Generators HTML/Markdown: don't print header/footer when there are no docs

As things were, the Markdown/HTML header and footer would always be printed, even if there were no docs to display.

In my opinion, there should be no output if there are no docs. This is in line with the `Text` output, which would already not generate any output when there are no docs.

Includes updated test expectations.

Author: jrfnl

src/Generators/HTML.php

@@ -103,6 +103,10 @@ class HTML extends Generator
      */
     public function generate()
     {
+        if (empty($this->docFiles) === true) {
+            return;
+        }
+
         ob_start();
         $this->printHeader();
         $this->printToc();

src/Generators/Markdown.php

@@ -27,6 +27,10 @@ class Markdown extends Generator
      */
     public function generate()
     {
+        if (empty($this->docFiles) === true) {
+            return;
+        }
+
         ob_start();
         $this->printHeader();
 

tests/Core/Generators/Expectations/ExpectedOutputNoDocs.html

@@ -62,7 +62,7 @@ public static function dataDocs()
         return [
             'Standard without docs'            => [
                 'standard'       => __DIR__.'/NoDocsTest.xml',
-                'pathToExpected' => __DIR__.'/Expectations/ExpectedOutputNoDocs.html',
+                'pathToExpected' => __DIR__.'/Expectations/ExpectedOutputEmpty.txt',
             ],
             'Standard with one doc file'       => [
                 'standard'       => __DIR__.'/OneDocTest.xml',

tests/Core/Generators/Expectations/ExpectedOutputNoDocs.md

@@ -62,7 +62,7 @@ public static function dataDocs()
         return [
             'Standard without docs'            => [
                 'standard'       => __DIR__.'/NoDocsTest.xml',
-                'pathToExpected' => __DIR__.'/Expectations/ExpectedOutputNoDocs.md',
+                'pathToExpected' => __DIR__.'/Expectations/ExpectedOutputEmpty.txt',
             ],
             'Standard with one doc file'       => [
                 'standard'       => __DIR__.'/OneDocTest.xml',