hotfix: Fix empty string matching being too eager

.changeset/strange-crabs-love.md

···
+---
+'@0no-co/graphql.web': patch
+---
+
+Fix empty string matches being too eager, e.g. `"", ""`

src/__tests__/parser.test.ts

···
       value: 'x',
       block: false,
     });
+
+    expect(parseValue('"" ""')).toEqual({
+      kind: Kind.STRING,
+      value: '',
+      block: false,
+    });
+
+    expect(parseValue('" \\" " ""')).toEqual({
+      kind: Kind.STRING,
+      value: ' " ',
+      block: false,
+    });
   });
 
   it('parses objects', () => {
···
     expect(parseValue('"""x""" """x"""')).toEqual({
       kind: Kind.STRING,
       value: 'x',
+      block: true,
+    });
+
+    expect(parseValue('"""""" """"""')).toEqual({
+      kind: Kind.STRING,
+      value: '',
+      block: true,
+    });
+
+    expect(parseValue('""" \\""" """ """"""')).toEqual({
+      kind: Kind.STRING,
+      value: ' """ ',
       block: true,
     });
   });

src/parser.ts

···
 const floatPartRe = /(?:\.\d+)?[eE][+-]?\d+|\.\d+/y;
 
 const complexStringRe = /\\/g;
-const blockStringRe = /"""(?:[\s\S]*?[^\\])?"""/y;
-const stringRe = /"(?:[^\r\n]*?[^\\])?"/y;
+const blockStringRe = /"""(?:"""|(?:[\s\S]*?[^\\])""")/y;
+const stringRe = /"(?:"|[^\r\n]*?[^\\]")/y;
 
 function value(constant: true): ast.ConstValueNode;
 function value(constant: boolean): ast.ValueNode;