//! Encoding of portable pixmap Images

pub use self::encoder::PPMEncoder as PPMEncoder;
pub use self::decoder::PPMDecoder as PPMDecoder;

mod encoder;
mod decoder;

#[cfg(test)]
mod test {
    use color::ColorType;
    use image::{ImageDecoder, DecodingResult};

    #[test]
    fn test_roundtrip_ppm() {
        // 3x3 image that tries all the 0/255 RGB combinations
        let buf: [u8; 27] = [
              0,   0,   0,
              0,   0, 255,
              0, 255,   0,
              0, 255, 255,
            255,   0,   0,
            255,   0, 255,
            255, 255,   0,
            255, 255, 255,
            255, 255, 255,
        ];

        let mut stream = Vec::<u8>::new();
        {
            let mut encoder = super::PPMEncoder::new(&mut stream);
            match encoder.encode(&buf, 3, 3, ColorType::RGB(8)) {
                Ok(_) => {},
                Err(_) => panic!("PPM encoder failed"),
            };
        }

        let mut decoder = match super::PPMDecoder::new(&stream[..]) {
            Ok(img) => img,
            Err(e) => panic!("PPM decoder failed with {}", e),
        };
        match decoder.read_image() {
            Ok(DecodingResult::U8(vec)) => {
                assert_eq!(&buf[..], &vec[..]);
            },
            _ => {
                panic!("PPM: Got a strange image result");
            }
        }
    }
}

//! Encoding of portable pixmap Images

pub use self::encoder::PPMEncoder as PPMEncoder;
pub use self::decoder::PPMDecoder as PPMDecoder;

mod encoder;
mod decoder;

--- 
+++ 
@@ -5,3 +5,47 @@
 
 mod encoder;
 mod decoder;
+
+#[cfg(test)]
+mod test {
+    use color::ColorType;
+    use image::{ImageDecoder, DecodingResult};
+
+    #[test]
+    fn test_roundtrip_ppm() {
+        // 3x3 image that tries all the 0/255 RGB combinations
+        let buf: [u8; 27] = [
+              0,   0,   0,
+              0,   0, 255,
+              0, 255,   0,
+              0, 255, 255,
+            255,   0,   0,
+            255,   0, 255,
+            255, 255,   0,
+            255, 255, 255,
+            255, 255, 255,
+        ];
+
+        let mut stream = Vec::<u8>::new();
+        {
+            let mut encoder = super::PPMEncoder::new(&mut stream);
+            match encoder.encode(&buf, 3, 3, ColorType::RGB(8)) {
+                Ok(_) => {},
+                Err(_) => panic!("PPM encoder failed"),
+            };
+        }
+
+        let mut decoder = match super::PPMDecoder::new(&stream[..]) {
+            Ok(img) => img,
+            Err(e) => panic!("PPM decoder failed with {}", e),
+        };
+        match decoder.read_image() {
+            Ok(DecodingResult::U8(vec)) => {
+                assert_eq!(&buf[..], &vec[..]);
+            },
+            _ => {
+                panic!("PPM: Got a strange image result");
+            }
+        }
+    }
+}
Add a roundtrip test to PPM
