Merge branch 'main' into port/61372

Author: Andarist

internal/checker/checker.go

@@ -12417,17 +12417,32 @@ func (c *Checker) checkNullishCoalesceOperands(left *ast.Node, right *ast.Node)
 			c.grammarErrorOnNode(right, diagnostics.X_0_and_1_operations_cannot_be_mixed_without_parentheses, scanner.TokenToString(ast.KindQuestionQuestionToken), scanner.TokenToString(operatorToken.Kind))
 		}
 	}
+	c.checkNullishCoalesceOperandLeft(left)
+	c.checkNullishCoalesceOperandRight(right)
+}
+
+func (c *Checker) checkNullishCoalesceOperandLeft(left *ast.Node) {
 	leftTarget := ast.SkipOuterExpressions(left, ast.OEKAll)
 	nullishSemantics := c.getSyntacticNullishnessSemantics(leftTarget)
 	if nullishSemantics != PredicateSemanticsSometimes {
-		if left.Parent.Parent.Kind == ast.KindBinaryExpression {
-			c.error(leftTarget, diagnostics.This_binary_expression_is_never_nullish_Are_you_missing_parentheses)
+		if nullishSemantics == PredicateSemanticsAlways {
+			c.error(leftTarget, diagnostics.This_expression_is_always_nullish)
 		} else {
-			if nullishSemantics == PredicateSemanticsAlways {
-				c.error(leftTarget, diagnostics.This_expression_is_always_nullish)
-			} else {
-				c.error(leftTarget, diagnostics.Right_operand_of_is_unreachable_because_the_left_operand_is_never_nullish)
-			}
+			c.error(leftTarget, diagnostics.Right_operand_of_is_unreachable_because_the_left_operand_is_never_nullish)
+		}
+	}
+}
+
+func (c *Checker) checkNullishCoalesceOperandRight(right *ast.Node) {
+	binaryExpression := right.Parent
+	if binaryExpression.Parent != nil && ast.IsBinaryExpression(binaryExpression.Parent) && binaryExpression.Parent.AsBinaryExpression().OperatorToken.Kind == ast.KindQuestionQuestionToken {
+		rightTarget := ast.SkipOuterExpressions(right, ast.OEKAll)
+		nullishSemantics := c.getSyntacticNullishnessSemantics(rightTarget)
+		switch nullishSemantics {
+		case PredicateSemanticsAlways:
+			c.error(rightTarget, diagnostics.This_expression_is_always_nullish)
+		case PredicateSemanticsNever:
+			c.error(rightTarget, diagnostics.This_expression_is_never_nullish)
 		}
 	}
 }
@@ -15716,14 +15731,14 @@ func (c *Checker) getWriteTypeOfSymbolWithDeferredType(symbol *ast.Symbol) *Type
 // properties deriving from set accessors will either pre-compute or defer the union or
 // intersection of the writeTypes of their constituents.
 func (c *Checker) getWriteTypeOfSymbol(symbol *ast.Symbol) *Type {
-	if symbol.Flags&ast.SymbolFlagsProperty != 0 {
-		if symbol.CheckFlags&ast.CheckFlagsSyntheticProperty != 0 {
-			if symbol.CheckFlags&ast.CheckFlagsDeferredType != 0 {
-				return c.getWriteTypeOfSymbolWithDeferredType(symbol)
-			}
-			links := c.valueSymbolLinks.Get(symbol)
-			return core.OrElse(links.writeType, links.resolvedType)
+	if symbol.CheckFlags&ast.CheckFlagsSyntheticProperty != 0 {
+		if symbol.CheckFlags&ast.CheckFlagsDeferredType != 0 {
+			return c.getWriteTypeOfSymbolWithDeferredType(symbol)
 		}
+		links := c.valueSymbolLinks.Get(symbol)
+		return core.OrElse(links.writeType, links.resolvedType)
+	}
+	if symbol.Flags&ast.SymbolFlagsProperty != 0 {
 		return c.removeMissingType(c.getTypeOfSymbol(symbol), symbol.Flags&ast.SymbolFlagsOptional != 0)
 	}
 	if symbol.Flags&ast.SymbolFlagsAccessor != 0 {
@@ -20614,6 +20629,7 @@ func (c *Checker) getUnionOrIntersectionProperty(t *Type, name string, skipObjec
 }
 
