Allow empty comments

src/token_stream.mjs

@@ -2,6 +2,7 @@ import { CharacterStream } from './character_stream.mjs';
 import { TemplateSyntaxError } from './errors/template_syntax_error.mjs';
 
 export class TokenStream {
+  static ESCAPE = '\\';
   static OPEN_INLINE = '<%';
   static CLOSE_INLINE = '%>';
   static OPEN_INLINE_UNESCAPED = '<!%';
@@ -62,6 +63,11 @@ export class TokenStream {
         // Skip shebang (can be used to execute templates directly with an
         // interpreter that first builds the template and then executes)
         this._skipShebang();
+      } else if (this._cs.isNext(TokenStream.ESCAPE)) {
+        // Skip space
+        this._cs.next();
+        // Treat everything as raw until next space
+        raw += this._cs.nextWhile((c) => /\S/.test(c));
       } else if (this._cs.isNext(TokenStream.OPEN_INLINE)) {
         return flushRaw() || this._readInline();
       } else if (this._cs.isNext(TokenStream.OPEN_INLINE_UNESCAPED)) {
@@ -174,13 +180,13 @@ export class TokenStream {
     // Skip tag
     this._cs.next(tag.length);
 
-    // Check for mandatory space
-    if (this._cs.peek() !== ' ') {
+    // Check for mandatory space/tab/new line
+    if (this._isSpace(this._cs.peek())) {
+      // Consume space
+      this._cs.next();
+    } else if (/[^\r\n]/.test(this._cs.peek())) {
       this._missingFullLineSpaceError(tag);
     }
-    
-    // Consume space
-    this._cs.next();
 
     // Remainder of line is value
     const value = this._cs.nextWhile((c) => c !== '\n');