remove support for `const` (#1910)

As this is not part of ES5.

12 files changed, 19 insertions, 512 deletions

diff --git a/test/compress/collapse_vars.js b/test/compress/collapse_vars.js
index 0d578d7d..90d7ac93 100644
--- a/test/compress/collapse_vars.js
+++ b/test/compress/collapse_vars.js
@@ -583,8 +583,8 @@ collapse_vars_assignment: {
             return a = a;
         }
         function f1(c) {
-            const a = 3 / c;
-            const b = 1 - a;
+            var a = 3 / c;
+            var b = 1 - a;
             return b;
         }
         function f2(c) {
@@ -724,10 +724,10 @@ collapse_vars_misc1: {
             return t;
         }
         function f1(x) { var y = 5 - x; return y; }
-        function f2(x) { const z = foo(), y = z / (5 - x); return y; }
+        function f2(x) { var z = foo(), y = z / (5 - x); return y; }
         function f3(x) { var z = foo(), y = (5 - x) / z; return y; }
         function f4(x) { var z = foo(), y = (5 - u) / z; return y; }
-        function f5(x) { const z = foo(), y = (5 - window.x) / z; return y; }
+        function f5(x) { var z = foo(), y = (5 - window.x) / z; return y; }
         function f6() { var b = window.a * window.z; return b && zap(); }
         function f7() { var b = window.a * window.z; return b + b; }
         function f8() { var b = window.a * window.z; var c = b + 5; return b + c; }
@@ -744,7 +744,7 @@ collapse_vars_misc1: {
         function f2(x) { return foo() / (5 - x) }
         function f3(x) { return (5 - x) / foo() }
         function f4(x) { var z = foo(); return (5 - u) / z }
-        function f5(x) { const z = foo(); return (5 - window.x) / z }
+        function f5(x) { var z = foo(); return (5 - window.x) / z }
         function f6() { return window.a * window.z && zap() }
         function f7() { var b = window.a * window.z; return b + b }
         function f8() { var b = window.a * window.z; return b + (b + 5) }
@@ -2186,49 +2186,3 @@ compound_assignment: {
     }
     expect_stdout: "4"
 }
-
-reassign_const_1: {
-    options = {
-        collapse_vars: true,
-    }
-    input: {
-        function f() {
-            const a = 1;
-            a = 2;
-            return a;
-        }
-        console.log(f());
-    }
-    expect: {
-        function f() {
-            const a = 1;
-            a = 2;
-            return a;
-        }
-        console.log(f());
-    }
-    expect_stdout: true
-}
-
-reassign_const_2: {
-    options = {
-        collapse_vars: true,
-    }
-    input: {
-        function f() {
-            const a = 1;
-            ++a;
-            return a;
-        }
-        console.log(f());
-    }
-    expect: {
-        function f() {
-            const a = 1;
-            ++a;
-            return a;
-        }
-        console.log(f());
-    }
-    expect_stdout: true
-}
diff --git a/test/compress/const.js b/test/compress/const.js
deleted file mode 100644
index a88d5946..00000000
--- a/test/compress/const.js
+++ /dev/null
@@ -1,166 +0,0 @@
-issue_1191: {
-    options = {
-        evaluate      : true,
-        booleans      : true,
-        comparisons   : true,
-        dead_code     : true,
-        conditionals  : true,
-        side_effects  : true,
-        unused        : true,
-        hoist_funs    : true,
-        if_return     : true,
-        join_vars     : true,
-        sequences     : false,
-        collapse_vars : false,
-        reduce_vars   : true,
-    }
-    input: {
-        function foo(rot) {
-            const rotTol = 5;
-            if (rot < -rotTol || rot > rotTol)
-                bar();
-            baz();
-        }
-    }
-    expect: {
-        function foo(rot) {
-            (rot < -5 || rot > 5) && bar();
-            baz();
-        }
-    }
-}
-
-issue_1194: {
-    options = {
-        evaluate      : true,
