Add NoDiscard attributes

proofs/file/content.php

@@ -95,7 +95,7 @@ static function($assert) use ($io) {
             ));
 
             $count = 0;
-            $content->foreach(static function() use (&$count) {
+            $_ = $content->foreach(static function() use (&$count) {
                 $count++;
             });
 

properties/Adapter/AddDirectory.php

@@ -80,7 +80,7 @@ private function assertSame(
         }
 
         if ($target instanceof Directory) {
-            $target->foreach(function($file) use ($assert, $source) {
+            $_ = $target->foreach(function($file) use ($assert, $source) {
                 $assert->true($source->contains($file->name()));
 
                 $this->assertSame(

properties/Content/ForeachExposeAllLines.php

@@ -31,7 +31,7 @@ public function applicableTo(object $systemUnderTest): bool
     public function ensureHeldBy(Assert $assert, object $systemUnderTest): object
     {
         $count = 0;
-        $systemUnderTest->foreach(static function($line) use ($assert, &$count) {
+        $_ = $systemUnderTest->foreach(static function($line) use ($assert, &$count) {
             $assert->object($line)->instance(Line::class);
             $count++;
         });

properties/Directory/AllFilesInTheDirectoryAreAccessible.php

@@ -27,7 +27,7 @@ public function applicableTo(object $directory): bool
 
     public function ensureHeldBy(Assert $assert, object $directory): object
     {
-        $directory->foreach(static function($file) use ($assert, $directory) {
+        $_ = $directory->foreach(static function($file) use ($assert, $directory) {
             $assert->same(
                 $file->name(),
                 $directory->get($file->name())->match(

properties/Directory/ContainsMethodAlwaysReturnTrueForFilesInTheDirectory.php

@@ -27,7 +27,7 @@ public function applicableTo(object $directory): bool
 
     public function ensureHeldBy(Assert $assert, object $directory): object
     {
-        $directory->foreach(static function($file) use ($assert, $directory) {
+        $_ = $directory->foreach(static function($file) use ($assert, $directory) {
             $assert->true($directory->contains($file->name()));
         });
 

properties/Directory/FilteringDoesntAffectTheDirectory.php

@@ -30,9 +30,9 @@ public function ensureHeldBy(Assert $assert, object $directory): object
         $all = $directory->filter(static fn(): bool => true);
         $none = $directory->filter(static fn(): bool => false);
 
-        $directory->foreach(static fn($file) => $assert->false($none->contains($file->name())));
-        $directory->foreach(static fn($file) => $assert->true($all->contains($file->name())));
-        $all->foreach(static fn($file) => $assert->true($directory->contains($file->name())));
+        $_ = $directory->foreach(static fn($file) => $assert->false($none->contains($file->name())));
+        $_ = $directory->foreach(static fn($file) => $assert->true($all->contains($file->name())));
+        $_ = $all->foreach(static fn($file) => $assert->true($directory->contains($file->name())));
         $assert->same($directory->removed(), $all->removed());
         $assert->same($directory->removed(), $none->removed());
 

psalm.xml

@@ -14,4 +14,7 @@
             <directory name="vendor" />
         </ignoreFiles>
     </projectFiles>
+    <issueHandlers>
+        <UndefinedAttributeClass errorLevel="suppress" />
+    </issueHandlers>
 </psalm>

src/Adapter.php

@@ -42,6 +42,7 @@ private function __construct(
     /**
      * @return Attempt<self>
      */
+    #[\NoDiscard]
     public static function mount(
         Path $path,
         CaseSensitivity $case = CaseSensitivity::sensitive,
@@ -65,6 +66,7 @@ public static function mount(
             });
     }
 
+    #[\NoDiscard]
     public static function inMemory(): self
     {
         return new self(
@@ -73,6 +75,7 @@ public static function inMemory(): self
         );
     }
 
+    #[\NoDiscard]
     public static function logger(
         self $adapter,
         LoggerInterface $logger,
@@ -86,6 +89,7 @@ public static function logger(
     /**
      * @return Attempt<SideEffect>
      */
+    #[\NoDiscard]
     public function add(File|Directory $file): Attempt
     {
         return $this->write(TreePath::root(), $file);
@@ -94,6 +98,7 @@ public function add(File|Directory $file): Attempt
     /**
      * @return Maybe<File|Directory>
      */
+    #[\NoDiscard]
     public function get(Name $file): Maybe
     {
         return $this->access(
@@ -102,6 +107,7 @@ public function get(Name $file): Maybe
         );
     }
 
+    #[\NoDiscard]
     public function contains(Name $file): bool
     {
         return $this->implementation->exists(TreePath::of($file))->match(
@@ -113,11 +119,13 @@ public function contains(Name $file): bool
     /**
      * @return Attempt<SideEffect>
      */
+    #[\NoDiscard]
     public function remove(Name $file): Attempt
     {
         return $this->implementation->remove(TreePath::root(), $file);
     }
 
