From 4dc89370ce127940883bc3e9cbc456f250fd6ea9 Mon Sep 17 00:00:00 2001
From: jrfnl <jrfnl@users.noreply.github.com>
Date: Tue, 11 Nov 2025 21:49:43 +0100
Subject: [PATCH] Generic/UnnecessaryHeredoc: bug fix - fixer changes
 indentation type

In a tab indented file with `--tab-width` set, the fixer for the `Generic.Strings.UnnecessaryHeredoc` sniff would replace tabs with spaces in lines in the heredoc body, which were being replaced to update the escaping of special characters.

For heredocs using PHP 7.3+ flexible heredoc syntax with tab indentation, that also meant that the fixer would end up causing a parse error in the updated file (see: https://3v4l.org/vpD1u#veol )

Fixed now.

Includes extensively expanded tests to safeguard this fix for all variations of heredoc syntax vs indentation whitespace which I could think of.

Fixes 1320
---
 .../Strings/UnnecessaryHeredocSniff.php       |  10 +-
 .../Strings/UnnecessaryHeredocUnitTest.1.inc  |  10 +-
 .../UnnecessaryHeredocUnitTest.1.inc.fixed    |  10 +-
 .../Strings/UnnecessaryHeredocUnitTest.2.inc  |  10 +-
 .../UnnecessaryHeredocUnitTest.2.inc.fixed    |  10 +-
 .../Strings/UnnecessaryHeredocUnitTest.4.inc  | 126 ++++++++++++++++++
 .../UnnecessaryHeredocUnitTest.4.inc.fixed    | 126 ++++++++++++++++++
 .../Strings/UnnecessaryHeredocUnitTest.5.inc  | 126 ++++++++++++++++++
 .../UnnecessaryHeredocUnitTest.5.inc.fixed    | 126 ++++++++++++++++++
 .../Strings/UnnecessaryHeredocUnitTest.6.inc  | 126 ++++++++++++++++++
 .../UnnecessaryHeredocUnitTest.6.inc.fixed    | 126 ++++++++++++++++++
 .../Strings/UnnecessaryHeredocUnitTest.php    |  25 +++-
 12 files changed, 815 insertions(+), 16 deletions(-)
 create mode 100644 src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.4.inc
 create mode 100644 src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.4.inc.fixed
 create mode 100644 src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.5.inc
 create mode 100644 src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.5.inc.fixed
 create mode 100644 src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.6.inc
 create mode 100644 src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.6.inc.fixed

diff --git a/src/Standards/Generic/Sniffs/Strings/UnnecessaryHeredocSniff.php b/src/Standards/Generic/Sniffs/Strings/UnnecessaryHeredocSniff.php
index 226215c96e..0ffa197c2e 100644
--- a/src/Standards/Generic/Sniffs/Strings/UnnecessaryHeredocSniff.php
+++ b/src/Standards/Generic/Sniffs/Strings/UnnecessaryHeredocSniff.php
@@ -128,9 +128,13 @@ public function process(File $phpcsFile, int $stackPtr)
             $phpcsFile->fixer->replaceToken($stackPtr, $replacement);
 
             for ($i = ($stackPtr + 1); $i < $closer; $i++) {
-                $content = $tokens[$i]['content'];
-                $content = str_replace(['\\$', '\\\\'], ['$', '\\'], $content);
-                if ($tokens[$i]['content'] !== $content) {
+                $origContent = $tokens[$i]['content'];
+                if (isset($tokens[$i]['orig_content']) === true) {
+                    $origContent = $tokens[$i]['orig_content'];
+                }
+
+                $content = str_replace(['\\$', '\\\\'], ['$', '\\'], $origContent);
+                if ($origContent !== $content) {
                     $phpcsFile->fixer->replaceToken($i, $content);
                 }
             }
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.1.inc b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.1.inc
index 428b4b8a40..efd30df5c2 100644
--- a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.1.inc
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.1.inc
@@ -1,10 +1,14 @@
 <?php
 
 /*
- * Test file 1 and 2 mirror each other, with file 1 containing non-indented cross-version compatible heredoc/nowdoc syntax,
- * while the code samples in file 2 use PHP 7.3+ flexible heredoc/nowdoc syntax.
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
  *
- * These two files should be kept in sync!
+ * These files should be kept in sync!
  */
 
