Upgrade to PHP 8.1 (#6711)

* Upgrade to PHP 8.1
As discussed in https://github.com/FreshRSS/FreshRSS/discussions/5474

https://www.php.net/releases/8.0/en.php
https://www.php.net/releases/8.1/en.php

Upgrade to available native type declarations
https://php.net/language.types.declarations

Upgrade to https://phpunit.de/announcements/phpunit-10.html which requires PHP 8.1+ (good timing, as version 9 was not maintained anymore)

Upgrade `:oldest` Docker dev image to oldest Alpine version supporting PHP 8.1: Alpine 3.16, which includes PHP 8.1.22.

* Include 6736
https://github.com/FreshRSS/FreshRSS/pull/6736

4 files changed, 63 insertions, 88 deletions

diff --git a/tests/cli/CliOptionsParserTest.php b/tests/cli/CliOptionsParserTest.php
index facb5dbc5..046617721 100644
--- a/tests/cli/CliOptionsParserTest.php
+++ b/tests/cli/CliOptionsParserTest.php
@@ -52,163 +52,138 @@ final class CliOptionsOptionalAndRequiredTest extends CliOptionsParser {
 
 class CliOptionsParserTest extends TestCase {
 
-	public function testInvalidOptionSetWithValueReturnsError(): void {
-		$result = $this->runOptionalOptions('--invalid=invalid');
-
+	public static function testInvalidOptionSetWithValueReturnsError(): void {
+		$result = self::runOptionalOptions('--invalid=invalid');
 		self::assertEquals(['invalid' => 'unknown option: invalid'], $result->errors);
 	}
 
-	public function testInvalidOptionSetWithoutValueReturnsError(): void {
-		$result = $this->runOptionalOptions('--invalid');
-
+	public static function testInvalidOptionSetWithoutValueReturnsError(): void {
+		$result = self::runOptionalOptions('--invalid');
 		self::assertEquals(['invalid' => 'unknown option: invalid'], $result->errors);
 	}
 
-	public function testValidOptionSetWithValidValueAndInvalidOptionSetWithValueReturnsValueForValidOptionAndErrorForInvalidOption(): void {
-		$result = $this->runOptionalOptions('--string=string --invalid=invalid');
-
+	public static function testValidOptionSetWithValidValueAndInvalidOptionSetWithValueReturnsValueForValidOptionAndErrorForInvalidOption(): void {
+		$result = self::runOptionalOptions('--string=string --invalid=invalid');
 		self::assertEquals('string', $result->string);
 		self::assertEquals(['invalid' => 'unknown option: invalid'], $result->errors);
 	}
 
-	public function testOptionWithValueTypeOfStringSetOnceWithValidValueReturnsValueAsString(): void {
-		$result = $this->runOptionalOptions('--string=string');
-
+	public static function testOptionWithValueTypeOfStringSetOnceWithValidValueReturnsValueAsString(): void {
+		$result = self::runOptionalOptions('--string=string');
 		self::assertEquals('string', $result->string);
 	}
 
-	public function testOptionWithRequiredValueTypeOfIntSetOnceWithValidValueReturnsValueAsInt(): void {
-		$result = $this->runOptionalOptions('--int=111');
-
+	public static function testOptionWithRequiredValueTypeOfIntSetOnceWithValidValueReturnsValueAsInt(): void {
+		$result = self::runOptionalOptions('--int=111');
 		self::assertEquals(111, $result->int);
 	}
 
-	public function testOptionWithRequiredValueTypeOfBoolSetOnceWithValidValueReturnsValueAsBool(): void {
-		$result = $this->runOptionalOptions('--bool=on');
-
+	public static function testOptionWithRequiredValueTypeOfBoolSetOnceWithValidValueReturnsValueAsBool(): void {
+		$result = self::runOptionalOptions('--bool=on');
 		self::assertEquals(true, $result->bool);
 	}
 
-	public function testOptionWithValueTypeOfArrayOfStringSetOnceWithValidValueReturnsValueAsArrayOfString(): void {
-		$result = $this->runOptionalOptions('--array-of-string=string');
-
+	public static function testOptionWithValueTypeOfArrayOfStringSetOnceWithValidValueReturnsValueAsArrayOfString(): void {
+		$result = self::runOptionalOptions('--array-of-string=string');
 		self::assertEquals(['string'], $result->arrayOfString);
 	}
 
-	public function testOptionWithValueTypeOfStringSetMultipleTimesWithValidValueReturnsLastValueSetAsString(): void {
-		$result = $this->runOptionalOptions('--string=first --string=second');
-
+	public static function testOptionWithValueTypeOfStringSetMultipleTimesWithValidValueReturnsLastValueSetAsString(): void {
+		$result = self::runOptionalOptions('--string=first --string=second');
 		self::assertEquals('second', $result->string);
 	}
 
