Add some single token tests for the tokens we have

lexer/tests/single_tokens.rs

@@ -0,0 +1,30 @@
+/* lexer/tests/single_token.rs
+ * Eryn Wells <eryn@erynwells.me>
+ */
+
+//! Tests that single tokens are matches by the lexer.
+
+extern crate sibillexer;
+
+use sibillexer::{Lexer, Token};
+
+#[test]
+fn lexer_finds_left_paren() {
+    let mut lex = Lexer::new("(".chars());
+    assert_eq!(lex.next(), Some(Ok(Token::LeftParen)));
+    assert_eq!(lex.next(), None);
+}
+
+#[test]
+fn lexer_finds_right_paren() {
+    let mut lex = Lexer::new(")".chars());
+    assert_eq!(lex.next(), Some(Ok(Token::RightParen)));
+    assert_eq!(lex.next(), None);
+}
+
+#[test]
+fn lexer_finds_id() {
+    let mut lex = Lexer::new("abc".chars());
+    assert_eq!(lex.next(), Some(Ok(Token::Id("abc".to_string()))));
+    assert_eq!(lex.next(), None);
+}