replace keep_fargs default to false (#4443)

README.md

@@ -683,9 +683,9 @@ to be `false` and all symbol names will be omitted.
 
 - `join_vars` (default: `true`) -- join consecutive `var` statements
 
-- `keep_fargs` (default: `strict`) -- Discard unused function arguments. Code
+- `keep_fargs` (default: `false`) -- discard unused function arguments except
-  which relies on `Function.length` will break if this is done indiscriminately,
+  when unsafe to do so, e.g. code which relies on `Function.prototype.length`.
-  i.e. when passing `true`. Pass `false` to always retain function arguments.
+  Pass `true` to always retain function arguments.
 
 - `keep_fnames` (default: `false`) -- Pass `true` to prevent the
   compressor from discarding function names.  Useful for code relying on

lib/compress.js

@@ -71,7 +71,7 @@ function Compressor(options, false_by_default) {
         if_return       : !false_by_default,
         inline          : !false_by_default,
         join_vars       : !false_by_default,
-        keep_fargs      : false_by_default || "strict",
+        keep_fargs      : false_by_default,
         keep_fnames     : false,
         keep_infinity   : false,
         loops           : !false_by_default,
@@ -113,8 +113,7 @@ function Compressor(options, false_by_default) {
         }
     }
     if (this.options["inline"] === true) this.options["inline"] = 3;
-    var keep_fargs = this.options["keep_fargs"];
+    this.drop_fargs = this.options["keep_fargs"] ? return_false : function(lambda, parent) {
-    this.drop_fargs = keep_fargs == "strict" ? function(lambda, parent) {
         if (lambda.length_read) return false;
         var name = lambda.name;
         if (!name) return parent && parent.TYPE == "Call" && parent.expression === lambda;
@@ -123,7 +122,7 @@ function Compressor(options, false_by_default) {
         if (def.direct_access) return false;
         var escaped = def.escaped;
         return escaped && escaped.depth != 1;
-    } : keep_fargs ? return_false : return_true;
+    };
     var pure_funcs = this.options["pure_funcs"];
     if (typeof pure_funcs == "function") {
         this.pure_funcs = pure_funcs;

test/compress/arguments.js

@@ -78,7 +78,7 @@ replace_index_strict: {
     ]
 }
 
-replace_index_keep_fargs: {
+replace_index_drop_fargs_1: {
     options = {
         arguments: true,
         evaluate: true,
@@ -128,7 +128,7 @@ replace_index_keep_fargs: {
     ]
 }
 
-replace_index_keep_fargs_strict: {
+replace_index_drop_fargs_2: {
     options = {
         arguments: true,
         evaluate: true,
@@ -412,7 +412,7 @@ issue_3273_global_strict_reduce_vars: {
     ]
 }
 
-issue_3273_keep_fargs_false: {
+issue_3273_drop_fargs_1: {
     options = {
         arguments: true,
         keep_fargs: false,
@@ -435,10 +435,10 @@ issue_3273_keep_fargs_false: {
     expect_stdout: "1"
 }
 
-issue_3273_keep_fargs_strict: {
+issue_3273_drop_fargs_2: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
     }
     input: {
@@ -633,7 +633,7 @@ issue_3282_2_passes: {
 issue_3420_1: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         console.log(function() {
@@ -655,7 +655,7 @@ issue_3420_1: {
 issue_3420_2: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         var foo = function() {
@@ -675,7 +675,7 @@ issue_3420_2: {
 issue_3420_3: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         "use strict";
@@ -697,7 +697,7 @@ issue_3420_3: {
 issue_3420_4: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         !function() {
@@ -722,7 +722,7 @@ issue_3420_4: {
 issue_3420_5: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         "use strict";
@@ -749,7 +749,7 @@ issue_3420_5: {
 issue_3420_6: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         console.log(function() {
@@ -767,7 +767,7 @@ issue_3420_6: {
 issue_3420_7: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         "use strict";
@@ -811,7 +811,7 @@ issue_4200: {
 issue_4291_1: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         console.log(function() {
@@ -831,7 +831,7 @@ issue_4291_1: {
 issue_4291_2: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         var a = function() {
@@ -855,7 +855,7 @@ issue_4291_2: {
 issue_4397: {
     options = {
         arguments: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         console.log(typeof function() {