-	public function testOptionWithValueTypeOfIntSetMultipleTimesWithValidValueReturnsLastValueSetAsInt(): void {
-		$result = $this->runOptionalOptions('--int=111 --int=222');
-
+	public static function testOptionWithValueTypeOfIntSetMultipleTimesWithValidValueReturnsLastValueSetAsInt(): void {
+		$result = self::runOptionalOptions('--int=111 --int=222');
 		self::assertEquals(222, $result->int);
 	}
 
-	public function testOptionWithValueTypeOfBoolSetMultipleTimesWithValidValueReturnsLastValueSetAsBool(): void {
-		$result = $this->runOptionalOptions('--bool=on --bool=off');
-
+	public static function testOptionWithValueTypeOfBoolSetMultipleTimesWithValidValueReturnsLastValueSetAsBool(): void {
+		$result = self::runOptionalOptions('--bool=on --bool=off');
 		self::assertEquals(false, $result->bool);
 	}
 
-	public function testOptionWithValueTypeOfArrayOfStringSetMultipleTimesWithValidValueReturnsAllSetValuesAsArrayOfString(): void {
-		$result = $this->runOptionalOptions('--array-of-string=first --array-of-string=second');
-
+	public static function testOptionWithValueTypeOfArrayOfStringSetMultipleTimesWithValidValueReturnsAllSetValuesAsArrayOfString(): void {
+		$result = self::runOptionalOptions('--array-of-string=first --array-of-string=second');
 		self::assertEquals(['first', 'second'], $result->arrayOfString);
 	}
 
-	public function testOptionWithValueTypeOfIntSetWithInvalidValueReturnsAnError(): void {
-		$result = $this->runOptionalOptions('--int=one');
-
+	public static function testOptionWithValueTypeOfIntSetWithInvalidValueReturnsAnError(): void {
+		$result = self::runOptionalOptions('--int=one');
 		self::assertEquals(['int' => 'invalid input: int must be an integer'], $result->errors);
 	}
 
-	public function testOptionWithValueTypeOfBoolSetWithInvalidValuesReturnsAnError(): void {
-		$result = $this->runOptionalOptions('--bool=bad');
-
+	public static function testOptionWithValueTypeOfBoolSetWithInvalidValuesReturnsAnError(): void {
+		$result = self::runOptionalOptions('--bool=bad');
 		self::assertEquals(['bool' => 'invalid input: bool must be a boolean'], $result->errors);
 	}
 
-	public function testOptionWithValueTypeOfIntSetMultipleTimesWithValidAndInvalidValuesReturnsLastValidValueSetAsIntAndError(): void {
-		$result = $this->runOptionalOptions('--int=111 --int=one --int=222 --int=two');
-
+	public static function testOptionWithValueTypeOfIntSetMultipleTimesWithValidAndInvalidValuesReturnsLastValidValueSetAsIntAndError(): void {
+		$result = self::runOptionalOptions('--int=111 --int=one --int=222 --int=two');
 		self::assertEquals(222, $result->int);
 		self::assertEquals(['int' => 'invalid input: int must be an integer'], $result->errors);
 	}
 
-	public function testOptionWithValueTypeOfBoolSetMultipleTimesWithWithValidAndInvalidValuesReturnsLastValidValueSetAsBoolAndError(): void {
-		$result = $this->runOptionalOptions('--bool=on --bool=good --bool=off --bool=bad');
-
+	public static function testOptionWithValueTypeOfBoolSetMultipleTimesWithWithValidAndInvalidValuesReturnsLastValidValueSetAsBoolAndError(): void {
+		$result = self::runOptionalOptions('--bool=on --bool=good --bool=off --bool=bad');
 		self::assertEquals(false, $result->bool);
 		self::assertEquals(['bool' => 'invalid input: bool must be a boolean'], $result->errors);
 	}
 
-	public function testNotSetOptionWithDefaultInputReturnsDefaultInput(): void {
-		$result = $this->runOptionalOptions('');
-
+	public static function testNotSetOptionWithDefaultInputReturnsDefaultInput(): void {
+		$result = self::runOptionalOptions('');
 		self::assertEquals('default', $result->defaultInput);
 	}
 
-	public function testOptionWithDefaultInputSetWithValidValueReturnsCorrectlyTypedValue(): void {
-		$result = $this->runOptionalOptions('--default-input=input');
-
+	public static function testOptionWithDefaultInputSetWithValidValueReturnsCorrectlyTypedValue(): void {
+		$result = self::runOptionalOptions('--default-input=input');
 		self::assertEquals('input', $result->defaultInput);
 	}
 
