From 3d84f82cc1d847f072d4c0e0bee6f4da16a066e8 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:16:49 -0400
Subject: [PATCH 01/15] Exclude unnecessary files from release archive exports

---
 .gitattributes | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 .gitattributes

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..2fb94da
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,9 @@
+# Path-based git attributes
+# https://www.kernel.org/pub/software/scm/git/docs/gitattributes.html
+
+# Ignore all test and documentation with "export-ignore".
+/.gitattributes       export-ignore
+/.gitignore           export-ignore
+/.travis.yml          export-ignore
+/phpunit.xml.dist     export-ignore
+/tests                export-ignore

From a48109d7945c2d803c8c489f6d0b3e8366a7915f Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 10:59:33 -0400
Subject: [PATCH 02/15] Bump minimum PHP version to 7.1; test up to PHP 7.4

This will allow us to use class constant visibility and nullable types
---
 .travis.yml   | 3 ++-
 README.md     | 2 +-
 composer.json | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 7dc0a79..d35938c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,10 @@
 language: php
 
 php:
-  - 7.0
   - 7.1
   - 7.2
+  - 7.3
+  - 7.4
 
 before_script:
   - wget -nc http://getcomposer.org/composer.phar
diff --git a/README.md b/README.md
index ebcbbbb..9a73d6f 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ Given a deep data structure, access data by dot notation.
 Requirements
 ------------
 
- * PHP (7.0+)
+ * PHP (7.1+)
 
 > For PHP (5.3+) please refer to version `1.0`.
 
diff --git a/composer.json b/composer.json
index 9911c53..378eaf2 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
         }
     ],
     "require": {
-        "php": "^7.0"
+        "php": "^7.1"
     },
     "require-dev": {
         "phpunit/phpunit": "^6.0"

From d37c5d1382561fc68b283daa3e9586a9ab9264b9 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:03:49 -0400
Subject: [PATCH 03/15] Switch from Travis CI to Github Actions

Github Actions is significantly faster and provides nicer feedback about
test failures.
---
 .gitattributes              |  2 +-
 .github/workflows/tests.yml | 29 +++++++++++++++++++++++++++++
 .travis.yml                 | 13 -------------
 3 files changed, 30 insertions(+), 14 deletions(-)
 create mode 100644 .github/workflows/tests.yml
 delete mode 100644 .travis.yml

diff --git a/.gitattributes b/.gitattributes
index 2fb94da..3238799 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -3,7 +3,7 @@
 
 # Ignore all test and documentation with "export-ignore".
 /.gitattributes       export-ignore
+/.github              export-ignore
 /.gitignore           export-ignore
-/.travis.yml          export-ignore
 /phpunit.xml.dist     export-ignore
 /tests                export-ignore
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
new file mode 100644
index 0000000..3c3891b
--- /dev/null
+++ b/.github/workflows/tests.yml
@@ -0,0 +1,29 @@
+name: Tests
+
+on:
+    push: ~
+    pull_request: ~
+
+jobs:
+    phpunit:
+        name: PHPUnit on ${{ matrix.php }} ${{ matrix.composer-flags }}
+        runs-on: ubuntu-latest
+        strategy:
+            matrix:
+                php: ['7.1', '7.2', '7.3', '7.4']
+
+        steps:
+            - uses: actions/checkout@v2
+
+            - uses: shivammathur/setup-php@v2
+              with:
+                  php-version: ${{ matrix.php }}
+                  extensions: curl
+                  coverage: pcov
+                  tools: composer:v2
+
+            - run: echo "::add-matcher::${{ runner.tool_cache }}/phpunit.json"
+
+            - run: composer update --no-progress
+
+            - run: vendor/bin/phpunit --coverage-text
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index d35938c..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-language: php
-
-php:
-  - 7.1
-  - 7.2
-  - 7.3
-  - 7.4
-
-before_script:
-  - wget -nc http://getcomposer.org/composer.phar
-  - php composer.phar install
-
-script: ./vendor/bin/phpunit --coverage-text

