diff --git a/src/Symfony/Component/Yaml/Tests/DumperTest.php b/src/Symfony/Component/Yaml/Tests/DumperTest.php
index 2ebbbd047313..59a47a8130f3 100644
--- a/src/Symfony/Component/Yaml/Tests/DumperTest.php
+++ b/src/Symfony/Component/Yaml/Tests/DumperTest.php
@@ -14,6 +14,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Yaml\Dumper;
 use Symfony\Component\Yaml\Exception\DumpException;
+use Symfony\Component\Yaml\Exception\ParseException;
 use Symfony\Component\Yaml\Parser;
 use Symfony\Component\Yaml\Tag\TaggedValue;
 use Symfony\Component\Yaml\Yaml;
@@ -78,7 +79,8 @@ public function testIndentationInConstructor()
                      - foo
 
 EOF;
-        $this->assertEquals($expected, $dumper->dump($this->array, 4, 0));
+        $this->assertSame($expected, $dumper->dump($this->array, 4, 0));
+        $this->assertSameData($this->array, $this->parser->parse($expected));
     }
 
     public function testSpecifications()
@@ -94,14 +96,17 @@ public function testSpecifications()
                 }
 
                 $test = $this->parser->parse($yaml);
-                if (isset($test['dump_skip']) && $test['dump_skip']) {
+                if ($test['dump_skip'] ?? false) {
                     continue;
-                } elseif (isset($test['todo']) && $test['todo']) {
+                }
+
+                if ($test['todo'] ?? false) {
                     // TODO
-                } else {
-                    eval('$expected = '.trim($test['php']).';');
-                    $this->assertSame($expected, $this->parser->parse($this->dumper->dump($expected, 10)), $test['test']);
+                    continue;
                 }
+
+                $expected = eval('return '.trim($test['php']).';');
+                $this->assertSame($expected, $this->parser->parse($this->dumper->dump($expected, 10)), $test['test']);
             }
         }
     }
@@ -111,8 +116,9 @@ public function testInlineLevel()
         $expected = <<<'EOF'
 { '': bar, foo: '#bar', 'foo''bar': {  }, bar: [1, foo, { a: A }], foobar: { foo: bar, bar: [1, foo], foobar: { foo: bar, bar: [1, foo] } } }
 EOF;
-        $this->assertEquals($expected, $this->dumper->dump($this->array, -10), '->dump() takes an inline level argument');
-        $this->assertEquals($expected, $this->dumper->dump($this->array, 0), '->dump() takes an inline level argument');
+        $this->assertSame($expected, $this->dumper->dump($this->array, -10), '->dump() takes an inline level argument');
+        $this->assertSame($expected, $this->dumper->dump($this->array, 0), '->dump() takes an inline level argument');
+        $this->assertSameData($this->array, $this->parser->parse($expected));
 
         $expected = <<<'EOF'
 '': bar
@@ -122,7 +128,8 @@ public function testInlineLevel()
 foobar: { foo: bar, bar: [1, foo], foobar: { foo: bar, bar: [1, foo] } }
 
 EOF;
-        $this->assertEquals($expected, $this->dumper->dump($this->array, 1), '->dump() takes an inline level argument');
+        $this->assertSame($expected, $this->dumper->dump($this->array, 1), '->dump() takes an inline level argument');
+        $this->assertSameData($this->array, $this->parser->parse($expected));
 
         $expected = <<<'EOF'
 '': bar
@@ -138,7 +145,8 @@ public function testInlineLevel()
     foobar: { foo: bar, bar: [1, foo] }
 
 EOF;
-        $this->assertEquals($expected, $this->dumper->dump($this->array, 2), '->dump() takes an inline level argument');
+        $this->assertSame($expected, $this->dumper->dump($this->array, 2), '->dump() takes an inline level argument');
+        $this->assertSameData($this->array, $this->parser->parse($expected));
 
         $expected = <<<'EOF'
 '': bar
@@ -159,7 +167,8 @@ public function testInlineLevel()
         bar: [1, foo]
 
 EOF;
-        $this->assertEquals($expected, $this->dumper->dump($this->array, 3), '->dump() takes an inline level argument');
+        $this->assertSame($expected, $this->dumper->dump($this->array, 3), '->dump() takes an inline level argument');
+        $this->assertSameData($this->array, $this->parser->parse($expected));
 
