Complete PHPStan Level 6 (#5305)

* Complete PHPStan Level 6
Fix https://github.com/FreshRSS/FreshRSS/issues/4112
And initiate PHPStan Level 7

* PHPStan Level 6 for tests
* Use phpstan/phpstan-phpunit
* Update to PHPStan version 1.10

* Fix mixed bug

* Fix mixed return bug

* Fix paginator bug

* Fix FreshRSS_UserConfiguration

* A couple more Minz_Configuration bug fixes

* A few trivial PHPStan Level 7 fixes

* A few more simple PHPStan Level 7

* More files passing PHPStan Level 7
Add interface to replace removed class from https://github.com/FreshRSS/FreshRSS/pull/5251

* A few more PHPStan Level 7 preparations

* A few last details

18 files changed, 236 insertions, 197 deletions

diff --git a/tests/app/Models/CategoryTest.php b/tests/app/Models/CategoryTest.php
index 93fbdbc63..a438afe9e 100644
--- a/tests/app/Models/CategoryTest.php
+++ b/tests/app/Models/CategoryTest.php
@@ -2,23 +2,22 @@
 
 class CategoryTest extends PHPUnit\Framework\TestCase {
 
-	public function test__construct_whenNoParameters_createsObjectWithDefaultValues() {
+	public function test__construct_whenNoParameters_createsObjectWithDefaultValues(): void {
 		$category = new FreshRSS_Category();
 		$this->assertEquals(0, $category->id());
 		$this->assertEquals('', $category->name());
 	}
 
 	/**
-	 * @param string $input
-	 * @param string $expected
 	 * @dataProvider provideValidNames
 	 */
-	public function test_name_whenValidValue_storesModifiedValue($input, $expected) {
+	public function test_name_whenValidValue_storesModifiedValue(string $input, string $expected): void {
 		$category = new FreshRSS_Category($input);
 		$this->assertEquals($expected, $category->name());
 	}
 
-	public function provideValidNames() {
+	/** @return array<array{string,string}> */
+	public function provideValidNames(): array {
 		return array(
 			array('', ''),
 			array('this string does not need trimming', 'this string does not need trimming'),
@@ -30,7 +29,7 @@ class CategoryTest extends PHPUnit\Framework\TestCase {
 		);
 	}
 
-	public function test_feedOrdering() {
+	public function test_feedOrdering(): void {
 		$feed_1 = $this->getMockBuilder(FreshRSS_Feed::class)
 			->disableOriginalConstructor()
 			->getMock();
diff --git a/tests/app/Models/LogDAOTest.php b/tests/app/Models/LogDAOTest.php
index 18cad4968..abe6c6c1f 100644
--- a/tests/app/Models/LogDAOTest.php
+++ b/tests/app/Models/LogDAOTest.php
@@ -36,7 +36,7 @@ class LogDAOTest extends TestCase {
 
 		$this->logDAO::truncate(self::LOG_FILE_TEST);
 
-		$this->assertStringContainsString('', file_get_contents($this->logPath));
+		$this->assertStringContainsString('', file_get_contents($this->logPath) ?: '');
 	}
 
 	protected function tearDown(): void {
diff --git a/tests/app/Models/SearchTest.php b/tests/app/Models/SearchTest.php
index 52c10244d..2b2501589 100644
--- a/tests/app/Models/SearchTest.php
+++ b/tests/app/Models/SearchTest.php
@@ -6,9 +6,8 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 
 	/**
 	 * @dataProvider provideEmptyInput
-	 * @param string|null $input
 	 */
-	public function test__construct_whenInputIsEmpty_getsOnlyNullValues($input) {
+	public function test__construct_whenInputIsEmpty_getsOnlyNullValues(?string $input): void {
 		$search = new FreshRSS_Search($input);
 		$this->assertEquals('', $search->getRawInput());
 		$this->assertNull($search->getIntitle());
@@ -24,9 +23,9 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 	/**
 	 * Return an array of values for the search object.
 	 * Here is the description of the values
-	 * @return array
+	 * @return array{array{''},array{null}}
 	 */
-	public function provideEmptyInput() {
+	public function provideEmptyInput(): array {
 		return array(
 			array(''),
 			array(null),
@@ -35,20 +34,19 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 
 	/**
 	 * @dataProvider provideIntitleSearch
-	 * @param string $input
-	 * @param string $intitle_value
-	 * @param string|null $search_value
+	 * @param array<string>|null $intitle_value
+	 * @param array<string>|null $search_value
 	 */
-	public function test__construct_whenInputContainsIntitle_setsIntitleProperty($input, $intitle_value, $search_value) {
+	public function test__construct_whenInputContainsIntitle_setsIntitleProperty(string $input, ?array $intitle_value, ?array $search_value): void {
 		$search = new FreshRSS_Search($input);
 		$this->assertEquals($intitle_value, $search->getIntitle());
 		$this->assertEquals($search_value, $search->getSearch());
 	}
 
 	/**
-	 * @return array
+	 * @return array<array<mixed>>
 	 */
-	public function provideIntitleSearch() {
+	public function provideIntitleSearch(): array {
 		return array(
 			array('intitle:word1', array('word1'), null),
 			array('intitle:word1-word2', array('word1-word2'), null),
@@ -73,20 +71,19 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 
 	/**
 	 * @dataProvider provideAuthorSearch
-	 * @param string $input
-	 * @param string $author_value
-	 * @param string|null $search_value
+	 * @param array<string>|null $author_value
+	 * @param array<string>|null $search_value
 	 */
-	public function test__construct_whenInputContainsAuthor_setsAuthorValue($input, $author_value, $search_value) {
+	public function test__construct_whenInputContainsAuthor_setsAuthorValue(string $input, ?array $author_value, ?array $search_value): void {
 		$search = new FreshRSS_Search($input);
 		$this->assertEquals($author_value, $search->getAuthor());
 		$this->assertEquals($search_value, $search->getSearch());
 	}
 
 	/**
-	 * @return array
+	 * @return array<array<mixed>>
 	 */
-	public function provideAuthorSearch() {
+	public function provideAuthorSearch(): array {
 		return array(
 			array('author:word1', array('word1'), null),
 			array('author:word1-word2', array('word1-word2'), null),
@@ -111,20 +108,19 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 
 	/**
 	 * @dataProvider provideInurlSearch
-	 * @param string $input
-	 * @param string $inurl_value
-	 * @param string|null $search_value
+	 * @param array<string>|null $inurl_value
+	 * @param array<string>|null $search_value
 	 */
-	public function test__construct_whenInputContainsInurl_setsInurlValue($input, $inurl_value, $search_value) {
+	public function test__construct_whenInputContainsInurl_setsInurlValue(string $input, ?array $inurl_value, ?array $search_value): void {
 		$search = new FreshRSS_Search($input);
 		$this->assertEquals($inurl_value, $search->getInurl());
 		$this->assertEquals($search_value, $search->getSearch());
 	}
 
 	/**
-	 * @return array
+	 * @return array<array<mixed>>
 	 */
-	public function provideInurlSearch() {
+	public function provideInurlSearch(): array {
 		return array(
 			array('inurl:word1', array('word1'), null),
 			array('inurl: word1', array(), array('word1')),
@@ -139,72 +135,65 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 
 	/**
 	 * @dataProvider provideDateSearch
-	 * @param string $input
-	 * @param string $min_date_value
-	 * @param string $max_date_value
 	 */
-	public function test__construct_whenInputContainsDate_setsDateValues($input, $min_date_value, $max_date_value) {
+	public function test__construct_whenInputContainsDate_setsDateValues(string $input, ?int $min_date_value, ?int $max_date_value): void {
 		$search = new FreshRSS_Search($input);
 		$this->assertEquals($min_date_value, $search->getMinDate());
 		$this->assertEquals($max_date_value, $search->getMaxDate());
 	}
 
