From 5060505e83b222b8042f436541034eb0ad1a388b Mon Sep 17 00:00:00 2001
From: Iliy <iliy.kulichenko@gmail.com>
Date: Mon, 17 Feb 2020 08:55:10 +1000
Subject: [PATCH 01/10] Added the ability to set the css property font-display:
 swap, through the url parameter.

---
 README.md                                          |  5 +++++
 src/Controllers/CSSGeneratorController.php         |  3 ++-
 .../WebfontCSSGenerator/WebfontCSSGenerator.php    | 14 +++++++++-----
 .../WebfontCSSGeneratorTest.php                    |  7 +++++--
 4 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index ff48ebb..1e97181 100644
--- a/README.md
+++ b/README.md
@@ -153,6 +153,11 @@ body {
 }
 ```
 
+You can set use reserve fonts before custom fonts will full download. For this, set 'display' parameter to 'swap' into url. As example:
+
+```html
+<link rel="stylesheet" href="http://web-fonts-repository.local/css?family=Open+Sans:400,400i,700&display=swap" />
+```
 
 ## Versions compatibility
 
diff --git a/src/Controllers/CSSGeneratorController.php b/src/Controllers/CSSGeneratorController.php
index a1ae500..87f6399 100644
--- a/src/Controllers/CSSGeneratorController.php
+++ b/src/Controllers/CSSGeneratorController.php
@@ -60,7 +60,8 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
             return $this->createErrorResponse('The app settings are invalid: '.$error->getMessage(), 500);
         }
         try {
-            $cssCode = $webfontCSSGenerator->makeCSS($requestedFonts);
+            $displaySwap = isset($requestParams['display']) ? $requestParams['display'] === 'swap' : false;
+            $cssCode = $webfontCSSGenerator->makeCSS($requestedFonts, $displaySwap);
         } catch (\InvalidArgumentException $error) {
             return $this->createErrorResponse($error->getMessage());
         }
diff --git a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
index 9a4adbb..6bd0e52 100644
--- a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
+++ b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
@@ -90,15 +90,16 @@ public static function createFromSettings(array $settings, string $rootURL = '')
      *      'Roboto'    => ['100', '100i', '400', '400i']
      *  ]
      * </pre>
+     * @param bool $displaySwap
      * @return string
      * @throws \InvalidArgumentException
      */
-    public function makeCSS(array $requestedFamilies): string
+    public function makeCSS(array $requestedFamilies, bool $displaySwap): string
     {
         $cssCode = '';
 
         foreach ($requestedFamilies as $fontName => $styles) {
-            $cssCode .= $this->makeFontFamilyCSS($fontName, $styles);
+            $cssCode .= $this->makeFontFamilyCSS($fontName, $styles, $displaySwap);
         }
 
         return $cssCode;
@@ -120,10 +121,11 @@ protected function getFontFamily(string $name)
      *
      * @param string $name Family name
      * @param string[] $styles Font styles. The styles must have format `[0-9]+i?`.
+     * @param bool $displaySwap Enable font-display css properties to `swap`. Default value is `false`
      * @return string
      * @throws \InvalidArgumentException
      */
-    protected function makeFontFamilyCSS(string $name, array $styles = ['400']): string
+    protected function makeFontFamilyCSS(string $name, array $styles = ['400'], bool $displaySwap = false): string
     {
         $cssCode = '';
         $readyStyles = [];
@@ -133,7 +135,7 @@ protected function makeFontFamilyCSS(string $name, array $styles = ['400']): str
                 continue;
             }
 
-            $styleCssCode = $this->makeFontStyleCSS($name, $style);
+            $styleCssCode = $this->makeFontStyleCSS($name, $style, $displaySwap);
             if ($styleCssCode !== '') {
                 $cssCode .= $styleCssCode."\n";
             }
@@ -149,10 +151,11 @@ protected function makeFontFamilyCSS(string $name, array $styles = ['400']): str
      *
      * @param string $familyName Font family name
      * @param string $styleName Font style. The styles must have format `[0-9]+i?`.
+     * @param bool $displaySwap Enable font-display css properties to `swap`
      * @return string
      * @throws \InvalidArgumentException
      */
-    protected function makeFontStyleCSS(string $familyName, string $styleName): string
+    protected function makeFontStyleCSS(string $familyName, string $styleName, bool $displaySwap): string
     {
         // Does the given family exist?
         $family = $this->getFontFamily($familyName);
@@ -204,6 +207,7 @@ protected function makeFontStyleCSS(string $familyName, string $styleName): stri
             . "\tfont-style: ".($style->isItalic ? 'italic' : 'normal').";\n"
             . (isset($files['eot']) ? "\tsrc: url(".CSSHelpers::formatString($files['eot']).");\n" : '')
             . "\tsrc: ".implode(', ', $sources).";\n"
+            . ($displaySwap ? "\tfont-display: swap;\n" : "")
             . "}";
     }
 
diff --git a/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php b/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
index 1d44598..f9bc14b 100644
--- a/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
+++ b/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
@@ -118,7 +118,7 @@ public function testMakeCSS()
         ", $generator->makeCSS([
             'Open Sans' => ['400', '400i', '700', '700i', '100', '200', '300', '800'],
             'Roboto' => ['400', '400i', '700', '700i']
-        ]));
+        ], false));
 
         $this->assertCSSEquals("
 @font-face {
@@ -127,6 +127,7 @@ public function testMakeCSS()
 	font-style: italic;
 	src: url('/generator/fonts/OpenSans/opensans_italic.eot');
 	src: local('Open Sans Italic'), local('OpenSans-Italic'), url('/generator/fonts/OpenSans/opensans_italic.eot?#iefix') format('embedded-opentype'), url('/generator/fonts/OpenSans/opensans_italic.woff2') format('woff2'), url('/generator/fonts/OpenSans/opensans_italic.woff') format('woff'), url('/generator/fonts/OpenSans/opensans_italic.ttf') format('truetype'), url('/generator/fonts/OpenSans/opensans_italic.otf') format('opentype'), url('/generator/fonts/OpenSans/opensans_italic.svg#webfontregular') format('svg');