From d525666ed5564b15a98607b618ed6f7fea7894f8 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:09:01 -0400
Subject: [PATCH 04/15] Test using newer versions of PHPUnit

---
 .gitignore       |  2 ++
 composer.json    |  2 +-
 phpunit.xml.dist | 11 ++++++++++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/.gitignore b/.gitignore
index 987e2a2..f973ee0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
+.phpunit.result.cache
 composer.lock
+phpunit.xml
 vendor
diff --git a/composer.json b/composer.json
index 378eaf2..156a314 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
         "php": "^7.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6.0"
+        "phpunit/phpunit": "^7.5 || ^8.5 || ^9.3"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index ce9bb37..b2c4433 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,5 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit colors="true">
+<phpunit bootstrap="vendor/autoload.php"
+         backupGlobals="false"
+         backupStaticAttributes="false"
+         colors="true"
+         verbose="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         processIsolation="false"
+         stopOnFailure="false">
     <testsuites>
         <testsuite name="Dot Access Data Test Suite">
             <directory>./tests</directory>

From bac904fda42a2830c6e3275be1a868cfc65d2659 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:11:32 -0400
Subject: [PATCH 05/15] Test on PHP 8

---
 .github/workflows/tests.yml | 16 +++++++++++++++-
 composer.json               |  2 +-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 3c3891b..50728f7 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -11,6 +11,12 @@ jobs:
         strategy:
             matrix:
                 php: ['7.1', '7.2', '7.3', '7.4']
+                coverage: [true]
+                composer-flags: ['']
+                include:
+                    - php: '8.0'
+                      coverage: false
+                      composer-flags: '--ignore-platform-req=php'
 
         steps:
             - uses: actions/checkout@v2
@@ -24,6 +30,14 @@ jobs:
 
             - run: echo "::add-matcher::${{ runner.tool_cache }}/phpunit.json"
 
-            - run: composer update --no-progress
+            - name: "Use PHPUnit 9.3+ on PHP 8"
+              run: composer require --no-update --dev phpunit/phpunit:^9.3
+              if: "matrix.php == '8.0'"
+
+            - run: composer update --no-progress ${{ matrix.composer-flags }}
+
+            - run: vendor/bin/phpunit --no-coverage
+              if: ${{ !matrix.coverage }}
 
             - run: vendor/bin/phpunit --coverage-text
+              if: ${{ matrix.coverage }}
diff --git a/composer.json b/composer.json
index 156a314..07bbb91 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
         }
     ],
     "require": {
-        "php": "^7.1"
+        "php": "^7.1 || ^8.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^7.5 || ^8.5 || ^9.3"

From 9961e9a040774a489383bfa67c7a3d939081e910 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:14:02 -0400
Subject: [PATCH 06/15] Add phpstan and psalm for static analysis

---
 .gitattributes              |  2 ++
 .github/workflows/tests.yml | 36 ++++++++++++++++++++++++++++++++++++
 .gitignore                  |  2 ++
 composer.json               |  4 +++-
 phpstan.neon.dist           |  4 ++++
 psalm.xml.dist              | 16 ++++++++++++++++
 6 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 phpstan.neon.dist
 create mode 100644 psalm.xml.dist

diff --git a/.gitattributes b/.gitattributes
index 3238799..218cd6e 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -5,5 +5,7 @@
 /.gitattributes       export-ignore
 /.github              export-ignore
 /.gitignore           export-ignore
+/phpstan.neon.dist    export-ignore
 /phpunit.xml.dist     export-ignore
+/psalm.xml.dist       export-ignore
 /tests                export-ignore
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 50728f7..463e1ea 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -41,3 +41,39 @@ jobs:
 