 $nowdoc = <<<'EOD'
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.1.inc.fixed b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.1.inc.fixed
index 84bc6a52e7..a9a10b3f98 100644
--- a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.1.inc.fixed
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.1.inc.fixed
@@ -1,10 +1,14 @@
 <?php
 
 /*
- * Test file 1 and 2 mirror each other, with file 1 containing non-indented cross-version compatible heredoc/nowdoc syntax,
- * while the code samples in file 2 use PHP 7.3+ flexible heredoc/nowdoc syntax.
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
  *
- * These two files should be kept in sync!
+ * These files should be kept in sync!
  */
 
 $nowdoc = <<<'EOD'
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.2.inc b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.2.inc
index a2eebc8120..15a8575013 100644
--- a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.2.inc
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.2.inc
@@ -1,10 +1,14 @@
 <?php
 
 /*
- * Test file 1 and 2 mirror each other, with file 1 containing non-indented cross-version compatible heredoc/nowdoc syntax,
- * while the code samples in file 2 use PHP 7.3+ flexible heredoc/nowdoc syntax.
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
  *
- * These two files should be kept in sync!
+ * These files should be kept in sync!
  */
 
 $nowdoc = <<<'EOD'
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.2.inc.fixed b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.2.inc.fixed
index 47f5eecd8a..5dc81d4481 100644
--- a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.2.inc.fixed
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.2.inc.fixed
@@ -1,10 +1,14 @@
 <?php
 
 /*
- * Test file 1 and 2 mirror each other, with file 1 containing non-indented cross-version compatible heredoc/nowdoc syntax,
- * while the code samples in file 2 use PHP 7.3+ flexible heredoc/nowdoc syntax.
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
  *
- * These two files should be kept in sync!
+ * These files should be kept in sync!
  */
 
