Add transform exceptions for string literals

src/babel/__snapshots__/plugin.test.js.snap

···
 exports[`deduplicates hoisted expressions 1`] = `
 "import { match, __private } from \\"reghex\\";
 const re = /1/;
+const str = '1';
 
 var _re_expression = __private.pattern(re);
 
···
   var x;
 
   if (x = __private.exec(state, _re_expression)) {
+    node.push(x);
+  } else {
+    state.y = y1;
+    state.x = x1;
+    return;
+  }
+
+  if (x = __private.exec(state, str)) {
     node.push(x);
   } else {
     state.y = y1;
···
   var x;
 
   if (x = __private.exec(state, _re_expression)) {
+    node.push(x);
+  } else {
+    state.y = y1;
+    state.x = x1;
+    return;
+  }
+
+  if (x = __private.exec(state, \\"2\\")) {
     node.push(x);
   } else {
     state.y = y1;

src/babel/plugin.test.js

···
   ).toMatchSnapshot();
 });
 
-it('deduplicates hoisted expressions', () => {
+it.only('deduplicates hoisted expressions', () => {
   const code = `
     import { match } from 'reghex/macro';
 
     const re = /1/;
+    const str = '1';
 
     const a = match('a')\`
       \${re}
+      \${str}
     \`;
 
     const b = match('b')\`
       \${re}
+      \${'2'}
     \`;
   `;
 

src/babel/transform.js

···
             t.isIdentifier(expression.body.body[0].argument)
           ) {
             expression = expression.body.body[0].argument;
+          } else if (t.isStringLiteral(expression)) {
+            return expression;
           }
 
           const isBindingExpression =
···
             if (t.isVariableDeclarator(binding.path.node)) {
               const matchPath = binding.path.get('init');
               if (this.isMatch(matchPath)) {
+                return expression;
+              } else if (t.isStringLiteral(matchPath)) {
                 return expression;
               } else if (_hoistedExpressions.has(expression.name)) {
                 return t.identifier(_hoistedExpressions.get(expression.name));
···
           if (t.isIdentifier(expression)) {
             _hoistedExpressions.set(expression.name, id.name);
           }
+
           return id;
         }
       );