[Master] Emit parenthesis around propert/element access expression of casted object literal expression

src/compiler/factory.ts

@@ -3492,7 +3492,8 @@ namespace ts {
 
     export function parenthesizeConciseBody(body: ConciseBody): ConciseBody {
         const emittedBody = skipPartiallyEmittedExpressions(body);
-        if (emittedBody.kind === SyntaxKind.ObjectLiteralExpression) {
+        const leftMostExpression = isExpression(emittedBody) ? getLeftmostExpression(emittedBody) : undefined;
+        if (leftMostExpression && leftMostExpression.kind === SyntaxKind.ObjectLiteralExpression) {
             return setTextRange(createParen(<Expression>body), body);
         }
 

src/compiler/transformers/ts.ts

@@ -2324,13 +2324,13 @@ namespace ts {
                 // code if the casted expression has a lower precedence than the rest of the
                 // expression.
                 //
+                // To preserve comments, we return a "PartiallyEmittedExpression" here which will
+                // preserve the position information of the original expression.
+                //
                 // Due to the auto-parenthesization rules used by the visitor and factory functions
                 // we can safely elide the parentheses here, as a new synthetic
                 // ParenthesizedExpression will be inserted if we remove parentheses too
                 // aggressively.
-                //
-                // To preserve comments, we return a "PartiallyEmittedExpression" here which will
-                // preserve the position information of the original expression.
                 return createPartiallyEmittedExpression(expression, node);
             }
 

tests/baselines/reference/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.js

@@ -0,0 +1,7 @@
+//// [emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts]
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x];
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x;
+
+//// [emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.js]
+(function (x) { return ({ "1": "one", "2": "two" }[x]); });
+(function (x) { return ({ "1": "one", "2": "two" }.x); });

tests/baselines/reference/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.symbols

@@ -0,0 +1,10 @@
+=== tests/cases/compiler/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts ===
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x];
+>x : Symbol(x, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts, 0, 1))
+>key : Symbol(key, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts, 0, 41))
+>x : Symbol(x, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts, 0, 1))
+
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x;
+>x : Symbol(x, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts, 1, 1))
+>key : Symbol(key, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts, 1, 41))
+

tests/baselines/reference/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.types

@@ -0,0 +1,25 @@
+=== tests/cases/compiler/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts ===
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x];
+>(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x] : (x: any) => string
+>x : any
+>({ "1": "one", "2": "two" } as { [key: string]: string })[x] : string
+>({ "1": "one", "2": "two" } as { [key: string]: string }) : { [key: string]: string; }
+>{ "1": "one", "2": "two" } as { [key: string]: string } : { [key: string]: string; }
+>{ "1": "one", "2": "two" } : { "1": string; "2": string; }
+>"one" : "one"
+>"two" : "two"
+>key : string
+>x : any
+
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x;
+>(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x : (x: any) => string
+>x : any
+>({ "1": "one", "2": "two" } as { [key: string]: string }).x : string
+>({ "1": "one", "2": "two" } as { [key: string]: string }) : { [key: string]: string; }
+>{ "1": "one", "2": "two" } as { [key: string]: string } : { [key: string]: string; }
+>{ "1": "one", "2": "two" } : { "1": string; "2": string; }
+>"one" : "one"
+>"two" : "two"
+>key : string
+>x : string
+

tests/baselines/reference/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.js

@@ -0,0 +1,7 @@
+//// [emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts]
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x];
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x;
+
+//// [emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.js]
+(x) => ({ "1": "one", "2": "two" }[x]);
+(x) => ({ "1": "one", "2": "two" }.x);

tests/baselines/reference/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.symbols

@@ -0,0 +1,10 @@
+=== tests/cases/compiler/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts ===
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x];
+>x : Symbol(x, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts, 0, 1))
+>key : Symbol(key, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts, 0, 41))
+>x : Symbol(x, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts, 0, 1))
+
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x;
+>x : Symbol(x, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts, 1, 1))
+>key : Symbol(key, Decl(emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts, 1, 41))
+

tests/baselines/reference/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.types

@@ -0,0 +1,25 @@
+=== tests/cases/compiler/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts ===
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x];
+>(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x] : (x: any) => string
+>x : any
+>({ "1": "one", "2": "two" } as { [key: string]: string })[x] : string
+>({ "1": "one", "2": "two" } as { [key: string]: string }) : { [key: string]: string; }
+>{ "1": "one", "2": "two" } as { [key: string]: string } : { [key: string]: string; }
+>{ "1": "one", "2": "two" } : { "1": string; "2": string; }
+>"one" : "one"
+>"two" : "two"
+>key : string
+>x : any
+
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x;
+>(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x : (x: any) => string
+>x : any
+>({ "1": "one", "2": "two" } as { [key: string]: string }).x : string
+>({ "1": "one", "2": "two" } as { [key: string]: string }) : { [key: string]: string; }
+>{ "1": "one", "2": "two" } as { [key: string]: string } : { [key: string]: string; }
+>{ "1": "one", "2": "two" } : { "1": string; "2": string; }
+>"one" : "one"
+>"two" : "two"
+>key : string
+>x : string
+

tests/cases/compiler/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES5.ts

@@ -0,0 +1,4 @@
+// @target: es5
+
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x];
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x;

tests/cases/compiler/emitAccessExpressionOfCastedObjectLiteralExpressionInArrowFunctionES6.ts

@@ -0,0 +1,4 @@
+// @target: es6
+
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string })[x];
+(x) => ({ "1": "one", "2": "two" } as { [key: string]: string }).x;