Add support for recording/running ref tests

Ref tests use a recording of the terminal protocol and a serialization
of the grid state to check that the parsing and action handling systems
produce the correct result. Ref tests may be recorded by running
alacritty with `--ref-test` and closing the terminal by using the window
"X" button. At that point, the recording is fully written to disk, and a
serialization of important state is recorded. Those files should be
moved to an appropriate folder in the `tests/ref/` tree, and the
`ref_test!` macro invocation should be updated accordingly.

A couple of changes were necessary to make this work:

* Ref tests shouldn't create a pty; the pty was refactored out of the
  `Term` type.
* Repeatable lines/cols were needed; on startup, the terminal is resized
* by default to 80x24 though that may be changed by passing
  `--dimensions w h`.
* Calculating window size based on desired rows/columns and font metrics
  required making load_font callable multiple times.
* Refactor types into library crate so they may be imported in an
  integration test.
* A whole bunch of types needed symmetric serialization and
  deserialization. Mostly this was just adding derives, but the custom
  deserialization of Rgb had to change to a deserialize_with function.

This initially adds one ref test as a sanity check, and more will be
added in subsequent commits. This initial ref tests just starts the
terminal and runs `ll`.

1 files changed, 78 insertions, 0 deletions

diff --git a/tests/ref.rs b/tests/ref.rs
new file mode 100644
index 00000000..029bf91e
--- /dev/null
+++ b/tests/ref.rs
@@ -0,0 +1,78 @@
+extern crate alacritty;
+extern crate serde_json;
+
+/// ref tests
+mod reference {
+    use std::fs::File;
+    use std::io::Read;
+    use std::path::Path;
+
+    use serde_json as json;
+
+    use alacritty::Grid;
+    use alacritty::Term;
+    use alacritty::term::Cell;
+    use alacritty::term::SizeInfo;
+    use alacritty::ansi;
+
+    macro_rules! ref_file {
+        ($ref_name:ident, $file:expr) => {
+            concat!(
+                env!("CARGO_MANIFEST_DIR"),
+                "/tests/ref/", stringify!($ref_name), "/", $file
+            )
+        }
+    }
+
+    fn read_u8<P>(path: P) -> Vec<u8>
+        where P: AsRef<Path>
+    {
+        let mut res = Vec::new();
+        File::open(path.as_ref()).unwrap()
+            .read_to_end(&mut res).unwrap();
+
+        res
+    }
+
+    fn read_string<P>(path: P) -> String
+        where P: AsRef<Path>
+    {
+        let mut res = String::new();
+        File::open(path.as_ref()).unwrap()
+            .read_to_string(&mut res).unwrap();
+
+        res
+    }
+
+    macro_rules! ref_test {
+        ($name:ident) => {
+            #[test]
+            fn $name() {
+                let recording = read_u8(ref_file!($name, "alacritty.recording"));
+                let serialized_size = read_string(ref_file!($name, "size.json"));
+                let serialized_grid = read_string(ref_file!($name, "grid.json"));
+
+                let size: SizeInfo = json::from_str(&serialized_size[..]).unwrap();
+                let grid: Grid<Cell> = json::from_str(&serialized_grid[..]).unwrap();
+
+                let mut terminal = Term::new(size);
+                let mut parser = ansi::Processor::new();
+
+                for byte in recording {
+                    parser.advance(&mut terminal, byte);
+                }
+
+                assert_eq!(grid, *terminal.grid());
+            }
+        };
+
+        ($( $name:ident ),*) => {
+            $(
+                ref_test! { $name }
+            ),*
+        }
+    }
+
+    // Ref tests!
+    ref_test! { ll }
+}