         $expected = <<<'EOF'
 '': bar
@@ -182,22 +191,23 @@ public function testInlineLevel()
             - foo
 
 EOF;
-        $this->assertEquals($expected, $this->dumper->dump($this->array, 4), '->dump() takes an inline level argument');
-        $this->assertEquals($expected, $this->dumper->dump($this->array, 10), '->dump() takes an inline level argument');
+        $this->assertSame($expected, $this->dumper->dump($this->array, 4), '->dump() takes an inline level argument');
+        $this->assertSame($expected, $this->dumper->dump($this->array, 10), '->dump() takes an inline level argument');
+        $this->assertSameData($this->array, $this->parser->parse($expected));
     }
 
     public function testObjectSupportEnabled()
     {
         $dump = $this->dumper->dump(['foo' => new A(), 'bar' => 1], 0, 0, Yaml::DUMP_OBJECT);
 
-        $this->assertEquals('{ foo: !php/object \'O:30:"Symfony\Component\Yaml\Tests\A":1:{s:1:"a";s:3:"foo";}\', bar: 1 }', $dump, '->dump() is able to dump objects');
+        $this->assertSame('{ foo: !php/object \'O:30:"Symfony\Component\Yaml\Tests\A":1:{s:1:"a";s:3:"foo";}\', bar: 1 }', $dump, '->dump() is able to dump objects');
     }
 
     public function testObjectSupportDisabledButNoExceptions()
     {
         $dump = $this->dumper->dump(['foo' => new A(), 'bar' => 1]);
 
-        $this->assertEquals('{ foo: null, bar: 1 }', $dump, '->dump() does not dump objects when disabled');
+        $this->assertSame('{ foo: null, bar: 1 }', $dump, '->dump() does not dump objects when disabled');
     }
 
     public function testObjectSupportDisabledWithExceptions()
@@ -211,7 +221,8 @@ public function testObjectSupportDisabledWithExceptions()
      */
     public function testEscapedEscapeSequencesInQuotedScalar($input, $expected)
     {
-        $this->assertEquals($expected, $this->dumper->dump($input));
+        $this->assertSame($expected, $this->dumper->dump($input));
+        $this->assertSameData($input, $this->parser->parse($expected));
     }
 
     public function getEscapeSequences()
@@ -261,7 +272,7 @@ public function testDumpObjectAsMap($object, $expected)
     {
         $yaml = $this->dumper->dump($object, 0, 0, Yaml::DUMP_OBJECT_AS_MAP);
 
-        $this->assertEquals($expected, Yaml::parse($yaml, Yaml::PARSE_OBJECT_FOR_MAP));
+        $this->assertSameData($expected, $this->parser->parse($yaml, Yaml::PARSE_OBJECT_FOR_MAP));
     }
 
     public function objectAsMapProvider()
@@ -339,7 +350,7 @@ public function testDumpingArrayObjectInstancesWithNumericKeysRespectsInlineLeve
     2: { 0: d, 1: e }
 
 YAML;
-        $this->assertEquals($expected, $yaml);
+        $this->assertSame($expected, $yaml);
     }
 
     public function testDumpEmptyArrayObjectInstanceAsMap()
@@ -378,6 +389,7 @@ public function testDumpingStdClassInstancesRespectsInlineLevel()
 
 YAML;
         $this->assertSame($expected, $yaml);
+        $this->assertSameData($outer, $this->parser->parse($yaml, Yaml::PARSE_OBJECT_FOR_MAP));
     }
 
     public function testDumpingTaggedValueSequenceRespectsInlineLevel()
@@ -403,6 +415,59 @@ public function testDumpingTaggedValueSequenceRespectsInlineLevel()
 
