fixes template strings introducing errant plus when there are no items (

#327) * fixes template strings introducing errant plus when there are no items * simplify spec Co-authored-by: Bronley <[email protected]>
rokucommunity · Feb 20, 2021 · 345ee59 · 345ee59
1 parent 7db62ed
commit 345ee59
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/src/parser/Expression.ts b/src/parser/Expression.ts
@@ -1065,7 +1065,7 @@ export class TemplateStringExpression extends Expression {
                     ...items
                 );
             }
-            plus = ' + ';
+            plus = items.length > 0 ? ' + ' : '';
         }
 
         for (let i = 0; i < this.quasis.length; i++) {

diff --git a/src/parser/tests/expression/TemplateStringExpression.spec.ts b/src/parser/tests/expression/TemplateStringExpression.spec.ts
@@ -74,6 +74,13 @@ describe('TemplateStringExpression', () => {
             program.dispose();
         });
 
+        it('properly transpiles simple template string with no leading text', () => {
+            testTranspile(
+                'a = `${one},${two}`',
+                `a = bslib_toString(one) + "," + bslib_toString(two)`
+            );
+        });
+
         it('properly transpiles simple template string', () => {
             testTranspile(
                 'a = `hello world`',