test/compress/arrows.js

@@ -419,7 +419,7 @@ collapse_value: {
     options = {
         arrows: true,
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -437,7 +437,7 @@ collapse_value: {
 reduce_iife_1: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }

test/compress/async.js

@@ -353,7 +353,7 @@ property_access_expression: {
 reduce_iife_1: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }

test/compress/default-values.js

@@ -481,7 +481,7 @@ retain_fargs: {
 
 drop_fargs: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {

test/compress/destructured.js

@@ -40,7 +40,7 @@ redefine_arguments_2: {
 
 redefine_arguments_3: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -259,7 +259,7 @@ funarg_side_effects_3: {
 
 funarg_unused_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -318,7 +318,7 @@ funarg_unused_3: {
 
 funarg_unused_4: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: "strict",
         unused: true,
     }
@@ -384,7 +384,7 @@ funarg_unused_6_inline: {
 
 funarg_unused_6_keep_fargs: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -426,7 +426,7 @@ funarg_collapse_vars_1: {
 funarg_collapse_vars_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -505,7 +505,7 @@ funarg_reduce_vars_1: {
 funarg_reduce_vars_2: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: "strict",
         reduce_vars: true,
         unsafe: true,
@@ -1123,7 +1123,7 @@ join_vars: {
 
 keep_fargs: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1776,7 +1776,7 @@ issue_4319: {
 issue_4321: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         try {

test/compress/drop-unused.js

@@ -4,15 +4,16 @@ unused_funarg_1: {
         unused: true,
     }
     input: {
-        function f(a, b, c, d, e) {
+        console.log(function f(a, b, c, d, e) {
             return a + b;
-        }
+        }(14, 28));
     }
     expect: {
-        function f(a, b) {
+        console.log(function(a, b) {
             return a + b;
+        }(14, 28));
     }
-    }
+    expect_stdout: "42"
 }
 
 unused_funarg_2: {
@@ -21,15 +22,16 @@ unused_funarg_2: {
         unused: true,
     }
     input: {
-        function f(a, b, c, d, e) {
+        console.log(function f(a, b, c, d, e) {
             return a + c;
-        }
+        }(14, 21, 28));
     }
     expect: {
-        function f(a, b, c) {
+        console.log(function(a, c) {
             return a + c;
+        }(14, 28));
     }
-    }
+    expect_stdout: "42"
 }
 
 unused_nested_function: {
@@ -357,37 +359,6 @@ drop_toplevel_vars: {
     }
 }
 
-drop_toplevel_vars_fargs: {
-    options = {
-        keep_fargs: false,
-        toplevel: "vars",
-        unused: true,
-    }
-    input: {
-        var a, b = 1, c = g;
-        function f(d) {
-            return function() {
-                c = 2;
-            };
-        }
-        a = 2;
-        function g() {}
-        function h() {}
-        console.log(b = 3);
-    }
-    expect: {
-        function f() {
-            return function() {
-                2;
-            };
-        }
-        2;
-        function g() {}
-        function h() {}
-        console.log(3);
-    }
-}
-
 drop_toplevel_all: {
     options = {
         toplevel: true,
@@ -625,13 +596,14 @@ drop_fargs: {
         unused: true,
     }
     input: {
-        function f(a) {
+        console.log(function f(a) {
             var b = a;
-        }
+        }());
     }
     expect: {
-        function f() {}
+        console.log(function() {}());
     }
+    expect_stdout: "undefined"
 }
 
 drop_fnames: {
@@ -2027,7 +1999,7 @@ issue_3192_1: {
 
 issue_3192_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -2435,7 +2407,7 @@ issue_3673: {
 
 issue_3746: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -2713,7 +2685,7 @@ issue_3956: {
 issue_3962_1: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -2745,7 +2717,7 @@ issue_3962_1: {
 
 issue_3962_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         side_effects: true,
         toplevel: true,
@@ -2948,7 +2920,7 @@ issue_4133: {
 
