Use BSD tar on windows (#126)

* Use BSD tar on windows

* Linting

* Fallback to which tar if no system tar

* Fix formatting

* Bump prettier and typescript

src/tar.ts

@@ -0,0 +1,47 @@
+import { exec } from "@actions/exec";
+import * as io from "@actions/io";
+import { existsSync } from "fs";
+
+async function getTarPath(): Promise<string> {
+    // Explicitly use BSD Tar on Windows
+    const IS_WINDOWS = process.platform === "win32";
+    if (IS_WINDOWS) {
+        const systemTar = `${process.env["windir"]}\\System32\\tar.exe`;
+        if (existsSync(systemTar)) {
+            return systemTar;
+        }
+    }
+    return await io.which("tar", true);
+}
+
+async function execTar(args: string[]): Promise<void> {
+    try {
+        await exec(`"${await getTarPath()}"`, args);
+    } catch (error) {
+        const IS_WINDOWS = process.platform === "win32";
+        if (IS_WINDOWS) {
+            throw new Error(
+                `Tar failed with error: ${error?.message}. Ensure BSD tar is installed and on the PATH.`
+            );
+        }
+        throw new Error(`Tar failed with error: ${error?.message}`);
+    }
+}
+
+export async function extractTar(
+    archivePath: string,
+    targetDirectory: string
+): Promise<void> {
+    // Create directory to extract tar into
+    await io.mkdirP(targetDirectory);
+    const args = ["-xz", "-f", archivePath, "-C", targetDirectory];
+    await execTar(args);
+}
+
+export async function createTar(
+    archivePath: string,
+    sourceDirectory: string
+): Promise<void> {
+    const args = ["-cz", "-f", archivePath, "-C", sourceDirectory, "."];
+    await execTar(args);
+}