fix

Author: staabm

src/Type/Php/ImplodeFunctionReturnTypeExtension.php

@@ -91,7 +91,7 @@ private function implode(Type $arrayType, Type $separatorType): Type
 }
 
 // implode is one of the four functions that can produce literal strings as blessed by the original RFC: wiki.php.net/rfc/is_literal
-if ($valueTypeAsString->isLiteralString()->yes() && $separatorType->isLiteralString()->yes()) {
+if ($arrayType->getIterableValueType()->isLiteralString()->yes() && $separatorType->isLiteralString()->yes()) {
 $accessoryTypes[] = new AccessoryLiteralStringType();
 }
 if ($valueTypeAsString->isLowercaseString()->yes() && $separatorType->isLowercaseString()->yes()) {

tests/PHPStan/Analyser/nsrt/implode.php

@@ -61,6 +61,6 @@ public function constArrays5($constArr) {
 
 /** @param array{0: 1, 1: 'a'|'b', 3?: 'c'|'d', 4?: 'e'|'f', 5?: 'g'|'h', 6?: 'x'|'y'} $constArr */
 public function constArrays6($constArr) {
-assertType("literal-string&lowercase-string&non-falsy-string", implode('', $constArr));
+assertType("lowercase-string&non-falsy-string", implode('', $constArr));
 }
 }

tests/PHPStan/Analyser/nsrt/non-empty-string.php

@@ -213,6 +213,7 @@ public function sayHello(int $i): void
 $s = array(1, $i);
 
 assertType('lowercase-string&non-falsy-string', implode("a", $s));
+assertType('non-falsy-string&uppercase-string', implode("A", $s));
 }
 
 /**