enhance: add builtin:download-artifact (#1344)

Co-authored-by: bircni <[email protected]>

internal/pkg/action/action.go

@@ -103,6 +103,13 @@ func (c *Context) Windows() bool {
 	return c.Host() && runtime.GOOS == "windows"
 }
 
+func (c *Context) Join(elem ...string) string {
+	if c.Windows() {
+		return filepath.Join(elem...)
+	}
+	return path.Join(elem...)
+}
+
 func (c *Context) Dir(p string) string {
 	if c.Windows() {
 		return filepath.Dir(p)
@@ -117,6 +124,13 @@ func (c *Context) Base(p string) string {
 	return path.Base(p)
 }
 
+func (c *Context) Resolve(p string) string {
+	if c.Windows() && filepath.IsAbs(p) || !c.Windows() && path.IsAbs(p) {
+		return c.Join(p)
+	}
+	return c.Join(c.Workspace, p)
+}
+
 // Home is the job user's home directory, what os.homedir() returns to a JavaScript action.
 func (c *Context) Home(ctx context.Context) (string, error) {
 	if home := c.Env["HOME"]; home != "" {