-        booleans      : true,
-        comparisons   : true,
-        dead_code     : true,
-        conditionals  : true,
-        side_effects  : true,
-        unused        : true,
-        hoist_funs    : true,
-        if_return     : true,
-        join_vars     : true,
-        sequences     : false,
-        collapse_vars : false,
-        reduce_vars   : true,
-    }
-    input: {
-        function f1() {const a = "X"; return a + a;}
-        function f2() {const aa = "X"; return aa + aa;}
-        function f3() {const aaa = "X"; return aaa + aaa;}
-    }
-    expect: {
-        function f1(){return"XX"}
-        function f2(){return"XX"}
-        function f3(){return"XX"}
-    }
-}
-
-issue_1396: {
-    options = {
-        evaluate      : true,
-        booleans      : true,
-        comparisons   : true,
-        dead_code     : true,
-        conditionals  : true,
-        side_effects  : true,
-        unused        : true,
-        hoist_funs    : true,
-        if_return     : true,
-        join_vars     : true,
-        sequences     : false,
-        collapse_vars : false,
-        reduce_vars   : true,
-    }
-    input: {
-        function foo(a) {
-            const VALUE = 1;
-            console.log(2 | VALUE);
-            console.log(VALUE + 1);
-            console.log(VALUE);
-            console.log(a & VALUE);
-        }
-        function bar() {
-            const s = "01234567890123456789";
-            console.log(s + s + s + s + s);
-
-            const CONSTANT = "abc";
-            console.log(CONSTANT + CONSTANT + CONSTANT + CONSTANT + CONSTANT);
-        }
-    }
-    expect: {
-        function foo(a) {
-            console.log(3);
-            console.log(2);
-            console.log(1);
-            console.log(1 & a);
-        }
-        function bar() {
-            const s = "01234567890123456789";
-            console.log(s + s + s + s + s);
-
-            console.log("abcabcabcabcabc");
-        }
-    }
-}
-
-unused_regexp_literal: {
-    options = {
-        evaluate      : true,
-        booleans      : true,
-        comparisons   : true,
-        dead_code     : true,
-        conditionals  : true,
-        side_effects  : true,
-        unused        : true,
-        hoist_funs    : true,
-        if_return     : true,
-        join_vars     : true,
-        sequences     : false,
-        collapse_vars : false,
-    }
-    input: {
-        function f(){ var a = /b/; }
-    }
-    expect: {
-        function f(){}
-    }
-}
-
-regexp_literal_not_const: {
-    options = {
-        evaluate      : true,
-        booleans      : true,
-        comparisons   : true,
-        dead_code     : true,
-        conditionals  : true,
-        side_effects  : true,
-        unused        : true,
-        hoist_funs    : true,
-        if_return     : true,
-        join_vars     : true,
-        sequences     : false,
-        collapse_vars : false,
-        reduce_vars   : true,
-    }
-    input: {
-        (function(){
-            var result;
-            const s = 'acdabcdeabbb';
-            const REGEXP_LITERAL = /ab*/g;
-            while (result = REGEXP_LITERAL.exec(s)) {
-                console.log(result[0]);
-            }
-        })();
-    }
-    expect: {
-        (function() {
-            var result;
-            const REGEXP_LITERAL = /ab*/g;
-            while (result = REGEXP_LITERAL.exec("acdabcdeabbb")) console.log(result[0]);
-        })();
-    }
-    expect_stdout: true
-}
diff --git a/test/compress/dead-code.js b/test/compress/dead-code.js
index bb72451c..31d0664a 100644
--- a/test/compress/dead-code.js
+++ b/test/compress/dead-code.js
@@ -90,131 +90,6 @@ dead_code_constant_boolean_should_warn_more: {
     expect_stdout: true
 }
 
-dead_code_const_declaration: {