 	/**
-	 * @return array
+	 * @return array<array<mixed>>
 	 */
-	public function provideDateSearch() {
+	public function provideDateSearch(): array {
 		return array(
-			array('date:2007-03-01T13:00:00Z/2008-05-11T15:30:00Z', '1172754000', '1210519800'),
-			array('date:2007-03-01T13:00:00Z/P1Y2M10DT2H30M', '1172754000', '1210519799'),
-			array('date:P1Y2M10DT2H30M/2008-05-11T15:30:00Z', '1172754001', '1210519800'),
+			array('date:2007-03-01T13:00:00Z/2008-05-11T15:30:00Z', 1172754000, 1210519800),
+			array('date:2007-03-01T13:00:00Z/P1Y2M10DT2H30M', 1172754000, 1210519799),
+			array('date:P1Y2M10DT2H30M/2008-05-11T15:30:00Z', 1172754001, 1210519800),
 			array('date:2007-03-01/2008-05-11', strtotime('2007-03-01'), strtotime('2008-05-12') - 1),
-			array('date:2007-03-01/', strtotime('2007-03-01'), ''),
-			array('date:/2008-05-11', '', strtotime('2008-05-12') - 1),
+			array('date:2007-03-01/', strtotime('2007-03-01'), null),
+			array('date:/2008-05-11', null, strtotime('2008-05-12') - 1),
 		);
 	}
 
 	/**
 	 * @dataProvider providePubdateSearch
-	 * @param string $input
-	 * @param string $min_pubdate_value
-	 * @param string $max_pubdate_value
 	 */
-	public function test__construct_whenInputContainsPubdate_setsPubdateValues($input, $min_pubdate_value, $max_pubdate_value) {
+	public function test__construct_whenInputContainsPubdate_setsPubdateValues(string $input, ?int $min_pubdate_value, ?int $max_pubdate_value): void {
 		$search = new FreshRSS_Search($input);
 		$this->assertEquals($min_pubdate_value, $search->getMinPubdate());
 		$this->assertEquals($max_pubdate_value, $search->getMaxPubdate());
 	}
 
 	/**
-	 * @return array
+	 * @return array<array<mixed>>
 	 */
-	public function providePubdateSearch() {
+	public function providePubdateSearch(): array {
 		return array(
-			array('pubdate:2007-03-01T13:00:00Z/2008-05-11T15:30:00Z', '1172754000', '1210519800'),
-			array('pubdate:2007-03-01T13:00:00Z/P1Y2M10DT2H30M', '1172754000', '1210519799'),
-			array('pubdate:P1Y2M10DT2H30M/2008-05-11T15:30:00Z', '1172754001', '1210519800'),
+			array('pubdate:2007-03-01T13:00:00Z/2008-05-11T15:30:00Z', 1172754000, 1210519800),
+			array('pubdate:2007-03-01T13:00:00Z/P1Y2M10DT2H30M', 1172754000, 1210519799),
+			array('pubdate:P1Y2M10DT2H30M/2008-05-11T15:30:00Z', 1172754001, 1210519800),
 			array('pubdate:2007-03-01/2008-05-11', strtotime('2007-03-01'), strtotime('2008-05-12') - 1),
-			array('pubdate:2007-03-01/', strtotime('2007-03-01'), ''),
-			array('pubdate:/2008-05-11', '', strtotime('2008-05-12') - 1),
+			array('pubdate:2007-03-01/', strtotime('2007-03-01'), null),
+			array('pubdate:/2008-05-11', null, strtotime('2008-05-12') - 1),
 		);
 	}
 
 	/**
 	 * @dataProvider provideTagsSearch
-	 * @param string $input
-	 * @param string $tags_value
-	 * @param string|null $search_value
+	 * @param array<string>|null $tags_value
+	 * @param array<string>|null $search_value
 	 */
-	public function test__construct_whenInputContainsTags_setsTagsValue($input, $tags_value, $search_value) {
+	public function test__construct_whenInputContainsTags_setsTagsValue(string $input, ?array $tags_value, ?array $search_value): void {
 		$search = new FreshRSS_Search($input);
 		$this->assertEquals($tags_value, $search->getTags());
 		$this->assertEquals($search_value, $search->getSearch());
 	}
 
 	/**
-	 * @return array
+	 * @return array<array<string|array<string>|null>>
 	 */
-	public function provideTagsSearch() {
+	public function provideTagsSearch(): array {
 		return array(
 			array('#word1', array('word1'), null),
 			array('# word1', array(), array('#', 'word1')),
@@ -219,19 +208,15 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 
 	/**
 	 * @dataProvider provideMultipleSearch
-	 * @param string $input
-	 * @param string $author_value
-	 * @param string $min_date_value
-	 * @param string $max_date_value
-	 * @param string $intitle_value
-	 * @param string $inurl_value
-	 * @param string $min_pubdate_value
-	 * @param string $max_pubdate_value
-	 * @param array $tags_value
-	 * @param string|null $search_value
+	 * @param array<string>|null $author_value
+	 * @param array<string> $intitle_value
+	 * @param array<string>|null $inurl_value
+	 * @param array<string>|null $tags_value
+	 * @param array<string>|null $search_value
 	 */
-	public function test__construct_whenInputContainsMultipleKeywords_setsValues($input, $author_value, $min_date_value,
-			$max_date_value, $intitle_value, $inurl_value, $min_pubdate_value, $max_pubdate_value, $tags_value, $search_value) {
+	public function test__construct_whenInputContainsMultipleKeywords_setsValues(string $input, ?array $author_value, ?int $min_date_value,
+			?int $max_date_value, ?array $intitle_value, ?array $inurl_value, ?int $min_pubdate_value,
+			?int $max_pubdate_value, ?array $tags_value, ?array $search_value): void {
 		$search = new FreshRSS_Search($input);
 		$this->assertEquals($author_value, $search->getAuthor());
 		$this->assertEquals($min_date_value, $search->getMinDate());
@@ -245,7 +230,8 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals($input, $search->getRawInput());
 	}
 
-	public function provideMultipleSearch() {
+	/** @return array<array<mixed>> */
+	public function provideMultipleSearch(): array {
 		return array(
 			array(
 				'author:word1 date:2007-03-01/2008-05-11 intitle:word2 inurl:word3 pubdate:2007-03-01/2008-05-11 #word4 #word5',
@@ -302,13 +288,14 @@ class SearchTest extends PHPUnit\Framework\TestCase {
 	 * @dataProvider provideParentheses
 	 * @param array<string> $values
 	 */
-	public function test__construct_parentheses(string $input, string $sql, $values) {
+	public function test__construct_parentheses(string $input, string $sql, array $values): void {
 		list($filterValues, $filterSearch) = FreshRSS_EntryDAOPGSQL::sqlBooleanSearch('e.', new FreshRSS_BooleanSearch($input));
 		$this->assertEquals($sql, $filterSearch);
 		$this->assertEquals($values, $filterValues);
 	}
 
-	public function provideParentheses() {
+	/** @return array<array<mixed>> */
+	public function provideParentheses(): array {
 		return [
 			[
 				'f:1 (f:2 OR f:3 OR f:4) (f:5 OR (f:6 OR f:7))',
diff --git a/tests/app/Models/UserQueryTest.php b/tests/app/Models/UserQueryTest.php
index 7b1e88907..d8610a81b 100644
--- a/tests/app/Models/UserQueryTest.php
+++ b/tests/app/Models/UserQueryTest.php
@@ -5,21 +5,21 @@
  */
 class UserQueryTest extends PHPUnit\Framework\TestCase {
 
-	public function test__construct_whenAllQuery_storesAllParameters() {
+	public function test__construct_whenAllQuery_storesAllParameters(): void {
 		$query = array('get' => 'a');
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertEquals('all', $user_query->getGetName());
 		$this->assertEquals('all', $user_query->getGetType());
 	}
 
-	public function test__construct_whenFavoriteQuery_storesFavoriteParameters() {
+	public function test__construct_whenFavoriteQuery_storesFavoriteParameters(): void {
 		$query = array('get' => 's');
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertEquals('favorite', $user_query->getGetName());
 		$this->assertEquals('favorite', $user_query->getGetType());
 	}
 