+	font-display: swap;
 }
 @font-face {
 	font-family: 'Open Sans';
@@ -134,16 +135,18 @@ public function testMakeCSS()
 	font-style: normal;
 	src: url('/generator/fonts/OpenSans/opensans_demi.eot');
 	src: local('Open Sans DemiBold'), local('OpenSans-DemiBold'), url('/generator/fonts/OpenSans/opensans_demi.eot?#iefix') format('embedded-opentype'), url('/generator/fonts/OpenSans/opensans_demi.woff2') format('woff2'), url('/generator/fonts/OpenSans/opensans_demi.woff') format('woff'), url('/generator/fonts/OpenSans/opensans_demi.ttf') format('truetype'), url('/generator/fonts/OpenSans/opensans_demi.otf') format('opentype'), url('/generator/fonts/OpenSans/opensans_demi.svg#webfontregular') format('svg');
+	font-display: swap;
 }
 @font-face {
 	font-family: 'Roboto';
 	font-weight: 400;
 	font-style: normal;
 	src: local('Roboto Regular'), local('Roboto-Regular'), url('/generator/fonts/Roboto/roboto.woff2') format('woff2');
+	font-display: swap;
 }
         ", $generator->makeCSS([
             'Open Sans' => ['400i', '500'],
             'Roboto' => ['400', '400', '900'] // Regular style two times
-        ]));
+        ], true));
     }
 }

From 484d74957d57af5ebb38e83222d349ef01a76159 Mon Sep 17 00:00:00 2001
From: Iliy <iliy.kulichenko@gmail.com>
Date: Sat, 22 Feb 2020 16:12:07 +1000
Subject: [PATCH 02/10] Add css property font-display on fonts generator

---
 src/Controllers/CSSGeneratorController.php    | 34 +++++++++++++++++--
 .../WebfontCSSGenerator.php                   | 18 +++++-----
 .../WebfontCSSGeneratorTest.php               | 29 +++++++++++++---
 3 files changed, 65 insertions(+), 16 deletions(-)

diff --git a/src/Controllers/CSSGeneratorController.php b/src/Controllers/CSSGeneratorController.php
index 87f6399..08d93a1 100644
--- a/src/Controllers/CSSGeneratorController.php
+++ b/src/Controllers/CSSGeneratorController.php
@@ -59,9 +59,13 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
             $this->container->get('logger')->error($error);
             return $this->createErrorResponse('The app settings are invalid: '.$error->getMessage(), 500);
         }
+
         try {
-            $displaySwap = isset($requestParams['display']) ? $requestParams['display'] === 'swap' : false;
-            $cssCode = $webfontCSSGenerator->makeCSS($requestedFonts, $displaySwap);
+            $fontDisplay = null;
+            if (isset($requestParams['display'])) {
+                $fontDisplay = $this->checkFontDisplay($requestParams['display']);
+            }
+            $cssCode = $webfontCSSGenerator->makeCSS($requestedFonts, $fontDisplay);
         } catch (\InvalidArgumentException $error) {
             return $this->createErrorResponse($error->getMessage());
         }
@@ -115,6 +119,32 @@ protected function parseFamilyParameter(string $value): array
         return $result;
     }
 
+    /**
+     * Check font-display value. Value must be one of: auto, block, swap, fallback, optional.
+     *
+     * @param string|null $fontDisplay Font-display value or null
+     * @return string|null Valid font-display css value, or null, if $fontDisplay is null or empty.
+     * @throws \InvalidArgumentException If the parameter set, but has not valid value. The message may be sent
+     *          back to the client.
+     */
+    protected function checkFontDisplay(string $fontDisplay): string
+    {
+        if (!isset($fontDisplay) || $fontDisplay === '') {
+            return null;
+        }
+        $validFontDisplayValues = [
+            'auto',
+            'block',
+            'swap',
+            'fallback',
+            'optional'
+        ];
+        if (!array_search($fontDisplay, $validFontDisplayValues)) {
+            throw new \InvalidArgumentException('Invalid font display value');
+        }
+        return $fontDisplay;
+    }
+
     /**
      * Creates a response with the client side error message.
      *
diff --git a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
index 6bd0e52..67cdb1f 100644
--- a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
+++ b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
@@ -90,16 +90,16 @@ public static function createFromSettings(array $settings, string $rootURL = '')
      *      'Roboto'    => ['100', '100i', '400', '400i']
      *  ]
      * </pre>
-     * @param bool $displaySwap
+     * @param string|null $fontDisplay Font-display css property
      * @return string
      * @throws \InvalidArgumentException
      */
-    public function makeCSS(array $requestedFamilies, bool $displaySwap): string
+    public function makeCSS(array $requestedFamilies, string $fontDisplay = null): string
     {
         $cssCode = '';
 
         foreach ($requestedFamilies as $fontName => $styles) {
-            $cssCode .= $this->makeFontFamilyCSS($fontName, $styles, $displaySwap);
+            $cssCode .= $this->makeFontFamilyCSS($fontName, $styles, $fontDisplay);
         }
 
         return $cssCode;
@@ -121,11 +121,11 @@ protected function getFontFamily(string $name)
      *
      * @param string $name Family name
      * @param string[] $styles Font styles. The styles must have format `[0-9]+i?`.
-     * @param bool $displaySwap Enable font-display css properties to `swap`. Default value is `false`
+     * @param string|null $fontDisplay Font-display css property value
      * @return string
      * @throws \InvalidArgumentException
      */
-    protected function makeFontFamilyCSS(string $name, array $styles = ['400'], bool $displaySwap = false): string
+    protected function makeFontFamilyCSS(string $name, array $styles = ['400'], string $fontDisplay = null): string
     {
         $cssCode = '';
         $readyStyles = [];