-	public function testOptionWithOptionalValueSetWithoutValueReturnsEmptyString(): void {
-		$result = $this->runOptionalOptions('--optional-value');
-
+	public static function testOptionWithOptionalValueSetWithoutValueReturnsEmptyString(): void {
+		$result = self::runOptionalOptions('--optional-value');
 		self::assertEquals('', $result->optionalValue);
 	}
 
-	public function testOptionWithOptionalValueDefaultSetWithoutValueReturnsOptionalValueDefault(): void {
-		$result = $this->runOptionalOptions('--optional-value-with-default');
-
+	public static function testOptionWithOptionalValueDefaultSetWithoutValueReturnsOptionalValueDefault(): void {
+		$result = self::runOptionalOptions('--optional-value-with-default');
 		self::assertEquals(true, $result->optionalValueWithDefault);
 	}
 
-	public function testNotSetOptionWithOptionalValueDefaultAndDefaultInputReturnsDefaultInput(): void {
-		$result = $this->runOptionalOptions('');
-
+	public static function testNotSetOptionWithOptionalValueDefaultAndDefaultInputReturnsDefaultInput(): void {
+		$result = self::runOptionalOptions('');
 		self::assertEquals('default', $result->defaultInputAndOptionalValueWithDefault);
 	}
 
-	public function testOptionWithOptionalValueDefaultAndDefaultInputSetWithoutValueReturnsOptionalValueDefault(): void {
-		$result = $this->runOptionalOptions('--default-input-and-optional-value-with-default');
-
+	public static function testOptionWithOptionalValueDefaultAndDefaultInputSetWithoutValueReturnsOptionalValueDefault(): void {
+		$result = self::runOptionalOptions('--default-input-and-optional-value-with-default');
 		self::assertEquals('optional', $result->defaultInputAndOptionalValueWithDefault);
 	}
 
-	public function testRequiredOptionNotSetReturnsError(): void {
-		$result = $this->runOptionalAndRequiredOptions('');
-
+	public static function testRequiredOptionNotSetReturnsError(): void {
+		$result = self::runOptionalAndRequiredOptions('');
 		self::assertEquals(['required' => 'invalid input: required cannot be empty'], $result->errors);
 	}
 
-	public function testOptionSetWithDeprecatedAliasGeneratesDeprecationWarningAndReturnsValue(): void {
-		$result = $this->runCommandReadingStandardError('--deprecated-string=string');
-
+	public static function testOptionSetWithDeprecatedAliasGeneratesDeprecationWarningAndReturnsValue(): void {
+		$result = self::runCommandReadingStandardError('--deprecated-string=string');
 		self::assertEquals('FreshRSS deprecation warning: the CLI option(s): deprecated-string are deprecated ' .
 				'and will be removed in a future release. Use: string instead',
 			$result
 		);
 
-		$result = $this->runOptionalOptions('--deprecated-string=string');
-
+		$result = self::runOptionalOptions('--deprecated-string=string');
 		self::assertEquals('string', $result->string);
 	}
 
-	public function testAlwaysReturnUsageMessageWithUsageInfoForAllOptions(): void {
-		$result = $this->runOptionalAndRequiredOptions('');
-
+	public static function testAlwaysReturnUsageMessageWithUsageInfoForAllOptions(): void {
+		$result = self::runOptionalAndRequiredOptions('');
 		self::assertEquals('Usage: cli-parser-test.php --required=<required> [-s --string=<string>] [-i --int=<int>] [-b --bool=<bool>] [-f --flag]',
 			$result->usage,
 		);
 	}
 
-	private function runOptionalOptions(string $cliOptions = ''): CliOptionsOptionalTest {
+	private static function runOptionalOptions(string $cliOptions = ''): CliOptionsOptionalTest {
 		$command = __DIR__ . '/cli-parser-test.php';
 		$className = CliOptionsOptionalTest::class;
 
@@ -219,7 +194,7 @@ class CliOptionsParserTest extends TestCase {
 		return $result;
 	}
 
-	private function runOptionalAndRequiredOptions(string $cliOptions = ''): CliOptionsOptionalAndRequiredTest {
+	private static function runOptionalAndRequiredOptions(string $cliOptions = ''): CliOptionsOptionalAndRequiredTest {
 		$command = __DIR__ . '/cli-parser-test.php';
 		$className = CliOptionsOptionalAndRequiredTest::class;
 
@@ -230,7 +205,7 @@ class CliOptionsParserTest extends TestCase {
 		return $result;
 	}
 
-	private function runCommandReadingStandardError(string $cliOptions = ''): string {
+	private static function runCommandReadingStandardError(string $cliOptions = ''): string {
 		$command = __DIR__ . '/cli-parser-test.php';
 		$className = CliOptionsOptionalTest::class;
 
diff --git a/tests/cli/i18n/I18nCompletionValidatorTest.php b/tests/cli/i18n/I18nCompletionValidatorTest.php
index bc992edbe..f16285005 100644
--- a/tests/cli/i18n/I18nCompletionValidatorTest.php
+++ b/tests/cli/i18n/I18nCompletionValidatorTest.php
@@ -42,7 +42,7 @@ class I18nCompletionValidatorTest extends PHPUnit\Framework\TestCase {
 		$validator->displayReport();
 	}
 