 YAML;
         $this->assertSame($expected, $yaml);
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
+    }
+
+    public function testDumpingTaggedValueTopLevelScalar()
+    {
+        $data = new TaggedValue('user', 'jane');
+
+        $yaml = $this->dumper->dump($data);
+
+        $expected = '!user jane';
+        $this->assertSame($expected, $yaml);
+        $this->assertSameData($data, $this->parser->parse($yaml, Yaml::PARSE_CUSTOM_TAGS));
+    }
+
+    public function testDumpingTaggedValueTopLevelAssocInline()
+    {
+        $data = new TaggedValue('user', ['name' => 'jane']);
+
+        $yaml = $this->dumper->dump($data);
+
+        $expected = '!user { name: jane }';
+        $this->assertSame($expected, $yaml);
+        $this->assertSameData($data, $this->parser->parse($yaml, Yaml::PARSE_CUSTOM_TAGS));
+    }
+
+    public function testDumpingTaggedValueTopLevelAssoc()
+    {
+        $data = new TaggedValue('user', ['name' => 'jane']);
+
+        // @todo Fix the dumper, the output should not be ''.
+        $expected = '';
+        $yaml = $this->dumper->dump($data, 2);
+        $this->assertSame($expected, $yaml);
+    }
+
+    public function testDumpingTaggedValueTopLevelMultiLine()
+    {
+        $data = new TaggedValue('text', "a\nb\n");
+
+        // @todo Fix the dumper, the output should not be ''.
+        $expected = '';
+        $this->assertSame($expected, $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+    }
+
+    public function testDumpingTaggedValueSpecialCharsInTag()
+    {
+        // @todo Validate the tag name in the TaggedValue constructor.
+        $data = new TaggedValue('a b @ c', 5);
+        $expected = '!a b @ c 5';
+        $this->assertSame($expected, $this->dumper->dump($data));
+        // The data changes after a round trip, due to the illegal tag name.
+        $data = new TaggedValue('a', 'b @ c 5');
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
     }
 
     public function testDumpingTaggedValueSequenceWithInlinedTagValues()
@@ -415,6 +480,7 @@ public function testDumpingTaggedValueSequenceWithInlinedTagValues()
                 'john',
                 'claire',
             ]),
+            new TaggedValue('number', 5),
         ];
 
         $yaml = $this->dumper->dump($data, 1);
@@ -422,9 +488,13 @@ public function testDumpingTaggedValueSequenceWithInlinedTagValues()
         $expected = <<<YAML
 - !user { username: jane }
 - !names [john, claire]
+- !number 5
 
 YAML;
         $this->assertSame($expected, $yaml);
+        // @todo Fix the parser, preserve numbers.
+        $data[2] = new TaggedValue('number', '5');
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
     }
 
     public function testDumpingTaggedValueMapRespectsInlineLevel()
@@ -437,6 +507,7 @@ public function testDumpingTaggedValueMapRespectsInlineLevel()
                 'john',
                 'claire',
             ]),
+            'count' => new TaggedValue('number', 5),
         ];
 
         $yaml = $this->dumper->dump($data, 2);
@@ -447,9 +518,13 @@ public function testDumpingTaggedValueMapRespectsInlineLevel()
 names1: !names
     - john
     - claire
+count: !number 5
 
 YAML;
         $this->assertSame($expected, $yaml);
+        // @todo Fix the parser, preserve numbers.
+        $data['count'] = new TaggedValue('number', '5');
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
     }
 
     public function testDumpingTaggedValueMapWithInlinedTagValues()
@@ -472,6 +547,7 @@ public function testDumpingTaggedValueMapWithInlinedTagValues()
 
 YAML;
         $this->assertSame($expected, $yaml);
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
     }
 
     public function testDumpingNotInlinedScalarTaggedValue()
@@ -487,6 +563,7 @@ public function testDumpingNotInlinedScalarTaggedValue()
 YAML;
 
         $this->assertSame($expected, $this->dumper->dump($data, 2));
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
     }
 
     public function testDumpingNotInlinedNullTaggedValue()
@@ -500,6 +577,10 @@ public function testDumpingNotInlinedNullTaggedValue()
 YAML;
 
         $this->assertSame($expected, $this->dumper->dump($data, 2));
+
+        // @todo Fix the parser, don't stringify null.
+        $data['foo'] = new TaggedValue('bar', 'null');
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS | Yaml::PARSE_CONSTANT));
     }
 
     public function testDumpingMultiLineStringAsScalarBlockTaggedValue()
@@ -519,6 +600,53 @@ public function testDumpingMultiLineStringAsScalarBlockTaggedValue()
             '    baz';
 
