From 1ab8ca471959bc72c025a33cd385615d9c220da3 Mon Sep 17 00:00:00 2001
From: jjgrainger <github@jjgrainger.co.uk>
Date: Sun, 1 Feb 2026 16:40:31 +0000
Subject: [PATCH 1/8] update phpstan level to 5 and fixes

---
 phpstan.neon.dist  |   2 +-
 src/Collection.php | 245 +++++++++++++++++++++++++++------------------
 2 files changed, 148 insertions(+), 99 deletions(-)

diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 1636bf2..18c973a 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -1,5 +1,5 @@
 parameters:
-    level: 0
+    level: 5
     paths:
         - src
     ignoreErrors:
diff --git a/src/Collection.php b/src/Collection.php
index ea5536e..66b65ef 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -11,34 +11,52 @@
 
 class Collection implements Countable, IteratorAggregate, JsonSerializable
 {
-
-    protected $items;
+    /**
+     * Collection items.
+     *
+     * @var array
+     */
+    protected array $items;
 
     /**
-     * Create a collection from passed items
+     * Create a collection with items passed.
+     * 
      * @param array $items
      */
-    public function __construct($items = [])
+    public function __construct(array $items = [])
     {
         $this->items = $items;
     }
 
     /**
-     * Return udnerlying array in collection
+     * Create a collection statically.
+     *
+     * @param array $items
+     * @return static
+     */
+    public static function collect(array $items): static
+    {
+        return new static($items);
+    }
+
+    /**
+     * Return items in the collection.
+     * 
      * @return array
      */
-    public function all()
+    public function all(): array
     {
         return $this->items;
     }
 
     /**
-     * Get an item in the collection by its key
-     * @param  mixed $key
-     * @param  mixed $default
+     * Get an item by key.
+     * 
+     * @param string|int $key
+     * @param mixed $default
      * @return mixed
      */
-    public function get($key, $default = null)
+    public function get(string|int $key, mixed $default = null): mixed
     {
         if ($this->has($key)) {
             return $this->items[$key];
@@ -48,45 +66,45 @@ public function get($key, $default = null)
     }
 
     /**
-     * Check if key exists in the collection
-     * @param  mixed  $key
+     * Check if key exists in the collection.
+     * 
+     * @param string|int $key
      * @return boolean
      */
-    public function has($key)
+    public function has(string|int $key): bool
     {
-        if (isset($this->items[$key])) {
-            return true;
-        }
-
-        return false;
+        return isset($this->items[$key]);
     }
 
     /**
-     * Set a key and value to the collection
-     * @param  mixed $key
-     * @param  mixed $value
+     * Put value to collection with key.
+     *
+     * @param string|int $key
+     * @param mixed $value
      */
-    public function put($key, $value)
+    public function put(string|int $key, mixed $value): void
     {
         $this->items[$key] = $value;
     }
 
     /**
-     * Add item to the end of the collection
-     * @param  mixed $value
+     * Add item to the end of the collection.
+     * 
+     * @param mixed $value
      */
-    public function push($value)
+    public function push(mixed $value): void
     {
         $this->items[] = $value;
     }
 
     /**
-     * Remove and return an item via its key
-     * @param  mixed $key
-     * @param  mixed $default
+     * Remove and return an item via its key.
+     * 
+     * @param string|int $key
+     * @param mixed $default
      * @return mixed
      */
-    public function pull($key, $default = null)
+    public function pull(string|int $key, mixed $default = null): mixed
     {
         $value = $this->get($key, $default);
 
@@ -96,63 +114,71 @@ public function pull($key, $default = null)
     }
 
     /**
-     * Return the first item in the collection
+     * Return the first item in the collection.
+     * 
      * @return mixed
      */
-    public function first()
+    public function first(): mixed
     {
         return count($this->items) ? reset($this->items) : null;
     }
 
     /**
-     * Return the last item in the collection
+     * Return the last item in the collection.
+     * 
      * @return mixed
      */
-    public function last()
+    public function last(): mixed
     {
         return count($this->items) ? end($this->items) : null;
     }
 