             - run: vendor/bin/phpunit --coverage-text
               if: ${{ matrix.coverage }}
+
+    phpstan:
+        name: PHPStan
+        runs-on: ubuntu-latest
+
+        steps:
+            - uses: actions/checkout@v2
+
+            - uses: shivammathur/setup-php@v2
+              with:
+                  php-version: 7.1
+                  extensions: curl
+                  coverage: none
+                  tools: composer:v2
+
+            - run: composer update --no-progress
+
+            - run: vendor/bin/phpstan analyse --no-progress
+
+    psalm:
+        name: Psalm
+        runs-on: ubuntu-latest
+
+        steps:
+            - uses: actions/checkout@v2
+
+            - uses: shivammathur/setup-php@v2
+              with:
+                  php-version: 7.1
+                  extensions: curl
+                  coverage: none
+                  tools: composer:v2
+
+            - run: composer update --no-progress
+
+            - run: vendor/bin/psalm --no-progress --output-format=github
diff --git a/.gitignore b/.gitignore
index f973ee0..b31c0cf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
 .phpunit.result.cache
 composer.lock
+phpstan.neon
 phpunit.xml
+psalm.xml
 vendor
diff --git a/composer.json b/composer.json
index 07bbb91..0d56a7f 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,9 @@
         "php": "^7.1 || ^8.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.5 || ^8.5 || ^9.3"
+        "phpstan/phpstan": "^0.12.42",
+        "phpunit/phpunit": "^7.5 || ^8.5 || ^9.3",
+        "vimeo/psalm": "^3.14"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
new file mode 100644
index 0000000..a1c637a
--- /dev/null
+++ b/phpstan.neon.dist
@@ -0,0 +1,4 @@
+parameters:
+  level: max
+  paths:
+    - src
diff --git a/psalm.xml.dist b/psalm.xml.dist
new file mode 100644
index 0000000..729e9a9
--- /dev/null
+++ b/psalm.xml.dist
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<psalm
+    totallyTyped="false"
+    errorLevel="3"
+    resolveFromConfigFile="true"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
+>
+    <projectFiles>
+        <directory name="src" />
+        <ignoreFiles>
+            <directory name="vendor" />
+        </ignoreFiles>
+    </projectFiles>
+</psalm>

From bbbc4c3861a6e1d1896c943e8a9a1e8f240aba56 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:30:04 -0400
Subject: [PATCH 07/15] Remove redundant array check found by Psalm

---
 src/Util.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Util.php b/src/Util.php
index 546da22..3f72c7a 100644
--- a/src/Util.php
+++ b/src/Util.php
@@ -25,7 +25,7 @@ class Util
      */
     public static function isAssoc(array $arr)
     {
-        return (is_array($arr) && (!count($arr) || count(array_filter(array_keys($arr),'is_string')) == count($arr)));
+        return !count($arr) || count(array_filter(array_keys($arr),'is_string')) == count($arr);
     }
 
     /**

From 8d9590873b46fe70ee7e0becc8c0aa94fb38382f Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:46:20 -0400
Subject: [PATCH 08/15] Clean up type definition issues found by phpstan

---
 src/Data.php          | 26 +++++++++++++-------------
 src/DataInterface.php | 24 ++++++++++++------------
 src/Util.php          | 12 +++++++-----
 3 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/src/Data.php b/src/Data.php
index 1cec9a6..695aefc 100644
--- a/src/Data.php
+++ b/src/Data.php
@@ -18,24 +18,24 @@ class Data implements DataInterface
     /**
      * Internal representation of data data
      *
-     * @var array
+     * @var array<string, mixed>
      */
     protected $data;
 
     /**
      * Constructor
      *
-     * @param array|null $data
+     * @param array<string, mixed> $data
      */
-    public function __construct(array $data = null)
+    public function __construct(array $data = [])
     {
-        $this->data = $data ?: [];
+        $this->data = $data;
     }
 