 issue_4144: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }

test/compress/functions.js

@@ -229,7 +229,7 @@ issue_203: {
     }
     expect: {
         var m = {};
-        var fn = Function("n,o", "o.exports=42");
+        var fn = Function("n,o,t", "o.exports=42");
         fn(null, m, m.exports);
         console.log(m.exports);
     }
@@ -4230,7 +4230,7 @@ substitute: {
 substitute_add_farg: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
     }
     input: {
         function f(g) {
@@ -4411,7 +4411,9 @@ substitute_drop_farg: {
                 return f;
             },
             function() {
-                return f;
+                return function(d, e) {
+                    return f(d, e);
+                };
             },
         ].forEach(function(g) {
             console.log(g()(o), g().call(o, o));
@@ -4594,7 +4596,7 @@ substitute_use_strict: {
 issue_3833: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -4751,7 +4753,7 @@ issue_4006: {
         dead_code: true,
         evaluate: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         side_effects: true,

test/compress/issue-976.js

@@ -63,42 +63,81 @@ eval_unused: {
         unused: true,
     }
     input: {
-        function f1(a, eval, c, d, e) {
+        function o(k) {
-            return a('c') + eval;
+            return { c: 14 }[k];
-        }
-        function f2(a, b, c, d, e) {
-            return a + eval('c');
-        }
-        function f3(a, eval, c, d, e) {
-            return a + eval('c');
         }
+        console.log(function f1(a, eval, c, d, e) {
+            return a("c") + eval;
+        }(o, 28, true));
+        console.log(function f2(a, b, c, d, e) {
+            return a + eval("c");
+        }(14, true, 28));
+        console.log(function f3(a, eval, c, d, e) {
+            return a + eval("c");
+        }(28, o, true));
     }
     expect: {
-        function f1(a, eval) {
+        function o(k) {
-            return a('c') + eval;
+            return { c: 14 }[k];
-        }
-        function f2(a, b, c, d, e) {
-            return a + eval('c');
-        }
-        function f3(a, eval, c, d, e) {
-            return a + eval('c');
         }
+        console.log(function(a, eval) {
+            return a("c") + eval;
+        }(o, 28));
+        console.log(function f2(a, b, c, d, e) {
+            return a + eval("c");
+        }(14, true, 28));
+        console.log(function f3(a, eval, c, d, e) {
+            return a + eval("c");
+        }(28, o, true));
     }
+    expect_stdout: [
+        "42",
+        "42",
+        "42",
+    ]
 }
 
 eval_mangle: {
-    mangle = {
+    mangle = {}
-    };
+    beautify = {
+        beautify: true,
+    }
     input: {
-        function f1(a, eval, c, d, e) {
+        function o(k) {
-            return a('c') + eval;
+            return { cc: 14 }[k + "c"];
         }
-        function f2(a, b, c, d, e) {
+        console.log(function f1(a, eval, c, d, e) {
-            return a + eval('c');
+            return a("c") + eval;
+        }(o, 28, true));
+        console.log(function f2(a, b, c, d, e) {
+            return a + eval("c");
+        }(14, true, 28));
+        console.log(function f3(a, eval, c, d, e) {
+            return a + eval("c");
+        }(28, o, true));
     }
-        function f3(a, eval, c, d, e) {
+    expect_exact: [
-            return a + eval('c');
+        "function o(o) {",
-        }
+        "    return {",
-    }
+        "        cc: 14",
-    expect_exact: 'function f1(n,c,e,a,f){return n("c")+c}function f2(a,b,c,d,e){return a+eval("c")}function f3(a,eval,c,d,e){return a+eval("c")}'
+        '    }[o + "c"];',
+        "}",
+        "",
+        "console.log(function o(c, e, n, r, t) {",
+        '    return c("c") + e;',
+        "}(o, 28, true));",
+        "",
+        "console.log(function f2(a, b, c, d, e) {",
+        '    return a + eval("c");',
+        "}(14, true, 28));",
+        "",
+        "console.log(function f3(a, eval, c, d, e) {",
+        '    return a + eval("c");',
+        "}(28, o, true));",
+    ]
+    expect_stdout: [
+        "42",
+        "42",
+        "42",
+    ]
 }