         $this->assertSame($expected, $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
+    }
+
+    public function testDumpingTaggedMultiLineInList()
+    {
+        $data = [
+            new TaggedValue('bar', "a\nb"),
+        ];
+        $expected = "- !bar |\n    a\n    b";
+        $this->assertSame($expected, $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+
+        // @todo Fix the parser, eliminate these exceptions.
+        $this->expectException(ParseException::class);
+        $this->expectExceptionMessage('Unable to parse at line 3 (near "!bar |").');
+
+        $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS);
+    }
+
+    public function testDumpingTaggedMultiLineTrailingNewlinesInMap()
+    {
+        $data = [
+            'foo' => new TaggedValue('bar', "a\nb\n\n\n"),
+        ];
+        $expected = "foo: !bar |\n    a\n    b\n    \n    \n    ";
+        $this->assertSame($expected, $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+
+        // @todo Fix the parser, the result should be identical to $data.
+        $this->assertSameData(
+            [
+                'foo' => new TaggedValue('bar', "a\nb\n"),
+            ],
+            $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
+    }
+
+    public function testDumpingTaggedMultiLineTrailingNewlinesInList()
+    {
+        $data = [
+            new TaggedValue('bar', "a\nb\n\n\n"),
+        ];
+        $expected = "- !bar |\n    a\n    b\n    \n    \n    ";
+        $this->assertSame($expected, $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+
+        // @todo Fix the parser, eliminate these exceptions.
+        $this->expectException(ParseException::class);
+        $this->expectExceptionMessage('Unable to parse at line 6 (near "!bar |").');
+
+        $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS);
     }
 
     public function testDumpingInlinedMultiLineIfRnBreakLineInTaggedValue()
@@ -528,8 +656,14 @@ public function testDumpingInlinedMultiLineIfRnBreakLineInTaggedValue()
                 'foo' => new TaggedValue('bar', "foo\r\nline with trailing spaces:\n  \nbar\ninteger like line:\n123456789\nempty line:\n\nbaz"),
             ],
         ];
+        $expected = <<<'YAML'
+data:
+    foo: !bar "foo\r\nline with trailing spaces:\n  \nbar\ninteger like line:\n123456789\nempty line:\n\nbaz"
 
-        $this->assertSame(file_get_contents(__DIR__.'/Fixtures/multiple_lines_as_literal_block_for_tagged_values.yml'), $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+YAML;
+        $yml = $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK);
+        $this->assertSame($expected, $yml);
+        $this->assertSameData($data, $this->parser->parse($expected, Yaml::PARSE_CUSTOM_TAGS));
     }
 
     public function testDumpMultiLineStringAsScalarBlock()
@@ -544,8 +678,27 @@ public function testDumpMultiLineStringAsScalarBlock()
                 ],
             ],
         ];
-
-        $this->assertSame(file_get_contents(__DIR__.'/Fixtures/multiple_lines_as_literal_block.yml'), $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+        $yml = $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK);
+        $expected = str_replace("@\n", "\n", <<<'YAML'
+data:
+    single_line: 'foo bar baz'
+    multi_line: |-
+        foo
+        line with trailing spaces:
+          @
+        bar
+        integer like line:
+        123456789
+        empty line:
+
+        baz
+    multi_line_with_carriage_return: "foo\nbar\r\nbaz"
+    nested_inlined_multi_line_string: { inlined_multi_line: "foo\nbar\r\nempty line:\n\nbaz" }
+
+YAML
+);
+        $this->assertSame($expected, $yml);
+        $this->assertSame($data, $this->parser->parse($yml));
     }
 
     public function testDumpMultiLineStringAsScalarBlockWhenFirstLineHasLeadingSpace()
@@ -558,27 +711,33 @@ public function testDumpMultiLineStringAsScalarBlockWhenFirstLineHasLeadingSpace
 
         $expected = "data:\n    multi_line: |4-\n            the first line has leading spaces\n        The second line does not.";
 
