Properly emit quotes after interpolation

src/lib.rs

@@ -107,6 +107,13 @@ impl Token {
             pos: Pos::new(),
         }
     }
+
+    pub fn from_symbol(s: Symbol) -> Self {
+        Token {
+            kind: TokenKind::Symbol(s),
+            pos: Pos::new(),
+        }
+    }
 }
 
 impl IsWhitespace for Token {

src/style.rs

@@ -1,4 +1,4 @@
-use crate::common::{Pos, Scope, Symbol};
+use crate::common::{Pos, QuoteKind, Scope, Symbol};
 use crate::error::SassResult;
 use crate::selector::Selector;
 use crate::utils::{devour_whitespace, parse_interpolation, parse_quoted_string};
@@ -87,12 +87,20 @@ impl<'a> StyleParser<'a> {
                 ref q @ TokenKind::Symbol(Symbol::DoubleQuote)
                 | ref q @ TokenKind::Symbol(Symbol::SingleQuote) => {
                     let q = q.clone();
-                    let tok = toks.next().unwrap();
-                    style.push(tok.clone());
-                    style.push(Token::from_string(
-                        parse_quoted_string(toks, scope, q)?.unquote().to_string(),
-                    ));
-                    style.push(tok);
+                    toks.next();
+                    let (s, q) = if let Value::Ident(s, q) = parse_quoted_string(toks, scope, q)? {
+                        (s, q)
+                    } else {
+                        unreachable!()
+                    };
+                    let quote_kind = Token::from_symbol(match q {
+                        QuoteKind::Single => Symbol::SingleQuote,
+                        QuoteKind::Double => Symbol::DoubleQuote,
+                        _ => unreachable!(),
+                    });
+                    style.push(quote_kind.clone());
+                    style.push(Token::from_string(s));
+                    style.push(quote_kind);
                     continue;
                 }
                 TokenKind::Symbol(Symbol::OpenCurlyBrace)

tests/interpolation.rs

@@ -28,3 +28,8 @@ test!(
     "a {\n  color:  #{\"''\"};\n}\n",
     "a {\n  color: '';\n}\n"
 );
+test!(
+    single_quotes_converted_to_double_when_interpolated,
+    "a {\n  color:  '#{foo}';\n}\n",
+    "a {\n  color: \"foo\";\n}\n"
+);

tests/values.rs

@@ -3,6 +3,8 @@
 #[macro_use]
 mod macros;
 
+test!(single_quote, "a {\n  color: 'foo';\n}\n");
+test!(double_quote, "a {\n  color: \"foo\";\n}\n");
 test!(comma_list_ident, "a {\n  color: foo, bar, baz;\n}\n");
 test!(space_list_ident, "a {\n  color: foo bar baz;\n}\n");
 test!(comma_list_number, "a {\n  color: 1, 2, 3;\n}\n");