VecDeque offers improved performance beyond a plain Vec for common
scrolling situations (full screen scroll). Additionally, VecDeque is
necessary for performant scrollback since recycling old rows for a Vec
would be expensive (push/pop front would shift entire vec).
This uses the rustc-test crate, a copy of the standard test crate, to
dynamically create tests for each reference test. No need to remember to
update the macro, just add the directory to ref!
ANSI escape sequences like `\x1b[48;5;10m` were not supported until now.
Specifically, the second attribute, 5, says that the following attribute
is a color index.
The ref tests were updated since `enum Color` variants changed.
The terminal now has a `renderable_cells()` function that returns a
`RenderableCellIter` iterator. This allows reuse of the cell selection
code by multiple renderers, makes it testable, and makes it
independently optimizable.
The render API now takes an `Iterator<Item=IndexedCell>` to support both
the new renderable cells iterator and the `render_string()` method which
generates its own iterator.
The `vim_large_window_scoll` ref test was added here because it provides
a nice large and busy grid to benchmark the cell selection with.
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`.