-        $this->assertSame($expected, $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+        $yml = $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK);
+        $this->assertSame($expected, $yml);
+        $this->assertSame($data, $this->parser->parse($yml));
     }
 
     public function testCarriageReturnFollowedByNewlineIsMaintainedWhenDumpingAsMultiLineLiteralBlock()
     {
-        $this->assertSame("- \"a\\r\\nb\\nc\"\n", $this->dumper->dump(["a\r\nb\nc"], 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+        $data = ["a\r\nb\nc"];
+        $expected = "- \"a\\r\\nb\\nc\"\n";
+        $this->assertSame($expected, $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+        $this->assertSame($data, $this->parser->parse($expected));
     }
 
     public function testCarriageReturnNotFollowedByNewlineIsPreservedWhenDumpingAsMultiLineLiteralBlock()
     {
+        $data = [
+            'parent' => [
+                'foo' => "bar\n\rbaz: qux",
+            ],
+        ];
         $expected = <<<'YAML'
 parent:
     foo: "bar\n\rbaz: qux"
 
 YAML;
-
-        $this->assertSame($expected, $this->dumper->dump([
-            'parent' => [
-                'foo' => "bar\n\rbaz: qux",
-            ],
-        ], 4, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+        $this->assertSame($expected, $this->dumper->dump($data, 4, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK));
+        $this->assertSame($data, $this->parser->parse($expected));
     }
 
     public function testNoExtraTrailingNewlineWhenDumpingAsMultiLineLiteralBlock()
@@ -590,7 +749,15 @@ public function testNoExtraTrailingNewlineWhenDumpingAsMultiLineLiteralBlock()
         $yaml = $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK);
 
         $this->assertSame("- |-\n    a\n    b\n- |-\n    c\n    d", $yaml);
-        $this->assertSame($data, Yaml::parse($yaml));
+        $this->assertSame($data, $this->parser->parse($yaml));
+    }
+
+    public function testTopLevelMultiLineStringLiteral()
+    {
+        $data = "a\nb\n";
+        $yaml = $this->dumper->dump($data, 2, 0, Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK);
+        $this->assertSame('"a\nb\n"', $yaml);
+        $this->assertSame($data, $this->parser->parse($yaml));
     }
 
     public function testDumpTrailingNewlineInMultiLineLiteralBlocks()
@@ -600,6 +767,7 @@ public function testDumpTrailingNewlineInMultiLineLiteralBlocks()
             'clip 2' => "one\ntwo\n",
             'keep 1' => "one\ntwo\n",
             'keep 2' => "one\ntwo\n\n",
+            'keep 3' => "one\ntwo\n\n\n",
             'strip 1' => "one\ntwo",
             'strip 2' => "one\ntwo",
         ];
@@ -619,6 +787,11 @@ public function testDumpTrailingNewlineInMultiLineLiteralBlocks()
     one
     two
 
+'keep 3': |+
+    one
+    two
+
+
 'strip 1': |-
     one
     two
@@ -628,7 +801,7 @@ public function testDumpTrailingNewlineInMultiLineLiteralBlocks()
 YAML;
 
         $this->assertSame($expected, $yaml);
-        $this->assertSame($data, Yaml::parse($yaml));
+        $this->assertSame($data, $this->parser->parse($yaml));
     }
 
     public function testZeroIndentationThrowsException()
@@ -664,6 +837,15 @@ public function testDumpIdeographicSpaces()
             'regular_space' => 'a b',
         ], 2));
     }
+
+    private function assertSameData($expected, $actual)
+    {
+        $this->assertEquals($expected, $actual);
+        $this->assertSame(
+            var_export($expected, true),
+            var_export($actual, true)
+        );
+    }
 }
 
 class A
diff --git a/src/Symfony/Component/Yaml/Tests/Fixtures/multiple_lines_as_literal_block.yml b/src/Symfony/Component/Yaml/Tests/Fixtures/multiple_lines_as_literal_block.yml
deleted file mode 100644
index 1f61eb1216a5..000000000000
--- a/src/Symfony/Component/Yaml/Tests/Fixtures/multiple_lines_as_literal_block.yml
+++ /dev/null
@@ -1,14 +0,0 @@
-data:
-    single_line: 'foo bar baz'
-    multi_line: |-
-        foo
-        line with trailing spaces:
-          
-        bar
-        integer like line:
-        123456789
-        empty line:
-
-        baz
-    multi_line_with_carriage_return: "foo\nbar\r\nbaz"
-    nested_inlined_multi_line_string: { inlined_multi_line: "foo\nbar\r\nempty line:\n\nbaz" }
diff --git a/src/Symfony/Component/Yaml/Tests/Fixtures/multiple_lines_as_literal_block_for_tagged_values.yml b/src/Symfony/Component/Yaml/Tests/Fixtures/multiple_lines_as_literal_block_for_tagged_values.yml
deleted file mode 100644
index f8c9112fd52a..000000000000
--- a/src/Symfony/Component/Yaml/Tests/Fixtures/multiple_lines_as_literal_block_for_tagged_values.yml
+++ /dev/null
@@ -1,2 +0,0 @@
-data:
-    foo: !bar "foo\r\nline with trailing spaces:\n  \nbar\ninteger like line:\n123456789\nempty line:\n\nbaz"
diff --git a/src/Symfony/Component/Yaml/Tests/ParserTest.php b/src/Symfony/Component/Yaml/Tests/ParserTest.php
index 9a14422e434f..08751d5fe8d9 100644
--- a/src/Symfony/Component/Yaml/Tests/ParserTest.php
+++ b/src/Symfony/Component/Yaml/Tests/ParserTest.php
@@ -34,6 +34,90 @@ protected function tearDown(): void
         chmod(__DIR__.'/Fixtures/not_readable.yml', 0644);
     }
 
