Apply more strict type checking

Makefile

@@ -13,7 +13,7 @@ fix-code-style:
 .PHONY: static-code-analysis
 static-code-analysis: vendor ## Runs a static code analysis with phpstan/phpstan and vimeo/psalm
 	docker run -it --rm -v${PWD}:/opt/project -w /opt/project php:7.4 vendor/bin/phpstan --configuration=phpstan.neon
-	docker run -it --rm -v${PWD}:/opt/project -w /opt/project php:7.4 vendor/bin/psalm
+	docker run -it --rm -v${PWD}:/opt/project -w /opt/project php:7.4 vendor/bin/psalm.phar
 
 .PHONY: test
 test: test-unit ## Runs all test suites with phpunit/phpunit

src/DocBlock/ExampleFinder.php

@@ -44,7 +44,7 @@ class ExampleFinder
         $filename = $example->getFilePath();
 
         $file = $this->getExampleFileContents($filename);
-        if (!$file) {
+        if ($file === null) {
             return sprintf('** File not found : %s **', $filename);
         }
 
@@ -112,7 +112,7 @@ class ExampleFinder
             }
         }
 
-        if (!$normalizedPath) {
+        if ($normalizedPath === null) {
             if (is_readable($this->getExamplePathFromSource($filename))) {
                 $normalizedPath = $this->getExamplePathFromSource($filename);
             } elseif (is_readable($this->getExamplePathFromExampleDirectory($filename))) {
@@ -122,7 +122,7 @@ class ExampleFinder
             }
         }
 
-        $lines = $normalizedPath && is_readable($normalizedPath) ? file($normalizedPath) : false;
+        $lines = $normalizedPath !== null && is_readable($normalizedPath) ? file($normalizedPath) : false;
 
         return $lines !== false ? $lines : null;
     }

src/DocBlock/Serializer.php

@@ -82,7 +82,7 @@ class Serializer
         $indent      = str_repeat($this->indentString, $this->indent);
         $firstIndent = $this->isFirstLineIndented ? $indent : '';
         // 3 === strlen(' * ')
-        $wrapLength = $this->lineLength ? $this->lineLength - strlen($indent) - 3 : null;
+        $wrapLength = $this->lineLength !== null ? $this->lineLength - strlen($indent) - 3 : null;
 
         $text = $this->removeTrailingSpaces(
             $indent,

src/DocBlock/StandardTagFactory.php

@@ -166,14 +166,14 @@ final class StandardTagFactory implements TagFactory
 
     public function addService(object $service, ?string $alias = null): void
     {
-        $this->serviceLocator[$alias ?: get_class($service)] = $service;
+        $this->serviceLocator[$alias ?? get_class($service)] = $service;
     }
 
     /** {@inheritDoc} */
     public function registerTagHandler(string $tagName, $handler): void
     {
         Assert::stringNotEmpty($tagName);
-        if (strpos($tagName, '\\') && $tagName[0] !== '\\') {
+        if (strpos($tagName, '\\') !== false && $tagName[0] !== '\\') {
             throw new InvalidArgumentException(
                 'A namespaced tag must have a leading backslash as it must be fully qualified'
             );

src/DocBlock/Tags/Deprecated.php

@@ -62,7 +62,7 @@ final class Deprecated extends BaseTag implements Factory\StaticMethod
         ?DescriptionFactory $descriptionFactory = null,
         ?TypeContext $context = null
     ): self {
-        if (empty($body)) {
+        if ($body === null || $body === '') {
             return new static();
         }
 

src/DocBlock/Tags/Param.php

@@ -160,7 +160,7 @@ final class Param extends TagWithType implements Factory\StaticMethod
         }
 
         $variableName = '';
-        if ($this->variableName) {
+        if ($this->variableName !== null && $this->variableName !== '') {
             $variableName .= ($this->isReference ? '&' : '') . ($this->isVariadic ? '...' : '');
             $variableName .= '$' . $this->variableName;
         }

src/DocBlock/Tags/Property.php

@@ -111,13 +111,13 @@ final class Property extends TagWithType implements Factory\StaticMethod
      */
     public function __toString(): string
     {
-        if ($this->description) {
+        if ($this->description !== null) {
             $description = $this->description->render();
         } else {
             $description = '';
         }
 
-        if ($this->variableName) {
+        if ($this->variableName !== null && $this->variableName !== '') {
             $variableName = '$' . $this->variableName;
         } else {
             $variableName = '';

src/DocBlock/Tags/PropertyRead.php

@@ -111,13 +111,13 @@ final class PropertyRead extends TagWithType implements Factory\StaticMethod
      */
     public function __toString(): string
     {
-        if ($this->description) {
+        if ($this->description !== null) {
             $description = $this->description->render();
         } else {
             $description = '';
         }
 
-        if ($this->variableName) {
+        if ($this->variableName !== null && $this->variableName !== '') {
             $variableName = '$' . $this->variableName;
         } else {
             $variableName = '';

src/DocBlock/Tags/Since.php

@@ -59,7 +59,7 @@ final class Since extends BaseTag implements Factory\StaticMethod
         ?DescriptionFactory $descriptionFactory = null,
         ?TypeContext $context = null
     ): ?self {
-        if (empty($body)) {
+        if ($body === null || $body === '') {
             return new static();
         }
 
@@ -89,7 +89,7 @@ final class Since extends BaseTag implements Factory\StaticMethod
      */
     public function __toString(): string
     {
-        if ($this->description) {
+        if ($this->description !== null) {
             $description = $this->description->render();
         } else {
             $description = '';

src/DocBlock/Tags/Var_.php

@@ -111,13 +111,13 @@ final class Var_ extends TagWithType implements Factory\StaticMethod
      */
     public function __toString(): string
     {
-        if ($this->description) {
+        if ($this->description !== null) {
             $description = $this->description->render();
         } else {
             $description = '';
         }
 
-        if ($this->variableName) {
+        if ($this->variableName !== null && $this->variableName !== '') {
             $variableName = '$' . $this->variableName;
         } else {
             $variableName = '';

src/DocBlock/Tags/Version.php

@@ -59,7 +59,7 @@ final class Version extends BaseTag implements Factory\StaticMethod
         ?DescriptionFactory $descriptionFactory = null,
         ?TypeContext $context = null
     ): ?self {
-        if (empty($body)) {
+        if ($body === null || $body === '') {
             return new static();
         }