@@ -135,7 +135,7 @@ protected function makeFontFamilyCSS(string $name, array $styles = ['400'], bool
                 continue;
             }
 
-            $styleCssCode = $this->makeFontStyleCSS($name, $style, $displaySwap);
+            $styleCssCode = $this->makeFontStyleCSS($name, $style, $fontDisplay);
             if ($styleCssCode !== '') {
                 $cssCode .= $styleCssCode."\n";
             }
@@ -151,11 +151,11 @@ protected function makeFontFamilyCSS(string $name, array $styles = ['400'], bool
      *
      * @param string $familyName Font family name
      * @param string $styleName Font style. The styles must have format `[0-9]+i?`.
-     * @param bool $displaySwap Enable font-display css properties to `swap`
+     * @param string $fontDisplay Font-display css property value
      * @return string
      * @throws \InvalidArgumentException
      */
-    protected function makeFontStyleCSS(string $familyName, string $styleName, bool $displaySwap): string
+    protected function makeFontStyleCSS(string $familyName, string $styleName, string $fontDisplay = null): string
     {
         // Does the given family exist?
         $family = $this->getFontFamily($familyName);
@@ -207,7 +207,7 @@ protected function makeFontStyleCSS(string $familyName, string $styleName, bool
             . "\tfont-style: ".($style->isItalic ? 'italic' : 'normal').";\n"
             . (isset($files['eot']) ? "\tsrc: url(".CSSHelpers::formatString($files['eot']).");\n" : '')
             . "\tsrc: ".implode(', ', $sources).";\n"
-            . ($displaySwap ? "\tfont-display: swap;\n" : "")
+            . (isset($fontDisplay) && $fontDisplay !== '' ? "\tfont-display: " . $fontDisplay . ";\n" : "")
             . "}";
     }
 
diff --git a/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php b/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
index f9bc14b..37e0ccd 100644
--- a/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
+++ b/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
@@ -118,7 +118,7 @@ public function testMakeCSS()
         ", $generator->makeCSS([
             'Open Sans' => ['400', '400i', '700', '700i', '100', '200', '300', '800'],
             'Roboto' => ['400', '400i', '700', '700i']
-        ], false));
+        ]));
 
         $this->assertCSSEquals("
 @font-face {
@@ -127,7 +127,6 @@ public function testMakeCSS()
 	font-style: italic;
 	src: url('/generator/fonts/OpenSans/opensans_italic.eot');
 	src: local('Open Sans Italic'), local('OpenSans-Italic'), url('/generator/fonts/OpenSans/opensans_italic.eot?#iefix') format('embedded-opentype'), url('/generator/fonts/OpenSans/opensans_italic.woff2') format('woff2'), url('/generator/fonts/OpenSans/opensans_italic.woff') format('woff'), url('/generator/fonts/OpenSans/opensans_italic.ttf') format('truetype'), url('/generator/fonts/OpenSans/opensans_italic.otf') format('opentype'), url('/generator/fonts/OpenSans/opensans_italic.svg#webfontregular') format('svg');
-	font-display: swap;
 }
 @font-face {
 	font-family: 'Open Sans';
@@ -135,18 +134,38 @@ public function testMakeCSS()
 	font-style: normal;
 	src: url('/generator/fonts/OpenSans/opensans_demi.eot');
 	src: local('Open Sans DemiBold'), local('OpenSans-DemiBold'), url('/generator/fonts/OpenSans/opensans_demi.eot?#iefix') format('embedded-opentype'), url('/generator/fonts/OpenSans/opensans_demi.woff2') format('woff2'), url('/generator/fonts/OpenSans/opensans_demi.woff') format('woff'), url('/generator/fonts/OpenSans/opensans_demi.ttf') format('truetype'), url('/generator/fonts/OpenSans/opensans_demi.otf') format('opentype'), url('/generator/fonts/OpenSans/opensans_demi.svg#webfontregular') format('svg');
-	font-display: swap;
 }
 @font-face {
 	font-family: 'Roboto';
 	font-weight: 400;
 	font-style: normal;
 	src: local('Roboto Regular'), local('Roboto-Regular'), url('/generator/fonts/Roboto/roboto.woff2') format('woff2');
-	font-display: swap;
 }
         ", $generator->makeCSS([
             'Open Sans' => ['400i', '500'],
             'Roboto' => ['400', '400', '900'] // Regular style two times
-        ], true));
+        ]));
+
+
+        $this->assertCSSEquals("
+@font-face {
+	font-family: 'Open Sans';
+	font-weight: 400;
+	font-style: italic;
+	src: url('/generator/fonts/OpenSans/opensans_italic.eot');
+	src: local('Open Sans Italic'), local('OpenSans-Italic'), url('/generator/fonts/OpenSans/opensans_italic.eot?#iefix') format('embedded-opentype'), url('/generator/fonts/OpenSans/opensans_italic.woff2') format('woff2'), url('/generator/fonts/OpenSans/opensans_italic.woff') format('woff'), url('/generator/fonts/OpenSans/opensans_italic.ttf') format('truetype'), url('/generator/fonts/OpenSans/opensans_italic.otf') format('opentype'), url('/generator/fonts/OpenSans/opensans_italic.svg#webfontregular') format('svg');
+	font-display: swap;
+}
+@font-face {
+	font-family: 'Open Sans';
+	font-weight: 500;
+	font-style: normal;
+	src: url('/generator/fonts/OpenSans/opensans_demi.eot');
+	src: local('Open Sans DemiBold'), local('OpenSans-DemiBold'), url('/generator/fonts/OpenSans/opensans_demi.eot?#iefix') format('embedded-opentype'), url('/generator/fonts/OpenSans/opensans_demi.woff2') format('woff2'), url('/generator/fonts/OpenSans/opensans_demi.woff') format('woff'), url('/generator/fonts/OpenSans/opensans_demi.ttf') format('truetype'), url('/generator/fonts/OpenSans/opensans_demi.otf') format('opentype'), url('/generator/fonts/OpenSans/opensans_demi.svg#webfontregular') format('svg');
+	font-display: swap;
+}
+        ", $generator->makeCSS([
+            'Open Sans' => ['400i', '500']
+        ], 'swap'));
     }
 }

From 445b514ec3a6332ca8ba0343d2d7a00301d5a8eb Mon Sep 17 00:00:00 2001
From: Iliy <iliy.kulichenko@gmail.com>
Date: Sat, 22 Feb 2020 16:20:57 +1000
Subject: [PATCH 03/10] Update README.md

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 1e97181..6204888 100644
--- a/README.md
+++ b/README.md
@@ -153,7 +153,8 @@ body {
 }
 ```
 
