tests: add main give test for verifying versions between plugin heade…

…r and readme header

tests/Unit/TestGive.php

@@ -0,0 +1,64 @@
+<?php
+
+namespace Give\Tests\Unit;
+
+use Give\Tests\TestCase;
+
+/**
+ * @unreleased
+ */
+class TestGive extends TestCase
+{
+    /**
+     * @unreleased
+     */
+    public function testReadMeVersionMatchesPluginVersion(): void
+    {
+        $readme = get_file_data(
+            trailingslashit(GIVE_PLUGIN_DIR) . "readme.txt",
+            [
+                "Version" => "Stable tag"
+            ]
+        );
+
+        $plugin = get_plugin_data(GIVE_PLUGIN_FILE);
+
+        $this->assertEquals(GIVE_VERSION, $readme['Version']);
+        $this->assertEquals(GIVE_VERSION, $plugin['Version']);
+        $this->assertEquals($readme['Version'], $plugin['Version']);
+    }
+
+    /**
+     * @unreleased
+     */
+    public function testReadMeRequiresPHPVersionMatchesPluginVersion(): void
+    {
+        $readme = get_file_data(
+            trailingslashit(GIVE_PLUGIN_DIR) . "readme.txt",
+            [
+                "RequiresPHP" => "Requires PHP"
+            ]
+        );
+
+        $plugin = get_plugin_data(GIVE_PLUGIN_FILE);
+
+        $this->assertEquals($plugin['RequiresPHP'], $readme['RequiresPHP']);
+    }
+
+    /**
+     * @unreleased
+     */
+    public function testReadMeRequiresWPVersionMatchesPluginHeaderVersion(): void
+    {
+        $readme = get_file_data(
+            trailingslashit(GIVE_PLUGIN_DIR) . "readme.txt",
+            [
+                "RequiresWP" => "Requires at least"
+            ]
+        );
+
+        $plugin = get_plugin_data(GIVE_PLUGIN_FILE);
+
+        $this->assertEquals($plugin['RequiresWP'], $readme['RequiresWP']);
+    }
+}