replaced promisify with native alternatives

in the process, also got rid of obsolete workarounds for legacy versions

Author: FND

lib/util/files/finder.js

@@ -1,9 +1,5 @@
-let fs = require("fs");
+let { readdir, stat } = require("fs/promises");
 let path = require("path");
-let { promisify } = require("util");
-
-let stat = promisify(fs.stat);
-let readDir = promisify(fs.readdir);
 
 module.exports = class FileFinder {
 	constructor(directory, { skipDotfiles, filter = () => true } = {}) {
@@ -36,7 +32,7 @@ function tree(filepath, referenceDir = filepath) {
 				return [path.relative(referenceDir, filepath)];
 			}
 
-			return readDir(filepath).
+			return readdir(filepath).
 				then(entries => {
 					let res = Promise.all(entries.map(entry => {
 						return tree(path.join(filepath, entry), referenceDir);

lib/util/files/index.js

@@ -1,15 +1,12 @@
 "use strict";
 
-let { abort, repr } = require("../");
-let fs = require("fs");
+let { writeFile } = require("fs/promises");
+let { mkdirSync } = require("fs");
 let path = require("path");
-let { promisify } = require("util");
 
 let KNOWN = {}; // avoids redundant `mkdirp` invocations
 let LOCKS = {};
 
-let writeFile = promisify(fs.writeFile);
-
 // avoids concurrent write operations and creates target directory if necessary
 module.exports = function createFile(filepath, contents) {
 	let lock = LOCKS[filepath];
@@ -21,7 +18,7 @@ module.exports = function createFile(filepath, contents) {
 	if(!KNOWN[filepath]) {
 		KNOWN[filepath] = true;
 		// NB: `sync` avoids race condition for subsequent operations
-		mkdirpSync(path.dirname(filepath));
+		mkdirSync(path.dirname(filepath), { recursive: true });
 	}
 
 	let prom = writeFile(filepath, contents);
@@ -30,13 +27,3 @@ module.exports = function createFile(filepath, contents) {
 		delete LOCKS[filepath];
 	});
 };
-
-function mkdirpSync(directory) {
-	try {
-		// NB: `recursive` option was introduced in Node v10.12.0
-		fs.mkdirSync(directory, { recursive: true });
-	} catch(err) {
-		abort(`ERROR: auto-creating ${repr(directory)} requires ` +
-				"Node v10.12.0 or above");
-	}
-}

lib/util/index.js

@@ -2,10 +2,8 @@
 
 let path = require("path");
 let crypto = require("crypto");
-let { promisify } = require("util");
 
 exports.abort = abort;
-exports.promisify = promisify; // deprecated
 exports.repr = repr;
 
 // reports success or failure for a given file path (typically regarding