Add generate_file_data implementation w/testing

1 files changed, 58 insertions, 3 deletions

diff --git a/CLI/rust/src/game_of_life/generators/input.rs b/CLI/rust/src/game_of_life/generators/input.rs
index 07ab43a..e22a9fc 100644
--- a/CLI/rust/src/game_of_life/generators/input.rs
+++ b/CLI/rust/src/game_of_life/generators/input.rs
@@ -66,10 +66,65 @@ mod new {
 }
 
 /// Reads a local file and parses it, converting alpha-numerical chars into living cells
-/// in a newly generated universe simulation
+/// and generate a new universe instance in the initial state from file
 #[cfg_attr(test, mockable)]
-fn generate_file_data(_opts: Opts) -> Result<Universe, Error> {
-    unimplemented!()
+fn generate_file_data(opts: Opts) -> Result<Universe, Error> {
+    let file = std::fs::read_to_string(opts.input.clone().unwrap())?;
+    let data: Vec<Vec<bool>> = file
+        .split("\n")
+        .map(|s| {
+            s.to_string()
+                .chars()
+                .map(|c| c.is_ascii_alphanumeric())
+                .collect()
+        })
+        .collect();
+    Ok(populate(opts, data))
+}
+
+#[cfg(test)]
+mod generate_file_data {
+    use super::*;
+    use std::env;
+    use std::fs::File;
+    use std::io::Write;
+
+    fn opts(input: Option<String>) -> Opts {
+        Opts {
+            input,
+            width: 4,
+            height: 3,
+            seed: 1337,
+            live_cell: 'L',
+            dead_cell: 'D',
+            delay: 13,
+        }
+    }
+
+    #[test]
+    fn file_exists() {
+        let temp_file = env::temp_dir().join("file.txt");
+        let path = temp_file.clone().into_os_string().into_string().unwrap();
+        let mut file = File::create(temp_file).unwrap();
+        writeln!(&mut file, "--Learning Rust--").unwrap();
+        writeln!(&mut file, "--First attempt--").unwrap();
+        let opts = opts(Some(path));
+        let universe = generate_file_data(opts.clone()).unwrap();
+        assert_eq!(universe, Universe {
+            opts,
+            future: vec![vec![false; 4]; 3],
+            current: vec![
+                vec![false, false, true, true],
+                vec![false, false, true, true],
+                vec![false, false, false, false],
+            ],
+        })
+    }
+
+    #[test]
+    fn file_does_not_exist() {
+        assert!(generate_file_data(opts(Some(String::from("./not-real.txt")),)).is_err());
+    }
 }
 
 /// Reads a URL and parses it, converting alpha-numerical chars into living cells