fix(40617): handle uninitialized class member with computed key

Author: a-tarasyuk

src/compiler/binder.ts

@@ -889,7 +889,7 @@ namespace ts {
             return isDottedName(expr)
                 || (isPropertyAccessExpression(expr) || isNonNullExpression(expr) || isParenthesizedExpression(expr)) && isNarrowableReference(expr.expression)
                 || isBinaryExpression(expr) && expr.operatorToken.kind === SyntaxKind.CommaToken && isNarrowableReference(expr.right)
-                || isElementAccessExpression(expr) && isStringOrNumericLiteralLike(expr.argumentExpression) && isNarrowableReference(expr.expression)
+                || isElementAccessExpression(expr) && (isStringOrNumericLiteralLike(expr.argumentExpression) || isIdentifier(expr.argumentExpression)) && isNarrowableReference(expr.expression)
                 || isAssignmentExpression(expr) && isNarrowableReference(expr.left);
         }
 

src/compiler/checker.ts

@@ -22396,11 +22396,27 @@ namespace ts {
         }
 
         function getAccessedPropertyName(access: AccessExpression | BindingElement): __String | undefined {
-            let propertyName;
-            return access.kind === SyntaxKind.PropertyAccessExpression ? access.name.escapedText :
-                access.kind === SyntaxKind.ElementAccessExpression && isStringOrNumericLiteralLike(access.argumentExpression) ? escapeLeadingUnderscores(access.argumentExpression.text) :
-                access.kind === SyntaxKind.BindingElement && (propertyName = getDestructuringPropertyName(access)) ? escapeLeadingUnderscores(propertyName) :
-                undefined;
+            if (isPropertyAccessExpression(access)) {
+                return access.name.escapedText;
+            }
+            if (isElementAccessExpression(access)) {
+                if (isStringOrNumericLiteralLike(access.argumentExpression)) {
+                    return escapeLeadingUnderscores(access.argumentExpression.text);
+                }
+                if (isIdentifier(access.argumentExpression)) {
+                    const symbol = getResolvedSymbol(access.argumentExpression);
+                    const type = getSymbolLinks(symbol).type;
+                    if (type === undefined) return undefined;
+                    return type.flags & TypeFlags.UniqueESSymbol ? (type as UniqueESSymbolType).escapedName :
+                        type.flags & TypeFlags.StringOrNumberLiteral ? escapeLeadingUnderscores("" + (type as StringLiteralType | NumberLiteralType).value) : undefined;
+                }
+                return undefined;
+            }
+            if (isBindingElement(access)) {
+                const name = getDestructuringPropertyName(access);
+                return name ? escapeLeadingUnderscores(name) : undefined;
+            }
+            return undefined;
         }
 
         function containsMatchingReference(source: Node, target: Node) {
@@ -38598,7 +38614,7 @@ namespace ts {
                 }
                 if (!isStatic(member) && isPropertyWithoutInitializer(member)) {
                     const propName = (member as PropertyDeclaration).name;
-                    if (isIdentifier(propName) || isPrivateIdentifier(propName)) {
+                    if (isIdentifier(propName) || isPrivateIdentifier(propName) || isComputedPropertyName(propName)) {
                         const type = getTypeOfSymbol(getSymbolOfNode(member));
                         if (!(type.flags & TypeFlags.AnyOrUnknown || getFalsyFlags(type) & TypeFlags.Undefined)) {
                             if (!constructor || !isPropertyInitializedInConstructor(propName, type, constructor)) {
@@ -38634,8 +38650,10 @@ namespace ts {
             return false;
         }
 
-        function isPropertyInitializedInConstructor(propName: Identifier | PrivateIdentifier, propType: Type, constructor: ConstructorDeclaration) {
-            const reference = factory.createPropertyAccessExpression(factory.createThis(), propName);
+        function isPropertyInitializedInConstructor(propName: Identifier | PrivateIdentifier | ComputedPropertyName, propType: Type, constructor: ConstructorDeclaration) {
+            const reference = isComputedPropertyName(propName)
+                ? factory.createElementAccessExpression(factory.createThis(), propName.expression)
+                : factory.createPropertyAccessExpression(factory.createThis(), propName);
             setParent(reference.expression, reference);
             setParent(reference, constructor);
             reference.flowNode = constructor.returnFlowNode;

src/compiler/commandLineParser.ts

@@ -2686,7 +2686,7 @@ namespace ts {
         function getPropFromRaw<T>(prop: "files" | "include" | "exclude" | "references", validateElement: (value: unknown) => boolean, elementTypeName: string): PropOfRaw<T> {
             if (hasProperty(raw, prop) && !isNullOrUndefined(raw[prop])) {
                 if (isArray(raw[prop])) {
-                    const result = raw[prop];
+                    const result = raw[prop] as T[];
                     if (!sourceFile && !every(result, validateElement)) {
                         errors.push(createCompilerDiagnostic(Diagnostics.Compiler_option_0_requires_a_value_of_type_1, prop, elementTypeName));
                     }

tests/baselines/reference/controlFlowOptionalChain.errors.txt

@@ -59,9 +59,10 @@ tests/cases/conformance/controlFlow/controlFlowOptionalChain.ts(501,13): error T
 tests/cases/conformance/controlFlow/controlFlowOptionalChain.ts(515,13): error TS2532: Object is possibly 'undefined'.
 tests/cases/conformance/controlFlow/controlFlowOptionalChain.ts(518,13): error TS2532: Object is possibly 'undefined'.
 tests/cases/conformance/controlFlow/controlFlowOptionalChain.ts(567,21): error TS2532: Object is possibly 'undefined'.
+tests/cases/conformance/controlFlow/controlFlowOptionalChain.ts(586,9): error TS2367: This condition will always return 'false' since the types '"left"' and '"right"' have no overlap.
 
