From e01de9bec783545ed31ef9ad58112f28b39b2075 Mon Sep 17 00:00:00 2001
From: Benedikt Franke <benedikt.franke@mll.com>
Date: Fri, 12 Jan 2024 16:01:34 +0100
Subject: [PATCH] Add `StringUtil::joinNonEmpty()`

---
 CHANGELOG.md             |  6 ++++++
 composer.json            |  6 +++---
 src/StringUtil.php       | 13 +++++++++++++
 tests/StringUtilTest.php | 22 ++++++++++++++++++++++
 4 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c158497..5e903e4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,12 @@ See [GitHub releases](https://github.com/mll-lab/php-utils/releases).
 
 ## Unreleased
 
+## v1.9.0
+
+### Added
+
+- Add `StringUtil::joinNonEmpty()`
+
 ## v1.8.1
 
 ### Changed
diff --git a/composer.json b/composer.json
index 0f5e44e..1ec4f98 100644
--- a/composer.json
+++ b/composer.json
@@ -52,10 +52,10 @@
   },
   "config": {
     "allow-plugins": {
-      "ocramius/package-versions": true,
-      "phpstan/extension-installer": true,
       "ergebnis/composer-normalize": true,
-      "infection/extension-installer": true
+      "infection/extension-installer": true,
+      "ocramius/package-versions": true,
+      "phpstan/extension-installer": true
     },
     "sort-packages": true
   },
diff --git a/src/StringUtil.php b/src/StringUtil.php
index d4cca00..c2abd75 100644
--- a/src/StringUtil.php
+++ b/src/StringUtil.php
@@ -6,6 +6,19 @@
 
 final class StringUtil
 {
+    /** @param iterable<string|null> $parts */
+    public static function joinNonEmpty(string $glue, iterable $parts): string
+    {
+        $nonEmptyParts = [];
+        foreach ($parts as $part) {
+            if ($part !== '' && $part !== null) {
+                $nonEmptyParts[] = $part;
+            }
+        }
+
+        return implode($glue, $nonEmptyParts);
+    }
+
     /**
      * The intention is to limit the length of a name.
      *
diff --git a/tests/StringUtilTest.php b/tests/StringUtilTest.php
index 8409f1f..7d56b98 100644
--- a/tests/StringUtilTest.php
+++ b/tests/StringUtilTest.php
@@ -2,11 +2,33 @@
 
 namespace MLL\Utils\Tests;
 
+use Illuminate\Support\Collection;
 use MLL\Utils\StringUtil;
 use PHPUnit\Framework\TestCase;
 
 final class StringUtilTest extends TestCase
 {
+    /**
+     * @dataProvider joinNonEmpty
+     *
+     * @param iterable<string|null> $parts
+     */
+    public function testJoinNonEmpty(string $expectedJoined, string $glue, iterable $parts): void
+    {
+        self::assertSame(
+            $expectedJoined,
+            StringUtil::joinNonEmpty($glue, $parts)
+        );
+    }
+
+    /** @return iterable<array{string, string, iterable<string|null>}> */
+    public static function joinNonEmpty(): iterable
+    {
+        yield ['a b', ' ', ['a', null, '', 'b']];
+        yield ['ab', '', ['a', null, '', 'b']];
+        yield ['a,b', ',', new Collection(['a', null, '', 'b'])];
+    }
+
     /** @dataProvider shortenFirstname */
     public function testShortenFirstname(string $expectedShortened, string $input): void
     {