 func (c *Checker) createUnionOrIntersectionProperty(containingType *Type, name string, skipObjectFunctionPropertyAugment bool) *ast.Symbol {
+	propFlags := ast.SymbolFlagsNone
 	var singleProp *ast.Symbol
 	var propSet collections.OrderedSet[*ast.Symbol]
 	var indexTypes []*Type
@@ -20643,6 +20659,7 @@ func (c *Checker) createUnionOrIntersectionProperty(containingType *Type, name s
 				}
 				if singleProp == nil {
 					singleProp = prop
+					propFlags = core.OrElse(prop.Flags&ast.SymbolFlagsAccessor, ast.SymbolFlagsProperty)
 				} else if prop != singleProp {
 					isInstantiation := c.getTargetSymbol(prop) == c.getTargetSymbol(singleProp)
 					// If the symbols are instances of one another with identical types - consider the symbols
@@ -20659,6 +20676,13 @@ func (c *Checker) createUnionOrIntersectionProperty(containingType *Type, name s
 						}
 						propSet.Add(prop)
 					}
+					// classes created by mixins are represented as intersections
+					// and overriding a property in a derived class redefines it completely at runtime
+					// so a get accessor can't be merged with a set accessor in a base class,
+					// for that reason the accessor flags are only used when they are the same in all constituents
+					if propFlags&ast.SymbolFlagsAccessor != 0 && (prop.Flags&ast.SymbolFlagsAccessor != (propFlags & ast.SymbolFlagsAccessor)) {
+						propFlags = (propFlags &^ ast.SymbolFlagsAccessor) | ast.SymbolFlagsProperty
+					}
 				}
 				if isUnion && c.isReadonlySymbol(prop) {
 					checkFlags |= ast.CheckFlagsReadonly
@@ -20686,6 +20710,7 @@ func (c *Checker) createUnionOrIntersectionProperty(containingType *Type, name s
 					indexInfo = c.getApplicableIndexInfoForName(t, name)
 				}
 				if indexInfo != nil {
+					propFlags = propFlags&^ast.SymbolFlagsAccessor | ast.SymbolFlagsProperty
 					checkFlags |= ast.CheckFlagsWritePartial | (core.IfElse(indexInfo.isReadonly, ast.CheckFlagsReadonly, 0))
 					if isTupleType(t) {
 						indexType := c.getRestTypeOfTupleType(t)
@@ -20778,7 +20803,7 @@ func (c *Checker) createUnionOrIntersectionProperty(containingType *Type, name s
 		propTypes = append(propTypes, t)
 	}
 	propTypes = append(propTypes, indexTypes...)
-	result := c.newSymbolEx(ast.SymbolFlagsProperty|optionalFlag, name, checkFlags|syntheticFlag)
+	result := c.newSymbolEx(propFlags|optionalFlag, name, checkFlags|syntheticFlag)
 	result.Declarations = declarations
 	if !hasNonUniformValueDeclaration && firstValueDeclaration != nil {
 		result.ValueDeclaration = firstValueDeclaration

internal/checker/emitresolver.go

@@ -409,7 +409,14 @@ func (r *emitResolver) hasVisibleDeclarations(symbol *ast.Symbol, shouldComputeA
 					continue
 				}
 				if symbol.Flags&ast.SymbolFlagsBlockScopedVariable != 0 {
-					variableStatement := ast.FindAncestor(declaration, ast.IsVariableStatement)
+					rootDeclaration := ast.WalkUpBindingElementsAndPatterns(declaration)
+					if ast.IsParameter(rootDeclaration) {
+						return nil
+					}
+					variableStatement := rootDeclaration.Parent.Parent
+					if !ast.IsVariableStatement(variableStatement) {
+						return nil
+					}
 					if ast.HasSyntacticModifier(variableStatement, ast.ModifierFlagsExport) {
 						continue // no alias to add, already exported
 					}