+    #[\NoDiscard]
     public function root(): Directory
     {
         $root = TreePath::root();

src/Directory.php

@@ -31,6 +31,7 @@ private function __construct(
      *
      * @param Sequence<File|self>|null $files
      */
+    #[\NoDiscard]
     public static function of(Name $name, ?Sequence $files = null): self
     {
         return new self(
@@ -46,6 +47,7 @@ public static function of(Name $name, ?Sequence $files = null): self
      * @param non-empty-string $name
      * @param Sequence<File|self>|null $files
      */
+    #[\NoDiscard]
     public static function named(string $name, ?Sequence $files = null): self
     {
         return new self(
@@ -61,6 +63,7 @@ public static function named(string $name, ?Sequence $files = null): self
      *
      * @param Sequence<File|self> $files
      */
+    #[\NoDiscard]
     public static function lazy(Name $name, Sequence $files): self
     {
         // we prevent the contrusctor from checking for duplicates when
@@ -71,11 +74,13 @@ public static function lazy(Name $name, Sequence $files): self
         return new self($name, $files, Set::of());
     }
 
+    #[\NoDiscard]
     public function name(): Name
     {
         return $this->name;
     }
 
+    #[\NoDiscard]
     public function rename(Name $name): self
     {
         return new self(
@@ -85,6 +90,7 @@ public function rename(Name $name): self
         );
     }
 
+    #[\NoDiscard]
     public function add(File|self $file): self
     {
         return new self(
@@ -100,11 +106,13 @@ public function add(File|self $file): self
     /**
      * @return Maybe<File|self>
      */
+    #[\NoDiscard]
     public function get(Name $name): Maybe
     {
         return $this->files->find(static fn($file) => $file->name()->equals($name));
     }
 
+    #[\NoDiscard]
     public function contains(Name $name): bool
     {
         return $this->get($name)->match(
@@ -113,6 +121,7 @@ public function contains(Name $name): bool
         );
     }
 
+    #[\NoDiscard]
     public function remove(Name $name): self
     {
         return new self(
@@ -125,6 +134,7 @@ public function remove(Name $name): self
     /**
      * @param callable(File|self): void $function
      */
+    #[\NoDiscard]
     public function foreach(callable $function): SideEffect
     {
         return $this->files->foreach($function);
@@ -133,6 +143,7 @@ public function foreach(callable $function): SideEffect
     /**
      * @param callable(File|self): bool $predicate
      */
+    #[\NoDiscard]
     public function filter(callable $predicate): self
     {
         // it is safe to not check for duplicates here as either the current
@@ -150,6 +161,7 @@ public function filter(callable $predicate): self
     /**
      * @param callable(File|self): File $map
      */
+    #[\NoDiscard]
     public function map(callable $map): self
     {
         return new self(
@@ -162,6 +174,7 @@ public function map(callable $map): self
     /**
      * @param callable(File|self): self $map
      */
+    #[\NoDiscard]
     public function flatMap(callable $map): self
     {
         /** @var callable(File|self): Sequence<File|self> */
@@ -182,6 +195,7 @@ public function flatMap(callable $map): self
      *
      * @return R
      */
+    #[\NoDiscard]
     public function reduce($carry, callable $reducer)
     {
         return $this->files->reduce($carry, $reducer);
@@ -195,6 +209,7 @@ public function reduce($carry, callable $reducer)
      *
      * @return Set<Name>
      */
+    #[\NoDiscard]
     public function removed(): Set
     {
         return $this->removed;
@@ -203,6 +218,7 @@ public function removed(): Set
     /**
      * @return Sequence<File|self>
      */
+    #[\NoDiscard]
     public function all(): Sequence
     {
         return $this->files;

src/Exception/MountPathDoesntExist.php

@@ -22,6 +22,7 @@ public function __construct(
     /**
      * @return Attempt<Implementation>
      */
+    #[\NoDiscard]
     public function recover(): Attempt
     {
         return ($this->recover)();

src/Exception/RecoverMount.php

@@ -22,6 +22,7 @@ public function __construct(
     /**
      * @return Attempt<Adapter>
      */
+    #[\NoDiscard]
     public function recover(): Attempt
     {
         return ($this->recover)();

src/File.php

@@ -21,6 +21,7 @@ private function __construct(
     /**
      * @psalm-pure
      */
+    #[\NoDiscard]
     public static function of(
         Name $name,
         Content $content,
@@ -34,6 +35,7 @@ public static function of(
      *
      * @param non-empty-string $name
      */
+    #[\NoDiscard]
     public static function named(
         string $name,
         Content $content,
@@ -42,26 +44,31 @@ public static function named(
         return self::of(Name::of($name), $content, $mediaType);
     }
 
+    #[\NoDiscard]
     public function name(): Name
     {
         return $this->name;
     }
 
+    #[\NoDiscard]
     public function content(): Content
     {
         return $this->content;
     }
 
+    #[\NoDiscard]
     public function mediaType(): MediaType
     {
         return $this->mediaType;
     }
 
+    #[\NoDiscard]
     public function rename(Name $name): self
     {
         return new self($name, $this->content, $this->mediaType);
     }
 
+    #[\NoDiscard]
     public function withContent(Content $content, ?MediaType $mediaType = null): self
     {
         return new self(
@@ -74,6 +81,7 @@ public function withContent(Content $content, ?MediaType $mediaType = null): sel
     /**
      * @param callable(Content): Content $map
      */
+    #[\NoDiscard]
     public function mapContent(callable $map): self
     {
         /** @psalm-suppress ImpureFunctionCall */