refactor: Use encode_png to generate PNG bytes

resvg_py.pyi

@@ -20,3 +20,4 @@ class Resvg:
 
 class RenderedImage:
     def as_array(self: RenderedImage) -> ndarray: ...
+    def as_png(self: RenderedImage) -> bytes: ...

src/lib.rs

@@ -1,6 +1,7 @@
 use numpy::ndarray::Array3;
 use numpy::{IntoPyArray, PyArray3};
 use pyo3::prelude::*;
+use pyo3::types::PyBytes;
 use resvg::tiny_skia::Pixmap;
 use usvg::{Size, Tree, TreeParsing};
 
@@ -151,11 +152,14 @@ impl RenderedImage {
         .into_pyarray(py))
     }
 
-    /// TODO(edgarrmondragon): Check if this is can be used instead of as_array.
-    fn as_png(&self) -> PyResult<Vec<u8>> {
-        self.pixmap.encode_png().map_err(|e| {
-            pyo3::exceptions::PyException::new_err(format!("Failed to encode PNG: {}", e))
-        })
+    /// Returns the rendered image as bytes in PNG format.
+    fn as_png(&self, py: Python) -> PyResult<PyObject> {
+        self.pixmap
+            .encode_png()
+            .map(|b| PyBytes::new(py, &b).into())
+            .map_err(|e| {
+                pyo3::exceptions::PyException::new_err(format!("Failed to encode PNG: {}", e))
+            })
     }
 }
 

tests/test_render.py

@@ -2,12 +2,10 @@
 
 from __future__ import annotations
 
-import io
 import typing as t
 from pathlib import Path
 
 import pytest
-from PIL import Image
 
 import resvg_py
 
@@ -27,9 +25,4 @@ def test_render(snapshot: Snapshot, svg_file: str) -> None:
 
     with Path(svg_file).open("r") as input_file:
         rendered = r.render(input_file.read(), 400, 400)
-        array = rendered.as_array()
-
-        with io.BytesIO() as png_file:
-            im = Image.fromarray(array)
-            im.save(png_file, format="PNG")
-            snapshot.assert_match(png_file.getvalue(), "output.png")
+        snapshot.assert_match(rendered.as_png(), "output.png")