diff --git a/src/CSSList/Document.php b/src/CSSList/Document.php
index c79ae9a2..00d4cabd 100644
--- a/src/CSSList/Document.php
+++ b/src/CSSList/Document.php
@@ -32,7 +32,6 @@ public static function parse(ParserState $parserState): Document
 
     /**
      * Gets all `DeclarationBlock` objects recursively, no matter how deeply nested the selectors are.
-     * Aliased as `getAllSelectors()`.
      *
      * @return array<int, DeclarationBlock>
      */
diff --git a/tests/Unit/CSSList/DocumentTest.php b/tests/Unit/CSSList/DocumentTest.php
index 494b4a49..7b6a3df9 100644
--- a/tests/Unit/CSSList/DocumentTest.php
+++ b/tests/Unit/CSSList/DocumentTest.php
@@ -6,11 +6,18 @@
 
 use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\Comment\Commentable;
+use Sabberworm\CSS\CSSList\AtRuleBlockList;
 use Sabberworm\CSS\CSSList\Document;
+use Sabberworm\CSS\Property\Charset;
+use Sabberworm\CSS\Property\Import;
 use Sabberworm\CSS\Renderable;
 use Sabberworm\CSS\RuleSet\DeclarationBlock;
+use Sabberworm\CSS\Value\CSSString;
+use Sabberworm\CSS\Value\URL;
 
 /**
+ * @covers \Sabberworm\CSS\CSSList\CSSBlockList
+ * @covers \Sabberworm\CSS\CSSList\CSSList
  * @covers \Sabberworm\CSS\CSSList\Document
  */
 final class DocumentTest extends TestCase
@@ -142,4 +149,92 @@ public function insertContentBeforeAppendsIfSiblingNotFound(): void
         self::assertCount(4, $subject->getContents());
         self::assertSame([$bogusOne, $sibling, $bogusTwo, $item], $subject->getContents());
     }
+
+    /**
+     * @test
+     */
+    public function getAllDeclarationBlocksForNoContentsReturnsEmptyArray(): void
+    {
+        $subject = new Document();
+
+        self::assertSame([], $subject->getAllDeclarationBlocks());
+    }
+
+    /**
+     * @test
+     */
+    public function getAllDeclarationBlocksCanReturnOneDirectDeclarationBlockContent(): void
+    {
+        $subject = new Document();
+
+        $declarationBlock = new DeclarationBlock();
+        $subject->setContents([$declarationBlock]);
+
+        $result = $subject->getAllDeclarationBlocks();
+
+        self::assertSame([$declarationBlock], $result);
+    }
+
+    /**
+     * @test
+     */
+    public function getAllDeclarationBlocksCanReturnMultipleDirectDeclarationBlockContents(): void
+    {
+        $subject = new Document();
+
+        $declarationBlock1 = new DeclarationBlock();
+        $declarationBlock2 = new DeclarationBlock();
+        $subject->setContents([$declarationBlock1, $declarationBlock2]);
+
+        $result = $subject->getAllDeclarationBlocks();
+
+        self::assertSame([$declarationBlock1, $declarationBlock2], $result);
+    }
+
+    /**
+     * @test
+     */
+    public function getAllDeclarationBlocksReturnsDeclarationBlocksWithinAtRuleBlockList(): void
+    {
+        $subject = new Document();
+
+        $declarationBlock = new DeclarationBlock();
+        $atRuleBlockList = new AtRuleBlockList('media');
+        $atRuleBlockList->setContents([$declarationBlock]);
+        $subject->setContents([$atRuleBlockList]);
+
+        $result = $subject->getAllDeclarationBlocks();
+
+        self::assertSame([$declarationBlock], $result);
+    }
+
+    /**
+     * @test
+     */
+    public function getAllDeclarationBlocksIgnoresImport(): void
+    {
+        $subject = new Document();
+
+        $import = new Import(new URL(new CSSString('https://www.example.com/')), '');
+        $subject->setContents([$import]);
+
+        $result = $subject->getAllDeclarationBlocks();
+
+        self::assertSame([], $result);
+    }
+
+    /**
+     * @test
+     */
+    public function getAllDeclarationBlocksIgnoresCharset(): void
+    {
+        $subject = new Document();
+
+        $charset = new Charset(new CSSString('UTF-8'));
+        $subject->setContents([$charset]);
+
+        $result = $subject->getAllDeclarationBlocks();
+
+        self::assertSame([], $result);
+    }
 }