-	public function test__construct_whenCategoryQueryAndNoDao_throwsException() {
+	public function test__construct_whenCategoryQueryAndNoDao_throwsException(): void {
 		$this->expectException(FreshRSS_DAO_Exception::class);
 		$this->expectExceptionMessage('Category DAO is not loaded in UserQuery');
 
@@ -27,13 +27,15 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		new FreshRSS_UserQuery($query);
 	}
 
-	public function test__construct_whenCategoryQuery_storesCategoryParameters() {
+	public function test__construct_whenCategoryQuery_storesCategoryParameters(): void {
 		$category_name = 'some category name';
+		/** @var FreshRSS_Category&PHPUnit\Framework\MockObject\MockObject */
 		$cat = $this->createMock('FreshRSS_Category');
 		$cat->expects($this->atLeastOnce())
 			->method('name')
 			->withAnyParameters()
 			->willReturn($category_name);
+		/** @var FreshRSS_CategoryDAO&PHPUnit\Framework\MockObject\MockObject */
 		$cat_dao = $this->createMock('FreshRSS_CategoryDAO');
 		$cat_dao->expects($this->atLeastOnce())
 			->method('searchById')
@@ -45,7 +47,7 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('category', $user_query->getGetType());
 	}
 
-	public function test__construct_whenFeedQueryAndNoDao_throwsException() {
+	public function test__construct_whenFeedQueryAndNoDao_throwsException(): void {
 		$this->expectException(FreshRSS_DAO_Exception::class);
 		$this->expectExceptionMessage('Feed DAO is not loaded in UserQuery');
 
@@ -53,13 +55,15 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		new FreshRSS_UserQuery($query);
 	}
 
-	public function test__construct_whenFeedQuery_storesFeedParameters() {
+	public function test__construct_whenFeedQuery_storesFeedParameters(): void {
 		$feed_name = 'some feed name';
-		$feed = $this->createMock('FreshRSS_Feed', array(), array('', false));
+		/** @var FreshRSS_Feed&PHPUnit\Framework\MockObject\MockObject */
+		$feed = $this->createMock('FreshRSS_Feed');
 		$feed->expects($this->atLeastOnce())
 			->method('name')
 			->withAnyParameters()
 			->willReturn($feed_name);
+		/** @var FreshRSS_FeedDAO&PHPUnit\Framework\MockObject\MockObject */
 		$feed_dao = $this->createMock('FreshRSS_FeedDAO');
 		$feed_dao->expects($this->atLeastOnce())
 			->method('searchById')
@@ -71,48 +75,48 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('feed', $user_query->getGetType());
 	}
 
-	public function test__construct_whenUnknownQuery_doesStoreParameters() {
+	public function test__construct_whenUnknownQuery_doesStoreParameters(): void {
 		$query = array('get' => 'q');
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertEmpty($user_query->getGetName());
 		$this->assertEmpty($user_query->getGetType());
 	}
 
-	public function test__construct_whenName_storesName() {
+	public function test__construct_whenName_storesName(): void {
 		$name = 'some name';
 		$query = array('name' => $name);
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertEquals($name, $user_query->getName());
 	}
 
-	public function test__construct_whenOrder_storesOrder() {
+	public function test__construct_whenOrder_storesOrder(): void {
 		$order = 'some order';
 		$query = array('order' => $order);
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertEquals($order, $user_query->getOrder());
 	}
 
-	public function test__construct_whenState_storesState() {
+	public function test__construct_whenState_storesState(): void {
 		$state = FreshRSS_Entry::STATE_ALL;
 		$query = array('state' => $state);
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertEquals($state, $user_query->getState());
 	}
 
-	public function test__construct_whenUrl_storesUrl() {
+	public function test__construct_whenUrl_storesUrl(): void {
 		$url = 'some url';
 		$query = array('url' => $url);
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertEquals($url, $user_query->getUrl());
 	}
 
-	public function testToArray_whenNoData_returnsEmptyArray() {
+	public function testToArray_whenNoData_returnsEmptyArray(): void {
 		$user_query = new FreshRSS_UserQuery(array());
 		$this->assertIsIterable($user_query->toArray());
 		$this->assertCount(0, $user_query->toArray());
 	}
 
-	public function testToArray_whenData_returnsArray() {
+	public function testToArray_whenData_returnsArray(): void {
 		$query = array(
 			'get' => 's',
 			'name' => 'some name',
@@ -127,7 +131,7 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals($query, $user_query->toArray());
 	}
 
-	public function testHasSearch_whenSearch_returnsTrue() {
+	public function testHasSearch_whenSearch_returnsTrue(): void {
 		$query = array(
 			'search' => 'some search',
 		);
@@ -135,31 +139,33 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		$this->assertTrue($user_query->hasSearch());
 	}
 
-	public function testHasSearch_whenNoSearch_returnsFalse() {
+	public function testHasSearch_whenNoSearch_returnsFalse(): void {
 		$user_query = new FreshRSS_UserQuery(array());
 		$this->assertFalse($user_query->hasSearch());
 	}
 
-	public function testHasParameters_whenAllQuery_returnsFalse() {
+	public function testHasParameters_whenAllQuery_returnsFalse(): void {
 		$query = array('get' => 'a');
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertFalse($user_query->hasParameters());
 	}
 
-	public function testHasParameters_whenNoParameter_returnsFalse() {
+	public function testHasParameters_whenNoParameter_returnsFalse(): void {
 		$query = array();
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertFalse($user_query->hasParameters());
 	}
 
-	public function testHasParameters_whenParameter_returnTrue() {
+	public function testHasParameters_whenParameter_returnTrue(): void {
 		$query = array('get' => 's');
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertTrue($user_query->hasParameters());
 	}
 
-	public function testIsDeprecated_whenCategoryExists_returnFalse() {
+	public function testIsDeprecated_whenCategoryExists_returnFalse(): void {
+		/** @var FreshRSS_Category&PHPUnit\Framework\MockObject\MockObject */
 		$cat = $this->createMock('FreshRSS_Category');
+		/** @var FreshRSS_CategoryDAO&PHPUnit\Framework\MockObject\MockObject */
 		$cat_dao = $this->createMock('FreshRSS_CategoryDAO');
 		$cat_dao->expects($this->atLeastOnce())
 			->method('searchById')
@@ -170,7 +176,8 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		$this->assertFalse($user_query->isDeprecated());
 	}
 
-	public function testIsDeprecated_whenCategoryDoesNotExist_returnTrue() {
+	public function testIsDeprecated_whenCategoryDoesNotExist_returnTrue(): void {
+		/** @var FreshRSS_CategoryDAO&PHPUnit\Framework\MockObject\MockObject */
 		$cat_dao = $this->createMock('FreshRSS_CategoryDAO');
 		$cat_dao->expects($this->atLeastOnce())
 			->method('searchById')
@@ -181,8 +188,10 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		$this->assertTrue($user_query->isDeprecated());
 	}
 
-	public function testIsDeprecated_whenFeedExists_returnFalse() {
-		$feed = $this->createMock('FreshRSS_Feed', array(), array('', false));
+	public function testIsDeprecated_whenFeedExists_returnFalse(): void {
+		/** @var FreshRSS_Feed&PHPUnit\Framework\MockObject\MockObject */
+		$feed = $this->createMock('FreshRSS_Feed');
+		/** @var FreshRSS_FeedDAO&PHPUnit\Framework\MockObject\MockObject */
 		$feed_dao = $this->createMock('FreshRSS_FeedDAO');
 		$feed_dao->expects($this->atLeastOnce())
 			->method('searchById')
@@ -193,7 +202,8 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		$this->assertFalse($user_query->isDeprecated());
 	}
 