-You can set use reserve fonts before custom fonts will full download. For this, set 'display' parameter to 'swap' into url. As example:
+You can specify a value for the font-display property. To do this, add the display parameter to the request and set its value. 
+The value can be one of: auto, block, swap, fallback, optional.
 
 ```html
 <link rel="stylesheet" href="http://web-fonts-repository.local/css?family=Open+Sans:400,400i,700&display=swap" />

From 194b9e9a6d1642a947634b95a8de65aac12dad71 Mon Sep 17 00:00:00 2001
From: Surgie Finesse <finesserus@gmail.com>
Date: Thu, 27 Feb 2020 21:05:27 +1000
Subject: [PATCH 04/10] Update codeclimate-action to fix PR file report

---
 .github/workflows/test.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f96fefc..ef72ac4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -25,7 +25,7 @@ jobs:
           composer run-script post-create-project-cmd
       - name: Test and publish code coverage
         if: matrix.report-coverage
-        uses: paambaati/codeclimate-action@v2.3.0
+        uses: paambaati/codeclimate-action@v2.5.3
         env:
           # Get it on https://codeclimate.com/repos/{repo id}/settings/test_reporter
           CC_TEST_REPORTER_ID: 02c359b52f053b695269f876e5a55d46a7d02525a9a4e19d473c9a0b29f5a499

From 60807fc904bd6c307d2d2aa20d98cf76f73dd52d Mon Sep 17 00:00:00 2001
From: Iliy <iliy.kulichenko@gmail.com>
Date: Fri, 28 Feb 2020 17:20:27 +1000
Subject: [PATCH 05/10] Bug fixes

---
 src/Controllers/CSSGeneratorController.php       | 16 ++++------------
 .../WebfontCSSGenerator/WebfontCSSGenerator.php  |  7 ++++++-
 tests/Functional/CssGeneratorTest.php            |  5 ++++-
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/src/Controllers/CSSGeneratorController.php b/src/Controllers/CSSGeneratorController.php
index 08d93a1..470ed65 100644
--- a/src/Controllers/CSSGeneratorController.php
+++ b/src/Controllers/CSSGeneratorController.php
@@ -45,8 +45,11 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
         if (!isset($requestParams['family'])) {
             return $this->createErrorResponse('The `family` query parameter is not set');
         }
+
+
         try {
             $requestedFonts = $this->parseFamilyParameter($requestParams['family']);
+            $fontDisplay = isset($requestParams['display']) ? $this->checkFontDisplay($requestParams['display']) : null;
         } catch (\InvalidArgumentException $error) {
             return $this->createErrorResponse($error->getMessage());
         }
@@ -61,10 +64,6 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
         }
 
         try {
-            $fontDisplay = null;
-            if (isset($requestParams['display'])) {
-                $fontDisplay = $this->checkFontDisplay($requestParams['display']);
-            }
             $cssCode = $webfontCSSGenerator->makeCSS($requestedFonts, $fontDisplay);
         } catch (\InvalidArgumentException $error) {
             return $this->createErrorResponse($error->getMessage());
@@ -132,14 +131,7 @@ protected function checkFontDisplay(string $fontDisplay): string
         if (!isset($fontDisplay) || $fontDisplay === '') {
             return null;
         }
-        $validFontDisplayValues = [
-            'auto',
-            'block',
-            'swap',
-            'fallback',
-            'optional'
-        ];
-        if (!array_search($fontDisplay, $validFontDisplayValues)) {
+        if (!is_string($fontDisplay)) {
             throw new \InvalidArgumentException('Invalid font display value');
         }
         return $fontDisplay;
diff --git a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
index 67cdb1f..399a5d3 100644
--- a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
+++ b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
@@ -201,13 +201,18 @@ protected function makeFontStyleCSS(string $familyName, string $styleName, strin
             $sources[] = "url(".CSSHelpers::formatString($files['svg'].'#webfontregular').") format('svg')";
         }
 
+        $fontDisplayCSS = '';
+        if (isset($fontDisplay) && $fontDisplay !== '') {
+            $fontDisplayCSS = "\tfont-display: " . $fontDisplay . ";\n";
+        }
+
         return "@font-face {\n"
             . "\tfont-family: ".CSSHelpers::formatString($family->name).";\n"
             . "\tfont-weight: $style->weight;\n"
             . "\tfont-style: ".($style->isItalic ? 'italic' : 'normal').";\n"
             . (isset($files['eot']) ? "\tsrc: url(".CSSHelpers::formatString($files['eot']).");\n" : '')
             . "\tsrc: ".implode(', ', $sources).";\n"
-            . (isset($fontDisplay) && $fontDisplay !== '' ? "\tfont-display: " . $fontDisplay . ";\n" : "")
+            . $fontDisplayCSS
