Add some tests

src/lib.rs

@@ -2,4 +2,70 @@ mod tapemachine;
 
 #[cfg(test)]
 mod tests {
+    use crate::tapemachine::{CharTapeMachine, TapeError};
+    use crate::tapemachine::TapeResult;
+
+    const TEST_STRING: &str = "TEST STRING 1234 \\l \\n";
+
+    #[test]
+    fn it_returns_the_next_char() {
+        let mut ctm = CharTapeMachine::new(TEST_STRING.chars().collect());
+        let mut test_chars: Vec<char> = TEST_STRING.chars().collect();
+
+        let mut next = ctm.next_char().unwrap();
+        assert_eq!(next, *test_chars.get(1).unwrap());
+
+        next = ctm.next_char().unwrap();
+        assert_eq!(next, *test_chars.get(2).unwrap());
+
+        next = ctm.next_char().unwrap();
+        next = ctm.next_char().unwrap();
+        next = ctm.next_char().unwrap();
+        next = ctm.next_char().unwrap();
+        assert_eq!(next, *test_chars.get(6).unwrap());
+    }
+
+    #[test]
+    fn it_rewinds() {
+        let mut ctm = CharTapeMachine::new(TEST_STRING.chars().collect());
+        let mut test_chars: Vec<char> = TEST_STRING.chars().collect();
+
+        ctm.next_char().unwrap();
+        ctm.next_char().unwrap();
+        assert_eq!(ctm.next_char(), Some(*test_chars.get(3).unwrap()));
+
+        ctm.rewind(1);
+        assert_eq!(ctm.next_char(), Some(*test_chars.get(2).unwrap()));
+    }
+
+    #[test]
+    fn it_seeks() {
+        let mut ctm = CharTapeMachine::new(TEST_STRING.chars().collect());
+        let mut test_chars: Vec<char> = TEST_STRING.chars().collect();
+
+        assert_eq!(ctm.next_char(), Some(*test_chars.get(1).unwrap()));
+        ctm.seek_one().unwrap();
+        assert_eq!(ctm.next_char(), Some(*test_chars.get(3).unwrap()));
+        ctm.seek_one().unwrap();
+        ctm.seek_whitespace();
+        assert_eq!(ctm.next_char(), Some(*test_chars.get(6).unwrap()));
+    }
+
+    #[test]
+    fn it_asserts_chars() -> TapeResult<()> {
+        let mut ctm = CharTapeMachine::new(TEST_STRING.chars().collect());
+        ctm.assert_any(&['A', 'B', 'T'], None)?;
+        ctm.seek_one();
+        ctm.assert_char(&'E', None)?;
+        ctm.seek_one();
+        ctm.assert_sequence(&['S', 'T', ' '], None)?;
+        ctm.seek_one();
+        ctm.assert_any_sequence(&[&['C'], &['A'], &['A', 'B'], &['S', 'T', 'R']], None)?;
+
+        if let Ok(_) = ctm.assert_any_sequence(&[&['C'], &['A'], &['A', 'B'], &['S', 'T', 'R']], None) {
+            Err(TapeError::new(0))
+        } else {
+            Ok(())
+        }
+    }
 }