+    public function testTopLevelNumber()
+    {
+        $yml = '5';
+        $data = $this->parser->parse($yml);
+        $expected = 5;
+        $this->assertSameData($expected, $data);
+    }
+
+    public function testTopLevelNull()
+    {
+        $yml = 'null';
+        $data = $this->parser->parse($yml);
+        $expected = null;
+        $this->assertSameData($expected, $data);
+    }
+
+    public function testTaggedValueTopLevelNumber()
+    {
+        $yml = '!number 5';
+        $data = $this->parser->parse($yml, Yaml::PARSE_CUSTOM_TAGS);
+        // @todo Preserve the number, don't turn into string.
+        $expected = new TaggedValue('number', '5');
+        $this->assertSameData($expected, $data);
+    }
+
+    public function testTaggedValueTopLevelNull()
+    {
+        $yml = '!tag null';
+        $data = $this->parser->parse($yml, Yaml::PARSE_CUSTOM_TAGS);
+        // @todo Preserve literal null, don't turn into string.
+        $expected = new TaggedValue('tag', 'null');
+        $this->assertSameData($expected, $data);
+    }
+
+    public function testTaggedValueTopLevelString()
+    {
+        $yml = '!user barbara';
+        $data = $this->parser->parse($yml, Yaml::PARSE_CUSTOM_TAGS);
+        $expected = new TaggedValue('user', 'barbara');
+        $this->assertSameData($expected, $data);
+    }
+
+    public function testTaggedValueTopLevelAssocInline()
+    {
+        $yml = '!user { name: barbara }';
+        $data = $this->parser->parse($yml, Yaml::PARSE_CUSTOM_TAGS);
+        $expected = new TaggedValue('user', ['name' => 'barbara']);
+        $this->assertSameData($expected, $data);
+    }
+
+    public function testTaggedValueTopLevelAssoc()
+    {
+        $yml = <<<'YAML'
+!user
+name: barbara
+YAML;
+        $data = $this->parser->parse($yml, Yaml::PARSE_CUSTOM_TAGS);
+        $expected = new TaggedValue('user', ['name' => 'barbara']);
+        $this->assertSameData($expected, $data);
+    }
+
+    public function testTaggedValueTopLevelList()
+    {
+        $yml = <<<'YAML'
+!users
+- barbara
+YAML;
+        $data = $this->parser->parse($yml, Yaml::PARSE_CUSTOM_TAGS);
+        $expected = new TaggedValue('users', ['barbara']);
+        $this->assertSameData($expected, $data);
+    }
+
+    public function testTaggedTextAsListItem()
+    {
+        $yml = <<<'YAML'
+- !text |
+  first line
+YAML;
+        // @todo Fix the parser, eliminate this exception.
+        $this->expectException(ParseException::class);
+        $this->expectExceptionMessage('Unable to parse at line 2 (near "!text |").');
+        $this->parser->parse($yml, Yaml::PARSE_CUSTOM_TAGS);
+    }
+
     /**
      * @dataProvider getDataFormSpecifications
      */
@@ -104,7 +188,7 @@ public function testParserIsStateless()
     public function testValidTokenSeparation(string $given, array $expected)
     {
         $actual = $this->parser->parse($given);
-        $this->assertEquals($expected, $actual);
+        $this->assertSameData($expected, $actual);
     }
 