-    options = {
-        dead_code    : true,
-        loops        : true,
-        booleans     : true,
-        conditionals : true,
-        evaluate     : true,
-        reduce_vars  : true,
-    };
-    input: {
-        var unused;
-        const CONST_FOO = false;
-        if (CONST_FOO) {
-            console.log("unreachable");
-            var moo;
-            function bar() {}
-        }
-    }
-    expect: {
-        var unused;
-        const CONST_FOO = !1;
-        var moo;
-        function bar() {}
-    }
-    expect_stdout: true
-}
-
-dead_code_const_annotation: {
-    options = {
-        dead_code    : true,
-        loops        : true,
-        booleans     : true,
-        conditionals : true,
-        evaluate     : true,
-        reduce_vars  : true,
-        toplevel     : true,
-    };
-    input: {
-        var unused;
-        /** @const */ var CONST_FOO_ANN = false;
-        if (CONST_FOO_ANN) {
-            console.log("unreachable");
-            var moo;
-            function bar() {}
-        }
-    }
-    expect: {
-        var unused;
-        var CONST_FOO_ANN = !1;
-        var moo;
-        function bar() {}
-    }
-    expect_stdout: true
-}
-
-dead_code_const_annotation_regex: {
-    options = {
-        dead_code    : true,
-        loops        : true,
-        booleans     : true,
-        conditionals : true,
-        evaluate     : true
-    };
-    input: {
-        var unused;
-        // @constraint this shouldn't be a constant
-        var CONST_FOO_ANN = false;
-        if (CONST_FOO_ANN) {
-            console.log("reachable");
-        }
-    }
-    expect: {
-        var unused;
-        var CONST_FOO_ANN = !1;
-        CONST_FOO_ANN && console.log('reachable');
-    }
-    expect_stdout: true
-}
-
-dead_code_const_annotation_complex_scope: {
-    options = {
-        dead_code    : true,
-        loops        : true,
-        booleans     : true,
-        conditionals : true,
-        evaluate     : true,
-        reduce_vars  : true,
-        toplevel     : true,
-    };
-    input: {
-        var unused_var;
-        /** @const */ var test = 'test';
-        // @const
-        var CONST_FOO_ANN = false;
-        var unused_var_2;
-        if (CONST_FOO_ANN) {
-            console.log("unreachable");
-            var moo;
-            function bar() {}
-        }
-        if (test === 'test') {
-            var beef = 'good';
-            /** @const */ var meat = 'beef';
-            var pork = 'bad';
-            if (meat === 'pork') {
-                console.log('also unreachable');
-            } else if (pork === 'good') {
-                console.log('reached, not const');
-            }
-        }
-    }
-    expect: {
-        var unused_var;
-        var test = 'test';
-        var CONST_FOO_ANN = !1;
-        var unused_var_2;
-        var moo;
-        function bar() {}
-        var beef = 'good';
-        var meat = 'beef';
-        var pork = 'bad';
-    }
-    expect_stdout: true
-}
-
 try_catch_finally: {
     options = {
         conditionals: true,
diff --git a/test/compress/drop-unused.js b/test/compress/drop-unused.js
index 96bd336c..2ef6f796 100644
--- a/test/compress/drop-unused.js
+++ b/test/compress/drop-unused.js
@@ -649,37 +649,6 @@ drop_value: {
     }
 }
 
-const_assign: {
-    options = {
-        evaluate: true,
-        reduce_vars: true,
-        unused: true,
-    }
-    input: {
-        function f() {
-            const b = 2;
-            return 1 + b;
-        }
-
-        function g() {
-            const b = 2;
-            b = 3;
-            return 1 + b;
-        }
-    }
-    expect: {
-        function f() {
-            return 3;
-        }
-
-        function g() {
-            const b = 2;
-            b = 3;
-            return 1 + b;
-        }
-    }