             . "}";
     }
 
diff --git a/tests/Functional/CssGeneratorTest.php b/tests/Functional/CssGeneratorTest.php
index c832ad3..efd1960 100644
--- a/tests/Functional/CssGeneratorTest.php
+++ b/tests/Functional/CssGeneratorTest.php
@@ -37,11 +37,14 @@ public function testBadRequests()
         $container = $app->getContainer();
         $container['webfontCSSGenerator'] = function () {
             $generator = \Mockery::mock(WebfontCSSGenerator::class);
-            $generator->shouldReceive('makeCSS')->once()->andThrow(new \InvalidArgumentException('test'));
+            $generator->shouldReceive('makeCSS')->times(4)->andThrow(new \InvalidArgumentException('test'));
             return $generator;
         };
 
         $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700')->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700', ['display' => 1])->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700', ['display' => []])->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700', ['display' => false])->getStatusCode());
     }
 
     /**

From 173d26e5dd4b9091afe22ed6b71f36638d488b1d Mon Sep 17 00:00:00 2001
From: Iliy <iliy.kulichenko@gmail.com>
Date: Fri, 28 Feb 2020 17:27:15 +1000
Subject: [PATCH 06/10] Remove invalid tests for invalid display param

---
 tests/Functional/CssGeneratorTest.php | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tests/Functional/CssGeneratorTest.php b/tests/Functional/CssGeneratorTest.php
index efd1960..c832ad3 100644
--- a/tests/Functional/CssGeneratorTest.php
+++ b/tests/Functional/CssGeneratorTest.php
@@ -37,14 +37,11 @@ public function testBadRequests()
         $container = $app->getContainer();
         $container['webfontCSSGenerator'] = function () {
             $generator = \Mockery::mock(WebfontCSSGenerator::class);
-            $generator->shouldReceive('makeCSS')->times(4)->andThrow(new \InvalidArgumentException('test'));
+            $generator->shouldReceive('makeCSS')->once()->andThrow(new \InvalidArgumentException('test'));
             return $generator;
         };
 
         $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700')->getStatusCode());
-        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700', ['display' => 1])->getStatusCode());
-        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700', ['display' => []])->getStatusCode());
-        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700', ['display' => false])->getStatusCode());
     }
 
     /**

From 986e47b6ea38c66bb2bb6dbf4c75edcdd02dd3c7 Mon Sep 17 00:00:00 2001
From: Iliy <iliy.kulichenko@gmail.com>
Date: Fri, 28 Feb 2020 17:42:57 +1000
Subject: [PATCH 07/10] Create test for invalid display param

---
 src/Controllers/CSSGeneratorController.php | 4 ++--
 tests/Functional/CssGeneratorTest.php      | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Controllers/CSSGeneratorController.php b/src/Controllers/CSSGeneratorController.php
index 470ed65..be40f07 100644
--- a/src/Controllers/CSSGeneratorController.php
+++ b/src/Controllers/CSSGeneratorController.php
@@ -121,12 +121,12 @@ protected function parseFamilyParameter(string $value): array
     /**
      * Check font-display value. Value must be one of: auto, block, swap, fallback, optional.
      *
-     * @param string|null $fontDisplay Font-display value or null
+     * @param $fontDisplay Font-display value or null
      * @return string|null Valid font-display css value, or null, if $fontDisplay is null or empty.
      * @throws \InvalidArgumentException If the parameter set, but has not valid value. The message may be sent
      *          back to the client.
      */
-    protected function checkFontDisplay(string $fontDisplay): string
+    protected function checkFontDisplay($fontDisplay): string
     {
         if (!isset($fontDisplay) || $fontDisplay === '') {
             return null;
diff --git a/tests/Functional/CssGeneratorTest.php b/tests/Functional/CssGeneratorTest.php
index c832ad3..0c2c9e8 100644
--- a/tests/Functional/CssGeneratorTest.php
+++ b/tests/Functional/CssGeneratorTest.php
@@ -32,6 +32,7 @@ public function testBadRequests()
         $this->assertEquals(422, $this->runApp('GET', '/css?family=|Open+Sans:400,700')->getStatusCode());
         $this->assertEquals(422, $this->runApp('GET', '/css?family=:400,700')->getStatusCode());
         $this->assertEquals(422, $this->runApp('GET', '/css')->getStatusCode());
+        $this->assertEquals(422, $this->runApp('GET', '/css?family=Open+Sans:400,700&display[]=bad')->getStatusCode());
 
         $app = $this->makeApp();
         $container = $app->getContainer();

From 90eb962c4062646929df5d58aae5ac63597d6bee Mon Sep 17 00:00:00 2001
From: Iliy <iliy.kulichenko@gmail.com>
Date: Sun, 1 Mar 2020 19:47:00 +1000
