More precise implode() return type

Author: staabm

src/Type/Php/ImplodeFunctionReturnTypeExtension.php

@@ -80,22 +80,23 @@ private function implode(Type $arrayType, Type $separatorType): Type
 		}
 
 		$accessoryTypes = [];
+		$valueTypeAsString = $arrayType->getIterableValueType()->toString();
 		if ($arrayType->isIterableAtLeastOnce()->yes()) {
-			if ($arrayType->getIterableValueType()->isNonFalsyString()->yes() || $separatorType->isNonFalsyString()->yes()) {
+			if ($valueTypeAsString->isNonFalsyString()->yes() || $separatorType->isNonFalsyString()->yes()) {
 				$accessoryTypes[] = new AccessoryNonFalsyStringType();
-			} elseif ($arrayType->getIterableValueType()->isNonEmptyString()->yes() || $separatorType->isNonEmptyString()->yes()) {
+			} elseif ($valueTypeAsString->isNonEmptyString()->yes() || $separatorType->isNonEmptyString()->yes()) {
 				$accessoryTypes[] = new AccessoryNonEmptyStringType();
 			}
 		}
 
 		// 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 ($arrayType->getIterableValueType()->isLiteralString()->yes() && $separatorType->isLiteralString()->yes()) {
+		if ($valueTypeAsString->isLiteralString()->yes() && $separatorType->isLiteralString()->yes()) {
 			$accessoryTypes[] = new AccessoryLiteralStringType();
 		}
-		if ($arrayType->getIterableValueType()->isLowercaseString()->yes() && $separatorType->isLowercaseString()->yes()) {
+		if ($valueTypeAsString->isLowercaseString()->yes() && $separatorType->isLowercaseString()->yes()) {
 			$accessoryTypes[] = new AccessoryLowercaseStringType();
 		}
-		if ($arrayType->getIterableValueType()->isUppercaseString()->yes() && $separatorType->isUppercaseString()->yes()) {
+		if ($valueTypeAsString->isUppercaseString()->yes() && $separatorType->isUppercaseString()->yes()) {
 			$accessoryTypes[] = new AccessoryUppercaseStringType();
 		}
 

tests/PHPStan/Analyser/nsrt/bug-11201.php

@@ -41,7 +41,7 @@ function returnsBool(): bool {
 assertType('string', $s);
 
 $s = sprintf("%s", implode(', ', array_map('intval', returnsArray())));
-assertType('string', $s);
+assertType('lowercase-string&uppercase-string', $s);
 
 $s = sprintf('%2$s', 1234, returnsNonFalsyString());
 assertType('non-falsy-string', $s);

tests/PHPStan/Analyser/nsrt/implode.php

@@ -6,6 +6,18 @@
 
 class Foo
 {
+	/**
+	 * @param array<int> $arr
+	 */
+	public function ints(array $arr, int $i)
+	{
+		assertType("lowercase-string&uppercase-string", implode($arr));
+		assertType("lowercase-string&non-empty-string&uppercase-string", implode([$i, $i]));
+		if ($i !== 0) {
+			assertType("lowercase-string&non-falsy-string&uppercase-string", implode([$i, $i]));
+		}
+	}
+
 	const X = 'x';
 	const ONE = 1;
 

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

@@ -212,7 +212,7 @@ public function sayHello(int $i): void
 		// coming from issue #5291
 		$s = array(1, $i);
 
-		assertType('non-falsy-string', implode("a", $s));
+		assertType('lowercase-string&non-falsy-string', implode("a", $s));
 	}
 
 	/**
@@ -233,7 +233,7 @@ public function sayHello2(int $i): void
 		// coming from issue #5291
 		$s = array(1, $i);
 
-		assertType('non-falsy-string', join("a", $s));
+		assertType('lowercase-string&non-falsy-string', join("a", $s));
 	}
 
 	/**