-}
-
 issue_1539: {
     options = {
         cascade: true,
@@ -816,10 +785,6 @@ issue_1709: {
                 var x = 1;
                 return x;
             }(),
-            function y() {
-                const y = 2;
-                return y;
-            }(),
             function z() {
                 function z() {}
                 return z;
@@ -833,10 +798,6 @@ issue_1709: {
                 return x;
             }(),
             function() {
-                const y = 2;
-                return y;
-            }(),
-            function() {
                 function z() {}
                 return z;
             }()
@@ -1147,28 +1108,3 @@ var_catch_toplevel: {
         }();
     }
 }
-
-reassign_const: {
-    options = {
-        cascade: true,
-        sequences: true,
-        side_effects: true,
-        unused: true,
-    }
-    input: {
-        function f() {
-            const a = 1;
-            a = 2;
-            return a;
-        }
-        console.log(f());
-    }
-    expect: {
-        function f() {
-            const a = 1;
-            return a = 2, a;
-        }
-        console.log(f());
-    }
-    expect_stdout: true
-}
diff --git a/test/compress/evaluate.js b/test/compress/evaluate.js
index 585ee2b9..b8077564 100644
--- a/test/compress/evaluate.js
+++ b/test/compress/evaluate.js
@@ -645,16 +645,17 @@ call_args: {
     options = {
         evaluate: true,
         reduce_vars: true,
+        toplevel: true,
     }
     input: {
-        const a = 1;
+        var a = 1;
         console.log(a);
         +function(a) {
             return a;
         }(a);
     }
     expect: {
-        const a = 1;
+        var a = 1;
         console.log(1);
         +(1, 1);
     }
@@ -666,17 +667,17 @@ call_args_drop_param: {
         evaluate: true,
         keep_fargs: false,
         reduce_vars: true,
+        toplevel: true,
         unused: true,
     }
     input: {
-        const a = 1;
+        var a = 1;
         console.log(a);
         +function(a) {
             return a;
         }(a, b);
     }
     expect: {
-        const a = 1;
         console.log(1);
         +(b, 1);
     }
diff --git a/test/compress/global_defs.js b/test/compress/global_defs.js
index f1ba8f32..bfd1d5f6 100644
--- a/test/compress/global_defs.js
+++ b/test/compress/global_defs.js
@@ -120,7 +120,7 @@ mixed: {
         properties: true,
     }
     input: {
-        const FOO = { BAR: 0 };
+        var FOO = { BAR: 0 };
         console.log(FOO.BAR);
         console.log(++CONFIG.DEBUG);
         console.log(++CONFIG.VALUE);
@@ -130,7 +130,7 @@ mixed: {
         console.log(CONFIG);
     }
     expect: {
-        const FOO = { BAR: 0 };
+        var FOO = { BAR: 0 };
         console.log("moo");
         console.log(++CONFIG.DEBUG);
         console.log(++CONFIG.VALUE);
diff --git a/test/compress/issue-1041.js b/test/compress/issue-1041.js
index cdbc22cc..cc351405 100644
--- a/test/compress/issue-1041.js
+++ b/test/compress/issue-1041.js
@@ -1,16 +1,3 @@
-const_declaration: {
-    options = {
-        evaluate: true
-    };
-
-    input: {
-        const goog = goog || {};
-    }
-    expect: {
-        const goog = goog || {};
-    }
-}
-
 const_pragma: {
     options = {
         evaluate: true,
diff --git a/test/compress/issue-1588.js b/test/compress/issue-1588.js
index 4e20a21d..187d9f6c 100644
--- a/test/compress/issue-1588.js
+++ b/test/compress/issue-1588.js
@@ -85,15 +85,3 @@ unsafe_undefined: {
     }
     expect_stdout: true
 }
-
-runtime_error: {
-    input: {
-        const a = 1;
-        console.log(a++);
-    }
-    expect: {
-        const a = 1;
-        console.log(a++);
-    }
-    expect_stdout: true
-}
diff --git a/test/compress/issue-208.js b/test/compress/issue-208.js
index fb9861f6..faaf4139 100644
--- a/test/compress/issue-208.js