test/compress/join_vars.js

@@ -790,7 +790,7 @@ issue_3795: {
         dead_code: true,
         evaluate: true,
         join_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         loops: true,
         passes: 2,
         reduce_vars: true,

test/compress/keep_fargs.js

@@ -18,43 +18,6 @@ keep_fargs_false: {
         function j(e) {}
         console.log(h(), i().length, j.length);
     }
-    expect: {
-        console.log(function f() {
-            return f.length;
-        }(), function g() {
-            return g;
-        }().length);
-        function h() {
-            return h.length;
-        }
-        function i() {
-            return i;
-        }
-        function j() {}
-        console.log(h(), i().length, j.length);
-    }
-}
-
-keep_fargs_strict: {
-    options = {
-        keep_fargs: "strict",
-        unused: true,
-    }
-    input: {
-        console.log(function f(a) {
-            return f.length;
-        }(), function g(b) {
-            return g;
-        }().length);
-        function h(c) {
-            return h.length;
-        }
-        function i(d) {
-            return i;
-        }
-        function j(e) {}
-        console.log(h(), i().length, j.length);
-    }
     expect: {
         console.log(function f(a) {
             return f.length;
@@ -121,7 +84,7 @@ replace_index: {
     options = {
         arguments: true,
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         properties: true,
     }
     input: {
@@ -171,7 +134,7 @@ replace_index_strict: {
     options = {
         arguments: true,
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         properties: true,
         reduce_vars: true,
     }
@@ -202,7 +165,7 @@ replace_index_strict: {
 issue_1858: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: true,
         unused: true,
     }
@@ -224,7 +187,7 @@ issue_1858: {
 issue_2187_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -245,7 +208,7 @@ issue_2187_2: {
 issue_2203_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -280,7 +243,7 @@ issue_2203_2: {
 issue_2298: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -323,7 +286,7 @@ issue_2298: {
 issue_2319_1: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -346,7 +309,7 @@ issue_2319_1: {
 issue_2319_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -371,7 +334,7 @@ issue_2319_2: {
 issue_2319_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -396,7 +359,7 @@ issue_2319_3: {
 issue_2425_1: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -419,7 +382,7 @@ issue_2425_1: {
 issue_2425_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -442,7 +405,7 @@ issue_2425_2: {
 issue_2425_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -465,7 +428,7 @@ issue_2425_3: {
 issue_2436_13: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -499,7 +462,7 @@ issue_2436_13: {
 issue_2506: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -538,7 +501,7 @@ issue_2506: {
 
 issue_2226_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -585,7 +548,7 @@ issue_2226_1: {
 issue_2226_2: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         sequences: true,
         side_effects: true,
         unused: true,
@@ -607,7 +570,7 @@ issue_2226_2: {
 issue_2226_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         side_effects: true,
         unused: true,
     }
@@ -627,7 +590,7 @@ issue_2226_3: {
 
 issue_3192: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -657,7 +620,7 @@ issue_3192: {
 if_increment: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -679,7 +642,7 @@ if_increment: {
 try_increment: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -703,7 +666,7 @@ try_increment: {
 issue_2630_3: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -740,7 +703,7 @@ issue_2630_3: {
 issue_3364: {
     options = {
         functions: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         toplevel: true,
         unused: true,
@@ -805,7 +768,7 @@ issue_3364: {
 
 defun_label: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -837,7 +800,7 @@ defun_label: {
 
 iife_func_side_effects: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -889,7 +852,7 @@ iife_func_side_effects: {
 issue_1595_1: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -909,7 +872,7 @@ issue_1595_1: {
 issue_1595_2: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -929,7 +892,7 @@ issue_1595_2: {
 issue_1595_3: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -950,7 +913,7 @@ issue_1595_3: {
 issue_1595_4: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_funcs: true,
         reduce_vars: true,
         unused: true,
@@ -972,7 +935,7 @@ issue_1595_4: {
 
