feat(layout): add basic layout class

lib/ACFComposer/Layout.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace ACFComposer;
+
+use Exception;
+
+class Layout {
+  function __construct($config) {
+    if(is_string($config)) {
+      $config = apply_filters($config, null);
+    }
+    $this->config = $this->validateConfig($config);
+  }
+
+  protected function validateConfig($config) {
+    if(!array_key_exists('name', $config)) {
+      throw new Exception('Field config needs to contain a \'name\' property.');
+    }
+    if(!array_key_exists('label', $config)) {
+      throw new Exception('Field config needs to contain a \'label\' property.');
+    }
+    if(array_key_exists('key', $config)) {
+      throw new Exception('Field config must not contain a \'key\' property.');
+    }
+    return $config;
+  }
+}

tests/test-layout.php

@@ -0,0 +1,58 @@
+<?php
+
+require_once dirname(__DIR__) . '/lib/ACFComposer/Layout.php';
+
+use ACFComposer\TestCase;
+use ACFComposer\Layout;
+use Brain\Monkey\WP\Filters;
+
+class LayoutTest extends TestCase {
+  function testAssignsValidConfig() {
+    $config = [
+      'name' => 'someLayout',
+      'label' => 'Some Layout'
+    ];
+    $layout = new Layout($config);
+    $this->assertEquals($config, $layout->config);
+  }
+
+  function testFailsWithoutName() {
+    $config = [
+      'label' => 'Some Layout'
+    ];
+    $this->expectException(Exception::class);
+    new Layout($config);
+  }
+
+  function testFailsWithoutLabel() {
+    $config = [
+      'name' => 'someLayout'
+    ];
+    $this->expectException(Exception::class);
+    new Layout($config);
+  }
+
+  function testFailsWithKey() {
+    $config = [
+      'name' => 'someLayout',
+      'label' => 'Some Layout',
+      'key' => 'someKey'
+    ];
+    $this->expectException(Exception::class);
+    new Layout($config);
+  }
+
+  function testGetConfigFromFilter() {
+    $config = 'ACFComposer/Layouts/someLayout';
+    $someLayout = [
+      'name' => 'someLayout',
+      'label' => 'Some Layout',
+      'type' => 'someType'
+    ];
+    Filters::expectApplied($config)
+    ->once()
+    ->andReturn($someLayout);
+    $layout = new Layout($config);
+    $this->assertEquals($someLayout, $layout->config);
+  }
+}