Add initial blank frame (fixes #45)

src/events.rs

@@ -20,7 +20,7 @@ impl<I: Iterator<Item = Event>> Iterator for Batch<I> {
                     self.prev_data.push_str(&data);
 
                     self.next()
-                } else if !self.prev_data.is_empty() {
+                } else if !self.prev_data.is_empty() || self.prev_time == 0.0 {
                     let prev_time = self.prev_time;
                     self.prev_time = time;
                     let prev_data = std::mem::replace(&mut self.prev_data, data);
@@ -125,6 +125,18 @@ mod tests {
         assert_eq!(&stdout[0], &(0.0, "foobar".to_owned()));
         assert_eq!(&stdout[1], &(0.066, "baz".to_owned()));
         assert_eq!(&stdout[2], &(1.0, "qux".to_owned()));
+
+        let stdout = [
+            (0.0, "".to_owned()),
+            (1.0, "foo".to_owned()),
+            (2.0, "bar".to_owned()),
+        ];
+
+        let stdout = super::batch(stdout.into_iter(), 30).collect::<Vec<_>>();
+
+        assert_eq!(&stdout[0], &(0.0, "".to_owned()));
+        assert_eq!(&stdout[1], &(1.0, "foo".to_owned()));
+        assert_eq!(&stdout[2], &(2.0, "bar".to_owned()));
     }
 
     #[test]

src/lib.rs

@@ -3,7 +3,7 @@ use clap::ArgEnum;
 use log::info;
 use std::fmt::{Debug, Display};
 use std::io::{BufRead, Write};
-use std::{thread, time::Instant};
+use std::{iter, thread, time::Instant};
 mod asciicast;
 mod events;
 mod fonts;
@@ -124,6 +124,7 @@ pub fn run<I: BufRead, O: Write + Send>(input: I, output: O, config: Config) ->
         .unwrap_or(5.0);
 
     let stdout = asciicast::stdout(events);
+    let stdout = iter::once((0.0, "".to_owned())).chain(stdout);
     let stdout = events::limit_idle_time(stdout, itl);
     let stdout = events::accelerate(stdout, config.speed);
     let stdout = events::batch(stdout, config.fps_cap);