 $nowdoc = <<<'EOD'
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.4.inc b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.4.inc
new file mode 100644
index 0000000000..aa328d0dd4
--- /dev/null
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.4.inc
@@ -0,0 +1,126 @@
+<?php
+
+/*
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
+ *
+ * These files should be kept in sync!
+ */
+
+$nowdoc = <<<'EOD'
+    some text
+EOD;
+
+$heredoc = <<<END
+    some $foo text
+END;
+
+$heredoc = <<<"END"
+    some {$foo[0]} text
+END;
+
+$heredoc = <<<END
+    {$foo?->bar}
+END;
+
+$heredoc = <<<    "END"
+    some ${beers::softdrink}
+END;
+
+$heredoc = <<< END
+    {${$object->getName()}} text
+END;
+
+$heredoc = <<<"END"
+    some {${getName()}}
+END;
+
+$heredoc = <<<END
+    ${substr('laruence', 0, 2)}
+END;
+
+$heredoc = <<<"END"
+    some {$foo['bar']->baz()()}
+END;
+
+$heredoc = <<<END
+    {$obj->values[3]->name} text
+END;
+
+$heredoc = <<<"END"
+    some ${$bar}
+END;
+
+$heredoc = <<<END
+    ${foo->bar} text
+END;
+
+$heredoc = <<<"END"
+    ${foo["${bar}"]} text
+END;
+
+$heredoc = <<<END
+    some ${foo["${bar[\'baz\']}"]}
+END;
+
+$heredoc = <<<"END"
+    ${foo->{${'a'}}} text
+END;
+
+$heredoc = <<<END
+    some {$foo->{$baz[1]}}
+END;
+
+$heredoc = <<<END
+    some text
+    {${beers::$ale}}
+    some text
+END;
+
+$heredoc = <<<"END"
+    $people->john's wife greeted $people->robert.
+END;
+
+$heredoc = <<<END
+    Let's make sure it also works with this: {$arr[foo][3]}
+END;
+
+$heredoc = <<<END
+    Testing ${foo["${bar
+      ['baz']
+    }"]} and more testing
+END;
+
+$heredoc = <<<"END"
+    Testing {${foo["${bar
+      ['baz']
+    }"]}} and more testing
+END;
+
+$heredoc = <<<END
+    some text
+END;
+
+$heredoc = <<< "END"
+    some text
+    some \$text
+    some text \\ including a backslash
+END;
+
+$heredoc = <<<EOD
+    <?php
+    echo 'The below line contains escape characters and should be recognized as needing heredoc';
+    echo "aa\xC3\xC3	\xC3\xB8aa";
+EOD;
+
+echo <<<EOT
+    This should print a capital 'A': \x41
+EOT;
+
+echo <<<EOT
+    Here we should have a tab and 2 'A's: \t \101 \u{41}
+EOT;
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.4.inc.fixed b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.4.inc.fixed
new file mode 100644
index 0000000000..fb3de2d8ec
--- /dev/null
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.4.inc.fixed
@@ -0,0 +1,126 @@
+<?php
+
+/*
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
+ *
+ * These files should be kept in sync!
+ */
+
+$nowdoc = <<<'EOD'
+    some text
+EOD;
+
+$heredoc = <<<END
+    some $foo text
+END;
+
+$heredoc = <<<"END"
+    some {$foo[0]} text
+END;
+
+$heredoc = <<<END
+    {$foo?->bar}
+END;
+
+$heredoc = <<<    "END"
+    some ${beers::softdrink}
+END;
+
+$heredoc = <<< END
+    {${$object->getName()}} text
+END;
+
+$heredoc = <<<"END"
+    some {${getName()}}
+END;
+
+$heredoc = <<<END
+    ${substr('laruence', 0, 2)}
+END;
+
+$heredoc = <<<"END"
+    some {$foo['bar']->baz()()}
+END;
+
+$heredoc = <<<END
+    {$obj->values[3]->name} text
+END;
+
+$heredoc = <<<"END"
+    some ${$bar}
+END;
+
+$heredoc = <<<END
+    ${foo->bar} text
+END;
+
+$heredoc = <<<"END"
+    ${foo["${bar}"]} text
+END;
+
+$heredoc = <<<END
+    some ${foo["${bar[\'baz\']}"]}
+END;
+
+$heredoc = <<<"END"
+    ${foo->{${'a'}}} text
+END;
+
+$heredoc = <<<END
+    some {$foo->{$baz[1]}}
+END;
+
+$heredoc = <<<END
+    some text
+    {${beers::$ale}}
+    some text
+END;
+
+$heredoc = <<<"END"
+    $people->john's wife greeted $people->robert.
+END;
+
+$heredoc = <<<END
+    Let's make sure it also works with this: {$arr[foo][3]}
+END;
+
+$heredoc = <<<END
+    Testing ${foo["${bar
+      ['baz']
+    }"]} and more testing
+END;
+
+$heredoc = <<<"END"
+    Testing {${foo["${bar
+      ['baz']
+    }"]}} and more testing
+END;
+
+$heredoc = <<<'END'
+    some text
+END;
+
+$heredoc = <<< 'END'
+    some text
+    some $text
+    some text \ including a backslash
+END;
+
+$heredoc = <<<EOD
+    <?php
+    echo 'The below line contains escape characters and should be recognized as needing heredoc';
+    echo "aa\xC3\xC3	\xC3\xB8aa";
+EOD;
+
+echo <<<EOT
+    This should print a capital 'A': \x41
+EOT;
+
+echo <<<EOT
+    Here we should have a tab and 2 'A's: \t \101 \u{41}
+EOT;
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.5.inc b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.5.inc
new file mode 100644
index 0000000000..117f82915b
--- /dev/null
