Write render test

dyesub-tool/src/render.rs

@@ -63,3 +63,13 @@ pub fn render(input: &str) -> Result<String> {
     };
     Ok(document.render()?)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::render_file;
+
+    #[test]
+    fn render() {
+        render_file("layout.json", "output.svg").unwrap();
+    }
+}