case "+":
var ll = self.left.evaluate(compressor);
var rr = self.right.evaluate(compressor);
- if ((ll.length > 1 && ll[0] instanceof AST_String && ll[1]) ||
- (rr.length > 1 && rr[0] instanceof AST_String && rr[1])) {
+ if ((ll.length > 1 && ll[0] instanceof AST_String && ll[1] && !self.right.has_side_effects(compressor)) ||
+ (rr.length > 1 && rr[0] instanceof AST_String && rr[1] && !self.left.has_side_effects(compressor))) {
compressor.warn("+ in boolean context always true [{file}:{line},{col}]", self.start);
return make_node(AST_True, self);
}
--- /dev/null
+string_plus_optimization: {
+ options = {
+ side_effects : true,
+ evaluate : true,
+ conditionals : true,
+ comparisons : true,
+ dead_code : true,
+ booleans : true,
+ unused : true,
+ if_return : true,
+ join_vars : true,
+ cascade : true,
+ hoist_funs : true,
+ };
+ input: {
+ function foo(anything) {
+ function throwing_function() {
+ throw "nope";
+ }
+ try {
+ console.log('0' + throwing_function() ? "yes" : "no");
+ } catch (ex) {
+ console.log(ex);
+ }
+ console.log('0' + anything ? "yes" : "no");
+ console.log(anything + '0' ? "Yes" : "No");
+ console.log('' + anything);
+ console.log(anything + '');
+ }
+ foo();
+ }
+ expect: {
+ function foo(anything) {
+ function throwing_function() {
+ throw "nope";
+ }
+ try {
+ console.log('0' + throwing_function() ? "yes" : "no");
+ } catch (ex) {
+ console.log(ex);
+ }
+ console.log("yes");
+ console.log("Yes");
+ console.log('' + anything);
+ console.log(anything + '');
+ }
+ foo();
+ }
+}