     public function validTokenSeparators(): array
@@ -482,7 +566,7 @@ public function testObjectSupportEnabled()
 foo: !php/object O:30:"Symfony\Component\Yaml\Tests\B":1:{s:1:"b";s:3:"foo";}
 bar: 1
 EOF;
-        $this->assertEquals(['foo' => new B(), 'bar' => 1], $this->parser->parse($input, Yaml::PARSE_OBJECT), '->parse() is able to parse objects');
+        $this->assertSameData(['foo' => new B(), 'bar' => 1], $this->parser->parse($input, Yaml::PARSE_OBJECT), '->parse() is able to parse objects');
     }
 
     public function testObjectSupportDisabledButNoExceptions()
@@ -491,7 +575,7 @@ public function testObjectSupportDisabledButNoExceptions()
 foo: !php/object O:30:"Symfony\Tests\Component\Yaml\B":1:{s:1:"b";s:3:"foo";}
 bar: 1
 EOF;
-        $this->assertEquals(['foo' => null, 'bar' => 1], $this->parser->parse($input), '->parse() does not parse objects');
+        $this->assertSameData(['foo' => null, 'bar' => 1], $this->parser->parse($input), '->parse() does not parse objects');
     }
 
     /**
@@ -501,7 +585,7 @@ public function testObjectForMap($yaml, $expected)
     {
         $flags = Yaml::PARSE_OBJECT_FOR_MAP;
 
-        $this->assertEquals($expected, $this->parser->parse($yaml, $flags));
+        $this->assertSameData($expected, $this->parser->parse($yaml, $flags));
     }
 
     public function getObjectForMapTests()
@@ -957,12 +1041,12 @@ public function testEmptyValue()
 hash:
 EOF;
 
-        $this->assertEquals(['hash' => null], Yaml::parse($input));
+        $this->assertSame(['hash' => null], Yaml::parse($input));
     }
 
     public function testCommentAtTheRootIndent()
     {
-        $this->assertEquals([
+        $this->assertSame([
             'services' => [
                 'app.foo_service' => [
                     'class' => 'Foo',
@@ -988,7 +1072,7 @@ class: Bar
 
     public function testStringBlockWithComments()
     {
-        $this->assertEquals(['content' => <<<'EOT'
+        $this->assertSame(['content' => <<<'EOT'
 # comment 1
 header
 
@@ -1016,7 +1100,7 @@ public function testStringBlockWithComments()
 
     public function testFoldedStringBlockWithComments()
     {
-        $this->assertEquals([['content' => <<<'EOT'
+        $this->assertSame([['content' => <<<'EOT'
 # comment 1
 header
 
@@ -1045,7 +1129,7 @@ public function testFoldedStringBlockWithComments()
 
     public function testNestedFoldedStringBlockWithComments()
     {
-        $this->assertEquals([[
+        $this->assertSame([[
             'title' => 'some title',
             'content' => <<<'EOT'
 # comment 1
@@ -1077,7 +1161,7 @@ public function testNestedFoldedStringBlockWithComments()
 
     public function testReferenceResolvingInInlineStrings()
     {
-        $this->assertEquals([
+        $this->assertSame([
             'var' => 'var-value',
             'scalar' => 'var-value',
             'list' => ['var-value'],
@@ -1117,7 +1201,7 @@ public function testYamlDirective()
 foo: 1
 bar: 2
 EOF;
-        $this->assertEquals(['foo' => 1, 'bar' => 2], $this->parser->parse($yaml));
+        $this->assertSame(['foo' => 1, 'bar' => 2], $this->parser->parse($yaml));
     }
 
     public function testFloatKeys()
@@ -1167,7 +1251,7 @@ public function testExplicitStringCasting()
             '~' => 'null',
         ];
 
-        $this->assertEquals($expected, $this->parser->parse($yaml));
+        $this->assertSame($expected, $this->parser->parse($yaml));
     }
 
     public function testColonInMappingValueException()
@@ -1468,7 +1552,7 @@ public function testParseDateAsMappingValue()
         $expectedDate->setDate(2002, 12, 14);
         $expectedDate->setTime(0, 0, 0);
 