     /**
      * {@inheritdoc}
      */
-    public function append($key, $value = null)
+    public function append(string $key, $value = null): void
     {
         if (0 == strlen($key)) {
             throw new RuntimeException("Key cannot be an empty string");
@@ -81,7 +81,7 @@ public function append($key, $value = null)
     /**
      * {@inheritdoc}
      */
-    public function set($key, $value = null)
+    public function set(string $key, $value = null): void
     {
         if (0 == strlen($key)) {
             throw new RuntimeException("Key cannot be an empty string");
@@ -113,7 +113,7 @@ public function set($key, $value = null)
     /**
      * {@inheritdoc}
      */
-    public function remove($key)
+    public function remove(string $key): void
     {
         if (0 == strlen($key)) {
             throw new RuntimeException("Key cannot be an empty string");
@@ -142,7 +142,7 @@ public function remove($key)
     /**
      * {@inheritdoc}
      */
-    public function get($key, $default = null)
+    public function get(string $key, $default = null)
     {
         $currentValue = $this->data;
         $keyPath = explode('.', $key);
@@ -164,7 +164,7 @@ public function get($key, $default = null)
     /**
      * {@inheritdoc}
      */
-    public function has($key)
+    public function has(string $key): bool
     {
         $currentValue = &$this->data;
         $keyPath = explode('.', $key);
@@ -186,7 +186,7 @@ public function has($key)
     /**
      * {@inheritdoc}
      */
-    public function getData($key)
+    public function getData(string $key): DataInterface
     {
         $value = $this->get($key);
         if (is_array($value) && Util::isAssoc($value)) {
@@ -199,7 +199,7 @@ public function getData($key)
     /**
      * {@inheritdoc}
      */
-    public function import(array $data, $clobber = true)
+    public function import(array $data, bool $clobber = true): void
     {
         $this->data = Util::mergeAssocArray($this->data, $data, $clobber);
     }
@@ -207,7 +207,7 @@ public function import(array $data, $clobber = true)
     /**
      * {@inheritdoc}
      */
-    public function importData(DataInterface $data, $clobber = true)
+    public function importData(DataInterface $data, bool $clobber = true): void
     {
         $this->import($data->export(), $clobber);
     }
@@ -215,7 +215,7 @@ public function importData(DataInterface $data, $clobber = true)
     /**
      * {@inheritdoc}
      */
-    public function export()
+    public function export(): array
     {
         return $this->data;
     }
diff --git a/src/DataInterface.php b/src/DataInterface.php
index 3498f26..d5ddf04 100644
--- a/src/DataInterface.php
+++ b/src/DataInterface.php
@@ -19,7 +19,7 @@ interface DataInterface
      * @param string $key
      * @param mixed  $value
      */
-    public function append($key, $value = null);
+    public function append(string $key, $value = null): void;
 
     /**
      * Set a value for a key
@@ -27,14 +27,14 @@ public function append($key, $value = null);
      * @param string $key
      * @param mixed  $value
      */
-    public function set($key, $value = null);
+    public function set(string $key, $value = null): void;
 
     /**
      * Remove a key
      *
      * @param string $key
      */
-    public function remove($key);
+    public function remove(string $key): void;
 
     /**
      * Get the raw value for a key
@@ -44,7 +44,7 @@ public function remove($key);
      *
      * @return mixed
      */
-    public function get($key, $default = null);
+    public function get(string $key, $default = null);
 
     /**
      * Check if the key exists
@@ -53,7 +53,7 @@ public function get($key, $default = null);
      *
      * @return bool
      */
-    public function has($key);
+    public function has(string $key): bool;
 
     /**
      * Get a data instance for a key
@@ -62,15 +62,15 @@ public function has($key);
      *
      * @return DataInterface
      */
-    public function getData($key);
+    public function getData(string $key): DataInterface;
 
     /**
      * Import data into existing data
      *
-     * @param array $data
-     * @param bool  $clobber
+     * @param array<string, mixed> $data
+     * @param bool                 $clobber
      */
-    public function import(array $data, $clobber = true);
+    public function import(array $data, bool $clobber = true): void;
 
     /**
      * Import data from an external data into existing data
@@ -78,12 +78,12 @@ public function import(array $data, $clobber = true);
      * @param DataInterface $data
      * @param bool          $clobber
      */
-    public function importData(DataInterface $data, $clobber = true);
+    public function importData(DataInterface $data, bool $clobber = true): void;
 
