fix crash when inlining uninitialized variable into template string. Closes #876

fabiosantoscode · fabiosantoscode · commit 0e3d07921af2 · 2020-11-19T10:24:41.000Z
diff --git a/lib/compress/index.js b/lib/compress/index.js
@@ -6245,7 +6245,7 @@ def_optimize(AST_Binary, function(self, compressor) {
                 var l = self.left;
                 var r = self.right.evaluate(compressor);
                 if (r != self.right) {
-                    l.segments[l.segments.length - 1].value += r.toString();
+                    l.segments[l.segments.length - 1].value += String(r);
                     return l;
                 }
             }
@@ -6254,7 +6254,7 @@ def_optimize(AST_Binary, function(self, compressor) {
                 var r = self.right;
                 var l = self.left.evaluate(compressor);
                 if (l != self.left) {
-                    r.segments[0].value = l.toString() + r.segments[0].value ;
+                    r.segments[0].value = String(l) + r.segments[0].value;
                     return r;
                 }
             }
diff --git a/test/compress/template-string.js b/test/compress/template-string.js
@@ -198,6 +198,26 @@ template_concattenating_string: {
     }
 }
 
+template_evaluate_undefined: {
+    options = {
+        evaluate: true,
+        reduce_vars: true
+    }
+    input: {
+        // test.js
+        () => {
+            let x;
+            console.log(x + `?ts=${Date.now()}`);
+        };
+    }
+    expect: {
+        () => {
+            let x;
+            console.log(`undefined?ts=${Date.now()}`);
+        };
+    }
+}
+
 evaluate_nested_templates: {
     options = {
         evaluate: true

Original file line number	Diff line number	Diff line change
`@@ -6245,7 +6245,7 @@ def_optimize(AST_Binary, function(self, compressor) {`
`6245`	`6245`	`var l = self.left;`
`6246`	`6246`	`var r = self.right.evaluate(compressor);`
`6247`	`6247`	`if (r != self.right) {`
`6248`		`- l.segments[l.segments.length - 1].value += r.toString();`
	`6248`	`+ l.segments[l.segments.length - 1].value += String(r);`
`6249`	`6249`	`return l;`
`6250`	`6250`	`}`
`6251`	`6251`	`}`
`@@ -6254,7 +6254,7 @@ def_optimize(AST_Binary, function(self, compressor) {`
`6254`	`6254`	`var r = self.right;`
`6255`	`6255`	`var l = self.left.evaluate(compressor);`
`6256`	`6256`	`if (l != self.left) {`
`6257`		`- r.segments[0].value = l.toString() + r.segments[0].value ;`
	`6257`	`+ r.segments[0].value = String(l) + r.segments[0].value;`
`6258`	`6258`	`return r;`
`6259`	`6259`	`}`
`6260`	`6260`	`}`