     /**
-     * Return and remove the last item in the array
+     * Return and remove the last item in the array.
+     * 
      * @return mixed
      */
-    public function pop()
+    public function pop(): mixed
     {
         return array_pop($this->items);
     }
 
     /**
-     * Return and remove the first item in the array
+     * Return and remove the first item in the array.
+     * 
      * @return mixed
      */
-    public function shift()
+    public function shift(): mixed
     {
         return array_shift($this->items);
     }
 
     /**
-     * Remove item from the collection via its key
-     * @param  mixed $key
+     * Remove item from the collection via its key.
+     * 
+     * @param string|int $key
      */
-    public function remove($key)
+    public function remove(string|int $key): void
     {
         unset($this->items[$key]);
     }
 
     /**
-     * Return the collection keys as a new collection
-     * @return Collection
+     * Return the collection keys as a new collection.
+     * 
+     * @return static
      */
-    public function keys()
+    public function keys(): static
     {
         return new static(array_keys($this->items));
     }
 
     /**
-     * Reset the collections keys
+     * Reset the collections keys.
+     * 
+     * @return static
      */
-    public function values()
+    public function values(): static
     {
         $this->items = array_values($this->items);
 
@@ -160,10 +186,11 @@ public function values()
     }
 
     /**
-     * Transform the current collection
-     * @param  Closure $iterator
+     * Transform the current collection.
+     * 
+     * @param callable $iterator
      */
-    public function transform(Closure $iterator)
+    public function transform(callable $iterator): static
     {
         $this->items = array_map($iterator, $this->items);
 
@@ -171,28 +198,31 @@ public function transform(Closure $iterator)
     }
 
     /**
-     * Returns a collection without duplicate values
-     * @return Collection
+     * Returns a collection without duplicate values.
+     * 
+     * @return static
      */
-    public function unique()
+    public function unique(): static
     {
         return new static(array_unique($this->items, SORT_REGULAR));
     }
 
     /**
-     * Return a new collection with the items reverese
-     * @return Collection
+     * Return a new collection with the items reverse.
+     * 
+     * @return static
      */
-    public function reverse()
+    public function reverse(): static
     {
         return new static(array_reverse($this->items));
     }
 
     /**
-     * Return a new collection with the items shuffled
-     * @return Collection
+     * Return a new collection with the items shuffled.
+     * 
+     * @return static
      */
-    public function shuffle()
+    public function shuffle(): static
     {
         $items = $this->items;
 
@@ -202,10 +232,12 @@ public function shuffle()
     }
 
     /**
-     * Get one or more items randomly from the collection
-     * @param  integer $amount
+     * Get one or more items randomly from the collection.
+     * 
+     * @param int $amount
+     * @return mixed
      */
-    public function random($amount = 1)
+    public function random(int $amount = 1): mixed
     {
         if ($this->isEmpty()) {
             return null;
@@ -221,50 +253,55 @@ public function random($amount = 1)
     }
 
     /**
-     * Flip items in the collection
-     * @return Collection
+     * Flip items in the collection.
+     * 
+     * @return static
      */
-    public function flip()
+    public function flip(): static
     {
         return new static(array_flip($this->items));
     }
 
     /**
-     * Map over each of the items in the collection
-     * @param  Closure $iterator
-     * @return Collection
+     * Map over each of the items in the collection.
+     * 
+     * @param callable $iterator
+     * @return static
      */
-    public function map(Closure $iterator)
+    public function map(callable $iterator): static
     {
         return new static(array_map($iterator, $this->items));
     }
 
     /**
-     * Filter items within the collection
-     * @param  Closure $filter
-     * @return Collection
+     * Filter items within the collection.
+     * 
+     * @param callable $filter
+     * @return static
      */
-    public function filter(Closure $filter)
+    public function filter(?callable $filter): static
     {
         return new static(array_filter($this->items, $filter));
     }
 
     /**
-     * Reduce the collection to a single value
-     * @param  Closure $callback
-     * @param  mixed   $initial
-     * @return Collection
+     * Reduce the collection to a single value.
+     * 
+     * @param callable $callback
+     * @param mixed $initial
+     * @return mixed
      */
-    public function reduce(Closure $callback, $initial = null)
+    public function reduce(callable $callback, $initial = null): mixed
     {
         return array_reduce($this->items, $callback, $initial);
     }
 