Subject: [PATCH 08/10] Fix bugs

---
 src/Controllers/CSSGeneratorController.php               | 6 +++---
 src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/Controllers/CSSGeneratorController.php b/src/Controllers/CSSGeneratorController.php
index be40f07..3a1dc4b 100644
--- a/src/Controllers/CSSGeneratorController.php
+++ b/src/Controllers/CSSGeneratorController.php
@@ -49,7 +49,7 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
 
         try {
             $requestedFonts = $this->parseFamilyParameter($requestParams['family']);
-            $fontDisplay = isset($requestParams['display']) ? $this->checkFontDisplay($requestParams['display']) : null;
+            $fontDisplay = isset($requestParams['display']) ? $this->checkFontDisplay($requestParams['display']) : '';
         } catch (\InvalidArgumentException $error) {
             return $this->createErrorResponse($error->getMessage());
         }
@@ -122,14 +122,14 @@ protected function parseFamilyParameter(string $value): array
      * Check font-display value. Value must be one of: auto, block, swap, fallback, optional.
      *
      * @param $fontDisplay Font-display value or null
-     * @return string|null Valid font-display css value, or null, if $fontDisplay is null or empty.
+     * @return string Valid font-display css value, or empty string, if $fontDisplay is null or empty.
      * @throws \InvalidArgumentException If the parameter set, but has not valid value. The message may be sent
      *          back to the client.
      */
     protected function checkFontDisplay($fontDisplay): string
     {
         if (!isset($fontDisplay) || $fontDisplay === '') {
-            return null;
+            return '';
         }
         if (!is_string($fontDisplay)) {
             throw new \InvalidArgumentException('Invalid font display value');
diff --git a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
index 399a5d3..38a0dba 100644
--- a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
+++ b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
@@ -94,7 +94,7 @@ public static function createFromSettings(array $settings, string $rootURL = '')
      * @return string
      * @throws \InvalidArgumentException
      */
-    public function makeCSS(array $requestedFamilies, string $fontDisplay = null): string
+    public function makeCSS(array $requestedFamilies, string $fontDisplay = ''): string
     {
         $cssCode = '';
 
@@ -121,11 +121,11 @@ protected function getFontFamily(string $name)
      *
      * @param string $name Family name
      * @param string[] $styles Font styles. The styles must have format `[0-9]+i?`.
-     * @param string|null $fontDisplay Font-display css property value
+     * @param string $fontDisplay Font-display css property value
      * @return string
      * @throws \InvalidArgumentException
      */
-    protected function makeFontFamilyCSS(string $name, array $styles = ['400'], string $fontDisplay = null): string
+    protected function makeFontFamilyCSS(string $name, array $styles = ['400'], string $fontDisplay = ''): string
     {
         $cssCode = '';
         $readyStyles = [];
@@ -155,7 +155,7 @@ protected function makeFontFamilyCSS(string $name, array $styles = ['400'], stri
      * @return string
      * @throws \InvalidArgumentException
      */
-    protected function makeFontStyleCSS(string $familyName, string $styleName, string $fontDisplay = null): string
+    protected function makeFontStyleCSS(string $familyName, string $styleName, string $fontDisplay = ''): string
     {
         // Does the given family exist?
         $family = $this->getFontFamily($familyName);

From 6c3fda6b6275523e428f87873c04214eb3f6a502 Mon Sep 17 00:00:00 2001
From: Surgie Finesse <finesserus@gmail.com>
Date: Sun, 1 Mar 2020 20:00:10 +1000
Subject: [PATCH 09/10] Amendments

---
 LICENSE                                            |  2 +-
 README.md                                          | 14 +++++++-------
 src/Controllers/CSSGeneratorController.php         | 12 +++++-------
 .../WebfontCSSGenerator/WebfontCSSGenerator.php    |  9 ++-------
 .../WebfontCSSGeneratorTest.php                    |  5 ++---
 5 files changed, 17 insertions(+), 25 deletions(-)

diff --git a/LICENSE b/LICENSE
index 8f4ea21..fe4554a 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2017-2019 Surgie Finesse
+Copyright (c) 2017-2020 Surgie Finesse
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
diff --git a/README.md b/README.md
index 6204888..82de100 100644
--- a/README.md
+++ b/README.md
@@ -145,6 +145,13 @@ You may omit the styles list. In this case the regular style (`400`) is used.
 <link rel="stylesheet" href="http://web-fonts-repository.local/css?family=Open+Sans" />
 ```
 