 duplicate_lambda_defun_name_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
     }
     input: {
@@ -992,7 +955,7 @@ duplicate_lambda_defun_name_1: {
 
 duplicate_lambda_defun_name_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         unused: true,
@@ -1013,7 +976,7 @@ duplicate_lambda_defun_name_2: {
 
 function_name_mangle: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         keep_fnames: true,
         reduce_vars: true,
         unused: true,
@@ -1031,7 +994,7 @@ function_name_mangle: {
 
 function_name_mangle_ie8: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         keep_fnames: true,
         reduce_vars: true,
         unused: true,
@@ -1052,7 +1015,7 @@ function_name_mangle_ie8: {
 
 issue_3420_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1075,7 +1038,7 @@ issue_3420_1: {
 issue_3420_2: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1096,7 +1059,7 @@ issue_3420_2: {
 issue_3420_3: {
     options = {
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1118,7 +1081,7 @@ issue_3420_3: {
 
 issue_3423_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1138,7 +1101,7 @@ issue_3423_1: {
 
 issue_3423_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1165,7 +1128,7 @@ collapse_vars_repeated: {
         hoist_funs: true,
         if_return: true,
         join_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         loops: true,
         properties: true,
         reduce_funcs: true,
@@ -1212,7 +1175,7 @@ collapse_vars_repeated: {
 chained_3: {
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1236,7 +1199,7 @@ replace_all_var_scope: {
     rename = true
     options = {
         collapse_vars: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     mangle = {}
@@ -1265,7 +1228,7 @@ replace_all_var_scope: {
 
 issue_1583: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_funcs: true,
         reduce_vars: true,
@@ -1302,7 +1265,7 @@ issues_3267_1: {
         dead_code: true,
         evaluate: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         side_effects: true,
@@ -1331,7 +1294,7 @@ issues_3267_1: {
 
 trailing_argument_side_effects: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -1355,7 +1318,7 @@ trailing_argument_side_effects: {
 
 recursive_iife_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1374,7 +1337,7 @@ recursive_iife_1: {
 
 recursive_iife_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1455,7 +1418,7 @@ issue_3619: {
 
 issue_4353_1: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }
@@ -1470,7 +1433,7 @@ issue_4353_1: {
 
 issue_4353_2: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         unused: true,
     }

test/compress/loops.js

@@ -1026,7 +1026,7 @@ issue_4075: {
 
 issue_4082: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         loops: true,
         unused: true,
     }
@@ -1050,7 +1050,7 @@ issue_4082: {
 
 issue_4084: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         loops: true,
         passes: 2,
         reduce_vars: true,

test/compress/merge_vars.js

@@ -327,7 +327,7 @@ issue_4103: {
 
 issue_4107: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         merge_vars: true,
         reduce_vars: true,
         unused: true,

test/compress/pure_funcs.js

@@ -685,7 +685,7 @@ issue_3858: {
     options = {
         collapse_vars: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {
@@ -711,7 +711,7 @@ inline_pure_call_1: {
     options = {
         collapse_vars: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         side_effects: true,
@@ -733,7 +733,7 @@ inline_pure_call_2: {
     options = {
         collapse_vars: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         side_effects: true,
@@ -756,7 +756,7 @@ inline_pure_call_3: {
         collapse_vars: true,
         evaluate: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         reduce_vars: true,
         toplevel: true,

test/compress/reduce_vars.js

@@ -2373,7 +2373,7 @@ redefine_farg_1: {
         function f(a) {
             return typeof a;
         }
-        function g() {
+        function g(a) {
             return "number";
         }
         function h(a, b) {
@@ -6928,7 +6928,7 @@ issue_3622: {
     options = {
         evaluate: true,
         inline: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         reduce_vars: true,
         sequences: true,
         toplevel: true,
@@ -7196,7 +7196,7 @@ issue_3894: {
 issue_3922: {
     options = {
         evaluate: true,
-        keep_fargs: "strict",
+        keep_fargs: false,
         pure_getters: "strict",
         reduce_vars: true,
         side_effects: true,

test/compress/side_effects.js

@@ -436,7 +436,7 @@ trim_new: {
 
 issue_4325: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         passes: 2,
         pure_getters: "strict",
         reduce_vars: true,