     /**
-     * Sum the items in the collection
-     * @param  string $key
+     * Sum the items in the collection.
+     * 
+     * @param string|int|null $key
      */
-    public function sum($key = null)
+    public function sum(string|int|null $key = null): int
     {
         if (is_null($key)) {
             return array_sum($this->items);
@@ -276,16 +313,19 @@ public function sum($key = null)
     }
 
     /**
-     * Concatenate items into a string
-     * @param  string $glue
+     * Concatenate items into a string.
+     * 
+     * @param string $glue
+     * @return string
      */
-    public function implode($glue = '')
+    public function implode(string $glue = ''): string
     {
         return implode($glue, $this->items);
     }
 
     /**
-     * Return total items in collection
+     * Return total items in collection.
+     * 
      * @return int
      */
     public function count(): int
@@ -294,44 +334,51 @@ public function count(): int
     }
 
     /**
-     * Check if the collection is empty
+     * Check if the collection is empty.
+     * 
      * @return boolean
      */
-    public function isEmpty()
+    public function isEmpty(): bool
     {
         return empty($this->items);
     }
 
     /**
-     * Check if the collection is not empty
+     * Check if the collection is not empty.
+     * 
      * @return boolean
      */
-    public function isNotEmpty()
+    public function isNotEmpty(): bool
     {
-        return !empty($this->items);
+        return ! $this->isEmpty();
     }
 
     /**
-     * Return the collection as an array
-     * @return Array
+     * Return the collection as an array.
+     * 
+     * @return array
      */
-    public function toArray()
+    public function toArray(): array
     {
         return $this->items;
     }
 
     /**
-     * Return the collection as JSON
-     * @param  integer $options
-     * @return string
+     * Return the collection as JSON.
+     * 
+     * @param int $flags
+     * @param int $depth
+     * @return string|false
      */
-    public function toJson($options = 0)
+    public function toJson(int $flags = 0, int $depth = 512): string|false
     {
-        return json_encode($this->items, $options);
+        return json_encode($this->items, $flags, $depth);
     }
 
     /**
-     * Iterate over items in collection
+     * Iterate over items in collection.
+     * 
+     * @return Traversable
      */
     public function getIterator(): Traversable
     {
@@ -339,7 +386,9 @@ public function getIterator(): Traversable
     }
 
     /**
-     * JSON Serialize items in the collection
+     * JSON Serialize items in the collection.
+     * 
+     * @return mixed
      */
     public function jsonSerialize(): mixed
     {

From 5f2f5bf0a27089590e18a9bfa3a0c3358bc0c471 Mon Sep 17 00:00:00 2001
From: jjgrainger <github@jjgrainger.co.uk>
Date: Sun, 1 Feb 2026 16:41:31 +0000
Subject: [PATCH 2/8] add coverage reporting

---
 .github/workflows/tests.yml | 7 ++++++-
 .gitignore                  | 1 +
 composer.json               | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 65866da..29209c2 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -59,4 +59,9 @@ jobs:
         run: composer install --prefer-dist --no-progress
 
       - name: PHPUnit
-        run: composer phpunit
+        run: composer phpunit:coverage
+
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index f8892ba..f562caf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 .DS_Store
 /vendor
 .phpunit.result.cache
+coverage.xml
\ No newline at end of file
diff --git a/composer.json b/composer.json
index fa7999a..f151c84 100644
--- a/composer.json
+++ b/composer.json
@@ -26,6 +26,7 @@
     "scripts": {
         "phpcs": "./vendor/bin/phpcs --standard=psr2 src",
         "phpunit": "./vendor/bin/phpunit",
+        "phpunit:coverage": "./vendor/bin/phpunit --coverage-clover=coverage.xml",
         "phpstan": "phpstan analyse src"
     }
 }

From faa3b0669a03651c461c6bac5d21d71a70ad6c31 Mon Sep 17 00:00:00 2001
From: jjgrainger <github@jjgrainger.co.uk>
Date: Sun, 1 Feb 2026 16:43:57 +0000
Subject: [PATCH 3/8] add .editorconfig and remove whitespace

