Fix assigned type of assignment nested in literals

sandersn · sandersn · commit 125dd57a7576 · 2017-02-08T13:28:23.000-08:00
Fixes microsoft#12946
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -9469,11 +9469,19 @@ namespace ts {
         }
 
         function getAssignedTypeOfBinaryExpression(node: BinaryExpression): Type {
-            return node.parent.kind === SyntaxKind.ArrayLiteralExpression || node.parent.kind === SyntaxKind.PropertyAssignment ?
+            const isDestructuringDefaultAssignment =
+                node.parent.kind === SyntaxKind.ArrayLiteralExpression && isDestructuringAssignmentTarget(node.parent) ||
+                node.parent.kind === SyntaxKind.PropertyAssignment && isDestructuringAssignmentTarget(node.parent.parent);
+            return isDestructuringDefaultAssignment ?
                 getTypeWithDefault(getAssignedType(node), node.right) :
                 getTypeOfExpression(node.right);
         }
 
+        function isDestructuringAssignmentTarget(parent: Node) {
+            return parent.parent.kind === SyntaxKind.BinaryExpression && (parent.parent as BinaryExpression).left === parent ||
+                parent.parent.kind === SyntaxKind.ForOfStatement && (parent.parent as ForOfStatement).initializer === parent;
+        }
+
         function getAssignedTypeOfArrayLiteralElement(node: ArrayLiteralExpression, element: Expression): Type {
             return getTypeOfDestructuredArrayElement(getAssignedType(node), indexOf(node.elements, element));
         }
diff --git a/tests/baselines/reference/assignmentNestedInLiterals.js b/tests/baselines/reference/assignmentNestedInLiterals.js
@@ -0,0 +1,13 @@
+//// [assignmentNestedInLiterals.ts]
+var target, x, y;
+target = [x = 1, y = x];
+
+var aegis, a, b;
+aegis = { x: a = 1, y: b = a };
+
+
+//// [assignmentNestedInLiterals.js]
+var target, x, y;
+target = [x = 1, y = x];
+var aegis, a, b;
+aegis = { x: a = 1, y: b = a };
diff --git a/tests/baselines/reference/assignmentNestedInLiterals.symbols b/tests/baselines/reference/assignmentNestedInLiterals.symbols
@@ -0,0 +1,25 @@
+=== tests/cases/compiler/assignmentNestedInLiterals.ts ===
+var target, x, y;
+>target : Symbol(target, Decl(assignmentNestedInLiterals.ts, 0, 3))
+>x : Symbol(x, Decl(assignmentNestedInLiterals.ts, 0, 11))
+>y : Symbol(y, Decl(assignmentNestedInLiterals.ts, 0, 14))
+
+target = [x = 1, y = x];
+>target : Symbol(target, Decl(assignmentNestedInLiterals.ts, 0, 3))
+>x : Symbol(x, Decl(assignmentNestedInLiterals.ts, 0, 11))
+>y : Symbol(y, Decl(assignmentNestedInLiterals.ts, 0, 14))
+>x : Symbol(x, Decl(assignmentNestedInLiterals.ts, 0, 11))
+
+var aegis, a, b;
+>aegis : Symbol(aegis, Decl(assignmentNestedInLiterals.ts, 3, 3))
+>a : Symbol(a, Decl(assignmentNestedInLiterals.ts, 3, 10))
+>b : Symbol(b, Decl(assignmentNestedInLiterals.ts, 3, 13))
+
+aegis = { x: a = 1, y: b = a };
+>aegis : Symbol(aegis, Decl(assignmentNestedInLiterals.ts, 3, 3))
+>x : Symbol(x, Decl(assignmentNestedInLiterals.ts, 4, 9))
+>a : Symbol(a, Decl(assignmentNestedInLiterals.ts, 3, 10))
+>y : Symbol(y, Decl(assignmentNestedInLiterals.ts, 4, 19))
+>b : Symbol(b, Decl(assignmentNestedInLiterals.ts, 3, 13))
+>a : Symbol(a, Decl(assignmentNestedInLiterals.ts, 3, 10))
+
diff --git a/tests/baselines/reference/assignmentNestedInLiterals.types b/tests/baselines/reference/assignmentNestedInLiterals.types
@@ -0,0 +1,35 @@
+=== tests/cases/compiler/assignmentNestedInLiterals.ts ===
+var target, x, y;
+>target : any
+>x : any
+>y : any
+
+target = [x = 1, y = x];
+>target = [x = 1, y = x] : number[]
+>target : any
+>[x = 1, y = x] : number[]
+>x = 1 : 1
+>x : any
+>1 : 1
+>y = x : number
+>y : any
+>x : number
+
+var aegis, a, b;
+>aegis : any
+>a : any
+>b : any
+
+aegis = { x: a = 1, y: b = a };
+>aegis = { x: a = 1, y: b = a } : { x: number; y: number; }
+>aegis : any
+>{ x: a = 1, y: b = a } : { x: number; y: number; }
+>x : number
+>a = 1 : 1
+>a : any
+>1 : 1
+>y : number
+>b = a : number
+>b : any
+>a : number
+
diff --git a/tests/cases/compiler/assignmentNestedInLiterals.ts b/tests/cases/compiler/assignmentNestedInLiterals.ts
@@ -0,0 +1,6 @@
+// @noImplicitAny: true
+var target, x, y;
+target = [x = 1, y = x];
+
+var aegis, a, b;
+aegis = { x: a = 1, y: b = a };

Original file line number	Diff line number	Diff line change
`@@ -9469,11 +9469,19 @@ namespace ts {`
`9469`	`9469`	`}`
`9470`	`9470`
`9471`	`9471`	`function getAssignedTypeOfBinaryExpression(node: BinaryExpression): Type {`
`9472`		`- return node.parent.kind === SyntaxKind.ArrayLiteralExpression \|\| node.parent.kind === SyntaxKind.PropertyAssignment ?`
	`9472`	`+ const isDestructuringDefaultAssignment =`
	`9473`	`+ node.parent.kind === SyntaxKind.ArrayLiteralExpression && isDestructuringAssignmentTarget(node.parent) \|\|`
	`9474`	`+ node.parent.kind === SyntaxKind.PropertyAssignment && isDestructuringAssignmentTarget(node.parent.parent);`
	`9475`	`+ return isDestructuringDefaultAssignment ?`
`9473`	`9476`	`getTypeWithDefault(getAssignedType(node), node.right) :`
`9474`	`9477`	`getTypeOfExpression(node.right);`
`9475`	`9478`	`}`
`9476`	`9479`
	`9480`	`+ function isDestructuringAssignmentTarget(parent: Node) {`
	`9481`	`+ return parent.parent.kind === SyntaxKind.BinaryExpression && (parent.parent as BinaryExpression).left === parent \|\|`
	`9482`	`+ parent.parent.kind === SyntaxKind.ForOfStatement && (parent.parent as ForOfStatement).initializer === parent;`
	`9483`	`+ }`
	`9484`	`+`
`9477`	`9485`	`function getAssignedTypeOfArrayLiteralElement(node: ArrayLiteralExpression, element: Expression): Type {`
`9478`	`9486`	`return getTypeOfDestructuredArrayElement(getAssignedType(node), indexOf(node.elements, element));`
`9479`	`9487`	`}`