Disallow assignments to imported exports

src/compiler/checker.ts

@@ -7239,7 +7239,6 @@ module ts {
                     case SyntaxKind.ElementAccessExpression: {
                         let index = (<ElementAccessExpression>n).argumentExpression;
                         let symbol = findSymbol((<ElementAccessExpression>n).expression);
-
                         if (symbol && index && index.kind === SyntaxKind.StringLiteral) {
                             let name = (<LiteralExpression>index).text;
                             let prop = getPropertyOfType(getTypeOfSymbol(symbol), name);
@@ -7254,14 +7253,37 @@ module ts {
                 }
             }
 
+            function isImportedNameFromExternalModule(n: Node): boolean {
+                switch (n.kind) {
+                    case SyntaxKind.ElementAccessExpression:
+                    case SyntaxKind.PropertyAccessExpression: {
+                        // all bindings for external module should be immutable
+                        // so attempt to use a.b or a[b] as lhs will always fail
+                        // no matter what b is
+                        let symbol = findSymbol((<PropertyAccessExpression | ElementAccessExpression>n).expression);
+                        return symbol && symbol.flags & SymbolFlags.Alias && isExternalModuleSymbol(resolveAlias(symbol));
+                    }
+                    case SyntaxKind.ParenthesizedExpression:
+                        return isImportedNameFromExternalModule((<ParenthesizedExpression>n).expression);
+                    default:
+                        return false;
+                }
+            }
+
             if (!isReferenceOrErrorExpression(n)) {
                 error(n, invalidReferenceMessage);
                 return false;
             }
+
             if (isConstVariableReference(n)) {
                 error(n, constantVariableMessage);
                 return false;
             }
+
+            if (isImportedNameFromExternalModule(n)) {
+                error(n, invalidReferenceMessage);
+            }
+
             return true;
         }
 