-        $this->assertEquals(['date' => $expectedDate], $this->parser->parse($yaml, Yaml::PARSE_DATETIME));
+        $this->assertSameData(['date' => $expectedDate], $this->parser->parse($yaml, Yaml::PARSE_DATETIME));
     }
 
     /**
@@ -1688,7 +1772,7 @@ public function testBackslashInSingleQuotedString()
 
     public function testParseMultiLineString()
     {
-        $this->assertEquals("foo bar\nbaz", $this->parser->parse("foo\nbar\n\nbaz"));
+        $this->assertSame("foo bar\nbaz", $this->parser->parse("foo\nbar\n\nbaz"));
     }
 
     /**
@@ -1696,7 +1780,7 @@ public function testParseMultiLineString()
      */
     public function testParseMultiLineMappingValue($yaml, $expected, $parseError)
     {
-        $this->assertEquals($expected, $this->parser->parse($yaml));
+        $this->assertSame($expected, $this->parser->parse($yaml));
     }
 
     public function multiLineDataProvider()
@@ -1763,7 +1847,7 @@ public function multiLineDataProvider()
      */
     public function testInlineNotationSpanningMultipleLines($expected, string $yaml)
     {
-        $this->assertEquals($expected, $this->parser->parse($yaml));
+        $this->assertSame($expected, $this->parser->parse($yaml));
     }
 
     public function inlineNotationSpanningMultipleLinesProvider(): array
@@ -2137,7 +2221,7 @@ public function testRootLevelInlineMappingFollowedByMoreContentIsInvalid()
 
     public function testTaggedInlineMapping()
     {
-        $this->assertEquals(new TaggedValue('foo', ['foo' => 'bar']), $this->parser->parse('!foo {foo: bar}', Yaml::PARSE_CUSTOM_TAGS));
+        $this->assertSameData(new TaggedValue('foo', ['foo' => 'bar']), $this->parser->parse('!foo {foo: bar}', Yaml::PARSE_CUSTOM_TAGS));
     }
 
     public function testInvalidInlineSequenceContainingStringWithEscapedQuotationCharacter()
@@ -2152,7 +2236,7 @@ public function testInvalidInlineSequenceContainingStringWithEscapedQuotationCha
      */
     public function testCustomTagSupport($expected, $yaml)
     {
-        $this->assertEquals($expected, $this->parser->parse($yaml, Yaml::PARSE_CUSTOM_TAGS));
+        $this->assertSameData($expected, $this->parser->parse($yaml, Yaml::PARSE_CUSTOM_TAGS));
     }
 
     public function taggedValuesProvider()
@@ -2348,7 +2432,7 @@ public function testCanParseVeryLongValue()
         $yamlString = Yaml::dump($trickyVal);
         $arrayFromYaml = $this->parser->parse($yamlString);
 
-        $this->assertEquals($trickyVal, $arrayFromYaml);
+        $this->assertSame($trickyVal, $arrayFromYaml);
     }
 
     public function testParserCleansUpReferencesBetweenRuns()
@@ -2463,7 +2547,7 @@ public function testMergeKeysWhenMappingsAreParsedAsObjects()
             ],
         ];
 
-        $this->assertEquals($expected, $this->parser->parse($yaml, Yaml::PARSE_OBJECT_FOR_MAP));
+        $this->assertSameData($expected, $this->parser->parse($yaml, Yaml::PARSE_OBJECT_FOR_MAP));
     }
 
     public function testFilenamesAreParsedAsStringsWithoutFlag()
@@ -2556,7 +2640,7 @@ public function testParseReferencesOnMergeKeysWithMappingsParsedAsObjects()
             ],
         ];
 
-        $this->assertEquals($expected, $this->parser->parse($yaml, Yaml::PARSE_OBJECT_FOR_MAP));
+        $this->assertSameData($expected, $this->parser->parse($yaml, Yaml::PARSE_OBJECT_FOR_MAP));
     }
 
     public function testEvalRefException()
@@ -2831,6 +2915,14 @@ public function testParseIdeographicSpaces()
             'regular_space' => 'a b',
         ], $this->parser->parse($expected));
     }
+
+    private function assertSameData($expected, $actual)
+    {
+        $this->assertEquals($expected, $actual);
+        $this->assertSame(
+            var_export($expected, true),
+            var_export($actual, true));
+    }
 }
 
 class B