---
 .editorconfig      |  8 ++++++
 src/Collection.php | 62 +++++++++++++++++++++++-----------------------
 2 files changed, 39 insertions(+), 31 deletions(-)
 create mode 100644 .editorconfig

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..0763a70
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,8 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
diff --git a/src/Collection.php b/src/Collection.php
index 66b65ef..ebbe343 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -20,7 +20,7 @@ class Collection implements Countable, IteratorAggregate, JsonSerializable
 
     /**
      * Create a collection with items passed.
-     * 
+     *
      * @param array $items
      */
     public function __construct(array $items = [])
@@ -41,7 +41,7 @@ public static function collect(array $items): static
 
     /**
      * Return items in the collection.
-     * 
+     *
      * @return array
      */
     public function all(): array
@@ -51,7 +51,7 @@ public function all(): array
 
     /**
      * Get an item by key.
-     * 
+     *
      * @param string|int $key
      * @param mixed $default
      * @return mixed
@@ -67,7 +67,7 @@ public function get(string|int $key, mixed $default = null): mixed
 
     /**
      * Check if key exists in the collection.
-     * 
+     *
      * @param string|int $key
      * @return boolean
      */
@@ -89,7 +89,7 @@ public function put(string|int $key, mixed $value): void
 
     /**
      * Add item to the end of the collection.
-     * 
+     *
      * @param mixed $value
      */
     public function push(mixed $value): void
@@ -99,7 +99,7 @@ public function push(mixed $value): void
 
     /**
      * Remove and return an item via its key.
-     * 
+     *
      * @param string|int $key
      * @param mixed $default
      * @return mixed
@@ -115,7 +115,7 @@ public function pull(string|int $key, mixed $default = null): mixed
 
     /**
      * Return the first item in the collection.
-     * 
+     *
      * @return mixed
      */
     public function first(): mixed
@@ -125,7 +125,7 @@ public function first(): mixed
 
     /**
      * Return the last item in the collection.
-     * 
+     *
      * @return mixed
      */
     public function last(): mixed
@@ -135,7 +135,7 @@ public function last(): mixed
 
     /**
      * Return and remove the last item in the array.
-     * 
+     *
      * @return mixed
      */
     public function pop(): mixed
@@ -145,7 +145,7 @@ public function pop(): mixed
 
     /**
      * Return and remove the first item in the array.
-     * 
+     *
      * @return mixed
      */
     public function shift(): mixed
@@ -155,7 +155,7 @@ public function shift(): mixed
 
     /**
      * Remove item from the collection via its key.
-     * 
+     *
      * @param string|int $key
      */
     public function remove(string|int $key): void
@@ -165,7 +165,7 @@ public function remove(string|int $key): void
 
     /**
      * Return the collection keys as a new collection.
-     * 
+     *
      * @return static
      */
     public function keys(): static
@@ -175,7 +175,7 @@ public function keys(): static
 
     /**
      * Reset the collections keys.
-     * 
+     *
      * @return static
      */
     public function values(): static
@@ -187,7 +187,7 @@ public function values(): static
 
     /**
      * Transform the current collection.
-     * 
+     *
      * @param callable $iterator
      */
     public function transform(callable $iterator): static
@@ -199,7 +199,7 @@ public function transform(callable $iterator): static
 
     /**
      * Returns a collection without duplicate values.
-     * 
+     *
      * @return static
      */
     public function unique(): static
@@ -209,7 +209,7 @@ public function unique(): static
 
     /**
      * Return a new collection with the items reverse.
-     * 
+     *
      * @return static
      */
     public function reverse(): static
@@ -219,7 +219,7 @@ public function reverse(): static
 
     /**
      * Return a new collection with the items shuffled.
-     * 
+     *
      * @return static
      */
     public function shuffle(): static
@@ -233,7 +233,7 @@ public function shuffle(): static
 
     /**
      * Get one or more items randomly from the collection.
-     * 
+     *
      * @param int $amount
      * @return mixed
      */
@@ -254,7 +254,7 @@ public function random(int $amount = 1): mixed
 
     /**
      * Flip items in the collection.
-     * 
+     *
      * @return static
      */
     public function flip(): static
@@ -264,7 +264,7 @@ public function flip(): static
 