tests/baselines/reference/externalModuleImmutableBindings.errors.txt

@@ -0,0 +1,164 @@
+tests/cases/compiler/f2.ts(5,1): error TS2364: Invalid left-hand side of assignment expression.
+tests/cases/compiler/f2.ts(6,1): error TS2364: Invalid left-hand side of assignment expression.
+tests/cases/compiler/f2.ts(7,1): error TS2364: Invalid left-hand side of assignment expression.
+tests/cases/compiler/f2.ts(7,7): error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+tests/cases/compiler/f2.ts(8,1): error TS2364: Invalid left-hand side of assignment expression.
+tests/cases/compiler/f2.ts(10,1): error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+tests/cases/compiler/f2.ts(11,1): error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+tests/cases/compiler/f2.ts(12,1): error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+tests/cases/compiler/f2.ts(13,1): error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+tests/cases/compiler/f2.ts(15,1): error TS2364: Invalid left-hand side of assignment expression.
+tests/cases/compiler/f2.ts(16,1): error TS2364: Invalid left-hand side of assignment expression.
+tests/cases/compiler/f2.ts(17,1): error TS2364: Invalid left-hand side of assignment expression.
+tests/cases/compiler/f2.ts(17,8): error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+tests/cases/compiler/f2.ts(18,1): error TS2364: Invalid left-hand side of assignment expression.
+tests/cases/compiler/f2.ts(20,1): error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+tests/cases/compiler/f2.ts(21,1): error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+tests/cases/compiler/f2.ts(22,1): error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+tests/cases/compiler/f2.ts(23,1): error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+tests/cases/compiler/f2.ts(25,6): error TS2405: The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
+tests/cases/compiler/f2.ts(26,6): error TS2487: Invalid left-hand side in 'for...of' statement.
+tests/cases/compiler/f2.ts(27,6): error TS2405: The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
+tests/cases/compiler/f2.ts(28,6): error TS2487: Invalid left-hand side in 'for...of' statement.
+tests/cases/compiler/f2.ts(29,6): error TS2406: Invalid left-hand side in 'for...in' statement.
+tests/cases/compiler/f2.ts(29,12): error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+tests/cases/compiler/f2.ts(30,6): error TS2487: Invalid left-hand side in 'for...of' statement.
+tests/cases/compiler/f2.ts(30,12): error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+tests/cases/compiler/f2.ts(31,6): error TS2406: Invalid left-hand side in 'for...in' statement.
+tests/cases/compiler/f2.ts(32,6): error TS2487: Invalid left-hand side in 'for...of' statement.
+tests/cases/compiler/f2.ts(34,6): error TS2405: The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
+tests/cases/compiler/f2.ts(35,6): error TS2487: Invalid left-hand side in 'for...of' statement.
+tests/cases/compiler/f2.ts(36,6): error TS2405: The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
+tests/cases/compiler/f2.ts(37,6): error TS2487: Invalid left-hand side in 'for...of' statement.
+tests/cases/compiler/f2.ts(38,6): error TS2406: Invalid left-hand side in 'for...in' statement.
+tests/cases/compiler/f2.ts(38,13): error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+tests/cases/compiler/f2.ts(39,6): error TS2487: Invalid left-hand side in 'for...of' statement.
+tests/cases/compiler/f2.ts(39,13): error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+tests/cases/compiler/f2.ts(40,6): error TS2406: Invalid left-hand side in 'for...in' statement.
+tests/cases/compiler/f2.ts(41,6): error TS2487: Invalid left-hand side in 'for...of' statement.
+
+
+==== tests/cases/compiler/f1.ts (0 errors) ====
+    export var x = 1;
+
+==== tests/cases/compiler/f2.ts (38 errors) ====
+    import * as stuff from 'f1';
+
+    var n = 'baz';
+
+    stuff.x = 0;
+    ~~~~~~~
+!!! error TS2364: Invalid left-hand side of assignment expression.
+    stuff['x'] = 1;
+    ~~~~~~~~~~
+!!! error TS2364: Invalid left-hand side of assignment expression.
+    stuff.blah = 2;
+    ~~~~~~~~~~
+!!! error TS2364: Invalid left-hand side of assignment expression.
+          ~~~~
+!!! error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+    stuff[n] = 3;
+    ~~~~~~~~
+!!! error TS2364: Invalid left-hand side of assignment expression.
+
+    stuff.x++;
+    ~~~~~~~
+!!! error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+    stuff['x']++;
+    ~~~~~~~~~~
+!!! error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+    stuff['blah']++;
+    ~~~~~~~~~~~~~
+!!! error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+    stuff[n]++;
+    ~~~~~~~~
+!!! error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+
+    (stuff.x) = 0;
+    ~~~~~~~~~
+!!! error TS2364: Invalid left-hand side of assignment expression.
+    (stuff['x']) = 1;
+    ~~~~~~~~~~~~
+!!! error TS2364: Invalid left-hand side of assignment expression.
+    (stuff.blah) = 2;
+    ~~~~~~~~~~~~
+!!! error TS2364: Invalid left-hand side of assignment expression.
+           ~~~~
+!!! error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+    (stuff[n]) = 3;
+    ~~~~~~~~~~
+!!! error TS2364: Invalid left-hand side of assignment expression.
+
+    (stuff.x)++;
+    ~~~~~~~~~
+!!! error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+    (stuff['x'])++;
+    ~~~~~~~~~~~~
+!!! error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+    (stuff['blah'])++;
+    ~~~~~~~~~~~~~~~
+!!! error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+    (stuff[n])++;
+    ~~~~~~~~~~
+!!! error TS2357: The operand of an increment or decrement operator must be a variable, property or indexer.
+
+    for (stuff.x in []) {}
+         ~~~~~~~
+!!! error TS2405: The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
+    for (stuff.x of []) {}
+         ~~~~~~~
+!!! error TS2487: Invalid left-hand side in 'for...of' statement.
+    for (stuff['x'] in []) {}
+         ~~~~~~~~~~
+!!! error TS2405: The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
+    for (stuff['x'] of []) {}
+         ~~~~~~~~~~
+!!! error TS2487: Invalid left-hand side in 'for...of' statement.
+    for (stuff.blah in []) {}
+         ~~~~~~~~~~
+!!! error TS2406: Invalid left-hand side in 'for...in' statement.
+               ~~~~
+!!! error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+    for (stuff.blah of []) {}
+         ~~~~~~~~~~
+!!! error TS2487: Invalid left-hand side in 'for...of' statement.
+               ~~~~
+!!! error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+    for (stuff[n] in []) {}
+         ~~~~~~~~
+!!! error TS2406: Invalid left-hand side in 'for...in' statement.
+    for (stuff[n] of []) {}
+         ~~~~~~~~
+!!! error TS2487: Invalid left-hand side in 'for...of' statement.
+
+    for ((stuff.x) in []) {}
+         ~~~~~~~~~
+!!! error TS2405: The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
+    for ((stuff.x) of []) {}
+         ~~~~~~~~~
+!!! error TS2487: Invalid left-hand side in 'for...of' statement.
+    for ((stuff['x']) in []) {}
+         ~~~~~~~~~~~~
+!!! error TS2405: The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
+    for ((stuff['x']) of []) {}
+         ~~~~~~~~~~~~
+!!! error TS2487: Invalid left-hand side in 'for...of' statement.
+    for ((stuff.blah) in []) {}
+         ~~~~~~~~~~~~
+!!! error TS2406: Invalid left-hand side in 'for...in' statement.
+                ~~~~
+!!! error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+    for ((stuff.blah) of []) {}
+         ~~~~~~~~~~~~
+!!! error TS2487: Invalid left-hand side in 'for...of' statement.
+                ~~~~
+!!! error TS2339: Property 'blah' does not exist on type 'typeof "tests/cases/compiler/f1"'.
+    for ((stuff[n]) in []) {}
+         ~~~~~~~~~~
+!!! error TS2406: Invalid left-hand side in 'for...in' statement.
+    for ((stuff[n]) of []) {}
+         ~~~~~~~~~~
+!!! error TS2487: Invalid left-hand side in 'for...of' statement.
+
+
+

