Add some encoder tests

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Author: elmarco

tests/test_misc.rs

@@ -1,6 +1,6 @@
 use qoi::{
     consts::{QOI_OP_RGB, QOI_OP_RUN},
-    decode_to_vec, Channels, ColorSpace, Header, Result,
+    decode_to_vec, Channels, ColorSpace, Error, Header, RawChannels, Result,
 };
 
 #[test]
@@ -28,3 +28,76 @@ fn test_big_endian() {
     // so we can see it in the CI logs
     assert_eq!(u16::to_be_bytes(1), [0, 1]);
 }
+
+#[test]
+fn test_new_encoder() {
+    let arr3 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]; // 2 * 2 * 3
+    let arr4 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]; // 2 * 2 * 4
+
+    let enc = qoi::Encoder::new(&arr3, 2, 2).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgb);
+
+    let enc = qoi::Encoder::new(&arr4, 2, 2).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgba);
+
+    assert!(matches!(
+        qoi::Encoder::new(&arr3, 3, 3),
+        Err(Error::InvalidImageLength { size: 12, width: 3, height: 3 })
+    ));
+
+    assert!(matches!(qoi::Encoder::new(&arr3, 1, 1), Err(Error::InvalidChannels { channels: 12 })));
+
+    let enc = qoi::Encoder::new_raw(&arr3, 2, 2, 2 * 3, RawChannels::Bgr).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgb);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, [2, 1, 0, 5, 4, 3, 8, 7, 6, 11, 10, 9]);
+
+    let enc = qoi::Encoder::new_raw(&arr4, 2, 2, 2 * 4, RawChannels::Rgba).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgba);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, arr4);
+
+    let enc = qoi::Encoder::new_raw(&arr4, 2, 2, 2 * 4, RawChannels::Bgra).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgba);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, [2, 1, 0, 3, 6, 5, 4, 7, 10, 9, 8, 11, 14, 13, 12, 15]);
+
+    let enc = qoi::Encoder::new_raw(&arr4, 2, 2, 2 * 4, RawChannels::Rgbx).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgb);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, [0, 1, 2, 4, 5, 6, 8, 9, 10, 12, 13, 14]);
+
+    let enc = qoi::Encoder::new_raw(&arr4, 2, 2, 2 * 4, RawChannels::Xrgb).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgb);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, [1, 2, 3, 5, 6, 7, 9, 10, 11, 13, 14, 15]);
+
+    let enc = qoi::Encoder::new_raw(&arr4, 2, 2, 2 * 4, RawChannels::Bgra).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgba);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, [2, 1, 0, 3, 6, 5, 4, 7, 10, 9, 8, 11, 14, 13, 12, 15]);
+
+    let enc = qoi::Encoder::new_raw(&arr4, 2, 2, 2 * 4, RawChannels::Abgr).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgba);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, [3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8, 15, 14, 13, 12]);
+
+    let enc = qoi::Encoder::new_raw(&arr4, 2, 2, 2 * 4, RawChannels::Bgrx).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgb);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, [2, 1, 0, 6, 5, 4, 10, 9, 8, 14, 13, 12]);
+
+    let enc = qoi::Encoder::new_raw(&arr4, 2, 2, 2 * 4, RawChannels::Xbgr).unwrap();
+    assert_eq!(enc.channels(), Channels::Rgb);
+    let qoi = enc.encode_to_vec().unwrap();
+    let (_header, res) = decode_to_vec(qoi).unwrap();
+    assert_eq!(res, [3, 2, 1, 7, 6, 5, 11, 10, 9, 15, 14, 13]);
+}