     /**
      * Export data as raw data
      *
-     * @return array
+     * @return array<string, mixed>
      */
-    public function export();
+    public function export(): array;
 }
diff --git a/src/Util.php b/src/Util.php
index 3f72c7a..1310163 100644
--- a/src/Util.php
+++ b/src/Util.php
@@ -19,11 +19,11 @@ class Util
      * Note that this function will return true if an array is empty. Meaning
      * empty arrays will be treated as if they are associative arrays.
      *
-     * @param array $arr
+     * @param array<mixed> $arr
      *
-     * @return boolean
+     * @return bool
      */
-    public static function isAssoc(array $arr)
+    public static function isAssoc(array $arr): bool
     {
         return !count($arr) || count(array_filter(array_keys($arr),'is_string')) == count($arr);
     }
@@ -31,9 +31,11 @@ public static function isAssoc(array $arr)
     /**
      * Merge contents from one associtative array to another
      *
-     * @param array $to
-     * @param array $from
+     * @param mixed $to
+     * @param mixed $from
      * @param bool  $clobber
+     *
+     * @return mixed
      */
     public static function mergeAssocArray($to, $from, $clobber = true)
     {

From d52384261b723875f40e684528a1e46ec3161e1b Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 12:05:14 -0400
Subject: [PATCH 09/15] Add psalm purity markers

---
 src/Data.php          | 8 ++++++++
 src/DataInterface.php | 8 ++++++++
 src/Util.php          | 4 ++++
 3 files changed, 20 insertions(+)

diff --git a/src/Data.php b/src/Data.php
index 695aefc..c36c904 100644
--- a/src/Data.php
+++ b/src/Data.php
@@ -141,6 +141,8 @@ public function remove(string $key): void
 
     /**
      * {@inheritdoc}
+     *
+     * @psalm-mutation-free
      */
     public function get(string $key, $default = null)
     {
@@ -163,6 +165,8 @@ public function get(string $key, $default = null)
 
     /**
      * {@inheritdoc}
+     *
+     * @psalm-mutation-free
      */
     public function has(string $key): bool
     {
@@ -185,6 +189,8 @@ public function has(string $key): bool
 
     /**
      * {@inheritdoc}
+     *
+     * @psalm-mutation-free
      */
     public function getData(string $key): DataInterface
     {
@@ -214,6 +220,8 @@ public function importData(DataInterface $data, bool $clobber = true): void
 
     /**
      * {@inheritdoc}
+     *
+     * @psalm-mutation-free
      */
     public function export(): array
     {
diff --git a/src/DataInterface.php b/src/DataInterface.php
index d5ddf04..fa20196 100644
--- a/src/DataInterface.php
+++ b/src/DataInterface.php
@@ -43,6 +43,8 @@ public function remove(string $key): void;
      * @param mixed $default
      *
      * @return mixed
+     *
+     * @psalm-mutation-free
      */
     public function get(string $key, $default = null);
 
@@ -52,6 +54,8 @@ public function get(string $key, $default = null);
      * @param string $key
      *
      * @return bool
+     *
+     * @psalm-mutation-free
      */
     public function has(string $key): bool;
 
@@ -61,6 +65,8 @@ public function has(string $key): bool;
      * @param string $key
      *
      * @return DataInterface
+     *
+     * @psalm-mutation-free
      */
     public function getData(string $key): DataInterface;
 
@@ -84,6 +90,8 @@ public function importData(DataInterface $data, bool $clobber = true): void;
      * Export data as raw data
      *
      * @return array<string, mixed>
+     *
+     * @psalm-mutation-free
      */
     public function export(): array;
 }
diff --git a/src/Util.php b/src/Util.php
index 1310163..6419c41 100644
--- a/src/Util.php
+++ b/src/Util.php
@@ -22,6 +22,8 @@ class Util
      * @param array<mixed> $arr
      *
      * @return bool
+     *
+     * @psalm-pure
      */
     public static function isAssoc(array $arr): bool
     {
@@ -36,6 +38,8 @@ public static function isAssoc(array $arr): bool
      * @param bool  $clobber
      *
      * @return mixed
+     *
+     * @psalm-pure
      */
     public static function mergeAssocArray($to, $from, $clobber = true)
     {

From d55cd4959c45a15c21bfad9fa2030269dc0ca8a7 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:54:44 -0400
Subject: [PATCH 10/15] Check code style against PSR-12

