From 063ca377da8cedc7c2394a5762904d3ec37b3dd2 Mon Sep 17 00:00:00 2001
From: Caleb Jones <code@calebjones.net>
Date: Wed, 14 Dec 2016 01:56:48 -0500
Subject: [PATCH] Add tests for parsing number and symbol

Fix a bug in number parsing where it would accept invalid numbers like
123q.
---
 src/lib.rs | 43 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 38 insertions(+), 5 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index b8982f4..bd8aa71 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -74,12 +74,22 @@ named!(string<&str, Atom>,
 
 named!(symbol<&str, Atom>,
   do_parse!(
-    peek!(not!(digit)) >>
+    opt!(multispace) >>
+    peek!(valid_ident_prefix) >>
     name: take_while1_s!(valid_ident_char) >>
     (Atom::Sym(name.into()))
   )
 );
 
+fn valid_ident_prefix(ident: &str) -> IResult<&str, ()>  {
+    match ident.chars().next() {
+        Some(c) if !c.is_digit(10) && valid_ident_char(c) =>
+            IResult::Done(&ident[1..], ()),
+        None => IResult::Incomplete(nom::Needed::Unknown),
+        _ => IResult::Error(nom::ErrorKind::Custom(0)),
+    }
+}
+
 fn valid_ident_char(c: char) -> bool {
     !c.is_whitespace() && c != '"' && c != '(' && c != ')'
 }
@@ -88,13 +98,36 @@ named!(number<&str, Atom>,
   do_parse!(
     opt!(multispace) >>
     integral: digit >>
+    peek!(not!(valid_ident_prefix)) >>
     (Atom::Int(integral.chars().fold(0, |i, c| i * 10 + c as i64 - '0' as i64)))
   )
 );
 
 #[cfg(test)]
-mod tests {
-    #[test]
-    fn it_works() {
-    }
+#[test]
+fn test_parse_number() {
+    assert_eq!(number("0"), IResult::Done("", Atom::Int(0)));
+    assert_eq!(number("123"), IResult::Done("", Atom::Int(123)));
+    assert_eq!(number("0123456789"), IResult::Done("", Atom::Int(123456789)));
+    assert_eq!(number("    42"), IResult::Done("", Atom::Int(42)));
+
+    assert!(number(" 42a").is_err());
+    assert_eq!(number("13()"), IResult::Done("()", Atom::Int(13)));
+
+    assert!(number("abc").is_err());
+    assert!(number("()").is_err());
+    assert!(number("").is_incomplete());
+}
+
+#[cfg(test)]
+#[test]
+fn test_parse_ident() {
+    assert_eq!(symbol("+"), IResult::Done("", Atom::Sym("+".into())));
+    assert_eq!(symbol(" nil?"), IResult::Done("", Atom::Sym("nil?".into())));
+    assert_eq!(symbol(" ->socket"), IResult::Done("", Atom::Sym("->socket".into())));
+    assert_eq!(symbol("fib("), IResult::Done("(", Atom::Sym("fib".into())));
+
+    assert!(symbol("0").is_err());
+    assert!(symbol("()").is_err());
+    assert!(symbol("").is_incomplete());
 }
-- 
2.47.0