+You can specify a value for the [font-display](https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/font-display)
+style property using `display` parameter. Example:
+
+```html
+<link rel="stylesheet" href="http://web-fonts-repository.local/css?family=Open+Sans&display=swap" />
+```
+
 Then embed a font in a CSS code:
 
 ```css
@@ -153,13 +160,6 @@ body {
 }
 ```
 
-You can specify a value for the font-display property. To do this, add the display parameter to the request and set its value. 
-The value can be one of: auto, block, swap, fallback, optional.
-
-```html
-<link rel="stylesheet" href="http://web-fonts-repository.local/css?family=Open+Sans:400,400i,700&display=swap" />
-```
-
 ## Versions compatibility
 
 The project follows the [Semantic Versioning](http://semver.org).
diff --git a/src/Controllers/CSSGeneratorController.php b/src/Controllers/CSSGeneratorController.php
index 3a1dc4b..883e1a7 100644
--- a/src/Controllers/CSSGeneratorController.php
+++ b/src/Controllers/CSSGeneratorController.php
@@ -46,10 +46,9 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
             return $this->createErrorResponse('The `family` query parameter is not set');
         }
 
-
         try {
             $requestedFonts = $this->parseFamilyParameter($requestParams['family']);
-            $fontDisplay = isset($requestParams['display']) ? $this->checkFontDisplay($requestParams['display']) : '';
+            $fontDisplay = $this->parseDisplayParameter($requestParams['display'] ?? null);
         } catch (\InvalidArgumentException $error) {
             return $this->createErrorResponse($error->getMessage());
         }
@@ -62,7 +61,6 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
             $this->container->get('logger')->error($error);
             return $this->createErrorResponse('The app settings are invalid: '.$error->getMessage(), 500);
         }
-
         try {
             $cssCode = $webfontCSSGenerator->makeCSS($requestedFonts, $fontDisplay);
         } catch (\InvalidArgumentException $error) {
@@ -119,16 +117,16 @@ protected function parseFamilyParameter(string $value): array
     }
 
     /**
-     * Check font-display value. Value must be one of: auto, block, swap, fallback, optional.
+     * Checks `display` request query value.
      *
-     * @param $fontDisplay Font-display value or null
+     * @param mixed $fontDisplay Parameter value
      * @return string Valid font-display css value, or empty string, if $fontDisplay is null or empty.
      * @throws \InvalidArgumentException If the parameter set, but has not valid value. The message may be sent
      *          back to the client.
      */
-    protected function checkFontDisplay($fontDisplay): string
+    protected function parseDisplayParameter($fontDisplay): string
     {
-        if (!isset($fontDisplay) || $fontDisplay === '') {
+        if ($fontDisplay === null) {
             return '';
         }
         if (!is_string($fontDisplay)) {
diff --git a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
index 38a0dba..53767e4 100644
--- a/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
+++ b/src/Services/WebfontCSSGenerator/WebfontCSSGenerator.php
@@ -90,7 +90,7 @@ public static function createFromSettings(array $settings, string $rootURL = '')
      *      'Roboto'    => ['100', '100i', '400', '400i']
      *  ]
      * </pre>
-     * @param string|null $fontDisplay Font-display css property
+     * @param string $fontDisplay Font-display css property
      * @return string
      * @throws \InvalidArgumentException
      */
@@ -201,18 +201,13 @@ protected function makeFontStyleCSS(string $familyName, string $styleName, strin
             $sources[] = "url(".CSSHelpers::formatString($files['svg'].'#webfontregular').") format('svg')";
         }
 
-        $fontDisplayCSS = '';
-        if (isset($fontDisplay) && $fontDisplay !== '') {
-            $fontDisplayCSS = "\tfont-display: " . $fontDisplay . ";\n";
-        }
-
         return "@font-face {\n"
             . "\tfont-family: ".CSSHelpers::formatString($family->name).";\n"
             . "\tfont-weight: $style->weight;\n"
             . "\tfont-style: ".($style->isItalic ? 'italic' : 'normal').";\n"
+            . ($fontDisplay !== '' ? "\tfont-display: $fontDisplay;\n" : '')
             . (isset($files['eot']) ? "\tsrc: url(".CSSHelpers::formatString($files['eot']).");\n" : '')
             . "\tsrc: ".implode(', ', $sources).";\n"
-            . $fontDisplayCSS
             . "}";
     }
 
diff --git a/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php b/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
index 37e0ccd..88bc912 100644
--- a/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
+++ b/tests/Unit/WebfontCSSGenerator/WebfontCSSGeneratorTest.php
@@ -146,23 +146,22 @@ public function testMakeCSS()
             'Roboto' => ['400', '400', '900'] // Regular style two times
         ]));
 
-
         $this->assertCSSEquals("
 @font-face {
 	font-family: 'Open Sans';
 	font-weight: 400;
 	font-style: italic;
+	font-display: swap;
 	src: url('/generator/fonts/OpenSans/opensans_italic.eot');
 	src: local('Open Sans Italic'), local('OpenSans-Italic'), url('/generator/fonts/OpenSans/opensans_italic.eot?#iefix') format('embedded-opentype'), url('/generator/fonts/OpenSans/opensans_italic.woff2') format('woff2'), url('/generator/fonts/OpenSans/opensans_italic.woff') format('woff'), url('/generator/fonts/OpenSans/opensans_italic.ttf') format('truetype'), url('/generator/fonts/OpenSans/opensans_italic.otf') format('opentype'), url('/generator/fonts/OpenSans/opensans_italic.svg#webfontregular') format('svg');
-	font-display: swap;
 }
 @font-face {
 	font-family: 'Open Sans';
 	font-weight: 500;
 	font-style: normal;
+	font-display: swap;
 	src: url('/generator/fonts/OpenSans/opensans_demi.eot');
 	src: local('Open Sans DemiBold'), local('OpenSans-DemiBold'), url('/generator/fonts/OpenSans/opensans_demi.eot?#iefix') format('embedded-opentype'), url('/generator/fonts/OpenSans/opensans_demi.woff2') format('woff2'), url('/generator/fonts/OpenSans/opensans_demi.woff') format('woff'), url('/generator/fonts/OpenSans/opensans_demi.ttf') format('truetype'), url('/generator/fonts/OpenSans/opensans_demi.otf') format('opentype'), url('/generator/fonts/OpenSans/opensans_demi.svg#webfontregular') format('svg');
-	font-display: swap;
 }
         ", $generator->makeCSS([
             'Open Sans' => ['400i', '500']

From f1e6f1bc204f4efd24ce0355af2e12e3d2581752 Mon Sep 17 00:00:00 2001
From: Surgie Finesse <finesserus@gmail.com>
Date: Sun, 1 Mar 2020 20:34:18 +1000
Subject: [PATCH 10/10] Add tests to check GET parameters parsing

