Actually instantiate the type of the annotation used for contextual types (#45285)

Author: weswigham

src/compiler/checker.ts

@@ -25413,7 +25413,7 @@ namespace ts {
                     // We avoid calling back into `getTypeOfExpression` and reentering contextual typing to avoid a bogus circularity error in that case.
                     if (decl && (isPropertyDeclaration(decl) || isPropertySignature(decl))) {
                         const overallAnnotation = getEffectiveTypeAnnotationNode(decl);
-                        return (overallAnnotation && getTypeFromTypeNode(overallAnnotation)) ||
+                        return (overallAnnotation && instantiateType(getTypeFromTypeNode(overallAnnotation), getSymbolLinks(lhsSymbol).mapper)) ||
                             (decl.initializer && getTypeOfExpression(binaryExpression.left));
                     }
                     if (kind === AssignmentDeclarationKind.None) {

tests/baselines/reference/inheritedConstructorPropertyContextualType.js

@@ -0,0 +1,39 @@
+//// [inheritedConstructorPropertyContextualType.ts]
+interface State {
+    version: 2
+}
+declare class Base<S> {
+    state: S
+}
+class Assignment extends Base<State> {
+    constructor() {
+        super()
+        this.state = { version: 2 }
+    }
+}
+
+//// [inheritedConstructorPropertyContextualType.js]
+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = function (d, b) {
+        extendStatics = Object.setPrototypeOf ||
+            ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+            function (d, b) { for (var p in b) if (Object.prototype.hasOwnProperty.call(b, p)) d[p] = b[p]; };
+        return extendStatics(d, b);
+    };
+    return function (d, b) {
+        if (typeof b !== "function" && b !== null)
+            throw new TypeError("Class extends value " + String(b) + " is not a constructor or null");
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
+var Assignment = /** @class */ (function (_super) {
+    __extends(Assignment, _super);
+    function Assignment() {
+        var _this = _super.call(this) || this;
+        _this.state = { version: 2 };
+        return _this;
+    }
+    return Assignment;
+}(Base));

tests/baselines/reference/inheritedConstructorPropertyContextualType.symbols

@@ -0,0 +1,31 @@
+=== tests/cases/compiler/inheritedConstructorPropertyContextualType.ts ===
+interface State {
+>State : Symbol(State, Decl(inheritedConstructorPropertyContextualType.ts, 0, 0))
+
+    version: 2
+>version : Symbol(State.version, Decl(inheritedConstructorPropertyContextualType.ts, 0, 17))
+}
+declare class Base<S> {
+>Base : Symbol(Base, Decl(inheritedConstructorPropertyContextualType.ts, 2, 1))
+>S : Symbol(S, Decl(inheritedConstructorPropertyContextualType.ts, 3, 19))
+
+    state: S
+>state : Symbol(Base.state, Decl(inheritedConstructorPropertyContextualType.ts, 3, 23))
+>S : Symbol(S, Decl(inheritedConstructorPropertyContextualType.ts, 3, 19))
+}
+class Assignment extends Base<State> {
+>Assignment : Symbol(Assignment, Decl(inheritedConstructorPropertyContextualType.ts, 5, 1))
+>Base : Symbol(Base, Decl(inheritedConstructorPropertyContextualType.ts, 2, 1))
+>State : Symbol(State, Decl(inheritedConstructorPropertyContextualType.ts, 0, 0))
+
+    constructor() {
+        super()
+>super : Symbol(Base, Decl(inheritedConstructorPropertyContextualType.ts, 2, 1))
+
+        this.state = { version: 2 }
+>this.state : Symbol(Base.state, Decl(inheritedConstructorPropertyContextualType.ts, 3, 23))
+>this : Symbol(Assignment, Decl(inheritedConstructorPropertyContextualType.ts, 5, 1))
+>state : Symbol(Base.state, Decl(inheritedConstructorPropertyContextualType.ts, 3, 23))
+>version : Symbol(version, Decl(inheritedConstructorPropertyContextualType.ts, 9, 22))
+    }
+}

tests/baselines/reference/inheritedConstructorPropertyContextualType.types

@@ -0,0 +1,30 @@
+=== tests/cases/compiler/inheritedConstructorPropertyContextualType.ts ===
+interface State {
+    version: 2
+>version : 2
+}
+declare class Base<S> {
+>Base : Base<S>
+
+    state: S
+>state : S
+}
+class Assignment extends Base<State> {
+>Assignment : Assignment
+>Base : Base<State>
+
+    constructor() {
+        super()
+>super() : void
+>super : typeof Base
+
+        this.state = { version: 2 }
+>this.state = { version: 2 } : { version: 2; }
+>this.state : State
+>this : this
+>state : State
+>{ version: 2 } : { version: 2; }
+>version : 2
+>2 : 2
+    }
+}

tests/cases/compiler/inheritedConstructorPropertyContextualType.ts

@@ -0,0 +1,12 @@
+interface State {
+    version: 2
+}
+declare class Base<S> {
+    state: S
+}
+class Assignment extends Base<State> {
+    constructor() {
+        super()
+        this.state = { version: 2 }
+    }
+}