-	public function testIsDeprecated_whenFeedDoesNotExist_returnTrue() {
+	public function testIsDeprecated_whenFeedDoesNotExist_returnTrue(): void {
+		/** @var FreshRSS_FeedDAO&PHPUnit\Framework\MockObject\MockObject */
 		$feed_dao = $this->createMock('FreshRSS_FeedDAO');
 		$feed_dao->expects($this->atLeastOnce())
 			->method('searchById')
@@ -204,19 +214,19 @@ class UserQueryTest extends PHPUnit\Framework\TestCase {
 		$this->assertTrue($user_query->isDeprecated());
 	}
 
-	public function testIsDeprecated_whenAllQuery_returnFalse() {
+	public function testIsDeprecated_whenAllQuery_returnFalse(): void {
 		$query = array('get' => 'a');
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertFalse($user_query->isDeprecated());
 	}
 
-	public function testIsDeprecated_whenFavoriteQuery_returnFalse() {
+	public function testIsDeprecated_whenFavoriteQuery_returnFalse(): void {
 		$query = array('get' => 's');
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertFalse($user_query->isDeprecated());
 	}
 
-	public function testIsDeprecated_whenUnknownQuery_returnFalse() {
+	public function testIsDeprecated_whenUnknownQuery_returnFalse(): void {
 		$query = array('get' => 'q');
 		$user_query = new FreshRSS_UserQuery($query);
 		$this->assertFalse($user_query->isDeprecated());
diff --git a/tests/app/Utils/passwordUtilTest.php b/tests/app/Utils/passwordUtilTest.php
index ddccb784f..113476c63 100644
--- a/tests/app/Utils/passwordUtilTest.php
+++ b/tests/app/Utils/passwordUtilTest.php
@@ -1,7 +1,7 @@
 <?php
 
 class passwordUtilTest extends PHPUnit\Framework\TestCase {
-	public function testCheck() {
+	public function testCheck(): void {
 		$password = '1234567';
 
 		$ok = FreshRSS_password_Util::check($password);
@@ -9,7 +9,7 @@ class passwordUtilTest extends PHPUnit\Framework\TestCase {
 		$this->assertTrue($ok);
 	}
 
-	public function testCheckReturnsFalseIfEmpty() {
+	public function testCheckReturnsFalseIfEmpty(): void {
 		$password = '';
 
 		$ok = FreshRSS_password_Util::check($password);
@@ -17,7 +17,7 @@ class passwordUtilTest extends PHPUnit\Framework\TestCase {
 		$this->assertFalse($ok);
 	}
 
-	public function testCheckReturnsFalseIfLessThan7Characters() {
+	public function testCheckReturnsFalseIfLessThan7Characters(): void {
 		$password = '123456';
 
 		$ok = FreshRSS_password_Util::check($password);
diff --git a/tests/cli/i18n/I18nCompletionValidatorTest.php b/tests/cli/i18n/I18nCompletionValidatorTest.php
index 1aa871f20..1a361823d 100644
--- a/tests/cli/i18n/I18nCompletionValidatorTest.php
+++ b/tests/cli/i18n/I18nCompletionValidatorTest.php
@@ -4,6 +4,7 @@ require_once __DIR__ . '/../../../cli/i18n/I18nCompletionValidator.php';
 require_once __DIR__ . '/../../../cli/i18n/I18nValue.php';
 
 class I18nCompletionValidatorTest extends PHPUnit\Framework\TestCase {
+	/** @var I18nValue&PHPUnit\Framework\MockObject\MockObject */
 	private $value;
 
 	public function setUp(): void {
@@ -12,7 +13,7 @@ class I18nCompletionValidatorTest extends PHPUnit\Framework\TestCase {
 			->getMock();
 	}
 
-	public function testDisplayReport() {
+	public function testDisplayReport(): void {
 		$validator = new I18nCompletionValidator([], []);
 
 		$this->assertEquals("There is no data.\n", $validator->displayReport());
@@ -40,13 +41,13 @@ class I18nCompletionValidatorTest extends PHPUnit\Framework\TestCase {
 		$validator->displayReport();
 	}
 
-	public function testValidateWhenNoData() {
+	public function testValidateWhenNoData(): void {
 		$validator = new I18nCompletionValidator([], []);
 		$this->assertTrue($validator->validate());
 		$this->assertEquals('', $validator->displayResult());
 	}
 
-	public function testValidateWhenKeyIsMissing() {
+	public function testValidateWhenKeyIsMissing(): void {
 		$validator = new I18nCompletionValidator([
 			'file1.php' => [
 				'file1.l1.l2.k1' => $this->value,
@@ -60,7 +61,7 @@ class I18nCompletionValidatorTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals("Missing key file1.l1.l2.k1\nMissing key file2.l1.l2.k1\n", $validator->displayResult());
 	}
 
-	public function testValidateWhenKeyIsIgnored() {
+	public function testValidateWhenKeyIsIgnored(): void {
 		$this->value->expects($this->exactly(2))
 			->method('isIgnore')
 			->willReturn(true);
@@ -85,7 +86,7 @@ class I18nCompletionValidatorTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('', $validator->displayResult());
 	}
 
-	public function testValidateWhenValueIsEqual() {
+	public function testValidateWhenValueIsEqual(): void {
 		$this->value->expects($this->exactly(2))
 			->method('isIgnore')
 			->willReturn(false);
@@ -113,7 +114,7 @@ class I18nCompletionValidatorTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals("Untranslated key file1.l1.l2.k1 - \nUntranslated key file2.l1.l2.k1 - \n", $validator->displayResult());
 	}
 
-	public function testValidateWhenValueIsDifferent() {
+	public function testValidateWhenValueIsDifferent(): void {
 		$this->value->expects($this->exactly(2))
 			->method('isIgnore')
 			->willReturn(false);
diff --git a/tests/cli/i18n/I18nDataTest.php b/tests/cli/i18n/I18nDataTest.php
index b27ad830c..37811c193 100644
--- a/tests/cli/i18n/I18nDataTest.php
+++ b/tests/cli/i18n/I18nDataTest.php
@@ -4,7 +4,9 @@ require_once __DIR__ . '/../../../cli/i18n/I18nData.php';
 require_once __DIR__ . '/../../../cli/i18n/I18nValue.php';
 
 class I18nDataTest extends PHPUnit\Framework\TestCase {
+	/** @var array<string,array<string,array<string,I18nValue>>> */
 	private $referenceData;
+	/** @var I18nValue&PHPUnit\Framework\MockObject\MockObject */
 	private $value;
 
 	public function setUp(): void {
@@ -31,12 +33,12 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		];
 	}
 
-	public function testConstructWhenReferenceOnly() {
+	public function testConstructWhenReferenceOnly(): void {
 		$data = new I18nData($this->referenceData);
 		$this->assertEquals($this->referenceData, $data->getData());
 	}
 
-	public function testConstructorWhenLanguageIsMissingFile() {
+	public function testConstructorWhenLanguageIsMissingFile(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [
 				'file1.php' => [
@@ -79,7 +81,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getData());
 	}
 
-	public function testConstructorWhenLanguageIsMissingKeys() {
+	public function testConstructorWhenLanguageIsMissingKeys(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [
 				'file1.php' => [
@@ -125,7 +127,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getData());
 	}
 
-	public function testConstructorWhenLanguageHasExtraKeys() {
+	public function testConstructorWhenLanguageHasExtraKeys(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [
 				'file1.php' => [
@@ -179,7 +181,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getData());
 	}
 
-	public function testConstructorWhenValueIsIdenticalAndIsMarkedAsIgnore() {
+	public function testConstructorWhenValueIsIdenticalAndIsMarkedAsIgnore(): void {
 		$value = $this->getMockBuilder(I18nValue::class)
 			->disableOriginalConstructor()
 			->getMock();
@@ -204,7 +206,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		new I18nData($rawData);
 	}
 
-	public function testConstructorWhenValueIsIdenticalAndIsNotMarkedAsIgnore() {
+	public function testConstructorWhenValueIsIdenticalAndIsNotMarkedAsIgnore(): void {
 		$value = $this->getMockBuilder(I18nValue::class)
 			->disableOriginalConstructor()
 			->getMock();
@@ -229,7 +231,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		new I18nData($rawData);
 	}
 