---
 .gitattributes              |  1 +
 .github/workflows/tests.yml | 18 ++++++++++++++++++
 .gitignore                  |  2 ++
 composer.json               |  1 +
 phpcs.xml.dist              | 17 +++++++++++++++++
 5 files changed, 39 insertions(+)
 create mode 100644 phpcs.xml.dist

diff --git a/.gitattributes b/.gitattributes
index 218cd6e..16efe8b 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -5,6 +5,7 @@
 /.gitattributes       export-ignore
 /.github              export-ignore
 /.gitignore           export-ignore
+/phpcs.xml.dist       export-ignore
 /phpstan.neon.dist    export-ignore
 /phpunit.xml.dist     export-ignore
 /psalm.xml.dist       export-ignore
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 463e1ea..bc60942 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -5,6 +5,24 @@ on:
     pull_request: ~
 
 jobs:
+    phpcs:
+        name: PHPCS
+        runs-on: ubuntu-latest
+
+        steps:
+            - uses: actions/checkout@v2
+
+            - uses: shivammathur/setup-php@v2
+              with:
+                  php-version: 7.1
+                  extensions: curl, mbstring
+                  coverage: none
+                  tools: composer:v2, cs2pr
+
+            - run: composer update --no-progress
+
+            - run: vendor/bin/phpcs -q --report=checkstyle | cs2pr
+
     phpunit:
         name: PHPUnit on ${{ matrix.php }} ${{ matrix.composer-flags }}
         runs-on: ubuntu-latest
diff --git a/.gitignore b/.gitignore
index b31c0cf..a0a4f20 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,7 @@
+.phpcs-cache
 .phpunit.result.cache
 composer.lock
+phpcs.xml
 phpstan.neon
 phpunit.xml
 psalm.xml
diff --git a/composer.json b/composer.json
index 0d56a7f..8a12e42 100644
--- a/composer.json
+++ b/composer.json
@@ -28,6 +28,7 @@
     "require-dev": {
         "phpstan/phpstan": "^0.12.42",
         "phpunit/phpunit": "^7.5 || ^8.5 || ^9.3",
+        "squizlabs/php_codesniffer": "^3.5",
         "vimeo/psalm": "^3.14"
     },
     "autoload": {
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
new file mode 100644
index 0000000..d67debb
--- /dev/null
+++ b/phpcs.xml.dist
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<ruleset>
+    <arg name="basepath" value="."/>
+    <arg name="extensions" value="php"/>
+    <arg name="parallel" value="80"/>
+    <arg name="cache" value=".phpcs-cache"/>
+    <arg name="colors"/>
+
+    <!-- Ignore warnings, show progress of the run and show sniff names -->
+    <arg value="nps"/>
+
+    <!-- Directories to be checked -->
+    <file>src</file>
+    <file>tests</file>
+
+    <rule ref="PSR12"/>
+</ruleset>

From 392d36e122ac34147c8c14742b00f415919e21d6 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:55:12 -0400
Subject: [PATCH 11/15] Update code to match PSR-12 code style

---
 src/Data.php       | 14 +++++++-------
 src/Util.php       |  4 ++--
 tests/DataTest.php |  4 ++--
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/Data.php b/src/Data.php
index c36c904..53ea64a 100644
--- a/src/Data.php
+++ b/src/Data.php
@@ -59,9 +59,9 @@ public function append(string $key, $value = null): void
         }
 
         $endKey = array_pop($keyPath);
-        for ( $i = 0; $i < count($keyPath); $i++ ) {
+        for ($i = 0; $i < count($keyPath); $i++) {
             $currentKey =& $keyPath[$i];
-            if ( ! isset($currentValue[$currentKey]) ) {
+            if (! isset($currentValue[$currentKey])) {
                 $currentValue[$currentKey] = [];
             }
             $currentValue =& $currentValue[$currentKey];
@@ -97,7 +97,7 @@ public function set(string $key, $value = null): void
         }
 
