Move Rust exercises in a subdirectory

1 files changed, 192 insertions, 0 deletions

diff --git a/rust/paasio/tests/paasio.rs b/rust/paasio/tests/paasio.rs
new file mode 100644
index 0000000..6b44199
--- /dev/null
+++ b/rust/paasio/tests/paasio.rs
@@ -0,0 +1,192 @@
+/// test a few read scenarios
+macro_rules! test_read {
+    ($(#[$attr:meta])* $modname:ident ($input:expr, $len:expr)) => {
+        mod $modname {
+            use std::io::{Read, BufReader};
+            use paasio::*;
+
+            const CHUNK_SIZE: usize = 2;
+
+            $(#[$attr])*
+            #[test]
+            fn test_read_passthrough() {
+                let data = $input;
+                let size = $len(&data);
+                let mut reader = ReadStats::new(data);
+
+                let mut buffer = Vec::with_capacity(size);
+                let qty_read = reader.read_to_end(&mut buffer);
+
+                assert!(qty_read.is_ok());
+                assert_eq!(size, qty_read.unwrap());
+                assert_eq!(size, buffer.len());
+                // 2: first to read all the data, second to check that
+                // there wasn't any more pending data which simply didn't
+                // fit into the existing buffer
+                assert_eq!(2, reader.reads());
+                assert_eq!(size, reader.bytes_through());
+            }
+
+            $(#[$attr])*
+            #[test]
+            fn test_read_chunks() {
+                let data = $input;
+                let size = $len(&data);
+                let mut reader = ReadStats::new(data);
+
+                let mut buffer = [0_u8; CHUNK_SIZE];
+                let mut chunks_read = 0;
+                while reader.read(&mut buffer[..]).unwrap_or_else(|_| panic!("read failed at chunk {}", chunks_read+1)) > 0 {
+                    chunks_read += 1;
+                }
+
+                assert_eq!(size / CHUNK_SIZE + std::cmp::min(1, size % CHUNK_SIZE), chunks_read);
+                // we read once more than the number of chunks, because the final
+                // read returns 0 new bytes
+                assert_eq!(1+chunks_read, reader.reads());
+                assert_eq!(size, reader.bytes_through());
+            }
+
+            $(#[$attr])*
+            #[test]
+            fn test_read_buffered_chunks() {
+                let data = $input;
+                let size = $len(&data);
+                let mut reader = BufReader::new(ReadStats::new(data));
+
+                let mut buffer = [0_u8; CHUNK_SIZE];
+                let mut chunks_read = 0;
+                while reader.read(&mut buffer[..]).unwrap_or_else(|_| panic!("read failed at chunk {}", chunks_read+1)) > 0 {
+                    chunks_read += 1;
+                }
+
+                assert_eq!(size / CHUNK_SIZE + std::cmp::min(1, size % CHUNK_SIZE), chunks_read);
+                // the BufReader should smooth out the reads, collecting into
+                // a buffer and performing only two read operations:
+                // the first collects everything into the buffer,
+                // and the second ensures that no data remains
+                assert_eq!(2, reader.get_ref().reads());
+                assert_eq!(size, reader.get_ref().bytes_through());
+            }
+        }
+    };
+}
+
+/// test a few write scenarios
+macro_rules! test_write {
+    ($(#[$attr:meta])* $modname:ident ($input:expr, $len:expr)) => {
+        mod $modname {
+            use std::io::{self, Write, BufWriter};
+            use paasio::*;
+
+            const CHUNK_SIZE: usize = 2;
+            $(#[$attr])*
+            #[test]
+            fn test_write_passthrough() {
+                let data = $input;
+                let size = $len(&data);
+                let mut writer = WriteStats::new(Vec::with_capacity(size));
+                let written = writer.write(data);
+                assert!(written.is_ok());
+                assert_eq!(size, written.unwrap());
+                assert_eq!(size, writer.bytes_through());
+                assert_eq!(1, writer.writes());
+                assert_eq!(data, writer.get_ref().as_slice());
+            }
+
+            $(#[$attr])*
+            #[test]
+            fn test_sink_oneshot() {
+                let data = $input;
+                let size = $len(&data);
+                let mut writer = WriteStats::new(io::sink());
+                let written = writer.write(data);
+                assert!(written.is_ok());
+                assert_eq!(size, written.unwrap());
+                assert_eq!(size, writer.bytes_through());
+                assert_eq!(1, writer.writes());
+            }
+
+            $(#[$attr])*
+            #[test]
+            fn test_sink_windowed() {
+                let data = $input;
+                let size = $len(&data);
+                let mut writer = WriteStats::new(io::sink());
+
+                let mut chunk_count = 0;
+                for chunk in data.chunks(CHUNK_SIZE) {
+                    chunk_count += 1;
+                    let written = writer.write(chunk);
+                    assert!(written.is_ok());
+                    assert_eq!(CHUNK_SIZE, written.unwrap());
+                }
+                assert_eq!(size, writer.bytes_through());
+                assert_eq!(chunk_count, writer.writes());
+            }
+
+            $(#[$attr])*
+            #[test]
+            fn test_sink_buffered_windowed() {
+                let data = $input;
+                let size = $len(&data);
+                let mut writer = BufWriter::new(WriteStats::new(io::sink()));
+
+                for chunk in data.chunks(CHUNK_SIZE) {
+                    let written = writer.write(chunk);
+                    assert!(written.is_ok());
+                    assert_eq!(CHUNK_SIZE, written.unwrap());
+                }
+                // at this point, nothing should have yet been passed through to
+                // our writer
+                assert_eq!(0, writer.get_ref().bytes_through());
+                assert_eq!(0, writer.get_ref().writes());
+
+                // after flushing, everything should pass through in one go
+                assert!(writer.flush().is_ok());
+                assert_eq!(size, writer.get_ref().bytes_through());
+                assert_eq!(1, writer.get_ref().writes());
+            }
+        }
+    };
+}
+
+#[test]
+fn test_create_stats() {
+    let mut data: Vec<u8> = Vec::new();
+    let _ = paasio::ReadStats::new(data.as_slice());
+    let _ = paasio::WriteStats::new(data.as_mut_slice());
+}
+
+test_read!(read_string (
+    "Twas brillig, and the slithy toves/Did gyre and gimble in the wabe:/All mimsy were the borogoves,/And the mome raths outgrabe.".as_bytes(),
+    |d: &[u8]| d.len()
+));
+test_write!(write_string (
+    "Beware the Jabberwock, my son!/The jaws that bite, the claws that catch!/Beware the Jubjub bird, and shun/The frumious Bandersnatch!".as_bytes(),
+    |d: &[u8]| d.len()
+));
+
+test_read!(read_byte_literal(
+    &[1_u8, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144][..],
+    |d: &[u8]| d.len()
+));
+test_write!(write_byte_literal(
+    &[2_u8, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61,][..],
+    |d: &[u8]| d.len()
+));
+
+test_read!(read_file(
+    ::std::fs::File::open("README.md").expect("readme must be present"),
+    |f: &::std::fs::File| f.metadata().expect("metadata must be present").len() as usize
+));
+
+#[test]
+fn read_stats_by_ref_returns_wrapped_reader() {
+    use paasio::ReadStats;
+
+    let input =
+        "Why, sometimes I've believed as many as six impossible things before breakfast".as_bytes();
+    let reader = ReadStats::new(input);
+    assert_eq!(reader.get_ref(), &input);
+}