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.5.inc
@@ -0,0 +1,126 @@
+<?php
+
+/*
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
+ *
+ * These files should be kept in sync!
+ */
+
+$nowdoc = <<<'EOD'
+	some text
+EOD;
+
+$heredoc = <<<END
+	some $foo text
+END;
+
+$heredoc = <<<"END"
+	some {$foo[0]} text
+END;
+
+$heredoc = <<<END
+	{$foo?->bar}
+END;
+
+$heredoc = <<<    "END"
+	some ${beers::softdrink}
+END;
+
+$heredoc = <<< END
+	{${$object->getName()}} text
+END;
+
+$heredoc = <<<"END"
+	some {${getName()}}
+END;
+
+$heredoc = <<<END
+	${substr('laruence', 0, 2)}
+END;
+
+$heredoc = <<<"END"
+	some {$foo['bar']->baz()()}
+END;
+
+$heredoc = <<<END
+	{$obj->values[3]->name} text
+END;
+
+$heredoc = <<<"END"
+	some ${$bar}
+END;
+
+$heredoc = <<<END
+	${foo->bar} text
+END;
+
+$heredoc = <<<"END"
+	${foo["${bar}"]} text
+END;
+
+$heredoc = <<<END
+	some ${foo["${bar[\'baz\']}"]}
+END;
+
+$heredoc = <<<"END"
+	${foo->{${'a'}}} text
+END;
+
+$heredoc = <<<END
+	some {$foo->{$baz[1]}}
+END;
+
+$heredoc = <<<END
+	some text
+	{${beers::$ale}}
+	some text
+END;
+
+$heredoc = <<<"END"
+	$people->john's wife greeted $people->robert.
+END;
+
+$heredoc = <<<END
+	Let's make sure it also works with this: {$arr[foo][3]}
+END;
+
+$heredoc = <<<END
+	Testing ${foo["${bar
+	  ['baz']
+	}"]} and more testing
+END;
+
+$heredoc = <<<"END"
+	Testing {${foo["${bar
+	  ['baz']
+	}"]}} and more testing
+END;
+
+$heredoc = <<<END
+	some text
+END;
+
+$heredoc = <<< "END"
+	some text
+	some \$text
+	some text \\ including a backslash
+END;
+
+$heredoc = <<<EOD
+	<?php
+	echo 'The below line contains escape characters and should be recognized as needing heredoc';
+	echo "aa\xC3\xC3	\xC3\xB8aa";
+EOD;
+
+echo <<<EOT
+	This should print a capital 'A': \x41
+EOT;
+
+echo <<<EOT
+	Here we should have a tab and 2 'A's: \t \101 \u{41}
+EOT;
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.5.inc.fixed b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.5.inc.fixed
new file mode 100644
index 0000000000..53a076b9f8
--- /dev/null
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.5.inc.fixed
@@ -0,0 +1,126 @@
+<?php
+
+/*
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
+ *
+ * These files should be kept in sync!
+ */
+
+$nowdoc = <<<'EOD'
+	some text
+EOD;
+
+$heredoc = <<<END
+	some $foo text
+END;
+
+$heredoc = <<<"END"
+	some {$foo[0]} text
+END;
+
+$heredoc = <<<END
+	{$foo?->bar}
+END;
+
+$heredoc = <<<    "END"
+	some ${beers::softdrink}
+END;
+
+$heredoc = <<< END
+	{${$object->getName()}} text
+END;
+
+$heredoc = <<<"END"
+	some {${getName()}}
+END;
+
+$heredoc = <<<END
+	${substr('laruence', 0, 2)}
+END;
+
+$heredoc = <<<"END"
+	some {$foo['bar']->baz()()}
+END;
+
+$heredoc = <<<END
+	{$obj->values[3]->name} text
+END;
+
+$heredoc = <<<"END"
+	some ${$bar}
+END;
+
+$heredoc = <<<END
+	${foo->bar} text
+END;
+
+$heredoc = <<<"END"
+	${foo["${bar}"]} text
+END;
+
+$heredoc = <<<END
+	some ${foo["${bar[\'baz\']}"]}
+END;
+
+$heredoc = <<<"END"
+	${foo->{${'a'}}} text
+END;
+
+$heredoc = <<<END
+	some {$foo->{$baz[1]}}
+END;
+
+$heredoc = <<<END
+	some text
+	{${beers::$ale}}
+	some text
+END;
+
+$heredoc = <<<"END"
+	$people->john's wife greeted $people->robert.
+END;
+
+$heredoc = <<<END
+	Let's make sure it also works with this: {$arr[foo][3]}
+END;
+
+$heredoc = <<<END
+	Testing ${foo["${bar
+	  ['baz']
+	}"]} and more testing
+END;
+
+$heredoc = <<<"END"
+	Testing {${foo["${bar
+	  ['baz']
+	}"]}} and more testing
+END;
+
+$heredoc = <<<'END'
+	some text
+END;
+
+$heredoc = <<< 'END'
+	some text
+	some $text
+	some text \ including a backslash
+END;
+
+$heredoc = <<<EOD
+	<?php
+	echo 'The below line contains escape characters and should be recognized as needing heredoc';
+	echo "aa\xC3\xC3	\xC3\xB8aa";
+EOD;
+
+echo <<<EOT
+	This should print a capital 'A': \x41
+EOT;
+
+echo <<<EOT
+	Here we should have a tab and 2 'A's: \t \101 \u{41}
+EOT;
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.6.inc b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.6.inc
new file mode 100644
index 0000000000..fee0e42691
--- /dev/null
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.6.inc
@@ -0,0 +1,126 @@
+<?php
+
+/*
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
+ *
+ * These files should be kept in sync!
+ */
+
+$nowdoc = <<<'EOD'
+	some text
+	EOD;
+
+$heredoc = <<<END
+	some $foo text
+	END;
+
+$heredoc = <<<"END"
+	some {$foo[0]} text
+	END;
+
+$heredoc = <<<END
+	{$foo?->bar}
+	END;
+
+$heredoc = <<<    "END"
+	some ${beers::softdrink}