         $endKey = array_pop($keyPath);
-        for ( $i = 0; $i < count($keyPath); $i++ ) {
+        for ($i = 0; $i < count($keyPath); $i++) {
             $currentKey =& $keyPath[$i];
             if (!isset($currentValue[$currentKey])) {
                 $currentValue[$currentKey] = [];
@@ -129,7 +129,7 @@ public function remove(string $key): void
         }
 
         $endKey = array_pop($keyPath);
-        for ( $i = 0; $i < count($keyPath); $i++ ) {
+        for ($i = 0; $i < count($keyPath); $i++) {
             $currentKey =& $keyPath[$i];
             if (!isset($currentValue[$currentKey])) {
                 return;
@@ -149,9 +149,9 @@ public function get(string $key, $default = null)
         $currentValue = $this->data;
         $keyPath = explode('.', $key);
 
-        for ( $i = 0; $i < count($keyPath); $i++ ) {
+        for ($i = 0; $i < count($keyPath); $i++) {
             $currentKey = $keyPath[$i];
-            if (!isset($currentValue[$currentKey]) ) {
+            if (!isset($currentValue[$currentKey])) {
                 return $default;
             }
             if (!is_array($currentValue)) {
@@ -173,7 +173,7 @@ public function has(string $key): bool
         $currentValue = &$this->data;
         $keyPath = explode('.', $key);
 
-        for ( $i = 0; $i < count($keyPath); $i++ ) {
+        for ($i = 0; $i < count($keyPath); $i++) {
             $currentKey = $keyPath[$i];
             if (
                 !is_array($currentValue) ||
diff --git a/src/Util.php b/src/Util.php
index 6419c41..a9cc2cc 100644
--- a/src/Util.php
+++ b/src/Util.php
@@ -27,7 +27,7 @@ class Util
      */
     public static function isAssoc(array $arr): bool
     {
-        return !count($arr) || count(array_filter(array_keys($arr),'is_string')) == count($arr);
+        return !count($arr) || count(array_filter(array_keys($arr), 'is_string')) == count($arr);
     }
 
     /**
@@ -43,7 +43,7 @@ public static function isAssoc(array $arr): bool
      */
     public static function mergeAssocArray($to, $from, $clobber = true)
     {
-        if ( is_array($from) ) {
+        if (is_array($from)) {
             foreach ($from as $k => $v) {
                 if (!isset($to[$k])) {
                     $to[$k] = $v;
diff --git a/tests/DataTest.php b/tests/DataTest.php
index d80e052..b3b1ad1 100644
--- a/tests/DataTest.php
+++ b/tests/DataTest.php
@@ -88,7 +88,7 @@ public function testAppend()
 
     public function testSet()
     {
-        $data = new Data;
+        $data = new Data();
 
         $this->assertNull($data->get('a'));
         $this->assertNull($data->get('b.c'));
@@ -111,7 +111,7 @@ public function testSet()
 
     public function testSetClobberStringInPath()
     {
-        $data = new Data;
+        $data = new Data();
 
         $data->set('a.b.c', 'Should not be able to write to a.b.c.d.e');
 

From 6f7a42d35a5e5c3a7895a5135700c0de0e78d618 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:56:39 -0400
Subject: [PATCH 12/15] Add .editorconfig file to pre-configure contributor
 IDEs

---
 .editorconfig  | 11 +++++++++++
 .gitattributes |  1 +
 2 files changed, 12 insertions(+)
 create mode 100644 .editorconfig

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..2454616
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,11 @@
+; top-most EditorConfig file
+root = true
+
+# All files.
+[*]
+end_of_line = LF
+indent_style = space
+indent_size = 4
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
diff --git a/.gitattributes b/.gitattributes
index 16efe8b..7a6ef08 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -2,6 +2,7 @@
 # https://www.kernel.org/pub/software/scm/git/docs/gitattributes.html
 
 # Ignore all test and documentation with "export-ignore".
+/.editorconfig        export-ignore
 /.gitattributes       export-ignore
 /.github              export-ignore
 /.gitignore           export-ignore

From 97e1c611a3fc905d4c39b21277e6da73c6e7348f Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:57:05 -0400
Subject: [PATCH 13/15] Add Composer script shortcuts to simplify testing