-	public function testValidateWhenNoData(): void {
+	public static function testValidateWhenNoData(): void {
 		$validator = new I18nCompletionValidator([], []);
 		self::assertTrue($validator->validate());
 		self::assertEquals('', $validator->displayResult());
diff --git a/tests/cli/i18n/I18nUsageValidatorTest.php b/tests/cli/i18n/I18nUsageValidatorTest.php
index 3135cef22..1c604390f 100644
--- a/tests/cli/i18n/I18nUsageValidatorTest.php
+++ b/tests/cli/i18n/I18nUsageValidatorTest.php
@@ -42,7 +42,7 @@ class I18nUsageValidatorTest extends PHPUnit\Framework\TestCase {
 		$validator->displayReport();
 	}
 
-	public function testValidateWhenNoData(): void {
+	public static function testValidateWhenNoData(): void {
 		$validator = new I18nUsageValidator([], []);
 		self::assertTrue($validator->validate());
 		self::assertEquals('', $validator->displayResult());
diff --git a/tests/cli/i18n/I18nValueTest.php b/tests/cli/i18n/I18nValueTest.php
index 06d57eb08..44984d7b2 100644
--- a/tests/cli/i18n/I18nValueTest.php
+++ b/tests/cli/i18n/I18nValueTest.php
@@ -3,35 +3,35 @@ declare(strict_types=1);
 require_once __DIR__ . '/../../../cli/i18n/I18nValue.php';
 
 class I18nValueTest extends PHPUnit\Framework\TestCase {
-	public function testConstructorWithoutState(): void {
+	public static function testConstructorWithoutState(): void {
 		$value = new I18nValue('some value');
 		self::assertEquals('some value', $value->getValue());
 		self::assertFalse($value->isIgnore());
 		self::assertFalse($value->isTodo());
 	}
 
-	public function testConstructorWithUnknownState(): void {
+	public static function testConstructorWithUnknownState(): void {
 		$value = new I18nValue('some value -> unknown');
 		self::assertEquals('some value', $value->getValue());
 		self::assertFalse($value->isIgnore());
 		self::assertFalse($value->isTodo());
 	}
 
-	public function testConstructorWithTodoState(): void {
+	public static function testConstructorWithTodoState(): void {
 		$value = new I18nValue('some value -> todo');
 		self::assertEquals('some value', $value->getValue());
 		self::assertFalse($value->isIgnore());
 		self::assertTrue($value->isTodo());
 	}
 
-	public function testConstructorWithIgnoreState(): void {
+	public static function testConstructorWithIgnoreState(): void {
 		$value = new I18nValue('some value -> ignore');
 		self::assertEquals('some value', $value->getValue());
 		self::assertTrue($value->isIgnore());
 		self::assertFalse($value->isTodo());
 	}
 
-	public function testClone(): void {
+	public static function testClone(): void {
 		$value = new I18nValue('some value');
 		$clonedValue = clone $value;
 		self::assertEquals('some value', $value->getValue());
@@ -42,21 +42,21 @@ class I18nValueTest extends PHPUnit\Framework\TestCase {
 		self::assertTrue($clonedValue->isTodo());
 	}
 
-	public function testEqualWhenValueIsIdentical(): void {
+	public static function testEqualWhenValueIsIdentical(): void {
 		$value = new I18nValue('some value');
 		$clonedValue = clone $value;
 		self::assertTrue($value->equal($clonedValue));
 		self::assertTrue($clonedValue->equal($value));
 	}
 
-	public function testEqualWhenValueIsDifferent(): void {
+	public static function testEqualWhenValueIsDifferent(): void {
 		$value = new I18nValue('some value');
 		$otherValue = new I18nValue('some other value');
 		self::assertFalse($value->equal($otherValue));
 		self::assertFalse($otherValue->equal($value));
 	}
 
-	public function testStates(): void {
+	public static function testStates(): void {
 		$reflectionProperty = new ReflectionProperty(I18nValue::class, 'state');
 		$reflectionProperty->setAccessible(true);
 
@@ -74,7 +74,7 @@ class I18nValueTest extends PHPUnit\Framework\TestCase {
 		self::assertEquals('todo', $reflectionProperty->getValue($value));
 	}
 
-	public function testToString(): void {
+	public static function testToString(): void {
 		$value = new I18nValue('some value');
 		self::assertEquals('some value', $value->__toString());
 		$value->markAsTodo();