 
-==== tests/cases/conformance/controlFlow/controlFlowOptionalChain.ts (61 errors) ====
+==== tests/cases/conformance/controlFlow/controlFlowOptionalChain.ts (62 errors) ====
     // assignments in shortcutting chain
     declare const o: undefined | {
         [key: string]: any;
@@ -770,6 +771,8 @@ tests/cases/conformance/controlFlow/controlFlowOptionalChain.ts(567,21): error T
     while (arr[i]?.tag === "left") {
         i += 1;
         if (arr[i]?.tag === "right") {
+            ~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2367: This condition will always return 'false' since the types '"left"' and '"right"' have no overlap.
             console.log("I should ALSO be reachable");
         }
     }

tests/baselines/reference/controlFlowOptionalChain.types

@@ -2057,11 +2057,11 @@ while (arr[i]?.tag === "left") {
 
     if (arr[i]?.tag === "right") {
 >arr[i]?.tag === "right" : boolean
->arr[i]?.tag : "left" | "right"
+>arr[i]?.tag : "left"
 >arr[i] : { tag: "left" | "right"; }
 >arr : { tag: "left" | "right"; }[]
 >i : number
->tag : "left" | "right"
+>tag : "left"
 >"right" : "right"
 
         console.log("I should ALSO be reachable");

tests/baselines/reference/incrementOnNullAssertion.types

@@ -27,21 +27,21 @@ if (foo[x] === undefined) {
 }
 else {
     let nu = foo[x]
->nu : number | undefined
->foo[x] : number | undefined
+>nu : number
+>foo[x] : number
 >foo : Dictionary<number>
 >x : "bar"
 
     let n = foo[x]
->n : number | undefined
->foo[x] : number | undefined
+>n : number
+>foo[x] : number
 >foo : Dictionary<number>
 >x : "bar"
 
     foo[x]!++
 >foo[x]!++ : number
 >foo[x]! : number
->foo[x] : number | undefined
+>foo[x] : number
 >foo : Dictionary<number>
 >x : "bar"
 }

tests/baselines/reference/noUncheckedIndexedAccess.errors.txt

@@ -32,8 +32,7 @@ tests/cases/conformance/pedantic/noUncheckedIndexedAccess.ts(90,7): error TS2322
   Type 'undefined' is not assignable to type 'string'.
 tests/cases/conformance/pedantic/noUncheckedIndexedAccess.ts(98,5): error TS2322: Type 'undefined' is not assignable to type '{ [key: string]: string; a: string; b: string; }[Key]'.
   Type 'undefined' is not assignable to type 'string'.
-tests/cases/conformance/pedantic/noUncheckedIndexedAccess.ts(99,11): error TS2322: Type 'string | undefined' is not assignable to type 'string'.
-  Type 'undefined' is not assignable to type 'string'.
+tests/cases/conformance/pedantic/noUncheckedIndexedAccess.ts(99,11): error TS2322: Type 'undefined' is not assignable to type 'string'.
 
 
 ==== tests/cases/conformance/pedantic/noUncheckedIndexedAccess.ts (31 errors) ====
@@ -201,8 +200,7 @@ tests/cases/conformance/pedantic/noUncheckedIndexedAccess.ts(99,11): error TS232
 !!! error TS2322:   Type 'undefined' is not assignable to type 'string'.
         const v: string = myRecord2[key]; // Should error
               ~
-!!! error TS2322: Type 'string | undefined' is not assignable to type 'string'.
-!!! error TS2322:   Type 'undefined' is not assignable to type 'string'.
+!!! error TS2322: Type 'undefined' is not assignable to type 'string'.
     };
 
 

tests/baselines/reference/noUncheckedIndexedAccess.types

@@ -412,7 +412,7 @@ const fn3 = <Key extends keyof typeof myRecord2>(key: Key) => {
 
     const v: string = myRecord2[key]; // Should error
 >v : string
->myRecord2[key] : string | undefined
+>myRecord2[key] : undefined
 >myRecord2 : { [key: string]: string; a: string; b: string; }
 >key : Key
 

tests/baselines/reference/strictPropertyInitialization.errors.txt

@@ -164,4 +164,19 @@ tests/cases/conformance/classes/propertyMemberDeclarations/strictPropertyInitial
             this.#b = someValue();
         }
     }
+    
+    const a = 'a';
+    const b = Symbol();
+    
+    class C12 {
+        [a]: number;
+        [b]: number;
+        ['c']: number;
+    
+        constructor() {
+            this[a] = 1;
+            this[b] = 1;
+            this['c'] = 1;
+        }
+    }
 

tests/baselines/reference/strictPropertyInitialization.js

@@ -132,6 +132,21 @@ class C11 {
         this.#b = someValue();
     }
 }
+
+const a = 'a';
+const b = Symbol();
+
+class C12 {
+    [a]: number;
+    [b]: number;
+    ['c']: number;
+
+    constructor() {
+        this[a] = 1;
+        this[b] = 1;
+        this['c'] = 1;
+    }
+}
 
 
 //// [strictPropertyInitialization.js]
@@ -235,6 +250,15 @@ class C11 {
     }
 }
 _C11_b = new WeakMap();
+const a = 'a';
+const b = Symbol();
+class C12 {
+    constructor() {
+        this[a] = 1;
+        this[b] = 1;
+        this['c'] = 1;
+    }
+}
 
 
 //// [strictPropertyInitialization.d.ts]
@@ -303,3 +327,11 @@ declare class C11 {
     a: number;
     constructor();
 }
+declare const a = "a";
+declare const b: unique symbol;
+declare class C12 {
+    [a]: number;
+    [b]: number;
+    ['c']: number;
+    constructor();
+}