---
 composer.json | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/composer.json b/composer.json
index 8a12e42..7dcc1a2 100644
--- a/composer.json
+++ b/composer.json
@@ -45,5 +45,17 @@
         "branch-alias": {
             "dev-master": "2.0-dev"
         }
+    },
+    "scripts": {
+        "phpcs": "phpcs",
+        "phpstan": "phpstan analyse",
+        "phpunit": "phpunit --no-coverage",
+        "psalm": "psalm",
+        "test": [
+            "@phpcs",
+            "@phpstan",
+            "@psalm",
+            "@phpunit"
+        ]
     }
 }

From 900ac8c2cabdf144d4404c737af3626aafc5499c Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 11:58:56 -0400
Subject: [PATCH 14/15] Add CONTRIBUTING.md guide

---
 .github/CONTRIBUTING.md | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 .github/CONTRIBUTING.md

diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
new file mode 100644
index 0000000..665dc6c
--- /dev/null
+++ b/.github/CONTRIBUTING.md
@@ -0,0 +1,31 @@
+# Contributing
+
+Contributions are **welcome** and will be fully **credited**. We accept contributions via Pull Requests on [GitHub](https://github.com/dflydev/dflydev-dot-access-data).
+
+## Pull Requests
+
+- **[PSR-12 Coding Standard](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-12-extended-coding-style-guide.md)** - The easiest way to apply the conventions is to run `./vendor/bin/phpcbf`.
+
+- **Add tests!** - Your patch won't be accepted if it doesn't have tests.
+
+- **Tests must pass** - All automated tests, including things like code style checks, but be passing before we'll consider merging the change.
+
+- **Document any change in behaviour** - Make sure the `README.md` and any other relevant documentation are kept up-to-date.
+
+- **Consider our release cycle** - We try to follow [SemVer v2.0.0](https://semver.org/). Randomly breaking public APIs is not an option.
+
+- **Create feature branches** - Don't ask us to pull from your default branch.
+
+- **One pull request per feature** - If you want to do more than one thing, send multiple pull requests.
+
+- **Send coherent history** - Make sure each individual commit in your pull request is meaningful. If you had to make multiple intermediate commits while developing, please squash them before submitting.
+
+
+## Running Tests
+
+``` bash
+$ composer test
+```
+
+
+**Happy coding**!

From 28e715541498b606bb0504c4b0f899b16c883dd4 Mon Sep 17 00:00:00 2001
From: Colin O'Dell <colinodell@gmail.com>
Date: Sat, 19 Sep 2020 12:41:47 -0400
Subject: [PATCH 15/15] Fix code coverage on PHP 7.1

---
 .github/workflows/tests.yml | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index bc60942..60c38ea 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -28,10 +28,13 @@ jobs:
         runs-on: ubuntu-latest
         strategy:
             matrix:
-                php: ['7.1', '7.2', '7.3', '7.4']
-                coverage: [true]
+                php: ['7.2', '7.3', '7.4']
+                coverage: [pcov]
                 composer-flags: ['']
                 include:
+                    - php: '7.1'
+                      coverage: xdebug
+                      composer-flags: ''
                     - php: '8.0'
                       coverage: false
                       composer-flags: '--ignore-platform-req=php'
@@ -43,7 +46,7 @@ jobs:
               with:
                   php-version: ${{ matrix.php }}
                   extensions: curl
-                  coverage: pcov
+                  coverage: ${{ matrix.coverage }}
                   tools: composer:v2
 
             - run: echo "::add-matcher::${{ runner.tool_cache }}/phpunit.json"
@@ -55,10 +58,10 @@ jobs:
             - run: composer update --no-progress ${{ matrix.composer-flags }}
 
             - run: vendor/bin/phpunit --no-coverage
-              if: ${{ !matrix.coverage }}
+              if: ${{ matrix.coverage == 'none' }}
 
             - run: vendor/bin/phpunit --coverage-text
-              if: ${{ matrix.coverage }}
+              if: ${{ matrix.coverage != 'none' }}
 
     phpstan:
         name: PHPStan