reduce overlap of sequences & side_effects (#5344)

mishoo · Feb 7, 2022 · b6c72c8 · b6c72c8
1 parent 327e94a
commit b6c72c8
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Showing 9 changed files with 278 additions and 15 deletions.
diff --git a/lib/compress.js b/lib/compress.js
@@ -3637,9 +3637,7 @@ Compressor.prototype.compress = function(node) {
                 var stat = statements[i];
                 if (stat instanceof AST_SimpleStatement) {
                     if (seq.length >= compressor.sequences_limit) push_seq();
-                    var body = stat.body;
-                    if (seq.length > 0) body = body.drop_side_effect_free(compressor);
-                    if (body) merge_sequence(seq, body);
+                    merge_sequence(seq, stat.body);
                 } else if (is_declaration(stat)) {
                     statements[n++] = stat;
                 } else {

diff --git a/test/compress/drop-unused.js b/test/compress/drop-unused.js
@@ -3358,6 +3358,7 @@ issue_4806_1: {
 issue_4806_2: {
     options = {
         sequences: true,
+        side_effects: true,
         toplevel: true,
         unused: true,
     }

diff --git a/test/compress/functions.js b/test/compress/functions.js
@@ -6135,6 +6135,7 @@ issue_4265: {
         dead_code: true,
         inline: true,
         sequences: true,
+        side_effects: true,
     }
     input: {
         function f() {

diff --git a/test/compress/ie.js b/test/compress/ie.js
@@ -2631,13 +2631,14 @@ issue_3999: {
     ]
 }
 
-issue_4001: {
+issue_4001_1: {
     options = {
         collapse_vars: true,
         ie: true,
         inline: true,
         reduce_vars: true,
         sequences: true,
+        side_effects: false,
         toplevel: true,
         unused: true,
     }
@@ -2660,7 +2661,42 @@ issue_4001: {
             return a;
         }
         var a;
-        console.log((a = 42, void f()[42], void function a() {}));
+        console.log((a = 42, f()[42], void f, void function a() {}));
+    }
+    expect_stdout: "undefined"
+}
+
+issue_4001_2: {
+    options = {
+        collapse_vars: true,
+        ie: true,
+        inline: true,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        console.log(function(a) {
+            function f() {
+                return a;
+                var b;
+            }
+            var c = f();
+            (function g() {
+                c[42];
+                f;
+            })();
+            (function a() {});
+        }(42));
+    }
+    expect: {
+        function f() {
+            return a;
+        }
+        var a;
+        console.log((a = 42, void f()[42]));
     }
     expect_stdout: "undefined"
 }

diff --git a/test/compress/issue-640.js b/test/compress/issue-640.js
@@ -317,7 +317,35 @@ iife: {
         typeof function g() {}();
     }
     expect: {
-        x = 42, function a() {}(), function b() {}(), function c() {}(),
-        function d() {}(), function e() {}(), function f() {}(), typeof function g() {}();
+        x = 42,
+        function a() {}(),
+        !function b() {}(),
+        ~function c() {}(),
+        +function d() {}(),
+        -function e() {}(),
+        void function f() {}(),
+        typeof function g() {}();
+    }
+}
+
+iife_drop_side_effect_free: {
+    options = {
+        expression: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        x = 42;
+        (function a() {})();
+        !function b() {}();
+        ~function c() {}();
+        +function d() {}();
+        -function e() {}();
+        void function f() {}();
+        typeof function g() {}();
+    }
+    expect: {
+        x = 42,
+        typeof void 0;
     }
 }
diff --git a/test/compress/merge_vars.js b/test/compress/merge_vars.js
@@ -253,6 +253,7 @@ read_before_assign_1: {
         inline: true,
         merge_vars: true,
         sequences: true,
+        side_effects: true,
         toplevel: true,
     }
     input: {

diff --git a/test/compress/negate-iife.js b/test/compress/negate-iife.js
@@ -122,13 +122,41 @@ negate_iife_4: {
         sequences: true,
     }
     input: {
-        (function(){ return t })() ? console.log(true) : console.log(false);
-        (function(){
+        (function() {
+            return t;
+        })() ? console.log(true) : console.log(false);
+        (function() {
+            console.log("something");
+        })();
+    }
+    expect: {
+        !function() {
+            return t;
+        }() ? console.log(false) : console.log(true), !function() {
+            console.log("something");
+        }();
+    }
+}
+
+negate_iife_4_drop_side_effect_free: {
+    options = {
+        conditionals: true,
+        negate_iife: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        (function() {
+            return t;
+        })() ? console.log(true) : console.log(false);
+        (function() {
             console.log("something");
         })();
     }
     expect: {
-        !function(){ return t }() ? console.log(false) : console.log(true), function(){
+        !function() {
+            return t;
+        }() ? console.log(false) : console.log(true), function() {
             console.log("something");
         }();
     }
@@ -176,17 +204,49 @@ negate_iife_5: {
         sequences: true,
     }
     input: {
-        if ((function(){ return t })()) {
+        if (function() {
+            return t;
+        }()) {
             foo(true);
         } else {
             bar(false);
         }
-        (function(){
+        (function() {
             console.log("something");
         })();
     }
     expect: {
-        !function(){ return t }() ? bar(false) : foo(true), function(){
+        !function() {
+            return t;
+        }() ? bar(false) : foo(true), !function() {
+            console.log("something");
+        }();
+    }
+}
+
+negate_iife_5_drop_side_effect_free: {
+    options = {
+        conditionals: true,
+        negate_iife: true,
+        sequences: true,
+        side_effects: true,
+    }
+    input: {
+        if (function() {
+            return t;
+        }()) {
+            foo(true);
+        } else {
+            bar(false);
+        }
+        (function() {
+            console.log("something");
+        })();
+    }
+    expect: {
+        !function() {
+            return t;
+        }() ? bar(false) : foo(true), function() {
             console.log("something");
         }();
     }

diff --git a/test/compress/pure_getters.js b/test/compress/pure_getters.js
@@ -1289,6 +1289,7 @@ issue_2878: {
         collapse_vars: true,
         pure_getters: true,
         sequences: true,
+        side_effects: true,
     }
     input: {
         var c = 0;