remove panics from missing identifiers

src/args.rs

@@ -335,7 +335,7 @@ pub(crate) fn eat_call_args<I: Iterator<Item = Token>>(
         match toks.peek().unwrap().kind {
             '$' => {
                 let Token { pos, .. } = toks.next().unwrap();
-                let v = eat_ident_no_interpolation(toks, false)?;
+                let v = eat_ident_no_interpolation(toks, false, pos)?;
                 let whitespace = devour_whitespace_or_comment(toks)?;
                 if toks.peek().unwrap().kind == ':' {
                     toks.next();

src/selector/mod.rs

@@ -290,10 +290,11 @@ impl Selector {
         let mut iter = sel_toks.into_iter().peekmore();
 
         while let Some(tok) = iter.peek() {
-            inner.push(match tok.kind {
-                _ if is_selector_name_char(tok.kind) => {
+            let Token { kind, pos } = *tok;
+            inner.push(match kind {
+                _ if is_selector_name_char(kind) => {
                     inner.push(SelectorKind::Element(
-                        eat_ident_no_interpolation(&mut iter, false)?.node,
+                        eat_ident_no_interpolation(&mut iter, false, pos)?.node,
                     ));
                     continue;
                 }
@@ -304,14 +305,14 @@ impl Selector {
                 '.' => {
                     iter.next();
                     inner.push(SelectorKind::Class(
-                        eat_ident_no_interpolation(&mut iter, false)?.node,
+                        eat_ident_no_interpolation(&mut iter, false, pos)?.node,
                     ));
                     continue;
                 }
                 '#' => {
                     iter.next();
                     inner.push(SelectorKind::Id(
-                        eat_ident_no_interpolation(&mut iter, false)?.node,
+                        eat_ident_no_interpolation(&mut iter, false, pos)?.node,
                     ));
                     continue;
                 }
@@ -319,7 +320,7 @@ impl Selector {
                     iter.next();
                     is_invisible = true;
                     inner.push(SelectorKind::Placeholder(
-                        eat_ident_no_interpolation(&mut iter, false)?.node,
+                        eat_ident_no_interpolation(&mut iter, false, pos)?.node,
                     ));
                     continue;
                 }
@@ -405,8 +406,13 @@ impl Selector {
         } else {
             false
         };
-        if is_selector_name_char(toks.peek().unwrap().kind) {
-            let name = eat_ident_no_interpolation(toks, false)?.node;
+        let t = if let Some(tok) = toks.peek() {
+            *tok
+        } else {
+            todo!()
+        };
+        if is_selector_name_char(t.kind) {
+            let name = eat_ident_no_interpolation(toks, false, t.pos)?.node;
             Ok(
                 if toks.peek().is_some() && toks.peek().unwrap().kind == '(' {
                     toks.next();
@@ -425,7 +431,7 @@ impl Selector {
                 },
             )
         } else {
-            todo!()
+            return Err(("Expected identifier.", t.pos).into());
         }
     }
 

src/utils/strings.rs

@@ -232,8 +232,12 @@ pub(crate) fn eat_ident<I: Iterator<Item = Token>>(
 pub(crate) fn eat_ident_no_interpolation<I: Iterator<Item = Token>>(
     toks: &mut PeekMoreIterator<I>,
     unit: bool,
+    span_before: Span,
 ) -> SassResult<Spanned<String>> {
-    let mut span = toks.peek().unwrap().pos();
+    let mut span = toks
+        .peek()
+        .ok_or(("Expected identifier.", span_before))?
+        .pos();
     let mut text = String::new();
     if toks.peek().unwrap().kind == '-' {
         toks.next();

src/value/parse.rs

@@ -679,9 +679,10 @@ impl Value {
                     Err(e) => return Some(Err(e)),
                 };
                 let unit = if let Some(tok) = toks.peek() {
-                    match tok.kind {
+                    let Token { kind, pos } = *tok;
+                    match kind {
                         'a'..='z' | 'A'..='Z' | '_' | '\\' => {
-                            let u = match eat_ident_no_interpolation(toks, true) {
+                            let u = match eat_ident_no_interpolation(toks, true, pos) {
                                 Ok(v) => v,
                                 Err(e) => return Some(Err(e)),
                             };
@@ -804,7 +805,7 @@ impl Value {
             }
             '$' => {
                 toks.next();
-                let val = match eat_ident_no_interpolation(toks, false) {
+                let val = match eat_ident_no_interpolation(toks, false, span) {
                     Ok(v) => v,
                     Err(e) => return Some(Err(e)),
                 };

tests/if.rs

@@ -109,6 +109,10 @@ test!(
     "a {\n  color: red;\n}\n"
 );
 error!(nothing_after_if, "@if", "Error: Expected expression.");
+error!(
+    nothing_after_dollar,
+    "@if ${}", "Error: Expected identifier."
+);
 error!(no_condition, "@if{}", "Error: Expected expression.");
 error!(
     nothing_after_open_curly,

tests/selectors.rs

@@ -541,3 +541,11 @@ test!(
     "|f {\n  color: &;\n}\n",
     "|f {\n  color: |f;\n}\n"
 );
+error!(nothing_after_period, ". {}", "Error: Expected identifier.");
+error!(nothing_after_hash, "# {}", "Error: Expected identifier.");
+error!(nothing_after_percent, "% {}", "Error: Expected identifier.");
+error!(nothing_after_colon, ": {}", "Error: Expected identifier.");
+error!(
+    non_ident_after_colon,
+    ":#ab {}", "Error: Expected identifier."
+);