fix(parser): JSX attributes must only be assigned a non-empty 'expres…

…sion'
meriyah · Jul 6, 2019 · 712d8e6 · 712d8e6
1 parent 6acf9ad
commit 712d8e6
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Showing 3 changed files with 21 additions and 4 deletions.
diff --git a/src/errors.ts b/src/errors.ts
@@ -160,7 +160,8 @@ export const enum Errors {
   TrailingNumericSeparator,
   InvalidJSXAttributeValue,
   ExpectedJSXClosingTag,
-  AdjacentJSXElements
+  AdjacentJSXElements,
+  InvalidNonEmptyJSXExpr
 }
 
 /*@internal*/
@@ -332,7 +333,8 @@ export const errorMessages: {
   [Errors.ContinuousNumericSeparator]: 'Only one underscore is allowed as numeric separator',
   [Errors.InvalidJSXAttributeValue]: 'JSX value should be either an expression or a quoted JSX text',
   [Errors.ExpectedJSXClosingTag]: 'Expected corresponding JSX closing tag for %0',
-  [Errors.AdjacentJSXElements]: 'Adjacent JSX elements must be wrapped in an enclosing tag'
+  [Errors.AdjacentJSXElements]: 'Adjacent JSX elements must be wrapped in an enclosing tag',
+  [Errors.InvalidNonEmptyJSXExpr]: "JSX attributes must only be assigned a non-empty 'expression'"
 };
 
 export class ParseError extends SyntaxError {

diff --git a/src/parser.ts b/src/parser.ts
@@ -8155,7 +8155,7 @@ function parseJSXChild(parser: ParserState, context: Context, start: number, lin
     case Token.Identifier:
       return parseJSXText(parser, context, start, line, column);
     case Token.LeftBrace:
-      return parseJSXExpressionContainer(parser, context, /*isJSXChild*/ 0, start, line, column);
+      return parseJSXExpressionContainer(parser, context, /*isJSXChild*/ 0, /* isAttr */ 0, start, line, column);
     case Token.LessThan:
       return parseJSXRootElementOrFragment(parser, context, /*isJSXChild*/ 0, start, line, column);
     default:
@@ -8358,6 +8358,7 @@ function parseJsxAttribute(
     name = parseJSXNamespacedName(parser, context, name, start, line, column);
   }
 
+  // HTML empty attribute
   if (parser.token === Token.Assign) {
     const token = scanJSXAttributeValue(parser, context);
     const { tokenIndex, linePos, colPos } = parser;
@@ -8369,7 +8370,15 @@ function parseJsxAttribute(
         value = parseJSXRootElementOrFragment(parser, context, /*isJSXChild*/ 1, tokenIndex, linePos, colPos);
         break;
       case Token.LeftBrace:
-        value = parseJSXExpressionContainer(parser, context, /*isJSXChild*/ 1, tokenIndex, linePos, colPos);
+        value = parseJSXExpressionContainer(
+          parser,
+          context,
+          /*isJSXChild*/ 1,
+          /* isAttr */ 1,
+          tokenIndex,
+          linePos,
+          colPos
+        );
         break;
       default:
         report(parser, Errors.InvalidJSXAttributeValue);
@@ -8424,6 +8433,7 @@ function parseJSXExpressionContainer(
   parser: ParserState,
   context: Context,
   isJSXChild: 0 | 1,
+  isAttr: 0 | 1,
   start: number,
   line: number,
   column: number
@@ -8437,6 +8447,10 @@ function parseJSXExpressionContainer(
   if (parser.token !== Token.RightBrace) {
     expression = parseExpression(parser, context, 1, 0, 0, tokenIndex, linePos, colPos);
   } else {
+    // JSX attributes must only be assigned a non-empty 'expression'
+    if (isAttr) {
+      report(parser, Errors.InvalidNonEmptyJSXExpr);
+    }
     expression = parseJSXEmptyExpression(parser, context, tokenIndex, linePos, colPos);
   }
   if (isJSXChild) {

diff --git a/test/parser/miscellaneous/jsx.ts b/test/parser/miscellaneous/jsx.ts
@@ -20,6 +20,7 @@ describe('Miscellaneous - JSX', () => {
     ['<p></>', Context.OptionsJSX],
     ['<p><q></p>', Context.OptionsJSX],
     ['<1/>', Context.OptionsJSX],
+    [`<div id={}></div>`, Context.OptionsJSX],
     ['<div>one</div><div>two</div>', Context.OptionsJSX],
     ['</>', Context.OptionsJSX],
     ['<a/!', Context.OptionsJSX],