---
 src/Controllers/CSSGeneratorController.php |  6 +-
 tests/Functional/CssGeneratorTest.php      | 74 +++++++++++++++++++---
 2 files changed, 67 insertions(+), 13 deletions(-)

diff --git a/src/Controllers/CSSGeneratorController.php b/src/Controllers/CSSGeneratorController.php
index 883e1a7..41b7e7f 100644
--- a/src/Controllers/CSSGeneratorController.php
+++ b/src/Controllers/CSSGeneratorController.php
@@ -89,7 +89,7 @@ public function __invoke(ServerRequestInterface $request, ResponseInterface $res
      *  ]
      * </pre>
      * @throws \InvalidArgumentException If the parameter value is formatted badly. The message may be sent back to the
-     *     client.
+     *  client.
      */
     protected function parseFamilyParameter(string $value): array
     {
@@ -121,8 +121,8 @@ protected function parseFamilyParameter(string $value): array
      *
      * @param mixed $fontDisplay Parameter value
      * @return string Valid font-display css value, or empty string, if $fontDisplay is null or empty.
-     * @throws \InvalidArgumentException If the parameter set, but has not valid value. The message may be sent
-     *          back to the client.
+     * @throws \InvalidArgumentException If the parameter set, but has not valid value. The message may be sent back to
+     *  the client.
      */
     protected function parseDisplayParameter($fontDisplay): string
     {
diff --git a/tests/Functional/CssGeneratorTest.php b/tests/Functional/CssGeneratorTest.php
index 0c2c9e8..19c1296 100644
--- a/tests/Functional/CssGeneratorTest.php
+++ b/tests/Functional/CssGeneratorTest.php
@@ -13,27 +13,81 @@ class CssGeneratorTest extends FunctionalTestCase
      */
     public function testHeaders()
     {
-        $response = $this->runApp('GET', '/css?family=Open+Sans:400,700');
+        $response = $this->runApp('GET', '/css?family=Open+Sans');
 
         $this->assertEquals(200, $response->getStatusCode());
         $this->assertTrue((bool)preg_match('~^text/css(;|$)~', $response->getHeaderLine('Content-Type')));
         $this->assertTrue($response->hasHeader('Cache-Control'));
         $this->assertTrue($response->hasHeader('Pragma'));
+    }
+
+    /**
+     * Test the controller `family` parameter parsing
+     */
+    public function testFamilyParsing()
+    {
+        $app = $this->makeApp();
+        $container = $app->getContainer();
+        $container['webfontCSSGenerator'] = function () {
+            $generator = \Mockery::mock(WebfontCSSGenerator::class);
+            $generator->shouldReceive('makeCSS')
+                ->once()
+                ->with(['Roboto' => ['400']], '')
+                ->andReturn('');
+            $generator->shouldReceive('makeCSS')
+                ->once()
+                ->with([
+                    'Open Sans' => ['400'],
+                    'Roboto' => ['400', '400i', '700i'],
+                ], '')
+                ->andReturn('');
+            return $generator;
+        };
+
+        $this->assertEquals(200, $this->runSpecificApp($app, 'GET', '/css?family=Roboto')->getStatusCode());
+        $this->assertEquals(200, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans|Roboto:400,400i,700i')->getStatusCode());
 
-        $this->assertEquals(200, $this->runApp('GET', '/css?family=Open+Sans')->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=')->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=|Open+Sans:400,700')->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=:400,700')->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css')->getStatusCode());
     }
 
     /**
-     * Tests that the route returns an client error status with bad requests
+     * Test the controller `display` parameter parsing
      */
-    public function testBadRequests()
+    public function testDisplayParsing()
     {
-        $this->assertEquals(422, $this->runApp('GET', '/css?family=')->getStatusCode());
-        $this->assertEquals(422, $this->runApp('GET', '/css?family=|Open+Sans:400,700')->getStatusCode());
-        $this->assertEquals(422, $this->runApp('GET', '/css?family=:400,700')->getStatusCode());
-        $this->assertEquals(422, $this->runApp('GET', '/css')->getStatusCode());
-        $this->assertEquals(422, $this->runApp('GET', '/css?family=Open+Sans:400,700&display[]=bad')->getStatusCode());
+        $app = $this->makeApp();
+        $container = $app->getContainer();
+        $container['webfontCSSGenerator'] = function () {
+            $generator = \Mockery::mock(WebfontCSSGenerator::class);
+            $generator->shouldReceive('makeCSS')
+                ->once()
+                ->with(['Open Sans' => ['400']], '')
+                ->andReturn('');
+            $generator->shouldReceive('makeCSS')
+                ->once()
+                ->with(['Open Sans' => ['400']], '')
+                ->andReturn('');
+            $generator->shouldReceive('makeCSS')
+                ->once()
+                ->with(['Open Sans' => ['400']], 'swap')
+                ->andReturn('');
+            return $generator;
+        };
 
+        $this->assertEquals(200, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans')->getStatusCode());
+        $this->assertEquals(200, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans&display=')->getStatusCode());
+        $this->assertEquals(200, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans&display=swap')->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans&display[]=bad')->getStatusCode());
+    }
+
+    /**
+     * Test handling errors from webfontCSSGenerator
+     */
+    public function testGeneratorInputError()
+    {
         $app = $this->makeApp();
         $container = $app->getContainer();
         $container['webfontCSSGenerator'] = function () {
@@ -42,7 +96,7 @@ public function testBadRequests()
             return $generator;
         };
 
-        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans:400,700')->getStatusCode());
+        $this->assertEquals(422, $this->runSpecificApp($app, 'GET', '/css?family=Open+Sans')->getStatusCode());
     }
 
     /**