Merge pull request #1676 from Microsoft/disallowOptionalBindingParameters

Disallow optional destructured parameters in implementation signatures.

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -7212,6 +7212,9 @@ module ts {
                     error(node, Diagnostics.A_parameter_property_is_only_allowed_in_a_constructor_implementation);
                 }
             }
+            if (node.questionToken && isBindingPattern(node.name) && func.body) {
+                error(node, Diagnostics.A_binding_pattern_parameter_cannot_be_optional_in_an_implementation_signature);
+            }
             if (node.dotDotDotToken) {
                 if (!isArrayType(getTypeOfSymbol(node.symbol))) {
                     error(node, Diagnostics.A_rest_parameter_must_be_of_an_array_type);

src/compiler/diagnosticInformationMap.generated.ts

@@ -298,6 +298,7 @@ module ts {
         Type_0_has_no_property_1: { code: 2460, category: DiagnosticCategory.Error, key: "Type '{0}' has no property '{1}'." },
         Type_0_is_not_an_array_type: { code: 2461, category: DiagnosticCategory.Error, key: "Type '{0}' is not an array type." },
         A_rest_element_must_be_last_in_an_array_destructuring_pattern: { code: 2462, category: DiagnosticCategory.Error, key: "A rest element must be last in an array destructuring pattern" },
+        A_binding_pattern_parameter_cannot_be_optional_in_an_implementation_signature: { code: 2463, category: DiagnosticCategory.Error, key: "A binding pattern parameter cannot be optional in an implementation signature." },
         Import_declaration_0_is_using_private_name_1: { code: 4000, category: DiagnosticCategory.Error, key: "Import declaration '{0}' is using private name '{1}'." },
         Type_parameter_0_of_exported_class_has_or_is_using_private_name_1: { code: 4002, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported class has or is using private name '{1}'." },
         Type_parameter_0_of_exported_interface_has_or_is_using_private_name_1: { code: 4004, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported interface has or is using private name '{1}'." },

src/compiler/diagnosticMessages.json

@@ -1286,6 +1286,10 @@
         "category": "Error",
         "code": 2462
     },
+    "A binding pattern parameter cannot be optional in an implementation signature.": {
+        "category": "Error",
+        "code":  2463
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",

tests/baselines/reference/optionalBindingParameters1.errors.txt

@@ -0,0 +1,17 @@
+tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts(2,14): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
+tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts(8,5): error TS2345: Argument of type '[boolean, number, string]' is not assignable to parameter of type '[string, number, boolean]'.
+
+
+==== tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts (2 errors) ====
+    
+    function foo([x,y,z]?: [string, number, boolean]) {
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
+    
+    }
+    
+    foo(["", 0, false]);
+    
+    foo([false, 0, ""]);
+        ~~~~~~~~~~~~~~
+!!! error TS2345: Argument of type '[boolean, number, string]' is not assignable to parameter of type '[string, number, boolean]'.

tests/baselines/reference/optionalBindingParameters1.js

@@ -0,0 +1,16 @@
+//// [optionalBindingParameters1.ts]
+
+function foo([x,y,z]?: [string, number, boolean]) {
+
+}
+
+foo(["", 0, false]);
+
+foo([false, 0, ""]);
+
+//// [optionalBindingParameters1.js]
+function foo(_a) {
+    var x = _a[0], y = _a[1], z = _a[2];
+}
+foo(["", 0, false]);
+foo([false, 0, ""]);

tests/baselines/reference/optionalBindingParameters2.errors.txt

@@ -0,0 +1,21 @@
+tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts(2,14): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
+tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts(8,5): error TS2345: Argument of type '{ x: boolean; y: number; z: string; }' is not assignable to parameter of type '{ x: string; y: number; z: boolean; }'.
+  Types of property 'x' are incompatible.
+    Type 'boolean' is not assignable to type 'string'.
+
+
+==== tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts (2 errors) ====
+    
+    function foo({ x, y, z }?: { x: string; y: number; z: boolean }) {
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
+    
+    }
+    
+    foo({ x: "", y: 0, z: false });
+    
+    foo({ x: false, y: 0, z: "" });
+        ~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2345: Argument of type '{ x: boolean; y: number; z: string; }' is not assignable to parameter of type '{ x: string; y: number; z: boolean; }'.
+!!! error TS2345:   Types of property 'x' are incompatible.
+!!! error TS2345:     Type 'boolean' is not assignable to type 'string'.

tests/baselines/reference/optionalBindingParameters2.js

@@ -0,0 +1,16 @@
+//// [optionalBindingParameters2.ts]
+
+function foo({ x, y, z }?: { x: string; y: number; z: boolean }) {
+
+}
+
+foo({ x: "", y: 0, z: false });
+
+foo({ x: false, y: 0, z: "" });
+
+//// [optionalBindingParameters2.js]
+function foo(_a) {
+    var x = _a.x, y = _a.y, z = _a.z;
+}
+foo({ x: "", y: 0, z: false });
+foo({ x: false, y: 0, z: "" });

tests/baselines/reference/optionalBindingParametersInOverloads1.errors.txt

@@ -0,0 +1,15 @@
+tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.ts(9,5): error TS2345: Argument of type '[boolean, number, string]' is not assignable to parameter of type '[string, number, boolean]'.
+
+
+==== tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.ts (1 errors) ====
+    
+    function foo([x, y, z] ?: [string, number, boolean]);
+    function foo(...rest: any[]) {
+    
+    }
+    
+    foo(["", 0, false]);
+    
+    foo([false, 0, ""]);
+        ~~~~~~~~~~~~~~
+!!! error TS2345: Argument of type '[boolean, number, string]' is not assignable to parameter of type '[string, number, boolean]'.