-	public function testConstructorWhenValueIsDifferentAndIsMarkedAsToDo() {
+	public function testConstructorWhenValueIsDifferentAndIsMarkedAsToDo(): void {
 		$value = $this->getMockBuilder(I18nValue::class)
 			->disableOriginalConstructor()
 			->getMock();
@@ -249,7 +251,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		new I18nData($rawData);
 	}
 
-	public function testConstructorWhenValueIsDifferentAndIsNotMarkedAsTodo() {
+	public function testConstructorWhenValueIsDifferentAndIsNotMarkedAsTodo(): void {
 		$value = $this->getMockBuilder(I18nValue::class)
 			->disableOriginalConstructor()
 			->getMock();
@@ -269,7 +271,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		new I18nData($rawData);
 	}
 
-	public function testGetAvailableLanguagesWhenTheyAreSorted() {
+	public function testGetAvailableLanguagesWhenTheyAreSorted(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [],
 			'nl' => [],
@@ -282,7 +284,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getAvailableLanguages());
 	}
 
-	public function testGetAvailableLanguagesWhenTheyAreNotSorted() {
+	public function testGetAvailableLanguagesWhenTheyAreNotSorted(): void {
 		$rawData = array_merge($this->referenceData, [
 			'nl' => [],
 			'fr' => [],
@@ -297,14 +299,14 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getAvailableLanguages());
 	}
 
-	public function testAddLanguageWhenLanguageExists() {
+	public function testAddLanguageWhenLanguageExists(): void {
 		$this->expectException(\Exception::class);
 		$this->expectExceptionMessage('The selected language already exist.');
 		$data = new I18nData($this->referenceData);
 		$data->addLanguage('en');
 	}
 
-	public function testAddLanguageWhenNoReferenceProvided() {
+	public function testAddLanguageWhenNoReferenceProvided(): void {
 		$data = new I18nData($this->referenceData);
 		$data->addLanguage('fr');
 		$this->assertEquals([
@@ -341,7 +343,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getData());
 	}
 
-	public function testAddLanguageWhenUnknownReferenceProvided() {
+	public function testAddLanguageWhenUnknownReferenceProvided(): void {
 		$data = new I18nData($this->referenceData);
 		$data->addLanguage('fr', 'unknown');
 		$this->assertEquals([
@@ -378,7 +380,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getData());
 	}
 
-	public function testAddLanguageWhenKnownReferenceProvided() {
+	public function testAddLanguageWhenKnownReferenceProvided(): void {
 		$data = new I18nData($this->referenceData);
 		$data->addLanguage('fr', 'en');
 		$this->assertEquals([
@@ -415,24 +417,24 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getData());
 	}
 
-	public function testIsKnownWhenKeyExists() {
+	public function testIsKnownWhenKeyExists(): void {
 		$data = new I18nData($this->referenceData);
 		$this->assertTrue($data->isKnown('file2.l1.l2.k2'));
 	}
 
-	public function testIsKnownWhenKeyDoesNotExist() {
+	public function testIsKnownWhenKeyDoesNotExist(): void {
 		$data = new I18nData($this->referenceData);
 		$this->assertFalse($data->isKnown('file2.l1.l2.k3'));
 	}
 
-	public function testAddKeyWhenKeyExists() {
+	public function testAddKeyWhenKeyExists(): void {
 		$this->expectException(\Exception::class);
 		$this->expectExceptionMessage('The selected key already exist.');
 		$data = new I18nData($this->referenceData);
 		$data->addKey('file2.l1.l2.k1', 'value');
 	}
 
-	public function testAddKeyWhenParentKeyExists() {
+	public function testAddKeyWhenParentKeyExists(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [],
 		]);
@@ -447,7 +449,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$this->assertTrue($data->isKnown('file2.l1.l2.k1.sk1'));
 	}
 
-	public function testAddKeyWhenKeyIsParent() {
+	public function testAddKeyWhenKeyIsParent(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [],
 		]);
@@ -462,7 +464,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$this->assertTrue($data->isKnown('file1.l1.l2.k2'));
 	}
 
-	public function testAddKey() {
+	public function testAddKey(): void {
 		$getTargetedValue = static function (I18nData $data, string $language) {
 			return $data->getData()[$language]['file2.php']['file2.l1.l2.k3'];
 		};
@@ -484,21 +486,21 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals($frValue, $enValue);
 	}
 
-	public function testAddValueWhenLanguageDoesNotExist() {
+	public function testAddValueWhenLanguageDoesNotExist(): void {
 		$this->expectException(\Exception::class);
 		$this->expectExceptionMessage('The selected language does not exist.');
 		$data = new I18nData($this->referenceData);
 		$data->addValue('file2.l1.l2.k2', 'new value', 'fr');
 	}
 
-	public function testAddValueWhenKeyDoesNotExist() {
+	public function testAddValueWhenKeyDoesNotExist(): void {
 		$this->expectException(\Exception::class);
 		$this->expectExceptionMessage('The selected key does not exist for the selected language.');
 		$data = new I18nData($this->referenceData);
 		$data->addValue('unknown key', 'new value', 'en');
 	}
 
-	public function testAddValueWhenLanguageIsReferenceAndValueInOtherLanguageHasNotChange() {
+	public function testAddValueWhenLanguageIsReferenceAndValueInOtherLanguageHasNotChange(): void {
 		$getTargetedValue = static function (I18nData $data, string $language) {
 			return $data->getData()[$language]['file2.php']['file2.l1.l2.k2'];
 		};
@@ -526,7 +528,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('new value', $afterFrValue->getValue());
 	}
 
-	public function testAddValueWhenLanguageIsReferenceAndValueInOtherLanguageHasChange() {
+	public function testAddValueWhenLanguageIsReferenceAndValueInOtherLanguageHasChange(): void {
 		$getTargetedValue = static function (I18nData $data, string $language) {
 			return $data->getData()[$language]['file2.php']['file2.l1.l2.k2'];
 		};
@@ -561,7 +563,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals($value, $afterFrValue);
 	}
 
-	public function testAddValueWhenLanguageIsNotReference() {
+	public function testAddValueWhenLanguageIsNotReference(): void {
 		$getTargetedValue = static function (I18nData $data, string $language) {
 			return $data->getData()[$language]['file2.php']['file2.l1.l2.k2'];
 		};
@@ -583,21 +585,21 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('new value', $afterFrValue->getValue());
 	}
 
-	public function testRemoveKeyWhenKeyDoesNotExist() {
+	public function testRemoveKeyWhenKeyDoesNotExist(): void {
 		$this->expectException(\Exception::class);
 		$this->expectExceptionMessage('The selected key does not exist.');
 		$data = new I18nData($this->referenceData);
 		$data->removeKey('Unknown key');
 	}
 
-	public function testRemoveKeyWhenKeyHasNoEmptySibling() {
+	public function testRemoveKeyWhenKeyHasNoEmptySibling(): void {
 		$this->expectException(\Exception::class);
 		$this->expectExceptionMessage('The selected key does not exist.');
 		$data = new I18nData($this->referenceData);
 		$data->removeKey('file1.l1.l2');
 	}
 
-	public function testRemoveKeyWhenKeyIsEmptySibling() {
+	public function testRemoveKeyWhenKeyIsEmptySibling(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [],
 		]);
@@ -635,7 +637,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getData());
 	}
 
-	public function testRemoveKeyWhenKeyIsTheOnlyChild() {
+	public function testRemoveKeyWhenKeyIsTheOnlyChild(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [],
 		]);
@@ -673,7 +675,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		], $data->getData());
 	}
 
-	public function testIgnore() {
+	public function testIgnore(): void {
 		$value = $this->getMockBuilder(I18nValue::class)
 			->disableOriginalConstructor()
 			->getMock();
@@ -695,7 +697,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$data->ignore('file1.l1.l2.k1', 'fr', false);
 	}
 
