enhance conditionals (#5371)

mishoo · Mar 2, 2022 · fdbbef2 · fdbbef2
1 parent f8edf05
commit fdbbef2
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Showing 3 changed files with 13 additions and 23 deletions.
diff --git a/lib/compress.js b/lib/compress.js
@@ -9157,14 +9157,16 @@ Compressor.prototype.compress = function(node) {
             var cond = fuzzy_eval(compressor, self.condition);
             if (!cond) {
                 AST_Node.warn("Condition always false [{file}:{line},{col}]", self.condition.start);
-                var body = [ make_node(AST_SimpleStatement, self.condition, { body: self.condition }) ];
+                var body = [
+                    make_node(AST_SimpleStatement, self.condition, { body: self.condition }).transform(compressor),
+                ];
                 extract_declarations_from_unreachable_code(compressor, self.body, body);
                 if (self.alternative) body.push(self.alternative);
                 return make_node(AST_BlockStatement, self, { body: body }).optimize(compressor);
             } else if (!(cond instanceof AST_Node)) {
                 AST_Node.warn("Condition always true [{file}:{line},{col}]", self.condition.start);
                 var body = [
-                    make_node(AST_SimpleStatement, self.condition, { body: self.condition }),
+                    make_node(AST_SimpleStatement, self.condition, { body: self.condition }).transform(compressor),
                     self.body,
                 ];
                 if (self.alternative) extract_declarations_from_unreachable_code(compressor, self.alternative, body);
@@ -9493,20 +9495,12 @@ Compressor.prototype.compress = function(node) {
                     left: self.expression,
                     right: exp,
                 }),
-                body: make_node(AST_BlockStatement, self, {
-                    body: statements,
-                }),
+                body: make_node(AST_BlockStatement, self, { body: statements }),
                 alternative: null,
             }).optimize(compressor);
-            if (exp) statements.unshift(make_node(AST_SimpleStatement, exp, {
-                body: exp,
-            }));
-            statements.unshift(make_node(AST_SimpleStatement, self.expression, {
-                body:self.expression,
-            }));
-            return make_node(AST_BlockStatement, self, {
-                body: statements,
-            }).optimize(compressor);
+            if (exp) statements.unshift(make_node(AST_SimpleStatement, exp, { body: exp }));
+            statements.unshift(make_node(AST_SimpleStatement, self.expression, { body: self.expression }));
+            return make_node(AST_BlockStatement, self, { body: statements }).optimize(compressor);
           case 2:
             if (!member(default_branch, body) || !no_break(body[1])) break;
             var statements = body[0].body.slice();
@@ -9524,14 +9518,10 @@ Compressor.prototype.compress = function(node) {
                     left: self.expression,
                     right: body[0].expression,
                 }),
-                body: make_node(AST_BlockStatement, body[0], {
-                    body: statements,
-                }),
+                body: make_node(AST_BlockStatement, body[0], { body: statements }),
                 alternative: exclusive && alternative || null,
             });
-            if (!exclusive && alternative) node = make_node(AST_BlockStatement, self, {
-                body: [ node, alternative ],
-            });
+            if (!exclusive && alternative) node = make_node(AST_BlockStatement, self, { body: [ node, alternative ] });
             return node.optimize(compressor);
         }
         return self;

diff --git a/test/compress/conditionals.js b/test/compress/conditionals.js
@@ -82,14 +82,14 @@ ifs_3_should_warn: {
         "WARN: Boolean && always false [test/compress/conditionals.js:3,12]",
         "WARN: Condition left of && always false [test/compress/conditionals.js:3,12]",
         "WARN: Condition always false [test/compress/conditionals.js:3,12]",
+        "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:3,12]",
         "WARN: Dropping unreachable code [test/compress/conditionals.js:3,34]",
         "WARN: + in boolean context always true [test/compress/conditionals.js:10,19]",
         "WARN: Boolean || always true [test/compress/conditionals.js:10,12]",
         "WARN: Condition left of || always true [test/compress/conditionals.js:10,12]",
         "WARN: Condition always true [test/compress/conditionals.js:10,12]",
-        "WARN: Dropping unreachable code [test/compress/conditionals.js:12,15]",
-        "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:3,12]",
         "WARN: Dropping side-effect-free statement [test/compress/conditionals.js:10,12]",
+        "WARN: Dropping unreachable code [test/compress/conditionals.js:12,15]",
     ]
 }
 

diff --git a/test/compress/sequences.js b/test/compress/sequences.js
@@ -1329,7 +1329,7 @@ issue_3490_2: {
     expect: {
         var b = 42, c = "FAIL";
         var a;
-        for (c = "PASS", b; "" == typeof d;);
+        for (c = "PASS"; "" == typeof d;);
         console.log(c, b);
     }
     expect_stdout: "PASS 42"