+	END;
+
+$heredoc = <<< END
+	{${$object->getName()}} text
+	END;
+
+$heredoc = <<<"END"
+	some {${getName()}}
+	END;
+
+$heredoc = <<<END
+	${substr('laruence', 0, 2)}
+	END;
+
+$heredoc = <<<"END"
+	some {$foo['bar']->baz()()}
+	END;
+
+$heredoc = <<<END
+	{$obj->values[3]->name} text
+	END;
+
+$heredoc = <<<"END"
+	some ${$bar}
+	END;
+
+$heredoc = <<<END
+	${foo->bar} text
+	END;
+
+$heredoc = <<<"END"
+	${foo["${bar}"]} text
+	END;
+
+$heredoc = <<<END
+	some ${foo["${bar[\'baz\']}"]}
+	END;
+
+$heredoc = <<<"END"
+	${foo->{${'a'}}} text
+	END;
+
+$heredoc = <<<END
+	some {$foo->{$baz[1]}}
+	END;
+
+$heredoc = <<<END
+	some text
+	{${beers::$ale}}
+	some text
+	END;
+
+$heredoc = <<<"END"
+	$people->john's wife greeted $people->robert.
+	END;
+
+$heredoc = <<<END
+	Let's make sure it also works with this: {$arr[foo][3]}
+	END;
+
+$heredoc = <<<END
+	Testing ${foo["${bar
+	  ['baz']
+	}"]} and more testing
+	END;
+
+$heredoc = <<<"END"
+	Testing {${foo["${bar
+	  ['baz']
+	}"]}} and more testing
+	END;
+
+$heredoc = <<<END
+	some text
+	END;
+
+$heredoc = <<< "END"
+	some text
+	some \$text
+	some text \\ including a backslash
+	END;
+
+$heredoc = <<<EOD
+	<?php
+	echo 'The below line contains escape characters and should be recognized as needing heredoc';
+	echo "aa\xC3\xC3	\xC3\xB8aa";
+	EOD;
+
+echo <<<EOT
+	This should print a capital 'A': \x41
+	EOT;
+
+echo <<<EOT
+	Here we should have a tab and 2 'A's: \t \101 \u{41}
+	EOT;
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.6.inc.fixed b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.6.inc.fixed
new file mode 100644
index 0000000000..afa777ba8e
--- /dev/null
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.6.inc.fixed
@@ -0,0 +1,126 @@
+<?php
+
+/*
+ * Test files 1, 2, 4, 5 and 6 mirror each other for the test cases, with slight syntax variations.
+ * - File 1 contains non-indented cross-version compatible heredoc/nowdoc syntax with a non-indented heredoc/nowdoc body.
+ * - File 2 contains PHP 7.3+ flexible heredoc/nowdoc syntax with space indented heredoc/nowdoc body and scope closer.
+ * - File 4 contains non-indented cross-version compatible heredoc/nowdoc syntax with a space indented heredoc/nowdoc body.
+ * - File 5 contains non-indented cross-version compatible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body.
+ * - File 6 contains PHP 7.3+ flexible heredoc/nowdoc syntax with a tab indented heredoc/nowdoc body and scope closer.
+ *
+ * These files should be kept in sync!
+ */
+
+$nowdoc = <<<'EOD'
+	some text
+	EOD;
+
+$heredoc = <<<END
+	some $foo text
+	END;
+
+$heredoc = <<<"END"
+	some {$foo[0]} text
+	END;
+
+$heredoc = <<<END
+	{$foo?->bar}
+	END;
+
+$heredoc = <<<    "END"
+	some ${beers::softdrink}
+	END;
+
+$heredoc = <<< END
+	{${$object->getName()}} text
+	END;
+
+$heredoc = <<<"END"
+	some {${getName()}}
+	END;
+
+$heredoc = <<<END
+	${substr('laruence', 0, 2)}
+	END;
+
+$heredoc = <<<"END"
+	some {$foo['bar']->baz()()}
+	END;
+
+$heredoc = <<<END
+	{$obj->values[3]->name} text
+	END;
+
+$heredoc = <<<"END"
+	some ${$bar}
+	END;
+
+$heredoc = <<<END
+	${foo->bar} text
+	END;
+
+$heredoc = <<<"END"
+	${foo["${bar}"]} text
+	END;
+
+$heredoc = <<<END
+	some ${foo["${bar[\'baz\']}"]}
+	END;
+
+$heredoc = <<<"END"
+	${foo->{${'a'}}} text
+	END;
+
+$heredoc = <<<END
+	some {$foo->{$baz[1]}}
+	END;
+
+$heredoc = <<<END
+	some text
+	{${beers::$ale}}
+	some text
+	END;
+
+$heredoc = <<<"END"
+	$people->john's wife greeted $people->robert.
+	END;
+
+$heredoc = <<<END
+	Let's make sure it also works with this: {$arr[foo][3]}
+	END;
+
+$heredoc = <<<END
+	Testing ${foo["${bar
+	  ['baz']
+	}"]} and more testing
+	END;
+
+$heredoc = <<<"END"
+	Testing {${foo["${bar
+	  ['baz']
+	}"]}} and more testing
+	END;
+
+$heredoc = <<<'END'
+	some text
+	END;
+
+$heredoc = <<< 'END'
+	some text
+	some $text
+	some text \ including a backslash
+	END;
+
+$heredoc = <<<EOD
+	<?php
+	echo 'The below line contains escape characters and should be recognized as needing heredoc';
+	echo "aa\xC3\xC3	\xC3\xB8aa";
+	EOD;
+
+echo <<<EOT
+	This should print a capital 'A': \x41
+	EOT;
+
+echo <<<EOT
+	Here we should have a tab and 2 'A's: \t \101 \u{41}
+	EOT;
diff --git a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.php b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.php
index fc5575c4c7..378ac8c412 100644
--- a/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.php
+++ b/src/Standards/Generic/Tests/Strings/UnnecessaryHeredocUnitTest.php
@@ -9,6 +9,7 @@
 
