Use BSD tar on windows

src/tar.ts

@@ -0,0 +1,27 @@
+import { exec } from "@actions/exec";
+import * as io from "@actions/io";
+
+export async function extractTar(archivePath: string, targetDirectory: string) {
+    // Create directory to extract tar into
+    await io.mkdirP(targetDirectory);
+
+    // http://man7.org/linux/man-pages/man1/tar.1.html
+    // tar [-options] <name of the tar archive> [files or directories which to add into archive]
+    const args = ["-xz", "-f", archivePath, "-C", targetDirectory];
+    await exec(`"${await getTarPath()}"`, args);
+}
+
+export async function createTar(archivePath: string, sourceDirectory: string) {
+    // http://man7.org/linux/man-pages/man1/tar.1.html
+    // tar [-options] <name of the tar archive> [files or directories which to add into archive]
+    const args = ["-cz", "-f", archivePath, "-C", sourceDirectory, "."];
+    await exec(`"${await getTarPath()}"`, args);
+}
+
+async function getTarPath(): Promise<string> {
+    // Explicitly use BSD Tar on Windows
+    const IS_WINDOWS = process.platform === "win32";
+    return IS_WINDOWS
+        ? `${process.env["windir"]}\\System32\\tar.exe`
+        : await io.which("tar", true);
+}