internal/checker/nodebuilderimpl.go

@@ -2214,22 +2214,45 @@ func (b *nodeBuilderImpl) addPropertyToElementList(propertySymbol *ast.Symbol, t
 
 	if propertySymbol.Flags&ast.SymbolFlagsAccessor != 0 {
 		writeType := b.ch.getWriteTypeOfSymbol(propertySymbol)
-		if propertyType != writeType && !b.ch.isErrorType(propertyType) && !b.ch.isErrorType(writeType) {
-			getterDeclaration := ast.GetDeclarationOfKind(propertySymbol, ast.KindGetAccessor)
-			getterSignature := b.ch.getSignatureFromDeclaration(getterDeclaration)
-			getter := b.signatureToSignatureDeclarationHelper(getterSignature, ast.KindGetAccessor, &SignatureToSignatureDeclarationOptions{
-				name: propertyName,
-			})
-			b.setCommentRange(getter, getterDeclaration)
-			typeElements = append(typeElements, getter)
-			setterDeclaration := ast.GetDeclarationOfKind(propertySymbol, ast.KindSetAccessor)
-			setterSignature := b.ch.getSignatureFromDeclaration(setterDeclaration)
-			setter := b.signatureToSignatureDeclarationHelper(setterSignature, ast.KindSetAccessor, &SignatureToSignatureDeclarationOptions{
-				name: propertyName,
-			})
-			b.setCommentRange(setter, setterDeclaration)
-			typeElements = append(typeElements, setter)
-			return typeElements
+		if !b.ch.isErrorType(propertyType) && !b.ch.isErrorType(writeType) {
+			propDeclaration := ast.GetDeclarationOfKind(propertySymbol, ast.KindPropertyDeclaration)
+			if propertyType != writeType || propertySymbol.Parent.Flags&ast.SymbolFlagsClass != 0 && propDeclaration == nil {
+				if getterDeclaration := ast.GetDeclarationOfKind(propertySymbol, ast.KindGetAccessor); getterDeclaration != nil {
+					getterSignature := b.ch.getSignatureFromDeclaration(getterDeclaration)
+					getter := b.signatureToSignatureDeclarationHelper(getterSignature, ast.KindGetAccessor, &SignatureToSignatureDeclarationOptions{
+						name: propertyName,
+					})
+					b.setCommentRange(getter, getterDeclaration)
+					typeElements = append(typeElements, getter)
+				}
+				if setterDeclaration := ast.GetDeclarationOfKind(propertySymbol, ast.KindSetAccessor); setterDeclaration != nil {
+					setterSignature := b.ch.getSignatureFromDeclaration(setterDeclaration)
+					setter := b.signatureToSignatureDeclarationHelper(setterSignature, ast.KindSetAccessor, &SignatureToSignatureDeclarationOptions{
+						name: propertyName,
+					})
+					b.setCommentRange(setter, setterDeclaration)
+					typeElements = append(typeElements, setter)
+				}
+				return typeElements
+			} else if propertySymbol.Parent.Flags&ast.SymbolFlagsClass != 0 && propDeclaration != nil && core.Find(propDeclaration.ModifierNodes(), func(m *ast.Node) bool {
+				return m.Kind == ast.KindAccessorKeyword
+			}) != nil {
+				fakeGetterSignature := b.ch.newSignature(SignatureFlagsNone, nil, nil, nil, nil, propertyType, nil, 0)
+				fakeGetterDeclaration := b.signatureToSignatureDeclarationHelper(fakeGetterSignature, ast.KindGetAccessor, &SignatureToSignatureDeclarationOptions{
+					name: propertyName,
+				})
+				b.setCommentRange(fakeGetterDeclaration, propDeclaration)
+				typeElements = append(typeElements, fakeGetterDeclaration)
+
+				setterParam := b.ch.newSymbol(ast.SymbolFlagsFunctionScopedVariable, "arg")
+				b.ch.valueSymbolLinks.Get(setterParam).resolvedType = writeType
+				fakeSetterSignature := b.ch.newSignature(SignatureFlagsNone, nil, nil, nil, []*ast.Symbol{setterParam}, b.ch.voidType, nil, 0)
+				fakeSetterDeclaration := b.signatureToSignatureDeclarationHelper(fakeSetterSignature, ast.KindSetAccessor, &SignatureToSignatureDeclarationOptions{
+					name: propertyName,
+				})
+				typeElements = append(typeElements, fakeSetterDeclaration)
+				return typeElements
+			}
 		}
 	}
 