tests/baselines/reference/externalModuleImmutableBindings.js

@@ -0,0 +1,112 @@
+//// [tests/cases/compiler/externalModuleImmutableBindings.ts] ////
+
+//// [f1.ts]
+export var x = 1;
+
+//// [f2.ts]
+import * as stuff from 'f1';
+
+var n = 'baz';
+
+stuff.x = 0;
+stuff['x'] = 1;
+stuff.blah = 2;
+stuff[n] = 3;
+
+stuff.x++;
+stuff['x']++;
+stuff['blah']++;
+stuff[n]++;
+
+(stuff.x) = 0;
+(stuff['x']) = 1;
+(stuff.blah) = 2;
+(stuff[n]) = 3;
+
+(stuff.x)++;
+(stuff['x'])++;
+(stuff['blah'])++;
+(stuff[n])++;
+
+for (stuff.x in []) {}
+for (stuff.x of []) {}
+for (stuff['x'] in []) {}
+for (stuff['x'] of []) {}
+for (stuff.blah in []) {}
+for (stuff.blah of []) {}
+for (stuff[n] in []) {}
+for (stuff[n] of []) {}
+
+for ((stuff.x) in []) {}
+for ((stuff.x) of []) {}
+for ((stuff['x']) in []) {}
+for ((stuff['x']) of []) {}
+for ((stuff.blah) in []) {}
+for ((stuff.blah) of []) {}
+for ((stuff[n]) in []) {}
+for ((stuff[n]) of []) {}
+
+
+
+
+//// [f1.js]
+exports.x = 1;
+//// [f2.js]
+var stuff = require('f1');
+var n = 'baz';
+stuff.x = 0;
+stuff['x'] = 1;
+stuff.blah = 2;
+stuff[n] = 3;
+stuff.x++;
+stuff['x']++;
+stuff['blah']++;
+stuff[n]++;
+(stuff.x) = 0;
+(stuff['x']) = 1;
+(stuff.blah) = 2;
+(stuff[n]) = 3;
+(stuff.x)++;
+(stuff['x'])++;
+(stuff['blah'])++;
+(stuff[n])++;
+for (stuff.x in []) {
+}
+for (var _i = 0, _a = []; _i < _a.length; _i++) {
+    stuff.x = _a[_i];
+}
+for (stuff['x'] in []) {
+}
+for (var _b = 0, _c = []; _b < _c.length; _b++) {
+    stuff['x'] = _c[_b];
+}
+for (stuff.blah in []) {
+}
+for (var _d = 0, _e = []; _d < _e.length; _d++) {
+    stuff.blah = _e[_d];
+}
+for (stuff[n] in []) {
+}
+for (var _f = 0, _g = []; _f < _g.length; _f++) {
+    stuff[n] = _g[_f];
+}
+for ((stuff.x) in []) {
+}
+for (var _h = 0, _j = []; _h < _j.length; _h++) {
+    (stuff.x) = _j[_h];
+}
+for ((stuff['x']) in []) {
+}
+for (var _k = 0, _l = []; _k < _l.length; _k++) {
+    (stuff['x']) = _l[_k];
+}
+for ((stuff.blah) in []) {
+}
+for (var _m = 0, _o = []; _m < _o.length; _m++) {
+    (stuff.blah) = _o[_m];
+}
+for ((stuff[n]) in []) {
+}
+for (var _p = 0, _q = []; _p < _q.length; _p++) {
+    (stuff[n]) = _q[_p];
+}

tests/cases/compiler/externalModuleImmutableBindings.ts

@@ -0,0 +1,48 @@
+// @module: commonjs
+// @Filename: f1.ts
+export var x = 1;
+
+// @Filename: f2.ts
+import * as stuff from 'f1';
+
+var n = 'baz';
+
+stuff.x = 0;
+stuff['x'] = 1;
+stuff.blah = 2;
+stuff[n] = 3;
+
+stuff.x++;
+stuff['x']++;
+stuff['blah']++;
+stuff[n]++;
+
+(stuff.x) = 0;
+(stuff['x']) = 1;
+(stuff.blah) = 2;
+(stuff[n]) = 3;
+
+(stuff.x)++;
+(stuff['x'])++;
+(stuff['blah'])++;
+(stuff[n])++;
+
+for (stuff.x in []) {}
+for (stuff.x of []) {}
+for (stuff['x'] in []) {}
+for (stuff['x'] of []) {}
+for (stuff.blah in []) {}
+for (stuff.blah of []) {}
+for (stuff[n] in []) {}
+for (stuff[n] of []) {}
+
+for ((stuff.x) in []) {}
+for ((stuff.x) of []) {}
+for ((stuff['x']) in []) {}
+for ((stuff['x']) of []) {}
+for ((stuff.blah) in []) {}
+for ((stuff.blah) of []) {}
+for ((stuff[n]) in []) {}
+for ((stuff[n]) of []) {}
+
+