add keep_quoted=strict mode

README.md

@@ -807,6 +807,9 @@ UglifyJS.minify(code, { mangle: { toplevel: true } }).code;
   Pass an empty string `""` to enable, or a non-empty string to set the debug suffix.
 
 - `keep_quoted` (default: `false`) -— Only mangle unquoted property names.
+  - `true` -- quoted property names are reserved and any unquoted properties with the
+    same property name will not be mangled.
+  - `"strict"` -- advanced, all unquoted property names are mangled unless reserved.
 
 - `regex` (default: `null`) -— Pass a RegExp literal to only mangle property
   names matching the regular expression.

lib/ast.js

@@ -581,8 +581,11 @@ var AST_PropAccess = DEFNODE("PropAccess", "expression property", {
     }
 });
 
-var AST_Dot = DEFNODE("Dot", null, {
+var AST_Dot = DEFNODE("Dot", "quote", {
     $documentation: "A dotted property access expression",
+    $propdoc: {
+        quote: "[string] the original quote character when transformed from AST_Sub",
+    },
     _walk: function(visitor) {
         return visitor._visit(this, function(){
             this.expression._walk(visitor);

lib/compress.js

@@ -6208,7 +6208,8 @@ merge(Compressor.prototype, {
                     && property.length <= prop.print_to_string().length + 1) {
                     return make_node(AST_Dot, self, {
                         expression: expr,
-                        property: property
+                        property: property,
+                        quote: prop.quote,
                     }).optimize(compressor);
                 }
             }

lib/minify.js

@@ -151,7 +151,7 @@ function minify(files, options) {
             }
             toplevel = options.parse.toplevel;
         }
-        if (quoted_props) {
+        if (quoted_props && options.mangle.properties.keep_quoted !== "strict") {
             reserve_quoted_keys(toplevel, quoted_props);
         }
         if (options.wrap) {

lib/propmangle.js

@@ -135,20 +135,30 @@ function mangle_properties(ast, options) {
     var names_to_mangle = [];
     var unmangleable = [];
 
+    var keep_quoted_strict = options.keep_quoted === "strict";
+
     // step 1: find candidates to mangle
     ast.walk(new TreeWalker(function(node){
         if (node instanceof AST_ObjectKeyVal) {
-            add(node.key);
+            if (!keep_quoted_strict || !node.quote) {
+                add(node.key);
+            }
         }
         else if (node instanceof AST_ObjectProperty) {
             // setter or getter, since KeyVal is handled above
-            add(node.key.name);
+            if (!keep_quoted_strict || !node.key.start.quote) {
+                add(node.key.name);
+            }
         }
         else if (node instanceof AST_Dot) {
-            add(node.property);
+            if (!keep_quoted_strict || !node.quote) {
+                add(node.property);
+            }
         }
         else if (node instanceof AST_Sub) {
-            addStrings(node.property, add);
+            if (!keep_quoted_strict) {
+                addStrings(node.property, add);
+            }
         }
         else if (node instanceof AST_Call
             && node.expression.print_to_string() == "Object.defineProperty") {
@@ -159,14 +169,20 @@ function mangle_properties(ast, options) {
     // step 2: transform the tree, renaming properties
     return ast.transform(new TreeTransformer(function(node){
         if (node instanceof AST_ObjectKeyVal) {
-            node.key = mangle(node.key);
+            if (!keep_quoted_strict || !node.quote) {
+                node.key = mangle(node.key);
+            }
         }
         else if (node instanceof AST_ObjectProperty) {
             // setter or getter
-            node.key.name = mangle(node.key.name);
+            if (!keep_quoted_strict || !node.key.start.quote) {
+                node.key.name = mangle(node.key.name);
+            }
         }
         else if (node instanceof AST_Dot) {
-            node.property = mangle(node.property);
+            if (!keep_quoted_strict || !node.quote) {
+                node.property = mangle(node.property);
+            }
         }
         else if (!options.keep_quoted && node instanceof AST_Sub) {
             node.property = mangleStrings(node.property);

test/compress/keep_quoted_strict.js

@@ -0,0 +1,69 @@
+keep_quoted_strict: {
+    options = {
+        evaluate: true,
+        properties: true,
+    },
+    mangle = {
+        properties: {
+            keep_quoted: "strict",
+            reserved: ["propc", "propd"],
+        },
+    }
+    input: {
+        var a = {
+            propa: 1,
+            get propb() { return 2; },
+            propc: 3,
+            get propd() { return 4; },
+        };
+        var b = {
+            "propa": 5,
+            get "propb"() { return 6; },
+            "propc": 7,
+            get "propd"() { return 8; },
+        };
+        var c = {};
+        Object.defineProperty(c, "propa", {"value": 9});
+        Object.defineProperty(c, "propc", {"value": 10});
+        console.log(a.propa, a.propb, a.propc, a["propc"], a.propd, a["propd"]);
+        console.log(b["propa"], b["propb"], b.propc, b["propc"], b.propd, b["propd"]);
+        console.log(c.propa, c["propc"]);
+    }
+    expect: {
+        var a = {
+            r: 1,
+            get p() {
+                return 2;
+            },
+            propc: 3,
+            get propd() {
+                return 4;
+            }
+        };
+        var b = {
+            propa: 5,
+            get propb() {
+                return 6;
+            },
+            propc: 7,
+            get propd() {
+                return 8;
+            }
+        };
+        var c = {};
+        Object.defineProperty(c, "r", {
+            value: 9
+        });
+        Object.defineProperty(c, "propc", {
+            value: 10
+        });
+        console.log(a.r, a.p, a.propc, a.propc, a.propd, a.propd);
+        console.log(b.propa, b.propb, b.propc, b.propc, b.propd, b.propd);
+        console.log(c.r, c.propc);
+    }
+    expect_stdout: [
+        "1 2 3 3 4 4",
+        "5 6 7 7 8 8",
+        "9 10",
+    ]
+}

test/run-tests.js

@@ -114,7 +114,9 @@ function run_compress_tests() {
                 var quoted_props = test.mangle.properties.reserved;
                 if (!Array.isArray(quoted_props)) quoted_props = [];
                 test.mangle.properties.reserved = quoted_props;
-                U.reserve_quoted_keys(input, quoted_props);
+                if (test.mangle.properties.keep_quoted !== "strict") {
+                    U.reserve_quoted_keys(input, quoted_props);
+                }
             }
             if (test.rename) {
                 input.figure_out_scope(test.mangle);