internal/parser/parser.go

@@ -4324,6 +4324,7 @@ func (p *Parser) parseArrowFunctionExpressionBody(isAsync bool, allowReturnTypeI
 	}
 	saveContextFlags := p.contextFlags
 	p.setContextFlags(ast.NodeFlagsAwaitContext, isAsync)
+	p.setContextFlags(ast.NodeFlagsYieldContext, false)
 	node := p.parseAssignmentExpressionOrHigherWorker(allowReturnTypeInArrowFunction)
 	p.contextFlags = saveContextFlags
 	return node

testdata/baselines/reference/submodule/compiler/declarationEmitGenericTypeParamerSerialization3.js

@@ -36,11 +36,13 @@ export const Cls = wrapper("test");
 //// [declarationEmitGenericTypeParamerSerialization3.d.ts]
 export declare function wrapper<T>(value: T): {
     new (): {
-        name: T;
+        get name(): T;
+        set name(arg: T);
     };
 };
 export declare const Cls: {
     new (): {
-        name: string;
+        get name(): string;
+        set name(arg: string);
     };
 };

testdata/baselines/reference/submodule/compiler/declarationEmitGenericTypeParamerSerialization3.js.diff

@@ -6,15 +6,27 @@ predicateSemantics.ts(28,13): error TS2871: This expression is always nullish.
 predicateSemantics.ts(29,13): error TS2871: This expression is always nullish.
 predicateSemantics.ts(30,13): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(31,13): error TS2872: This kind of expression is always truthy.
-predicateSemantics.ts(32,13): error TS2870: This binary expression is never nullish. Are you missing parentheses?
-predicateSemantics.ts(33,13): error TS2870: This binary expression is never nullish. Are you missing parentheses?
-predicateSemantics.ts(34,13): error TS2870: This binary expression is never nullish. Are you missing parentheses?
+predicateSemantics.ts(32,13): error TS2871: This expression is always nullish.
+predicateSemantics.ts(32,21): error TS2871: This expression is always nullish.
+predicateSemantics.ts(33,13): error TS2871: This expression is always nullish.
+predicateSemantics.ts(34,13): error TS2871: This expression is always nullish.
+predicateSemantics.ts(34,22): error TS2871: This expression is always nullish.
+predicateSemantics.ts(36,20): error TS2871: This expression is always nullish.
+predicateSemantics.ts(37,20): error TS2871: This expression is always nullish.
 predicateSemantics.ts(38,21): error TS2871: This expression is always nullish.
 predicateSemantics.ts(39,21): error TS2871: This expression is always nullish.
-predicateSemantics.ts(40,21): error TS2870: This binary expression is never nullish. Are you missing parentheses?
-predicateSemantics.ts(45,13): error TS2870: This binary expression is never nullish. Are you missing parentheses?
-predicateSemantics.ts(46,13): error TS2870: This binary expression is never nullish. Are you missing parentheses?
-predicateSemantics.ts(47,13): error TS2870: This binary expression is never nullish. Are you missing parentheses?
+predicateSemantics.ts(40,21): error TS2871: This expression is always nullish.
+predicateSemantics.ts(40,29): error TS2871: This expression is always nullish.
+predicateSemantics.ts(41,21): error TS2871: This expression is always nullish.
+predicateSemantics.ts(42,20): error TS2881: This expression is never nullish.
+predicateSemantics.ts(43,21): error TS2881: This expression is never nullish.
+predicateSemantics.ts(45,13): error TS2871: This expression is always nullish.
+predicateSemantics.ts(45,21): error TS2871: This expression is always nullish.
+predicateSemantics.ts(45,29): error TS2871: This expression is always nullish.
+predicateSemantics.ts(46,13): error TS2871: This expression is always nullish.
+predicateSemantics.ts(46,21): error TS2881: This expression is never nullish.
+predicateSemantics.ts(47,13): error TS2871: This expression is always nullish.
+predicateSemantics.ts(47,22): error TS2881: This expression is never nullish.
 predicateSemantics.ts(50,8): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(51,11): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(52,8): error TS2872: This kind of expression is always truthy.
@@ -26,7 +38,7 @@ predicateSemantics.ts(89,1): error TS2869: Right operand of ?? is unreachable be
 predicateSemantics.ts(90,1): error TS2869: Right operand of ?? is unreachable because the left operand is never nullish.
 
