feat: update deno-commons-mod.ts

libraries/deno-commons-mod.ts

@@ -3,6 +3,7 @@
 
 import { assert } from "jsr:@std/assert/assert";
 import { assertEquals } from "jsr:@std/assert";
+import { dirname } from "https://deno.land/std@0.208.0/path/mod.ts";
 
 export async function sleep(timeoutMillis: number): Promise<void> {
     await new Promise(resolve => setTimeout(resolve, timeoutMillis))
@@ -235,6 +236,55 @@ class Logger {
 
 export const log = new Logger();
 
+export function getHomeDir(): string | null {
+    if (Deno.build.os === "windows") {
+        return Deno.env.get("USERPROFILE") || Deno.env.get("HOMEDRIVE") + Deno.env.get("HOMEPATH") || null;
+    }
+    return Deno.env.get("HOME") || null;
+}
+
+export function resolveFilename(filename: string): string {
+    if (filename.startsWith("~/")) {
+        return getHomeDir() + filename.substring(1);
+    }
+    return filename;
+}
+
+export async function existsPath(path: string): Promise<boolean> {
+    try {
+        const stat = await Deno.stat(path);
+        return stat != null;
+    } catch {
+        return false;
+    }
+}
+
+export async function readFileToString(filename: string): Promise<string | null> {
+    try {
+        return await Deno.readTextFile(resolveFilename(filename));
+    } catch (e) {
+        if (e instanceof Error && e.name == 'NotFound') {
+            return null;
+        }
+        throw e;
+    }
+}
+
+export async function writeStringToFile(filename: string, data: string | null): Promise<void> {
+    const newFilename = resolveFilename(filename);
+    if (data == null) {
+        if (await existsPath(newFilename)) {
+            await Deno.remove(newFilename)
+        }
+    } else {
+        const parentDirname = dirname(newFilename);
+        if (!await existsPath(parentDirname)) {
+            await Deno.mkdir(parentDirname, {recursive: true});
+        }
+        await Deno.writeTextFile(newFilename, data);
+    }
+}
+
 Deno.test("isOn", () => {
     assertEquals(false, isOn(undefined));
     assertEquals(false, isOn(""));