refactor: move things to core, imports not fixed yet

src/core/module-loading/readFile.ts

@@ -0,0 +1,64 @@
+import { readdirSync, statSync } from 'fs';
+import { join } from 'path';
+import { type Observable, from, mergeMap } from 'rxjs';
+import { SernError } from '../structures/errors';
+import { type Result, Err, Ok } from 'ts-results-es';
+import { ImportPayload } from '../../types/handler';
+import { pathToFileURL } from 'node:url';
+
+// Courtesy @Townsy45
+function readPath(dir: string, arrayOfFiles: string[] = []): string[] {
+    try {
+        const files = readdirSync(dir);
+        for (const file of files) {
+            if (statSync(dir + '/' + file).isDirectory()) readPath(dir + '/' + file, arrayOfFiles);
+            else arrayOfFiles.push(join(dir, '/', file));
+        }
+    } catch (err) {
+        throw err;
+    }
+
+    return arrayOfFiles;
+}
+export const fmtFileName = (n: string) => n.substring(0, n.length - 3);
+// export const isLazy = (n: string) => n.indexOf(".lazy.", n.length-9) !== -1;
+
+export async function defaultModuleLoader<T>(
+    absPath: string,
+): Promise<Result<ImportPayload<T>, SernError>> {
+    // prettier-ignore
+    let module: T | undefined
+    /// #if MODE === 'esm'
+    = (await import(pathToFileURL(absPath).toString())).default
+    /// #elif MODE === 'cjs'
+    = require(absPath).default; // eslint-disable-line
+    /// #endif
+    if (module === undefined) {
+        return Err(SernError.UndefinedModule);
+    }
+    try {
+        module = new (module as unknown as new () => T)();
+    } catch {}
+    return Ok({ module, absPath });
+}
+
+/**
+ * a directory string is converted into a stream of modules.
+ * starts the stream of modules that sern needs to process on init
+ * @returns {Observable<{ mod: Module; absPath: string; }[]>} data from command files
+ * @param commandDir
+ */
+export function buildModuleStream<T>(
+    commandDir: string,
+): Observable<Result<ImportPayload<T>, SernError>> {
+    const commands = getCommands(commandDir);
+    return from(commands).pipe(mergeMap(defaultModuleLoader<T>));
+}
+
+export function fullPathFrom(dir: string) {
+    return join(process.cwd(), dir);
+}
+
+export function getCommands(dir: string): string[] {
+    return readPath(fullPathFrom(dir));
+}