Dependency types are not hard-coded literals

Previously we hard-coded the list of dependency types wherever
we needed to use them. In order to manage language packs within
Whippet, we now need to add to the list of dependency types.
So, rather than have them scattered over the code, we now have
them in one place.

Once we have dropped PHP 7.4 support, we should really use an
enumeration here.

Fixes #70

spec/dependencies/dependency_types.spec.php

@@ -0,0 +1,9 @@
+<?php
+
+describe(\Dxw\Whippet\Dependencies\DependencyTypes::class, function () {
+	context("getDependencyTypes()", function () {
+		it('returns a list of dependencies as strings', function () {
+			expect(\Dxw\Whippet\Dependencies\DependencyTypes::getDependencyTypes())->toBe(['themes', 'plugins']);
+		});
+	});
+});

src/Dependencies/DependencyTypes.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Dxw\Whippet\Dependencies;
+
+class DependencyTypes
+{
+	public const PLUGINS = 'plugins';
+	public const THEMES = 'themes';
+
+
+	public static function getDependencyTypes()
+	{
+
+		return [DependencyTypes::THEMES, DependencyTypes::PLUGINS];
+	}
+}

src/Dependencies/Describer.php

@@ -22,10 +22,9 @@ public function describe()
 		if ($resultLoad->isErr()) {
 			return $resultLoad;
 		}
-		$dependencyTypes = ['themes', 'plugins'];
 		$git = new \Dxw\Whippet\Git\Git($this->dir);
 		$results = [];
-		foreach ($dependencyTypes as $type) {
+		foreach (DependencyTypes::getDependencyTypes() as $type) {
 			foreach ($this->lockFile->getDependencies($type) as $dep) {
 				$result = $git::tag_for_commit($dep['src'], $dep['revision']);
 				if ($result->isErr()) {

src/Dependencies/Installer.php

@@ -28,7 +28,7 @@ public function installAll()
 
 		$dependencies = [];
 
-		foreach (['themes', 'plugins'] as $type) {
+		foreach (DependencyTypes::getDependencyTypes() as $type) {
 			$dependencies[$type] = $this->lockFile->getDependencies($type);
 		}
 

src/Dependencies/Updater.php

@@ -57,7 +57,7 @@ public function updateAll()
 
 		$allDependencies = [];
 
-		foreach (['themes', 'plugins'] as $type) {
+		foreach (DependencyTypes::getDependencyTypes() as $type) {
 			$allDependencies[$type] = $this->jsonFile->getDependencies($type);
 		}
 
@@ -133,7 +133,7 @@ private function updateHash()
 
 	private function createGitIgnore()
 	{
-		foreach (['themes', 'plugins'] as $type) {
+		foreach (DependencyTypes::getDependencyTypes() as $type) {
 			foreach ($this->jsonFile->getDependencies($type) as $dep) {
 				$this->addDependencyToIgnoresArray($type, $dep['name']);
 			}
@@ -151,7 +151,7 @@ private function loadGitignore()
 		}
 
 		// Iterate through locked dependencies and remove from gitignore
-		foreach (['themes', 'plugins'] as $type) {
+		foreach (DependencyTypes::getDependencyTypes() as $type) {
 			foreach ($this->lockFile->getDependencies($type) as $dep) {
 				$line = $this->getGitignoreDependencyLine($type, $dep['name']);
 				$index = array_search($line, $this->ignores);

src/Dependencies/Validator.php

@@ -46,7 +46,7 @@ public function validate()
 
 		// Check that entries in whippet.json
 		// match entries in whippet.lock
-		foreach (['themes', 'plugins'] as $type) {
+		foreach (DependencyTypes::getDependencyTypes() as $type) {
 			$whippetJsonDependencies = $whippetJson->getDependencies($type);
 			$whippetLockDependencies = $whippetLock->getDependencies($type);
 			if (count($whippetJsonDependencies) !== count($whippetLockDependencies)) {