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Fix Seq::unique to use strict type-sensitive comparison #80

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Merged
lippserd merged 1 commit into from
Jun 24, 2026
Merged

Fix Seq::unique to use strict type-sensitive comparison #80

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36 changes: 25 additions & 11 deletions src/Seq.php
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@

use Closure;
use Generator;
use SplObjectStorage;

/**
* Collection of utilities for traversables
Expand Down Expand Up @@ -138,27 +139,40 @@ public static function map(iterable $traversable, callable $callback): Generator
/**
* Yield every unique value of the given traversable with its original key
*
* @param iterable $traversable
* Values are compared type-sensitively. Objects are compared by instance
* identity. Arrays are compared using strict equality, so the same key/value pairs
* in a different order are treated as different values. Case-insensitive
* comparison applies only to direct string values, not to strings nested
* inside arrays.
*
* @param iterable<mixed, mixed> $traversable
* @param bool $caseSensitive
*
* @return Generator
*/
public static function unique(iterable $traversable, bool $caseSensitive = true): Generator
{
$seen = [];
$seenObjects = new SplObjectStorage();
$seenValues = [];

foreach ($traversable as $key => $value) {
if (is_string($value)) {
$needle = $caseSensitive ? $value : strtolower($value);
} elseif (is_object($value)) {
$needle = spl_object_hash($value);
} else {
$needle = $value;
}
if (is_object($value)) {
if ($seenObjects->offsetExists($value)) {
continue;
}

if (! array_key_exists($needle, $seen)) {
$seen[$needle] = true;
$seenObjects->offsetSet($value);
yield $key => $value;
continue;
}

$seenValue = ! $caseSensitive && is_string($value) ? strtolower($value) : $value;
if (in_array($seenValue, $seenValues, true)) {
continue;
}

$seenValues[] = $seenValue;
yield $key => $value;
}
}
}
258 changes: 220 additions & 38 deletions tests/SeqTest.php
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Original file line number Diff line number Diff line change
Expand Up @@ -220,81 +220,263 @@ public function testMapWithKeyedGenerators()
);
}

public function testUniqueWithArray()
public function testUniqueWithArray(): void
{
$object1 = new stdClass();
$object2 = new stdClass();
$arr = [1, 2, 2, 3, '3', $object1, $object1, $object2];
$result = iterator_to_array(Seq::unique($arr));
$firstObject = new stdClass();
$secondObject = new stdClass();
$values = [1, 2, 2, 3, '3', $firstObject, $firstObject, $secondObject];
$result = iterator_to_array(Seq::unique($values));

$this->assertSame(
[0 => 1, 1 => 2, 3 => 3, 5 => $object1, 7 => $object2],
$result
[0 => 1, 1 => 2, 3 => 3, 4 => '3', 5 => $firstObject, 7 => $secondObject],
$result,
);
}

public function testUniqueWithKeyedArray()
public function testUniqueWithKeyedArray(): void
{
$object1 = new stdClass();
$object2 = new stdClass();
$arr = ['a' => 1, 'b' => 2, 0 => 2, -1 => 3, 1 => '3', 2 => $object1, 3 => $object1, 4 => $object2];
$result = iterator_to_array(Seq::unique($arr));
$firstObject = new stdClass();
$secondObject = new stdClass();
$values = [
'first-int' => 1,
'second-int' => 2,
'duplicate-int' => 2,
'different-int' => 3,
'string-int' => '3',
'first-object' => $firstObject,
'duplicate-object' => $firstObject,
'second-object' => $secondObject,
];
$result = iterator_to_array(Seq::unique($values));

$this->assertSame(
['a' => 1, 'b' => 2, -1 => 3, 2 => $object1, 4 => $object2],
$result
[
'first-int' => 1,
'second-int' => 2,
'different-int' => 3,
'string-int' => '3',
'first-object' => $firstObject,
'second-object' => $secondObject,
],
$result,
);
}

public function testUniqueWithGenerator()
public function testUniqueWithGenerator(): void
{
$object1 = new stdClass();
$object2 = new stdClass();
$generator = function () use ($object1, $object2) {
yield from [1, 2, 2, 3, '3', $object1, $object1, $object2];
$firstObject = new stdClass();
$secondObject = new stdClass();
$generator = function () use ($firstObject, $secondObject) {
yield from [1, 2, 2, 3, '3', $firstObject, $firstObject, $secondObject];
};
$result = iterator_to_array(Seq::unique($generator()));

$this->assertSame(
[0 => 1, 1 => 2, 3 => 3, 5 => $object1, 7 => $object2],
$result
[0 => 1, 1 => 2, 3 => 3, 4 => '3', 5 => $firstObject, 7 => $secondObject],
$result,
);
}

public function testUniqueWithKeyedGenerator()
public function testUniqueWithKeyedGenerator(): void
{
$object1 = new stdClass();
$object2 = new stdClass();
$generator = function () use ($object1, $object2) {
yield from ['a' => 1, 'b' => 2, 0 => 2, -1 => 3, 1 => '3', 2 => $object1, 3 => $object1, 4 => $object2];
$firstObject = new stdClass();
$secondObject = new stdClass();
$generator = function () use ($firstObject, $secondObject) {
yield from [
'first-int' => 1,
'second-int' => 2,
'duplicate-int' => 2,
'different-int' => 3,
'string-int' => '3',
'first-object' => $firstObject,
'duplicate-object' => $firstObject,
'second-object' => $secondObject,
];
};
$result = iterator_to_array(Seq::unique($generator()));

