Merge pull request #22675 from Microsoft/fixWideningInDestructuring

Fix widening in destructuring

Author: ahejlsberg

src/compiler/checker.ts

@@ -4310,12 +4310,12 @@ namespace ts {
         function getTypeFromObjectBindingPattern(pattern: ObjectBindingPattern, includePatternInType: boolean, reportErrors: boolean): Type {
             const members = createSymbolTable();
             let stringIndexInfo: IndexInfo;
-            let hasComputedProperties = false;
+            let objectFlags = ObjectFlags.ObjectLiteral;
             forEach(pattern.elements, e => {
                 const name = e.propertyName || <Identifier>e.name;
                 if (isComputedNonLiteralName(name)) {
                     // do not include computed properties in the implied type
-                    hasComputedProperties = true;
+                    objectFlags |= ObjectFlags.ObjectLiteralPatternWithComputedProperties;
                     return;
                 }
                 if (e.dotDotDotToken) {
@@ -4331,12 +4331,11 @@ namespace ts {
                 members.set(symbol.escapedName, symbol);
             });
             const result = createAnonymousType(undefined, members, emptyArray, emptyArray, stringIndexInfo, undefined);
+            result.flags |= TypeFlags.ContainsObjectLiteral;
+            result.objectFlags |= objectFlags;
             if (includePatternInType) {
                 result.pattern = pattern;
             }
-            if (hasComputedProperties) {
-                result.objectFlags |= ObjectFlags.ObjectLiteralPatternWithComputedProperties;
-            }
             return result;
         }
 

tests/baselines/reference/noImplicitAnyDestructuringParameterDeclaration.types

@@ -7,7 +7,7 @@ function f1([a], {b}, c, d) { // error
 >d : any
 }
 function f2([a = undefined], {b = null}, c = undefined, d = null) { // error
->f2 : ([a]: [any], { b }: { b?: null; }, c?: any, d?: any) => void
+>f2 : ([a]: [any], { b }: { b?: any; }, c?: any, d?: any) => void
 >a : any
 >undefined : undefined
 >b : any

tests/baselines/reference/parameterDestructuringObjectLiteral.js

@@ -0,0 +1,27 @@
+//// [parameterDestructuringObjectLiteral.ts]
+// Repro from #22644
+
+const fn1 = (options: { headers?: {} }) => { };
+fn1({ headers: { foo: 1 } });
+
+const fn2 = ({ headers = {} }) => { };
+fn2({ headers: { foo: 1 } });
+
+
+//// [parameterDestructuringObjectLiteral.js]
+// Repro from #22644
+var fn1 = function (options) { };
+fn1({ headers: { foo: 1 } });
+var fn2 = function (_a) {
+    var _b = _a.headers, headers = _b === void 0 ? {} : _b;
+};
+fn2({ headers: { foo: 1 } });
+
+
+//// [parameterDestructuringObjectLiteral.d.ts]
+declare const fn1: (options: {
+    headers?: {};
+}) => void;
+declare const fn2: ({ headers }: {
+    headers?: {};
+}) => void;

tests/baselines/reference/parameterDestructuringObjectLiteral.symbols

@@ -0,0 +1,22 @@
+=== tests/cases/compiler/parameterDestructuringObjectLiteral.ts ===
+// Repro from #22644
+
+const fn1 = (options: { headers?: {} }) => { };
+>fn1 : Symbol(fn1, Decl(parameterDestructuringObjectLiteral.ts, 2, 5))
+>options : Symbol(options, Decl(parameterDestructuringObjectLiteral.ts, 2, 13))
+>headers : Symbol(headers, Decl(parameterDestructuringObjectLiteral.ts, 2, 23))
+
+fn1({ headers: { foo: 1 } });
+>fn1 : Symbol(fn1, Decl(parameterDestructuringObjectLiteral.ts, 2, 5))
+>headers : Symbol(headers, Decl(parameterDestructuringObjectLiteral.ts, 3, 5))
+>foo : Symbol(foo, Decl(parameterDestructuringObjectLiteral.ts, 3, 16))
+
+const fn2 = ({ headers = {} }) => { };
+>fn2 : Symbol(fn2, Decl(parameterDestructuringObjectLiteral.ts, 5, 5))
+>headers : Symbol(headers, Decl(parameterDestructuringObjectLiteral.ts, 5, 14))
+
+fn2({ headers: { foo: 1 } });
+>fn2 : Symbol(fn2, Decl(parameterDestructuringObjectLiteral.ts, 5, 5))
+>headers : Symbol(headers, Decl(parameterDestructuringObjectLiteral.ts, 6, 5))
+>foo : Symbol(foo, Decl(parameterDestructuringObjectLiteral.ts, 6, 16))
+

tests/baselines/reference/parameterDestructuringObjectLiteral.types

@@ -0,0 +1,33 @@
+=== tests/cases/compiler/parameterDestructuringObjectLiteral.ts ===
+// Repro from #22644
+
+const fn1 = (options: { headers?: {} }) => { };
+>fn1 : (options: { headers?: {}; }) => void
+>(options: { headers?: {} }) => { } : (options: { headers?: {}; }) => void
+>options : { headers?: {}; }
+>headers : {}
+
+fn1({ headers: { foo: 1 } });
+>fn1({ headers: { foo: 1 } }) : void
+>fn1 : (options: { headers?: {}; }) => void
+>{ headers: { foo: 1 } } : { headers: { foo: number; }; }
+>headers : { foo: number; }
+>{ foo: 1 } : { foo: number; }
+>foo : number
+>1 : 1
+
+const fn2 = ({ headers = {} }) => { };
+>fn2 : ({ headers }: { headers?: {}; }) => void
+>({ headers = {} }) => { } : ({ headers }: { headers?: {}; }) => void
+>headers : {}
+>{} : {}
+
+fn2({ headers: { foo: 1 } });
+>fn2({ headers: { foo: 1 } }) : void
+>fn2 : ({ headers }: { headers?: {}; }) => void
+>{ headers: { foo: 1 } } : { headers: { foo: number; }; }
+>headers : { foo: number; }
+>{ foo: 1 } : { foo: number; }
+>foo : number
+>1 : 1
+

tests/cases/compiler/parameterDestructuringObjectLiteral.ts

@@ -0,0 +1,9 @@
+// @declaration: true
+
+// Repro from #22644
+
+const fn1 = (options: { headers?: {} }) => { };
+fn1({ headers: { foo: 1 } });
+
+const fn2 = ({ headers = {} }) => { };
+fn2({ headers: { foo: 1 } });