+++ b/test/compress/issue-208.js
@@ -38,7 +38,7 @@ mixed: {
         }
     }
     input: {
-        const ENV = 3;
+        var ENV = 3;
         var FOO = 4;
         f(ENV * 10);
         --FOO;
@@ -49,7 +49,7 @@ mixed: {
         x = DEBUG;
     }
     expect: {
-        const ENV = 3;
+        var ENV = 3;
         var FOO = 4;
         f(10);
         --FOO;
@@ -60,7 +60,7 @@ mixed: {
         x = 0;
     }
     expect_warnings: [
-        'WARN: global_defs ENV redefined [test/compress/issue-208.js:41,14]',
+        'WARN: global_defs ENV redefined [test/compress/issue-208.js:41,12]',
         'WARN: global_defs FOO redefined [test/compress/issue-208.js:42,12]',
         'WARN: global_defs FOO redefined [test/compress/issue-208.js:44,10]',
         'WARN: global_defs DEBUG redefined [test/compress/issue-208.js:45,8]',
diff --git a/test/compress/loops.js b/test/compress/loops.js
index 4d354bcf..89c7e7e9 100644
--- a/test/compress/loops.js
+++ b/test/compress/loops.js
@@ -146,50 +146,6 @@ parse_do_while_without_semicolon: {
     }
 }
 
-
-keep_collapse_const_in_own_block_scope: {
-    options = {
-        join_vars: true,
-        loops: true
-    }
-    input: {
-        var i=2;
-        const c=5;
-        while(i--)
-            console.log(i);
-        console.log(c);
-    }
-    expect: {
-        var i=2;
-        const c=5;
-        for(;i--;)
-            console.log(i);
-        console.log(c);
-    }
-    expect_stdout: true
-}
-
-keep_collapse_const_in_own_block_scope_2: {
-    options = {
-        join_vars: true,
-        loops: true
-    }
-    input: {
-        const c=5;
-        var i=2; // Moves to loop, while it did not in previous test
-        while(i--)
-            console.log(i);
-        console.log(c);
-    }
-    expect: {
-        const c=5;
-        for(var i=2;i--;)
-            console.log(i);
-        console.log(c);
-    }
-    expect_stdout: true
-}
-
 evaluate: {
     options = {
         loops: true,
diff --git a/test/compress/reduce_vars.js b/test/compress/reduce_vars.js
index d3b3d425..a0433b5d 100644
--- a/test/compress/reduce_vars.js
+++ b/test/compress/reduce_vars.js
@@ -2190,10 +2190,11 @@ issue_1814_1: {
     options = {
         evaluate: true,
         reduce_vars: true,
+        toplevel: true,
         unused: true,
     }
     input: {
-        const a = 42;
+        var a = 42;
         !function() {
             var b = a;
             !function(a) {
@@ -2202,7 +2203,6 @@ issue_1814_1: {
         }();
     }
     expect: {
-        const a = 42;
         !function() {
             !function(a) {
                 console.log(a++, 42);
@@ -2216,10 +2216,11 @@ issue_1814_2: {
     options = {
         evaluate: true,
         reduce_vars: true,
+        toplevel: true,
         unused: true,
     }
     input: {
-        const a = "32";
+        var a = "32";
         !function() {
             var b = a + 1;
             !function(a) {
@@ -2228,7 +2229,6 @@ issue_1814_2: {
         }();
     }
     expect: {
-        const a = "32";
         !function() {
             !function(a) {
                 console.log(a++, "321");
diff --git a/test/compress/sequences.js b/test/compress/sequences.js
index 9edf627e..10492565 100644
--- a/test/compress/sequences.js
+++ b/test/compress/sequences.js
@@ -710,27 +710,3 @@ issue_27: {
         })(jQuery);
     }
 }
-
-reassign_const: {
-    options = {
-        cascade: true,
-        sequences: true,
-        side_effects: true,
-    }
-    input: {
-        function f() {
-            const a = 1;
-            a++;
-            return a;
-        }
-        console.log(f());
-    }
-    expect: {
-        function f() {
-            const a = 1;
-            return a++, a;
-        }
-        console.log(f());
-    }
-    expect_stdout: true
-}