$this->assertSame(
['a' => 1, 'b' => 2, -1 => 3, 2 => $object1, 4 => $object2],
$result
[
'first-int' => 1,
'second-int' => 2,
'different-int' => 3,
'string-int' => '3',
'first-object' => $firstObject,
'second-object' => $secondObject,
],
$result,
);
}

public function testUniqueWithStringsIsCaseSensitiveByDefault()
public function testUniqueWithStringsIsCaseSensitiveByDefault(): void
{
$arr = ['foo', 'bar', 'FOO', 'BAR', 'foo'];
$result = iterator_to_array(Seq::unique($arr));
$values = ['icinga.com', 'host.name', 'ICINGA.COM', 'HOST.NAME', 'icinga.com'];
$result = iterator_to_array(Seq::unique($values));

$this->assertSame(
[0 => 'foo', 1 => 'bar', 2 => 'FOO', 3 => 'BAR'],
$result
[0 => 'icinga.com', 1 => 'host.name', 2 => 'ICINGA.COM', 3 => 'HOST.NAME'],
$result,
);
}

public function testUniqueWithStringsCaseInsensitive()
public function testUniqueWithStringsCaseInsensitive(): void
{
$arr = ['foo', 'bar', 'FOO', 'BAR', 'foo'];
$result = iterator_to_array(Seq::unique($arr, false));
$values = ['icinga.com', 'host.name', 'ICINGA.COM', 'HOST.NAME', 'icinga.com'];
$result = iterator_to_array(Seq::unique($values, false));

$this->assertSame(
[0 => 'foo', 1 => 'bar'],
$result
[0 => 'icinga.com', 1 => 'host.name'],
$result,
);
}

public function testUniqueKeepsDifferentScalarTypesDistinct(): void
{
$values = [
'int-zero' => 0,
'string-zero' => '0',
'false' => false,
'null' => null,
'empty-string' => '',
'int-one' => 1,
'string-one' => '1',
'true' => true,
'float-one' => 1.0,
'float-fraction' => 1.2,
'string-fraction' => '1.2',
];

$this->assertSame(
$values,
iterator_to_array(Seq::unique($values)),
);
}

public function testUniqueRemovesOnlySameTypedScalarDuplicates(): void
{
$values = [
'first-int-zero' => 0,
'second-int-zero' => 0,
'first-string-zero' => '0',
'second-string-zero' => '0',
'first-false' => false,
'second-false' => false,
'first-null' => null,
'second-null' => null,
'first-empty-string' => '',
'second-empty-string' => '',
'first-float-one' => 1.0,
'second-float-one' => 1.0,
];

$this->assertSame(
[
'first-int-zero' => 0,
'first-string-zero' => '0',
'first-false' => false,
'first-null' => null,
'first-empty-string' => '',
'first-float-one' => 1.0,
],
iterator_to_array(Seq::unique($values)),
);
}

public function testUniqueAcceptsArraysAsValues(): void
{
$values = [
'first-list' => [0],
'second-list' => [0],
'string-zero-list' => ['0'],
'false-list' => [false],
'null-list' => [null],
'empty-string-list' => [''],
'nested-int' => [['value' => 0]],
'nested-string' => [['value' => '0']],
'keyed-array' => ['a' => 1, 'b' => 2],
'same-order-keyed-array' => ['a' => 1, 'b' => 2],
'reordered-keyed-array' => ['b' => 2, 'a' => 1],
];

$this->assertSame(
[
'first-list' => [0],
'string-zero-list' => ['0'],
'false-list' => [false],
'null-list' => [null],
'empty-string-list' => [''],
'nested-int' => [['value' => 0]],
'nested-string' => [['value' => '0']],
'keyed-array' => ['a' => 1, 'b' => 2],
'reordered-keyed-array' => ['b' => 2, 'a' => 1],
],
iterator_to_array(Seq::unique($values)),
);
}

public function testUniqueCaseInsensitiveComparisonOnlyAppliesToDirectStrings(): void
{
$values = [
'direct-string' => 'icinga.com',
'direct-string-duplicate' => 'ICINGA.COM',
'array-string' => ['icinga.com'],
'array-string-with-different-case' => ['ICINGA.COM'],
];

$this->assertSame(
[
'direct-string' => 'icinga.com',
'array-string' => ['icinga.com'],
'array-string-with-different-case' => ['ICINGA.COM'],
],
iterator_to_array(Seq::unique($values, false)),
);
}

public function testUniqueKeepsObjectDistinctFromStringMatchingItsHash(): void
{
$object = new stdClass();
$otherObject = new stdClass();
$values = [
'object' => $object,
'object-hash-string' => spl_object_hash($object),
'same-object' => $object,
'other-object' => $otherObject,
];

$this->assertSame(
[
'object' => $object,
'object-hash-string' => spl_object_hash($object),
'other-object' => $otherObject,
],
iterator_to_array(Seq::unique($values)),
);
}

public function testUniqueAcceptsResourcesAsValues(): void
{
$stream = fopen('php://memory', 'rb');
if ($stream === false) {
$this->fail('Failed to open a memory stream');
}

$values = [
'resource' => $stream,
'resource-id-as-int' => get_resource_id($stream),
'same-resource' => $stream,
];

try {
$this->assertSame(
[
'resource' => $stream,
'resource-id-as-int' => get_resource_id($stream),
],
iterator_to_array(Seq::unique($values)),
);
} finally {
fclose($stream);
}
}
}
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