
					}),
					map: { mappings: "" },
				};
			} catch (err) {
				if (!(err instanceof SyntaxError)) {
					throw err;
				}
				const message = "Could not parse JSON5 file";
				const { lineNumber, columnNumber } = err as Json5SyntaxError;
				this.warn({
					message,
					id,
					loc: { line: lineNumber, column: columnNumber },
				});
				return null;
			}
		},
	};
}