trim MixedType

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -1313,14 +1313,15 @@ private function specifyTypesForConstantStringBinaryExpression(
 		) {
 			$argType = $scope->getType($exprNode->getArgs()[0]->value);
 
-			if ($argType->isString()->yes()) {
-				return $this->create(
-					$exprNode->getArgs()[0]->value,
+			return $this->create(
+				$exprNode->getArgs()[0]->value,
+				TypeCombinator::intersect(
+					new StringType(),
 					new AccessoryNonEmptyStringType(),
-					$context->negate(),
-					$scope,
-				)->setRootExpr($rootExpr);
-			}
+				),
+				$context->negate(),
+				$scope,
+			)->setRootExpr($rootExpr);
 		}
 
 		return null;

tests/PHPStan/Analyser/nsrt/bug-12973.php

@@ -16,6 +16,17 @@ function nullIfBlank(?string $value): ?string
 	return null;
 }
 
+function trimMixed($value): void
+{
+	if (trim($value) === '') {
+		assertType('mixed', $value);
+	} else {
+		assertType('non-empty-string', $value);
+	}
+	assertType('mixed', $value);
+
+}
+
 function trimTypes(string $value): void
 {
 	if (trim($value) === '') {