fix(40617): handle uninitialized class member with computed key (microsoft#45974)

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) || isEntityNameExpression(expr.argumentExpression)) && isNarrowableReference(expr.expression)
                 || isAssignmentExpression(expr) && isNarrowableReference(expr.left);
         }
 

src/compiler/checker.ts

@@ -22877,9 +22877,10 @@ namespace ts {
                     return isMatchingReference((source as NonNullExpression | ParenthesizedExpression).expression, target);
                 case SyntaxKind.PropertyAccessExpression:
                 case SyntaxKind.ElementAccessExpression:
-                    return isAccessExpression(target) &&
-                        getAccessedPropertyName(source as AccessExpression) === getAccessedPropertyName(target) &&
-                        isMatchingReference((source as AccessExpression).expression, target.expression);
+                    const sourcePropertyName = getAccessedPropertyName(source as AccessExpression);
+                    const targetPropertyName = isAccessExpression(target) ? getAccessedPropertyName(target) : undefined;
+                    return sourcePropertyName !== undefined && targetPropertyName !== undefined && targetPropertyName === sourcePropertyName &&
+                        isMatchingReference((source as AccessExpression).expression, (target as AccessExpression).expression);
                 case SyntaxKind.QualifiedName:
                     return isAccessExpression(target) &&
                         (source as QualifiedName).right.escapedText === getAccessedPropertyName(target) &&
@@ -22891,12 +22892,52 @@ namespace ts {
         }
 
         function getAccessedPropertyName(access: AccessExpression | BindingElement | ParameterDeclaration): __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) :
-                access.kind === SyntaxKind.Parameter ? ("" + access.parent.parameters.indexOf(access)) as __String :
-                undefined;
+            if (isPropertyAccessExpression(access)) {
+                return access.name.escapedText;
+            }
+            if (isElementAccessExpression(access)) {
+                return tryGetElementAccessExpressionName(access);
+            }
+            if (isBindingElement(access)) {
+                const name = getDestructuringPropertyName(access);
+                return name ? escapeLeadingUnderscores(name) : undefined;
+            }
+            if (isParameter(access)) {
+                return ("" + access.parent.parameters.indexOf(access)) as __String;
+            }
+            return undefined;
+        }
+
+        function tryGetNameFromType(type: Type) {
+            return type.flags & TypeFlags.UniqueESSymbol ? (type as UniqueESSymbolType).escapedName :
+                type.flags & TypeFlags.StringOrNumberLiteral ? escapeLeadingUnderscores("" + (type as StringLiteralType | NumberLiteralType).value) : undefined;
+        }
+
+        function tryGetElementAccessExpressionName(node: ElementAccessExpression) {
+            if (isStringOrNumericLiteralLike(node.argumentExpression)) {
+                return escapeLeadingUnderscores(node.argumentExpression.text);
+            }
+            if (isEntityNameExpression(node.argumentExpression)) {
+                const symbol = resolveEntityName(node.argumentExpression, SymbolFlags.Value, /*ignoreErrors*/ true);
+                if (!symbol || !isConstVariable(symbol)) return undefined;
+
+                const declaration = symbol.valueDeclaration;
+                if (declaration === undefined) return undefined;
+
+                const type = tryGetTypeFromEffectiveTypeNode(declaration);
+                if (type) {
+                    const name = tryGetNameFromType(type);
+                    if (name !== undefined) {
+                        return name;
+                    }
+                }
+
+                if (hasOnlyExpressionInitializer(declaration)) {
+                    const initializer = getEffectiveInitializer(declaration);
+                    return initializer && tryGetNameFromType(getTypeOfExpression(initializer));
+                }
+            }
+            return undefined;
         }
 
         function containsMatchingReference(source: Node, target: Node) {
@@ -39529,7 +39570,7 @@ 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)) {
@@ -39565,8 +39606,10 @@ 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

