feat(44190): check misspelled base members in override checks (#44213)

src/compiler/checker.ts

@@ -37308,7 +37308,10 @@ namespace ts {
 
                     const baseClassName = typeToString(baseWithThis);
                     if (prop && !baseProp && hasOverride) {
-                        error(member, Diagnostics.This_member_cannot_have_an_override_modifier_because_it_is_not_declared_in_the_base_class_0, baseClassName);
+                        const suggestion = getSpellingSuggestionForName(symbolName(declaredProp), arrayFrom(getMembersOfSymbol(baseType.symbol).values()), SymbolFlags.ClassMember);
+                        suggestion ?
+                            error(member, Diagnostics.This_member_cannot_have_an_override_modifier_because_it_is_not_declared_in_the_base_class_0_Did_you_mean_1, baseClassName, symbolToString(suggestion)) :
+                            error(member, Diagnostics.This_member_cannot_have_an_override_modifier_because_it_is_not_declared_in_the_base_class_0, baseClassName);
                     }
                     else if (prop && baseProp?.valueDeclaration && compilerOptions.noImplicitOverride && !nodeInAmbientContext) {
                         const baseHasAbstract = hasAbstractModifier(baseProp.valueDeclaration);

src/compiler/diagnosticMessages.json

@@ -3733,6 +3733,10 @@
         "category": "Error",
         "code": 4116
     },
+    "This member cannot have an 'override' modifier because it is not declared in the base class '{0}'. Did you mean '{1}'?": {
+        "category": "Error",
+        "code": 4117
+    },
 
     "The current host does not support the '{0}' option.": {
         "category": "Error",

tests/baselines/reference/override15.errors.txt

@@ -0,0 +1,14 @@
+tests/cases/conformance/override/override15.ts(6,14): error TS4117: This member cannot have an 'override' modifier because it is not declared in the base class 'A'. Did you mean 'doSomething'?
+
+
+==== tests/cases/conformance/override/override15.ts (1 errors) ====
+    class A {
+        doSomething() {}
+    }
+    
+    class B extends A {
+        override doSomethang() {}
+                 ~~~~~~~~~~~
+!!! error TS4117: This member cannot have an 'override' modifier because it is not declared in the base class 'A'. Did you mean 'doSomething'?
+    }
+    

tests/baselines/reference/override15.js

@@ -0,0 +1,40 @@
+//// [override15.ts]
+class A {
+    doSomething() {}
+}
+
+class B extends A {
+    override doSomethang() {}
+}
+
+
+//// [override15.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 A = /** @class */ (function () {
+    function A() {
+    }
+    A.prototype.doSomething = function () { };
+    return A;
+}());
+var B = /** @class */ (function (_super) {
+    __extends(B, _super);
+    function B() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    B.prototype.doSomethang = function () { };
+    return B;
+}(A));

tests/baselines/reference/override15.symbols

@@ -0,0 +1,16 @@
+=== tests/cases/conformance/override/override15.ts ===
+class A {
+>A : Symbol(A, Decl(override15.ts, 0, 0))
+
+    doSomething() {}
+>doSomething : Symbol(A.doSomething, Decl(override15.ts, 0, 9))
+}
+
+class B extends A {
+>B : Symbol(B, Decl(override15.ts, 2, 1))
+>A : Symbol(A, Decl(override15.ts, 0, 0))
+
+    override doSomethang() {}
+>doSomethang : Symbol(B.doSomethang, Decl(override15.ts, 4, 19))
+}
+

tests/baselines/reference/override15.types

@@ -0,0 +1,16 @@
+=== tests/cases/conformance/override/override15.ts ===
+class A {
+>A : A
+
+    doSomething() {}
+>doSomething : () => void
+}
+
+class B extends A {
+>B : B
+>A : A
+
+    override doSomethang() {}
+>doSomethang : () => void
+}
+

tests/cases/conformance/override/override15.ts

@@ -0,0 +1,9 @@
+// @noImplicitOverride: true
+
+class A {
+    doSomething() {}
+}
+
+class B extends A {
+    override doSomethang() {}
+}