refactor: build system

packages/easy-ast/src/util.ts

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2021 StApps
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+import path from "path";
+import {readdirSync, statSync} from "fs";
+
+/**
+ * Filters only defined elements
+ */
+export function rejectNil<T>(array: Array<T | undefined | null>): T[] {
+  // eslint-disable-next-line unicorn/no-null
+  return array.filter(it => it == null) as T[];
+}
+
+/**
+ * Map elements that are not null
+ */
+export function mapNotNil<T, S>(array: readonly T[], transform: (element: T) => S | undefined | null): S[] {
+  return rejectNil(array.map(transform));
+}
+
+/**
+ * Deletes all properties with the value 'undefined', [] or {}
+ */
+// eslint-disable-next-line @typescript-eslint/ban-types
+export function cleanupEmpty<T extends object>(object: T): T {
+  const out = {} as T;
+  for (const key in object) {
+    const value = object[key];
+    // eslint-disable-next-line unicorn/no-null
+    if (value != null && (typeof value !== 'object' || Object.values(value).length > 0)) {
+      out[key] = value;
+    }
+  }
+  return out;
+}
+
+/**
+ * Expand a path to a list of all files deeply contained in it
+ */
+export function expandPathToFilesSync(sourcePath: string, accept: (fileName: string) => boolean): string[] {
+  const fullPath = path.resolve(sourcePath);
+  const directory = statSync(fullPath);
+
+  return directory.isDirectory()
+    ? readdirSync(fullPath).flatMap(fragment =>
+      expandPathToFilesSync(path.resolve(sourcePath, fragment), accept),
+    )
+    : [fullPath].filter(accept);
+}