 
-==== predicateSemantics.ts (26 errors) ====
+==== predicateSemantics.ts (38 errors) ====
     declare let opt: number | undefined;
 
     // OK: One or other operand is possibly nullish
@@ -76,16 +88,24 @@ predicateSemantics.ts(90,1): error TS2869: Right operand of ?? is unreachable be
 !!! error TS2872: This kind of expression is always truthy.
     const p07 = null ?? null ?? null;
                 ~~~~
-!!! error TS2870: This binary expression is never nullish. Are you missing parentheses?
+!!! error TS2871: This expression is always nullish.
+                        ~~~~
+!!! error TS2871: This expression is always nullish.
     const p08 = null ?? opt ?? null;
                 ~~~~
-!!! error TS2870: This binary expression is never nullish. Are you missing parentheses?
+!!! error TS2871: This expression is always nullish.
     const p09 = null ?? (opt ? null : undefined) ?? null;
                 ~~~~
-!!! error TS2870: This binary expression is never nullish. Are you missing parentheses?
+!!! error TS2871: This expression is always nullish.
+                         ~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2871: This expression is always nullish.
 
     const p10 = opt ?? null ?? 1;
+                       ~~~~
+!!! error TS2871: This expression is always nullish.
     const p11 = opt ?? null ?? null;
+                       ~~~~
+!!! error TS2871: This expression is always nullish.
     const p12 = opt ?? (null ?? 1);
                         ~~~~
 !!! error TS2871: This expression is always nullish.
@@ -94,20 +114,36 @@ predicateSemantics.ts(90,1): error TS2869: Right operand of ?? is unreachable be
 !!! error TS2871: This expression is always nullish.
     const p14 = opt ?? (null ?? null ?? null);
                         ~~~~
-!!! error TS2870: This binary expression is never nullish. Are you missing parentheses?
+!!! error TS2871: This expression is always nullish.
+                                ~~~~
+!!! error TS2871: This expression is always nullish.
     const p15 = opt ?? (opt ? null : undefined) ?? null;
+                        ~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2871: This expression is always nullish.
     const p16 = opt ?? 1 ?? 2;
+                       ~
+!!! error TS2881: This expression is never nullish.
     const p17 = opt ?? (opt ? 1 : 2) ?? 3;
+                        ~~~~~~~~~~~
+!!! error TS2881: This expression is never nullish.
 
     const p21 = null ?? null ?? null ?? null;
                 ~~~~
-!!! error TS2870: This binary expression is never nullish. Are you missing parentheses?
+!!! error TS2871: This expression is always nullish.
+                        ~~~~
+!!! error TS2871: This expression is always nullish.
+                                ~~~~
+!!! error TS2871: This expression is always nullish.
     const p22 = null ?? 1 ?? 1;
                 ~~~~
-!!! error TS2870: This binary expression is never nullish. Are you missing parentheses?
+!!! error TS2871: This expression is always nullish.
+                        ~
+!!! error TS2881: This expression is never nullish.
     const p23 = null ?? (opt ? 1 : 2) ?? 1;
                 ~~~~
-!!! error TS2870: This binary expression is never nullish. Are you missing parentheses?
+!!! error TS2871: This expression is always nullish.
+                         ~~~~~~~~~~~
+!!! error TS2881: This expression is never nullish.
 
     // Outer expression tests
     while ({} as any) { }