Improve maybe inferences

Author: VincentLanglet

src/Type/Php/ReplaceFunctionsDynamicReturnTypeExtension.php

@@ -101,7 +101,10 @@ private function getPreliminarilyResolvedTypeFromFunctionCall(
 				}
 			} elseif ($functionReflection->getName() === 'strtr' && isset($functionCall->getArgs()[1])) {
 				// `strtr` has two signatures: `strtr($string1, $string2, $string3)` and `strtr($string1, $array)`
-				$secondArgumentType = $scope->getType($functionCall->getArgs()[1]->value);
+				$secondArgumentType = TypeCombinator::intersect(
+					new ArrayType(new MixedType(), new MixedType()),
+					$scope->getType($functionCall->getArgs()[1]->value)
+				);
 				if ($secondArgumentType->isArray()->yes()) {
 					$replaceArgumentType = $secondArgumentType->getIterableValueType();
 				}

tests/PHPStan/Analyser/nsrt/strtr.php

@@ -36,4 +36,12 @@ function doFoo(string $s, $nonEmptyString, $nonFalseyString) {
 	assertType('non-empty-string', strtr($nonFalseyString, [$s => $nonEmptyString]));
 	assertType('non-falsy-string', strtr($nonFalseyString, [$nonEmptyString => $nonFalseyString]));
 	assertType('non-falsy-string', strtr($nonFalseyString, [$nonFalseyString => $nonFalseyString]));
+
+	assertType('non-empty-string', strtr($nonEmptyString, rand(0, 1) ? [$s => $nonEmptyString] : null));
+	assertType('non-empty-string', strtr($nonEmptyString, rand(0, 1) ? [$nonEmptyString => $nonEmptyString] : null));
+	assertType('non-empty-string', strtr($nonEmptyString, rand(0, 1) ? [$nonFalseyString => $nonFalseyString] : null));
+
+	assertType('non-empty-string', strtr($nonFalseyString, rand(0, 1) ? [$s => $nonEmptyString] : null));
+	assertType('non-falsy-string', strtr($nonFalseyString, rand(0, 1) ? [$nonEmptyString => $nonFalseyString] : null));
+	assertType('non-falsy-string', strtr($nonFalseyString, rand(0, 1) ? [$nonFalseyString => $nonFalseyString] : null));
 }