 namespace PHP_CodeSniffer\Standards\Generic\Tests\Strings;
 
+use PHP_CodeSniffer\Config;
 use PHP_CodeSniffer\Tests\Standards\AbstractSniffTestCase;
 
 /**
@@ -20,6 +21,25 @@ final class UnnecessaryHeredocUnitTest extends AbstractSniffTestCase
 {
 
 
+    /**
+     * Get a list of CLI values to set before the file is tested.
+     *
+     * @param string                  $testFile The name of the file being tested.
+     * @param \PHP_CodeSniffer\Config $config   The config data for the test run.
+     *
+     * @return void
+     */
+    public function setCliValues(string $testFile, Config $config)
+    {
+        if ($testFile === 'UnnecessaryHeredocUnitTest.4.inc'
+            || $testFile === 'UnnecessaryHeredocUnitTest.5.inc'
+            || $testFile === 'UnnecessaryHeredocUnitTest.6.inc'
+        ) {
+            $config->tabWidth = 4;
+        }
+    }
+
+
     /**
      * Returns the lines where errors should occur.
      *
@@ -47,15 +67,18 @@ public function getErrorList()
     public function getWarningList($testFile = '')
     {
         $warnings = [
-            100 => 1,
             104 => 1,
+            108 => 1,
         ];
 
         switch ($testFile) {
             case 'UnnecessaryHeredocUnitTest.1.inc':
+            case 'UnnecessaryHeredocUnitTest.4.inc':
+            case 'UnnecessaryHeredocUnitTest.5.inc':
                 return $warnings;
 
             case 'UnnecessaryHeredocUnitTest.2.inc':
+            case 'UnnecessaryHeredocUnitTest.6.inc':
                 if (PHP_VERSION_ID >= 70300) {
                     return $warnings;
                 }