     /**
      * Map over each of the items in the collection.
-     * 
+     *
      * @param callable $iterator
      * @return static
      */
@@ -275,7 +275,7 @@ public function map(callable $iterator): static
 
     /**
      * Filter items within the collection.
-     * 
+     *
      * @param callable $filter
      * @return static
      */
@@ -286,7 +286,7 @@ public function filter(?callable $filter): static
 
     /**
      * Reduce the collection to a single value.
-     * 
+     *
      * @param callable $callback
      * @param mixed $initial
      * @return mixed
@@ -298,7 +298,7 @@ public function reduce(callable $callback, $initial = null): mixed
 
     /**
      * Sum the items in the collection.
-     * 
+     *
      * @param string|int|null $key
      */
     public function sum(string|int|null $key = null): int
@@ -314,7 +314,7 @@ public function sum(string|int|null $key = null): int
 
     /**
      * Concatenate items into a string.
-     * 
+     *
      * @param string $glue
      * @return string
      */
@@ -325,7 +325,7 @@ public function implode(string $glue = ''): string
 
     /**
      * Return total items in collection.
-     * 
+     *
      * @return int
      */
     public function count(): int
@@ -335,7 +335,7 @@ public function count(): int
 
     /**
      * Check if the collection is empty.
-     * 
+     *
      * @return boolean
      */
     public function isEmpty(): bool
@@ -345,7 +345,7 @@ public function isEmpty(): bool
 
     /**
      * Check if the collection is not empty.
-     * 
+     *
      * @return boolean
      */
     public function isNotEmpty(): bool
@@ -355,7 +355,7 @@ public function isNotEmpty(): bool
 
     /**
      * Return the collection as an array.
-     * 
+     *
      * @return array
      */
     public function toArray(): array
@@ -365,7 +365,7 @@ public function toArray(): array
 
     /**
      * Return the collection as JSON.
-     * 
+     *
      * @param int $flags
      * @param int $depth
      * @return string|false
@@ -377,7 +377,7 @@ public function toJson(int $flags = 0, int $depth = 512): string|false
 
     /**
      * Iterate over items in collection.
-     * 
+     *
      * @return Traversable
      */
     public function getIterator(): Traversable
@@ -387,7 +387,7 @@ public function getIterator(): Traversable
 
     /**
      * JSON Serialize items in the collection.
-     * 
+     *
      * @return mixed
      */
     public function jsonSerialize(): mixed

From f5a53be3e16b59a0f7cf06f23d144cf057d54390 Mon Sep 17 00:00:00 2001
From: jjgrainger <github@jjgrainger.co.uk>
Date: Sun, 1 Feb 2026 16:48:32 +0000
Subject: [PATCH 4/8] update phpunit.xml for coverage reporting

---
 phpunit.xml | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/phpunit.xml b/phpunit.xml
index 90b6d3e..5122c52 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -4,8 +4,14 @@
          verbose="true"
          stopOnFailure="false">
     <testsuites>
-        <testsuite name="Test suite">
+        <testsuite name="Collection Test Suite">
             <directory>tests</directory>
         </testsuite>
     </testsuites>
+
+    <coverage processUncoveredFiles="true">
+        <include>
+            <directory suffix=".php">src</directory>
+        </include>
+    </coverage>
 </phpunit>

From 1533a984ed22bc92cd5fdb1e4ef392d9a2eb9385 Mon Sep 17 00:00:00 2001
From: jjgrainger <github@jjgrainger.co.uk>
Date: Sun, 1 Feb 2026 16:55:08 +0000
Subject: [PATCH 5/8] add configuration to phpunit:coverage script

---
 composer.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/composer.json b/composer.json
index f151c84..77111d3 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
     "scripts": {
         "phpcs": "./vendor/bin/phpcs --standard=psr2 src",
         "phpunit": "./vendor/bin/phpunit",
-        "phpunit:coverage": "./vendor/bin/phpunit --coverage-clover=coverage.xml",
+        "phpunit:coverage": "./vendor/bin/phpunit --configuration phpunit.xml --coverage-clover=coverage.xml",
         "phpstan": "phpstan analyse src"
     }
 }