@@ -2755,7 +2755,7 @@ 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/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/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();
+}

tests/baselines/reference/strictPropertyInitialization.symbols

@@ -311,3 +311,40 @@ class C11 {
     }
 }
 
+const a = 'a';
+>a : Symbol(a, Decl(strictPropertyInitialization.ts, 134, 5))
+
+const b = Symbol();
+>b : Symbol(b, Decl(strictPropertyInitialization.ts, 135, 5))
+>Symbol : Symbol(Symbol, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+class C12 {
+>C12 : Symbol(C12, Decl(strictPropertyInitialization.ts, 135, 19))
+
+    [a]: number;
+>[a] : Symbol(C12[a], Decl(strictPropertyInitialization.ts, 137, 11))
+>a : Symbol(a, Decl(strictPropertyInitialization.ts, 134, 5))
+
+    [b]: number;
+>[b] : Symbol(C12[b], Decl(strictPropertyInitialization.ts, 138, 16))
+>b : Symbol(b, Decl(strictPropertyInitialization.ts, 135, 5))
+
+    ['c']: number;
+>['c'] : Symbol(C12['c'], Decl(strictPropertyInitialization.ts, 139, 16))
+>'c' : Symbol(C12['c'], Decl(strictPropertyInitialization.ts, 139, 16))
+
+    constructor() {
+        this[a] = 1;
+>this : Symbol(C12, Decl(strictPropertyInitialization.ts, 135, 19))
+>a : Symbol(a, Decl(strictPropertyInitialization.ts, 134, 5))
+
+        this[b] = 1;
+>this : Symbol(C12, Decl(strictPropertyInitialization.ts, 135, 19))
+>b : Symbol(b, Decl(strictPropertyInitialization.ts, 135, 5))
+
+        this['c'] = 1;
+>this : Symbol(C12, Decl(strictPropertyInitialization.ts, 135, 19))
+>'c' : Symbol(C12['c'], Decl(strictPropertyInitialization.ts, 139, 16))
+    }
+}
+

tests/baselines/reference/strictPropertyInitialization.types

@@ -347,3 +347,51 @@ class C11 {
     }
 }
 
+const a = 'a';
+>a : "a"
+>'a' : "a"
+
+const b = Symbol();
+>b : unique symbol
+>Symbol() : unique symbol
+>Symbol : SymbolConstructor
+
+class C12 {
+>C12 : C12
+
+    [a]: number;
+>[a] : number
+>a : "a"
+
+    [b]: number;
+>[b] : number
+>b : unique symbol
+
+    ['c']: number;
+>['c'] : number
+>'c' : "c"
+
+    constructor() {
+        this[a] = 1;
+>this[a] = 1 : 1
+>this[a] : number
+>this : this
+>a : "a"
+>1 : 1
+
+        this[b] = 1;
+>this[b] = 1 : 1
+>this[b] : number
+>this : this
+>b : unique symbol
+>1 : 1
+
+        this['c'] = 1;
+>this['c'] = 1 : 1
+>this['c'] : number
+>this : this
+>'c' : "c"
+>1 : 1
+    }
+}
+

tests/baselines/reference/typeGuardNarrowsIndexedAccessOfKnownProperty.js tests/baselines/reference/typeGuardNarrowsIndexedAccessOfKnownProperty1.js

@@ -1,4 +1,4 @@
-//// [typeGuardNarrowsIndexedAccessOfKnownProperty.ts]
+//// [typeGuardNarrowsIndexedAccessOfKnownProperty1.ts]
 interface Square {
     ["dash-ok"]: "square";
     ["square-size"]: number;
@@ -80,7 +80,7 @@ export function g(pair: [number, string?]): string {
 }
 
 
-//// [typeGuardNarrowsIndexedAccessOfKnownProperty.js]
+//// [typeGuardNarrowsIndexedAccessOfKnownProperty1.js]
 "use strict";
 exports.__esModule = true;
 exports.g = void 0;