fix: escape "${"

nix-js/src/value.rs

@@ -35,7 +35,7 @@ impl Display for Symbol {
         if self.normal() {
             write!(f, "{}", self.0)
         } else {
-            write!(f, r#""{}""#, self.0)
+            write!(f, "{}", escape_quote_string(&self.0))
         }
     }
 }
@@ -221,6 +221,25 @@ pub enum Value {
     Repeated,
 }
 
+fn escape_quote_string(s: &str) -> String {
+    let mut ret = String::with_capacity(s.len() + 2);
+    ret.push('"');
+    let mut iter = s.chars().peekable();
+    while let Some(c) = iter.next() {
+        match c {
+            '\\' => ret.push_str("\\\\"),
+            '"' => ret.push_str("\\\""),
+            '\n' => ret.push_str("\\n"),
+            '\r' => ret.push_str("\\r"),
+            '\t' => ret.push_str("\\t"),
+            '$' if iter.peek() == Some(&'{') => ret.push_str("\\$"),
+            c => ret.push(c),
+        }
+    }
+    ret.push('"');
+    ret
+}
+
 impl Display for Value {
     fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
         use Value::*;
@@ -229,20 +248,7 @@ impl Display for Value {
             &Float(x) => write!(f, "{x}"),
             &Bool(x) => write!(f, "{x}"),
             Null => write!(f, "null"),
-            String(x) => {
+            String(x) => write!(f, "{}", escape_quote_string(x)),
-                write!(f, "\"")?;
-                for c in x.chars() {
-                    match c {
-                        '\\' => write!(f, "\\\\")?,
-                        '"' => write!(f, "\\\"")?,
-                        '\n' => write!(f, "\\n")?,
-                        '\r' => write!(f, "\\r")?,
-                        '\t' => write!(f, "\\t")?,
-                        c => write!(f, "{c}")?,
-                    }
-                }
-                write!(f, "\"")
-            }
             Path(x) => write!(f, "{x}"),
             AttrSet(x) => write!(f, "{x}"),
             List(x) => write!(f, "{x}"),
@@ -271,20 +277,7 @@ impl Display for ValueCompatDisplay<'_> {
             &Float(x) => write!(f, "{x}"),
             &Bool(x) => write!(f, "{x}"),
             Null => write!(f, "null"),
-            String(x) => {
+            String(x) => write!(f, "{}", escape_quote_string(x)),
-                write!(f, "\"")?;
-                for c in x.chars() {
-                    match c {
-                        '\\' => write!(f, "\\\\")?,
-                        '"' => write!(f, "\\\"")?,
-                        '\n' => write!(f, "\\n")?,
-                        '\r' => write!(f, "\\r")?,
-                        '\t' => write!(f, "\\t")?,
-                        c => write!(f, "{c}")?,
-                    }
-                }
-                write!(f, "\"")
-            }
             Path(x) => write!(f, "{x}"),
             AttrSet(x) => write!(f, "{}", x.display_compat()),
             List(x) => write!(f, "{}", x.display_compat()),