Fix/issue 1124 (#1279)

* fix: support "#private in" syntax. Ref #1124

* fix: Add Test case to issue 1124

* Change some comments, error messages

Co-authored-by: Fábio Santos <[email protected]>

Author: Steven19Lee

lib/parse.js

@@ -1041,7 +1041,7 @@ var PRECEDENCE = (function(a, ret) {
     {}
 );
 
-var ATOMIC_START_TOKEN = makePredicate([ "atom", "num", "big_int", "string", "regexp", "name" ]);
+var ATOMIC_START_TOKEN = makePredicate([ "atom", "num", "big_int", "string", "regexp", "name", "privatename"]);
 
 /* -----[ Parser ]----- */
 
@@ -1213,6 +1213,9 @@ function parse($TEXT, options) {
             return simple_statement();
 
           case "name":
+          case "privatename":
+            if(is("privatename") && !S.in_class)
+                croak("Private field must be used in an enclosing class");
             if (S.token.value == "async" && is_token(peek(), "keyword", "function")) {
                 next();
                 next();
@@ -2176,6 +2179,11 @@ function parse($TEXT, options) {
           case "name":
             ret = _make_symbol(AST_SymbolRef);
             break;
+          case "privatename":
+            if(!S.in_class) 
+                croak("Private field must be used in an enclosing class");
+            ret = _make_symbol(AST_SymbolRef);
+            break;
           case "num":
             ret = new AST_Number({
                 start: tok,
@@ -2518,7 +2526,8 @@ function parse($TEXT, options) {
         }
 
         expect("{");
-
+        // mark in class feild,
+        S.in_class = true;
         while (is("punc", ";")) { next(); }  // Leading semicolons are okay in class bodies.
         while (!is("punc", "}")) {
             start = S.token;
@@ -2527,6 +2536,8 @@ function parse($TEXT, options) {
             a.push(method);
             while (is("punc", ";")) { next(); }
         }
+        // mark in class feild,
+        S.in_class = false;
 
         S.input.pop_directives_stack();
 
@@ -3033,6 +3044,8 @@ function parse($TEXT, options) {
         var start = expr.start;
         if (is("punc", ".")) {
             next();
+            if(is("privatename") && !S.in_class) 
+                croak("Private field must be used in an enclosing class");
             const AST_DotVariant = is("privatename") ? AST_DotHash : AST_Dot;
             return subscripts(new AST_DotVariant({
                 start      : start,
@@ -3086,6 +3099,8 @@ function parse($TEXT, options) {
 
                 chain_contents = subscripts(call, true, true);
             } else if (is("name") || is("privatename")) {
+                if(is("privatename") && !S.in_class) 
+                    croak("Private field must be used in an enclosing class");
                 const AST_DotVariant = is("privatename") ? AST_DotHash : AST_Dot;
                 chain_contents = subscripts(new AST_DotVariant({
                     start,
@@ -3131,7 +3146,6 @@ function parse($TEXT, options) {
                 end: prev()
             }), allow_calls);
         }
-
         return expr;
     };
 
@@ -3206,6 +3220,9 @@ function parse($TEXT, options) {
             && left.operator !== "--" && left.operator !== "++")
                 unexpected(left.start);
         var prec = op != null ? PRECEDENCE[op] : null;
+        // #<privatename> without subscription is only legal in `#<privatename> in <expression>` when inside a class.
+        if(left instanceof AST_SymbolRef && left.start.type === "privatename" && S.in_class && op !== "in")
+            croak("Unexpected privatename token");
         if (prec != null && (prec > min_prec || (op === "**" && min_prec === prec))) {
             next();
             var right = expr_op(maybe_unary(true), prec, no_in);

test/compress/class-properties.js

@@ -344,15 +344,6 @@ optional_chaining_private_fields: {
     // expect_stdout: "PASS" // < tested in chrome, fails with nodejs 14 (current LTS)
 }
 
-tolerate_out_of_class_private_fields: {
-    no_mozilla_ast = true;
-    node_version = ">=12"
-    input: {
-        Bar.#foo = "bad"
-    }
-    expect_exact: 'Bar.#foo="bad";'
-}
-
 private_properties_can_be_mangled: {
     no_mozilla_ast = true;
     node_version = ">=12"
@@ -455,3 +446,40 @@ nested_private_properties_can_be_mangled: {
         new X().log();
     }
 }
+
+allow_private_field_with_in_operator : {
+    no_mozilla_ast = true;
+    node_version = ">=12"
+    mangle = {
+        properties: true
+    }
+    input: {
+        class A {
+            #p;
+            isA (input) {
+                #p in input; 
+                #p in this;
+                return #p in this; 
+            }
+        }
+    }
+    expect:{class A{#i;i(i){p in i;p in this;return p in this}}}
+}
+
+allow_subscript_private_field: {
+    no_mozilla_ast = true;
+    node_version = ">=12"
+    mangle = {
+        properties: true
+    }
+    input: {
+        class A {
+            #p;
+            isA (input) {
+                console.log(input.#p);
+                return this.#p; 
+            }
+        }
+    }
+    expect: {class A{#s;i(s){console.log(s.#s);return this.#s}}}
+}

test/compress/syntax-errors.js

@@ -347,3 +347,50 @@ invalid_privatename_in_object: {
         col: 12
     })
 }
+
+private_field_out_of_class_field: {
+    input: `
+        function test() {
+            return this.#p;
+        }
+    `
+    expect_error: ({
+        name: "SyntaxError",
+        message: "Private field must be declared in an enclosing class",
+        line: 3,
+        col: 24
+    })
+}
+
+private_field_out_of_class_field_in_operator: {
+    input: `
+        function test(input) {
+            #p in input;
+            return 10;
+        }
+    `
+    expect_error:({
+        name: "SyntaxError",
+        message: "Private field must be declared in an enclosing class",
+        line: 3,
+        col: 12
+    })
+}
+
+invaild__in_operator_expression_in_class_field: {
+    input: `
+        class A {
+            #p;
+            isA () { 
+                #p + 10;
+                return this.#p;
+            } 
+        }
+    `
+    expect_error: ({
+        name: "SyntaxError",
+        message: "Unexpected privatename token",
+        line: 5,
+        col: 19
+    })
+}