From 8224f06f3e900443ee42d75cba30d4b9f5f6fd95 Mon Sep 17 00:00:00 2001 From: bott Date: Wed, 7 Nov 2018 13:53:30 +0100 Subject: Create askama_escape crate --- askama_escape/src/lib.rs | 100 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 askama_escape/src/lib.rs (limited to 'askama_escape/src/lib.rs') diff --git a/askama_escape/src/lib.rs b/askama_escape/src/lib.rs new file mode 100644 index 0000000..b967f1f --- /dev/null +++ b/askama_escape/src/lib.rs @@ -0,0 +1,100 @@ +use std::fmt::{self, Display, Formatter}; +use std::str; + +#[derive(Debug, PartialEq)] +pub enum MarkupDisplay +where + T: Display, +{ + Safe(T), + Unsafe(T), +} + +impl MarkupDisplay +where + T: Display, +{ + pub fn mark_safe(self) -> MarkupDisplay { + match self { + MarkupDisplay::Unsafe(t) => MarkupDisplay::Safe(t), + _ => self, + } + } +} + +impl From for MarkupDisplay +where + T: Display, +{ + fn from(t: T) -> MarkupDisplay { + MarkupDisplay::Unsafe(t) + } +} + +impl Display for MarkupDisplay +where + T: Display, +{ + fn fmt(&self, f: &mut Formatter) -> fmt::Result { + match *self { + MarkupDisplay::Unsafe(ref t) => escape(&t.to_string()).fmt(f), + MarkupDisplay::Safe(ref t) => t.fmt(f), + } + } +} + +pub fn escape(s: &str) -> Escaped { + Escaped { + bytes: s.as_bytes(), + } +} + +macro_rules! escaping_body { + ($start:ident, $i:ident, $fmt:ident, $_self:ident, $quote:expr) => {{ + if $start < $i { + $fmt.write_str(unsafe { str::from_utf8_unchecked(&$_self.bytes[$start..$i]) })?; + } + $fmt.write_str($quote)?; + $start = $i + 1; + }}; +} + +pub struct Escaped<'a> { + bytes: &'a [u8], +} + +impl<'a> ::std::fmt::Display for Escaped<'a> { + fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { + let mut start = 0; + for (i, b) in self.bytes.iter().enumerate() { + if b.wrapping_sub(b'"') <= FLAG { + match *b { + b'<' => escaping_body!(start, i, fmt, self, "<"), + b'>' => escaping_body!(start, i, fmt, self, ">"), + b'&' => escaping_body!(start, i, fmt, self, "&"), + b'"' => escaping_body!(start, i, fmt, self, """), + b'\'' => escaping_body!(start, i, fmt, self, "'"), + b'/' => escaping_body!(start, i, fmt, self, "/"), + _ => (), + } + } + } + fmt.write_str(unsafe { str::from_utf8_unchecked(&self.bytes[start..]) })?; + Ok(()) + } +} + +const FLAG: u8 = b'>' - b'"'; + +#[cfg(test)] +mod tests { + use super::*; + #[test] + fn test_escape() { + assert_eq!(escape("").to_string(), ""); + assert_eq!(escape("<&>").to_string(), "<&>"); + assert_eq!(escape("bla&").to_string(), "bla&"); + assert_eq!(escape("