tests/baselines/reference/optionalBindingParametersInOverloads1.js

@@ -0,0 +1,20 @@
+//// [optionalBindingParametersInOverloads1.ts]
+
+function foo([x, y, z] ?: [string, number, boolean]);
+function foo(...rest: any[]) {
+
+}
+
+foo(["", 0, false]);
+
+foo([false, 0, ""]);
+
+//// [optionalBindingParametersInOverloads1.js]
+function foo() {
+    var rest = [];
+    for (var _i = 0; _i < arguments.length; _i++) {
+        rest[_i - 0] = arguments[_i];
+    }
+}
+foo(["", 0, false]);
+foo([false, 0, ""]);

tests/baselines/reference/optionalBindingParametersInOverloads2.errors.txt

@@ -0,0 +1,19 @@
+tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts(9,5): error TS2345: Argument of type '{ x: boolean; y: number; z: string; }' is not assignable to parameter of type '{ x: string; y: number; z: boolean; }'.
+  Types of property 'x' are incompatible.
+    Type 'boolean' is not assignable to type 'string'.
+
+
+==== tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts (1 errors) ====
+    
+    function foo({ x, y, z }?: { x: string; y: number; z: boolean });
+    function foo(...rest: any[]) {
+    
+    }
+    
+    foo({ x: "", y: 0, z: false });
+    
+    foo({ x: false, y: 0, z: "" });
+        ~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2345: Argument of type '{ x: boolean; y: number; z: string; }' is not assignable to parameter of type '{ x: string; y: number; z: boolean; }'.
+!!! error TS2345:   Types of property 'x' are incompatible.
+!!! error TS2345:     Type 'boolean' is not assignable to type 'string'.

tests/baselines/reference/optionalBindingParametersInOverloads2.js

@@ -0,0 +1,20 @@
+//// [optionalBindingParametersInOverloads2.ts]
+
+function foo({ x, y, z }?: { x: string; y: number; z: boolean });
+function foo(...rest: any[]) {
+
+}
+
+foo({ x: "", y: 0, z: false });
+
+foo({ x: false, y: 0, z: "" });
+
+//// [optionalBindingParametersInOverloads2.js]
+function foo() {
+    var rest = [];
+    for (var _i = 0; _i < arguments.length; _i++) {
+        rest[_i - 0] = arguments[_i];
+    }
+}
+foo({ x: "", y: 0, z: false });
+foo({ x: false, y: 0, z: "" });

tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts

@@ -0,0 +1,8 @@
+
+function foo([x,y,z]?: [string, number, boolean]) {
+
+}
+
+foo(["", 0, false]);
+
+foo([false, 0, ""]);

tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts

@@ -0,0 +1,8 @@
+
+function foo({ x, y, z }?: { x: string; y: number; z: boolean }) {
+
+}
+
+foo({ x: "", y: 0, z: false });
+
+foo({ x: false, y: 0, z: "" });

tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.ts

@@ -0,0 +1,9 @@
+
+function foo([x, y, z] ?: [string, number, boolean]);
+function foo(...rest: any[]) {
+
+}
+
+foo(["", 0, false]);
+
+foo([false, 0, ""]);

tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts

@@ -0,0 +1,9 @@
+
+function foo({ x, y, z }?: { x: string; y: number; z: boolean });
+function foo(...rest: any[]) {
+
+}
+
+foo({ x: "", y: 0, z: false });
+
+foo({ x: false, y: 0, z: "" });