-	public function testIgnoreUnmodified() {
+	public function testIgnoreUnmodified(): void {
 		$value = $this->getMockBuilder(I18nValue::class)
 			->disableOriginalConstructor()
 			->getMock();
@@ -722,7 +724,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$data->ignore_unmodified('fr', false);
 	}
 
-	public function testGetLanguage() {
+	public function testGetLanguage(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [],
 			'nl' => [],
@@ -731,7 +733,7 @@ class I18nDataTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals($this->referenceData['en'], $data->getLanguage('en'));
 	}
 
-	public function testGetReferenceLanguage() {
+	public function testGetReferenceLanguage(): void {
 		$rawData = array_merge($this->referenceData, [
 			'fr' => [],
 			'nl' => [],
diff --git a/tests/cli/i18n/I18nFileTest.php b/tests/cli/i18n/I18nFileTest.php
index 26566ddf1..662c14608 100644
--- a/tests/cli/i18n/I18nFileTest.php
+++ b/tests/cli/i18n/I18nFileTest.php
@@ -3,7 +3,7 @@
 require_once __DIR__ . '/../../../cli/i18n/I18nFile.php';
 
 class I18nFileTest extends PHPUnit\Framework\TestCase {
-	public function test() {
+	public function test(): void {
 		$before = $this->computeFilesHash();
 
 		$file = new I18nFile();
@@ -15,7 +15,8 @@ class I18nFileTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals($before, $after);
 	}
 
-	private function computeFilesHash() {
+	/** @return array<string,string> */
+	private function computeFilesHash(): array {
 		$hashes = [];
 
 		$dirs = new DirectoryIterator(I18N_PATH);
diff --git a/tests/cli/i18n/I18nUsageValidatorTest.php b/tests/cli/i18n/I18nUsageValidatorTest.php
index 531e77c5d..fdd75bf64 100644
--- a/tests/cli/i18n/I18nUsageValidatorTest.php
+++ b/tests/cli/i18n/I18nUsageValidatorTest.php
@@ -4,6 +4,7 @@ require_once __DIR__ . '/../../../cli/i18n/I18nValue.php';
 require_once __DIR__ . '/../../../cli/i18n/I18nUsageValidator.php';
 
 class I18nUsageValidatorTest extends PHPUnit\Framework\TestCase {
+	/** @var I18nValue */
 	private $value;
 
 	public function setUp(): void {
@@ -12,7 +13,7 @@ class I18nUsageValidatorTest extends PHPUnit\Framework\TestCase {
 			->getMock();
 	}
 
-	public function testDisplayReport() {
+	public function testDisplayReport(): void {
 		$validator = new I18nUsageValidator([], []);
 
 		$this->assertEquals("There is no data.\n", $validator->displayReport());
@@ -40,13 +41,13 @@ class I18nUsageValidatorTest extends PHPUnit\Framework\TestCase {
 		$validator->displayReport();
 	}
 
-	public function testValidateWhenNoData() {
+	public function testValidateWhenNoData(): void {
 		$validator = new I18nUsageValidator([], []);
 		$this->assertTrue($validator->validate());
 		$this->assertEquals('', $validator->displayResult());
 	}
 
-	public function testValidateWhenParentKeyExistsWithoutTransformation() {
+	public function testValidateWhenParentKeyExistsWithoutTransformation(): void {
 		$validator = new I18nUsageValidator([
 			'file1' => [
 				'file1.l1.l2._' => $this->value,
@@ -62,7 +63,7 @@ class I18nUsageValidatorTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('', $validator->displayResult());
 	}
 
-	public function testValidateWhenParentKeyExistsWithTransformation() {
+	public function testValidateWhenParentKeyExistsWithTransformation(): void {
 		$validator = new I18nUsageValidator([
 			'file1' => [
 				'file1.l1.l2._' => $this->value,
@@ -78,7 +79,7 @@ class I18nUsageValidatorTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('', $validator->displayResult());
 	}
 
-	public function testValidateWhenParentKeyDoesNotExist() {
+	public function testValidateWhenParentKeyDoesNotExist(): void {
 		$validator = new I18nUsageValidator([
 			'file1' => [
 				'file1.l1.l2._' => $this->value,
@@ -91,7 +92,7 @@ class I18nUsageValidatorTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals("Unused key file1.l1.l2._ - \nUnused key file2.l1.l2._ - \n", $validator->displayResult());
 	}
 
-	public function testValidateWhenChildKeyExists() {
+	public function testValidateWhenChildKeyExists(): void {
 		$validator = new I18nUsageValidator([
 			'file1' => [
 				'file1.l1.l2.k1' => $this->value,
@@ -107,7 +108,7 @@ class I18nUsageValidatorTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('', $validator->displayResult());
 	}
 
-	public function testValidateWhenChildKeyDoesNotExist() {
+	public function testValidateWhenChildKeyDoesNotExist(): void {
 		$validator = new I18nUsageValidator([
 			'file1' => [
 				'file1.l1.l2.k1' => $this->value,
diff --git a/tests/cli/i18n/I18nValueTest.php b/tests/cli/i18n/I18nValueTest.php
index cabc8e072..7a1109a20 100644
--- a/tests/cli/i18n/I18nValueTest.php
+++ b/tests/cli/i18n/I18nValueTest.php
@@ -3,35 +3,35 @@
 require_once __DIR__ . '/../../../cli/i18n/I18nValue.php';
 
 class I18nValueTest extends PHPUnit\Framework\TestCase {
-	public function testConstructorWithoutState() {
+	public function testConstructorWithoutState(): void {
 		$value = new I18nValue('some value');
 		$this->assertEquals('some value', $value->getValue());
 		$this->assertFalse($value->isIgnore());
 		$this->assertFalse($value->isTodo());
 	}
 
-	public function testConstructorWithUnknownState() {
+	public function testConstructorWithUnknownState(): void {
 		$value = new I18nValue('some value -> unknown');
 		$this->assertEquals('some value', $value->getValue());
 		$this->assertFalse($value->isIgnore());
 		$this->assertFalse($value->isTodo());
 	}
 
-	public function testConstructorWithTodoState() {
+	public function testConstructorWithTodoState(): void {
 		$value = new I18nValue('some value -> todo');
 		$this->assertEquals('some value', $value->getValue());
 		$this->assertFalse($value->isIgnore());
 		$this->assertTrue($value->isTodo());
 	}
 
-	public function testConstructorWithIgnoreState() {
+	public function testConstructorWithIgnoreState(): void {
 		$value = new I18nValue('some value -> ignore');
 		$this->assertEquals('some value', $value->getValue());
 		$this->assertTrue($value->isIgnore());
 		$this->assertFalse($value->isTodo());
 	}
 
-	public function testClone() {
+	public function testClone(): void {
 		$value = new I18nValue('some value');
 		$clonedValue = clone $value;
 		$this->assertEquals('some value', $value->getValue());
@@ -42,21 +42,21 @@ class I18nValueTest extends PHPUnit\Framework\TestCase {
 		$this->assertTrue($clonedValue->isTodo());
 	}
 
-	public function testEqualWhenValueIsIdentical() {
+	public function testEqualWhenValueIsIdentical(): void {
 		$value = new I18nValue('some value');
 		$clonedValue = clone $value;
 		$this->assertTrue($value->equal($clonedValue));
 		$this->assertTrue($clonedValue->equal($value));
 	}
 
-	public function testEqualWhenValueIsDifferent() {
+	public function testEqualWhenValueIsDifferent(): void {
 		$value = new I18nValue('some value');
 		$otherValue = new I18nValue('some other value');
 		$this->assertFalse($value->equal($otherValue));
 		$this->assertFalse($otherValue->equal($value));
 	}
 
-	public function testStates() {
+	public function testStates(): void {
 		$reflectionProperty = new ReflectionProperty(I18nValue::class, 'state');
 		$reflectionProperty->setAccessible(true);
 