test/compress/spread.js

@@ -192,7 +192,7 @@ keep_property_access: {
 
 keep_fargs: {
     options = {
-        keep_fargs: "strict",
+        keep_fargs: false,
         unused: true,
     }
     input: {

test/input/reduce/diff_error.js

@@ -1,5 +1,5 @@
-(function f(a) {
+console.log(function(undefined) {
-    do {
+    return undefined[function() {
-        console.log(f.length);
+        {}
-    } while (console.log(f += 0));
+    }] || 1 + .1 + .1;
-})();
+}(42));

test/input/reduce/diff_error.reduced.js

@@ -1,19 +1,14 @@
 // (beautified)
-(function f(a) {
+console.log(function() {
-    do {
+    return 1 + .1 + .1;
-        console.log(f.length);
+}());
-    } while (console.log(f += 0));
+// output: 1.2000000000000002
-})();
-// output: 1
-// function(){}0
 // 
-// minify: 0
+// minify: 1.2
-// function(){}0
 // 
 // options: {
 //   "compress": {
-//     "keep_fargs": false,
+//     "unsafe_math": true
-//     "unsafe": true
 //   },
 //   "mangle": false
 // }

test/input/reduce/setter.js

@@ -1,8 +1,5 @@
-console.log(function f(a) {
 ({
     set p(v) {
-            f++;
+        console.log(+v + .1 + .1);
     }
-    });
+}).p = 1;
-    return f.length;
-}());

test/input/reduce/setter.reduced.js

@@ -1,20 +1,16 @@
 // (beautified)
-console.log(function f(a) {
 ({
     set p(v) {
-            f++;
+        console.log(1 + .1 + .1);
     }
-    });
+}).p = 0;
-    return f.length;
+// output: 1.2000000000000002
-}());
-// output: 1
 // 
-// minify: 0
+// minify: 1.2
 // 
 // options: {
 //   "compress": {
-//     "keep_fargs": false,
+//     "unsafe_math": true
-//     "unsafe": true
 //   },
 //   "mangle": false
 // }

test/mocha/reduce.js

@@ -37,8 +37,7 @@ describe("test/reduce.js", function() {
     it("Should retain setter arguments", function() {
         var result = reduce_test(read("test/input/reduce/setter.js"), {
             compress: {
-                keep_fargs: false,
+                unsafe_math: true,
-                unsafe: true,
             },
             mangle: false,
         }, {
@@ -110,28 +109,24 @@ describe("test/reduce.js", function() {
     });
     it("Should print correct output for irreducible test case", function() {
         var result = reduce_test([
-            "console.log(function f(a) {",
+            "console.log(1 + .1 + .1);",
-            "    return f.length;",
-            "}());",
         ].join("\n"), {
             compress: {
-                keep_fargs: false,
+                unsafe_math: true,
             },
             mangle: false,
         });
         if (result.error) throw result.error;
         assert.strictEqual(result.code, [
             "// (beautified)",
-            "console.log(function f(a) {",
+            "console.log(1 + .1 + .1);",
-            "    return f.length;",
+            "// output: 1.2000000000000002",
-            "}());",
-            "// output: 1",
             "// ",
-            "// minify: 0",
+            "// minify: 1.2",
             "// ",
             "// options: {",
             '//   "compress": {',
-            '//     "keep_fargs": false',
+            '//     "unsafe_math": true',
             "//   },",
             '//   "mangle": false',
             "// }",
@@ -303,8 +298,7 @@ describe("test/reduce.js", function() {
         if (semver.satisfies(process.version, "<=0.10")) return;
         var result = reduce_test(read("test/input/reduce/diff_error.js"), {
             compress: {
-                keep_fargs: false,
+                unsafe_math: true,
-                unsafe: true,
             },
             mangle: false,
         }, {

test/ufuzz/options.json

@@ -28,7 +28,6 @@
     },
     {
         "compress": {
-            "keep_fargs": false,
             "passes": 1e6,
             "sequences": 1e6,
             "unsafe": true,