From 4a146d69bce492f90c800d916fa053499bd7ea01 Mon Sep 17 00:00:00 2001
From: jjgrainger <github@jjgrainger.co.uk>
Date: Sun, 1 Feb 2026 17:01:50 +0000
Subject: [PATCH 6/8] fix directory

---
 phpunit.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/phpunit.xml b/phpunit.xml
index 5122c52..36ab660 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -11,7 +11,7 @@
 
     <coverage processUncoveredFiles="true">
         <include>
-            <directory suffix=".php">src</directory>
+            <directory suffix=".php">./src</directory>
         </include>
     </coverage>
 </phpunit>

From 5174adddc9490b9b29a71b766704c545057979cd Mon Sep 17 00:00:00 2001
From: jjgrainger <github@jjgrainger.co.uk>
Date: Sun, 1 Feb 2026 17:06:50 +0000
Subject: [PATCH 7/8] update phpunit.xml

---
 composer.json |  1 +
 phpunit.xml   | 13 +++++++------
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/composer.json b/composer.json
index 77111d3..c0f5495 100644
--- a/composer.json
+++ b/composer.json
@@ -25,6 +25,7 @@
     },
     "scripts": {
         "phpcs": "./vendor/bin/phpcs --standard=psr2 src",
+        "phpcbf": "./vendor/bin/phpcbf --standard=psr2 src",
         "phpunit": "./vendor/bin/phpunit",
         "phpunit:coverage": "./vendor/bin/phpunit --configuration phpunit.xml --coverage-clover=coverage.xml",
         "phpstan": "phpstan analyse src"
diff --git a/phpunit.xml b/phpunit.xml
index 36ab660..2252722 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,17 +1,18 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit bootstrap="vendor/autoload.php"
-         colors="true"
-         verbose="true"
-         stopOnFailure="false">
+<phpunit
+    bootstrap="vendor/autoload.php"
+    colors="true"
+    stopOnFailure="false"
+>
     <testsuites>
         <testsuite name="Collection Test Suite">
             <directory>tests</directory>
         </testsuite>
     </testsuites>
 
-    <coverage processUncoveredFiles="true">
+    <source>
         <include>
             <directory suffix=".php">./src</directory>
         </include>
-    </coverage>
+    </source>
 </phpunit>

From 6ba277181fbd3ac92e36e90033dd7d973c44943f Mon Sep 17 00:00:00 2001
From: jjgrainger <github@jjgrainger.co.uk>
Date: Sun, 1 Feb 2026 17:09:58 +0000
Subject: [PATCH 8/8] add coverage badge to README.md

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

diff --git a/README.md b/README.md
index 870809a..897b428 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 > A collection class for working with arrays
 
-[![tests](https://github.com/jjgrainger/Collection/actions/workflows/tests.yml/badge.svg)](https://github.com/jjgrainger/Collection/actions/workflows/tests.yml) [![Latest Stable Version](https://badgen.net/github/release/jjgrainger/Collection/stable)](https://packagist.org/packages/jjgrainger/collection) [![Total Downloads](https://badgen.net/packagist/dt/jjgrainger/Collection)](https://packagist.org/packages/jjgrainger/collection) [![License](https://badgen.net/github/license/jjgrainger/Collection)](https://packagist.org/packages/jjgrainger/collection)
+[![tests](https://github.com/jjgrainger/Collection/actions/workflows/tests.yml/badge.svg)](https://github.com/jjgrainger/Collection/actions/workflows/tests.yml) [![codecov](https://codecov.io/gh/jjgrainger/Collection/graph/badge.svg?token=XMLzVOcLHB)](https://codecov.io/gh/jjgrainger/Collection) [![Latest Stable Version](https://badgen.net/github/release/jjgrainger/Collection/stable)](https://packagist.org/packages/jjgrainger/collection) [![Total Downloads](https://badgen.net/packagist/dt/jjgrainger/Collection)](https://packagist.org/packages/jjgrainger/collection) [![License](https://badgen.net/github/license/jjgrainger/Collection)](https://packagist.org/packages/jjgrainger/collection)
 
 ## Principles