dependency-cruiser/src/extract/acorn/parse.mjs

Validate and visualize dependencies. With your rules. JavaScript, TypeScript, CoffeeScript. ES6, CommonJS, AMD.

import { readFileSync } from "node:fs";
import { Parser as acornParser, parse as acornParse } from "acorn";
import { parse as acornLooseParse } from "acorn-loose";
import acornJsx from "acorn-jsx";
import transpile from "../transpile/index.mjs";
import getExtension from "#utl/get-extension.mjs";

/** @type acorn.Options */
const ACORN_OPTIONS = {
	sourceType: "module",
	ecmaVersion: 11,
};
const TSCONFIG_CONSTANTS = {
	PRESERVE_JSX: 1,
};
/**@type {Map<string, acorn.Node>} */
const CACHE = new Map();

const acornJsxParser = acornParser.extend(acornJsx());

function needsJSXTreatment(pFileRecord, pTranspileOptions) {
	return (
		pFileRecord.extension === ".jsx" ||
		(pFileRecord.extension === ".tsx" &&
			pTranspileOptions?.tsConfig?.options?.jsx ===
				TSCONFIG_CONSTANTS.PRESERVE_JSX)
	);
}

export function getASTFromSource(pFileRecord, pTranspileOptions) {
	const lJavaScriptSource = transpile(pFileRecord, pTranspileOptions);

	try {
		if (needsJSXTreatment(pFileRecord, pTranspileOptions)) {
			return acornJsxParser.parse(lJavaScriptSource, {
				...ACORN_OPTIONS,
				// @ts-expect-error because ...
				// acornJsxParser.parse takes an acorn.Options which doesn't include
				// allowNamespacedObjects. acornJsx.Options doesn't include sourceType
				// though, so a bit rock < this code > hard place hence ignore it
				// type wise
				allowNamespacedObjects: true,
			});
		}

		// ecmaVersion 11 necessary for acorn to understand dynamic imports
		// explicitly passing ecmaVersion is recommended from acorn 8
		return acornParse(lJavaScriptSource, ACORN_OPTIONS);
	} catch (pError) {
		return acornLooseParse(lJavaScriptSource, ACORN_OPTIONS);
	}
}

/**
 * Returns the abstract syntax tree of the module identified by the passed
 * file name. It obtains this by (1) transpiling the contents of the file
 * into javascript (if necessary) (2) parsing it.
 *
 * If parsing fails we fall back to acorn's 'loose' parser
 *
 * Subsequent calls for the same file name will return the result from a cache.
 *
 * @param {string} pFileName - the name of the file to compile
 * @param {any} pTranspileOptions - options for the transpiler(s) - typically a tsconfig or a babel config
 * @return {acorn.Node} - a (javascript) AST
 */
export function getASTCached(pFileName, pTranspileOptions) {
	// taking the transpile options into account of the cache key seems like
	// a good idea, but a.t.m. isn't necessary. Easy to add later if needed.
	if (CACHE.has(pFileName)) {
		return CACHE.get(pFileName);
	}
	const lAST = getASTFromSource(
		{
			source: readFileSync(pFileName, "utf8"),
			extension: getExtension(pFileName),
			filename: pFileName,
		},
		pTranspileOptions,
	);
	CACHE.set(pFileName, lAST);
	return lAST;
}

export function clearCache() {
	CACHE.clear();
}