@@ -74,7 +74,7 @@ class I18nValueTest extends PHPUnit\Framework\TestCase {
 		$this->assertEquals('todo', $reflectionProperty->getValue($value));
 	}
 
-	public function testToString() {
+	public function testToString(): void {
 		$value = new I18nValue('some value');
 		$this->assertEquals('some value', $value->__toString());
 		$value->markAsTodo();
diff --git a/tests/fixtures/migrations/2019_12_22_FooBar.php b/tests/fixtures/migrations/2019_12_22_FooBar.php
index 4568ea8c9..21f673213 100644
--- a/tests/fixtures/migrations/2019_12_22_FooBar.php
+++ b/tests/fixtures/migrations/2019_12_22_FooBar.php
@@ -2,9 +2,9 @@
 
 class FreshRSS_Migration_2019_12_22_FooBar {
 	/**
-	 * @return boolean true if the migration was successful, false otherwise
+	 * @return bool true if the migration was successful, false otherwise
 	 */
-	public static function migrate() {
+	public static function migrate(): bool {
 		return true;
 	}
 }
diff --git a/tests/fixtures/migrations/2019_12_23_Baz.php b/tests/fixtures/migrations/2019_12_23_Baz.php
index c13b2a814..056b0836c 100644
--- a/tests/fixtures/migrations/2019_12_23_Baz.php
+++ b/tests/fixtures/migrations/2019_12_23_Baz.php
@@ -2,9 +2,9 @@
 
 class FreshRSS_Migration_2019_12_23_Baz {
 	/**
-	 * @return boolean true if the migration was successful, false otherwise
+	 * @return bool true if the migration was successful, false otherwise
 	 */
-	public static function migrate() {
+	public static function migrate(): bool {
 		return true;
 	}
 }
diff --git a/tests/fixtures/migrations_with_failing/2020_01_11_FooBar.php b/tests/fixtures/migrations_with_failing/2020_01_11_FooBar.php
index cdc2dd2c8..2edc79964 100644
--- a/tests/fixtures/migrations_with_failing/2020_01_11_FooBar.php
+++ b/tests/fixtures/migrations_with_failing/2020_01_11_FooBar.php
@@ -2,9 +2,9 @@
 
 class FreshRSS_Migration_2020_01_11_FooBar {
 	/**
-	 * @return boolean true if the migration was successful, false otherwise
+	 * @return bool true if the migration was successful, false otherwise
 	 */
-	public static function migrate() {
+	public static function migrate(): bool {
 		return true;
 	}
 }
diff --git a/tests/fixtures/migrations_with_failing/2020_01_12_Baz.php b/tests/fixtures/migrations_with_failing/2020_01_12_Baz.php
index cd8ff10f3..75f39f7b5 100644
--- a/tests/fixtures/migrations_with_failing/2020_01_12_Baz.php
+++ b/tests/fixtures/migrations_with_failing/2020_01_12_Baz.php
@@ -2,9 +2,9 @@
 
 class FreshRSS_Migration_2020_01_12_Baz {
 	/**
-	 * @return boolean true if the migration was successful, false otherwise
+	 * @return bool true if the migration was successful, false otherwise
 	 */
-	public static function migrate() {
+	public static function migrate(): bool {
 		return false;
 	}
 }
diff --git a/tests/lib/CssXPath/CssXPathTest.php b/tests/lib/CssXPath/CssXPathTest.php
index c6fe24fc8..8d5a943ec 100644
--- a/tests/lib/CssXPath/CssXPathTest.php
+++ b/tests/lib/CssXPath/CssXPathTest.php
@@ -2,7 +2,7 @@
 
 class CssXPathTest extends PHPUnit\Framework\TestCase
 {
-	public function testCssXPathTranslatorClassExists() {
+	public function testCssXPathTranslatorClassExists(): void {
 		$this->assertTrue(class_exists('Gt\\CssXPath\\Translator'));
 	}
 }
diff --git a/tests/lib/Minz/MigratorTest.php b/tests/lib/Minz/MigratorTest.php
index bcee45204..bd30ba87e 100644
--- a/tests/lib/Minz/MigratorTest.php
+++ b/tests/lib/Minz/MigratorTest.php
@@ -4,7 +4,7 @@ use PHPUnit\Framework\TestCase;
 
 class MigratorTest extends TestCase
 {
-	public function testAddMigration() {
+	public function testAddMigration(): void {
 		$migrator = new Minz_Migrator();
 
 		$migrator->addMigration('foo', function () {
@@ -17,7 +17,7 @@ class MigratorTest extends TestCase
 		$this->assertTrue($result);
 	}
 
-	public function testAddMigrationFailsIfUncallableMigration() {
+	public function testAddMigrationFailsIfUncallableMigration(): void {
 		$this->expectException(BadFunctionCallException::class);
 		$this->expectExceptionMessage('foo migration cannot be called.');
 
@@ -25,7 +25,7 @@ class MigratorTest extends TestCase
 		$migrator->addMigration('foo', null);
 	}
 
-	public function testMigrationsIsSorted() {
+	public function testMigrationsIsSorted(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('2_foo', function () {
 			return true;
@@ -43,7 +43,7 @@ class MigratorTest extends TestCase
 		$this->assertSame($expected_versions, array_keys($migrations));
 	}
 
-	public function testSetAppliedVersions() {
+	public function testSetAppliedVersions(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('foo', function () {
 			return true;
@@ -54,7 +54,7 @@ class MigratorTest extends TestCase
 		$this->assertSame(['foo'], $migrator->appliedVersions());
 	}
 
-	public function testSetAppliedVersionsTrimArgument() {
+	public function testSetAppliedVersionsTrimArgument(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('foo', function () {
 			return true;
@@ -65,7 +65,7 @@ class MigratorTest extends TestCase
 		$this->assertSame(['foo'], $migrator->appliedVersions());
 	}
 
-	public function testSetAppliedVersionsFailsIfMigrationDoesNotExist() {
+	public function testSetAppliedVersionsFailsIfMigrationDoesNotExist(): void {
 		$this->expectException(DomainException::class);
 		$this->expectExceptionMessage('foo migration does not exist.');
 
@@ -74,7 +74,7 @@ class MigratorTest extends TestCase
 		$migrator->setAppliedVersions(['foo']);
 	}
 
-	public function testVersions() {
+	public function testVersions(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('foo', function () {
 			return true;
@@ -88,7 +88,7 @@ class MigratorTest extends TestCase
 		$this->assertSame(['bar', 'foo'], $versions);
 	}
 
-	public function testMigrate() {
+	public function testMigrate(): void {
 		$migrator = new Minz_Migrator();
 		$spy = false;
 		$migrator->addMigration('foo', function () use (&$spy) {
@@ -106,7 +106,7 @@ class MigratorTest extends TestCase
 		], $result);
 	}
 
-	public function testMigrateCallsMigrationsInSortedOrder() {
+	public function testMigrateCallsMigrationsInSortedOrder(): void {
 		$migrator = new Minz_Migrator();
 		$spy_foo_1_is_called = false;
 		$migrator->addMigration('2_foo', function () use (&$spy_foo_1_is_called) {
@@ -126,7 +126,7 @@ class MigratorTest extends TestCase
 		], $result);
 	}
 
-	public function testMigrateDoesNotCallAppliedMigrations() {
+	public function testMigrateDoesNotCallAppliedMigrations(): void {
 		$migrator = new Minz_Migrator();
 		$spy = false;
 		$migrator->addMigration('1_foo', function () use (&$spy) {
@@ -141,7 +141,7 @@ class MigratorTest extends TestCase
 		$this->assertSame([], $result);
 	}
 
-	public function testMigrateCallNonAppliedBetweenTwoApplied() {
+	public function testMigrateCallNonAppliedBetweenTwoApplied(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('1_foo', function () {
 			return true;
@@ -162,7 +162,7 @@ class MigratorTest extends TestCase
 		], $result);
 	}
 
