Merge branch 'main' into port/import-defer

Author: Andarist

internal/checker/checker.go

@@ -12410,17 +12410,32 @@ func (c *Checker) checkNullishCoalesceOperands(left *ast.Node, right *ast.Node)
 	if ast.IsBinaryExpression(right) && ast.IsLogicalBinaryOperator(right.AsBinaryExpression().OperatorToken.Kind) {
 		c.grammarErrorOnNode(right, diagnostics.X_0_and_1_operations_cannot_be_mixed_without_parentheses, scanner.TokenToString(right.AsBinaryExpression().OperatorToken.Kind), scanner.TokenToString(ast.KindQuestionQuestionToken))
 	}
+	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)
 		}
 	}
 }

internal/parser/parser.go

@@ -4340,6 +4340,7 @@ 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/predicateSemantics.errors.txt

@@ -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) { }

testdata/baselines/reference/submodule/compiler/predicateSemantics.errors.txt.diff

@@ -0,0 +1,12 @@
+YieldExpression20_es6.ts(3,8): error TS1163: A 'yield' expression is only allowed in a generator body.
+
+
+==== YieldExpression20_es6.ts (1 errors) ====
+    function* test() {
+      return () => ({
+        b: yield 2, // error
+           ~~~~~
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
+      });
+    }
+