-	public function testMigrateWithMigrationReturningFalseDoesNotApplyVersion() {
+	public function testMigrateWithMigrationReturningFalseDoesNotApplyVersion(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('1_foo', function () {
 			return true;
@@ -180,7 +180,7 @@ class MigratorTest extends TestCase
 		], $result);
 	}
 
-	public function testMigrateWithMigrationReturningFalseDoesNotExecuteNextMigrations() {
+	public function testMigrateWithMigrationReturningFalseDoesNotExecuteNextMigrations(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('1_foo', function () {
 			return false;
@@ -200,7 +200,7 @@ class MigratorTest extends TestCase
 		], $result);
 	}
 
-	public function testMigrateWithFailingMigration() {
+	public function testMigrateWithFailingMigration(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('foo', function () {
 			throw new \Exception('Oops, it failed.');
@@ -214,7 +214,7 @@ class MigratorTest extends TestCase
 		], $result);
 	}
 
-	public function testUpToDate() {
+	public function testUpToDate(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('foo', function () {
 			return true;
@@ -226,7 +226,7 @@ class MigratorTest extends TestCase
 		$this->assertTrue($upToDate);
 	}
 
-	public function testUpToDateIfRemainingMigration() {
+	public function testUpToDateIfRemainingMigration(): void {
 		$migrator = new Minz_Migrator();
 		$migrator->addMigration('1_foo', function () {
 			return true;
@@ -241,7 +241,7 @@ class MigratorTest extends TestCase
 		$this->assertFalse($upToDate);
 	}
 
-	public function testUpToDateIfNoMigrations() {
+	public function testUpToDateIfNoMigrations(): void {
 		$migrator = new Minz_Migrator();
 
 		$upToDate = $migrator->upToDate();
@@ -249,7 +249,7 @@ class MigratorTest extends TestCase
 		$this->assertTrue($upToDate);
 	}
 
-	public function testConstructorLoadsDirectory() {
+	public function testConstructorLoadsDirectory(): void {
 		$migrations_path = TESTS_PATH . '/fixtures/migrations/';
 		$migrator = new Minz_Migrator($migrations_path);
 		$expected_versions = ['2019_12_22_FooBar', '2019_12_23_Baz'];
@@ -259,7 +259,7 @@ class MigratorTest extends TestCase
 		$this->assertSame($expected_versions, array_keys($migrations));
 	}
 
-	public function testExecute() {
+	public function testExecute(): void {
 		$migrations_path = TESTS_PATH . '/fixtures/migrations/';
 		$applied_migrations_path = tempnam('/tmp', 'applied_migrations.txt');
 
@@ -271,7 +271,7 @@ class MigratorTest extends TestCase
 		@unlink($applied_migrations_path);
 	}
 
-	public function testExecuteWithAlreadyAppliedMigration() {
+	public function testExecuteWithAlreadyAppliedMigration(): void {
 		$migrations_path = TESTS_PATH . '/fixtures/migrations/';
 		$applied_migrations_path = tempnam('/tmp', 'applied_migrations.txt');
 		file_put_contents($applied_migrations_path, '2019_12_22_FooBar');
@@ -284,7 +284,7 @@ class MigratorTest extends TestCase
 		@unlink($applied_migrations_path);
 	}
 
-	public function testExecuteWithAppliedMigrationInDifferentOrder() {
+	public function testExecuteWithAppliedMigrationInDifferentOrder(): void {
 		$migrations_path = TESTS_PATH . '/fixtures/migrations/';
 		$applied_migrations_path = tempnam('/tmp', 'applied_migrations.txt');
 		file_put_contents($applied_migrations_path, "2019_12_23_Baz\n2019_12_22_FooBar");
@@ -299,7 +299,7 @@ class MigratorTest extends TestCase
 		@unlink($applied_migrations_path);
 	}
 
-	public function testExecuteFailsIfVersionPathDoesNotExist() {
+	public function testExecuteFailsIfVersionPathDoesNotExist(): void {
 		$migrations_path = TESTS_PATH . '/fixtures/migrations/';
 		$applied_migrations_path = tempnam('/tmp', 'applied_migrations.txt');
 		$expected_result = "Cannot open the {$applied_migrations_path} file";
@@ -311,7 +311,7 @@ class MigratorTest extends TestCase
 		@unlink($applied_migrations_path);
 	}
 
-	public function testExecuteFailsIfAMigrationIsFailing() {
+	public function testExecuteFailsIfAMigrationIsFailing(): void {
 		$migrations_path = TESTS_PATH . '/fixtures/migrations_with_failing/';
 		$applied_migrations_path = tempnam('/tmp', 'applied_migrations.txt');
 		$expected_result = 'A migration failed to be applied, please see previous logs.';
diff --git a/tests/lib/PHPMailer/PHPMailerTest.php b/tests/lib/PHPMailer/PHPMailerTest.php
index 8fc14b815..b39cf2cb0 100644
--- a/tests/lib/PHPMailer/PHPMailerTest.php
+++ b/tests/lib/PHPMailer/PHPMailerTest.php
@@ -2,7 +2,7 @@
 
 class PHPMailerTest extends PHPUnit\Framework\TestCase
 {
-	public function testPHPMailerClassExists() {
+	public function testPHPMailerClassExists(): void {
 		$this->assertTrue(class_exists('PHPMailer\\PHPMailer\\PHPMailer'));
 	}
 }
diff --git a/tests/phpstan-next.txt b/tests/phpstan-next.txt
index 5b5b33e45..e2e081ecf 100644
--- a/tests/phpstan-next.txt
+++ b/tests/phpstan-next.txt
@@ -1,10 +1,48 @@
-# List of files, which are not yet passing PHPStan level 6 https://phpstan.org/user-guide/rule-levels
-# https://github.com/FreshRSS/FreshRSS/issues/4112
+# List of files, which are not yet passing PHPStan level 7 https://phpstan.org/user-guide/rule-levels
 # Used for automated tests to avoid regressions in files already passing that level.
 # Can be regenerated with something like:
-# find . -type d -name 'vendor' -prune -o -name '*.php' -exec sh -c 'vendor/bin/phpstan analyse --level 6 --memory-limit 512M {} >/dev/null 2>/dev/null || echo {}' \;
+# find . -type d -name 'vendor' -prune -o -name '*.php' -exec sh -c 'vendor/bin/phpstan analyse --level 7 --memory-limit 512M {} >/dev/null 2>/dev/null || echo {}' \;
 
-./app/install.php
+./app/Controllers/configureController.php
+./app/Controllers/feedController.php
+./app/Controllers/importExportController.php
+./app/Controllers/indexController.php
+./app/Controllers/updateController.php
+./app/Controllers/userController.php
+./app/Models/CategoryDAO.php
+./app/Models/Context.php
+./app/Models/DatabaseDAO.php
+./app/Models/DatabaseDAOPGSQL.php
+./app/Models/Entry.php
+./app/Models/EntryDAO.php
 ./app/Models/Feed.php
+./app/Models/FeedDAO.php
+./app/Models/ReadingMode.php
+./app/Models/Search.php
+./app/Models/Share.php
+./app/Models/StatsDAO.php
+./app/Models/TagDAO.php
+./app/Models/Themes.php
+./app/Models/UserQuery.php
+./app/Services/ExportService.php
 ./app/Services/ImportService.php
-./lib/Minz/Paginator.php
+./app/views/helpers/logs_pagination.phtml
+./app/views/index/reader.phtml
+./app/views/stats/index.phtml
+./app/views/stats/repartition.phtml
+./app/views/user/details.phtml
+./cli/check.translation.php
+./cli/delete-user.php
+./cli/do-install.php
+./cli/manipulate.translation.php
+./cli/user-info.php
+./lib/lib_date.php
+./lib/Minz/ActionController.php
+./lib/Minz/Error.php
+./lib/Minz/Mailer.php
+./lib/Minz/Migrator.php
+./lib/Minz/ModelPdo.php
+./lib/Minz/Request.php
+./p/api/greader.php
+./tests/cli/i18n/I18nFileTest.php
+./tests/lib/Minz/MigratorTest.php