Add Environment::local()

Author: thekid

src/main/php/com/amazon/aws/lambda/Environment.class.php

@@ -38,6 +38,11 @@ public function tempDir(): Path {
     return new Path(sys_get_temp_dir());
   }
 
+  /** Returns whether this is a local invocation */
+  public function local(): bool {
+    return isset($this->variables['AWS_LOCAL']);
+  }
+
   /**
    * Returns a given environment variable
    *

src/test/php/com/amazon/aws/lambda/unittest/EnvironmentTest.class.php

@@ -46,6 +46,16 @@ public function non_existant_variable() {
     Assert::null((new Environment('.', null, []))->variable('TEST'));
   }
 
+  #[Test]
+  public function not_local_by_default() {
+    Assert::false((new Environment('.', null, []))->local());
+  }
+
+  #[Test]
+  public function local() {
+    Assert::true((new Environment('.', null, ['AWS_LOCAL' => true]))->local());
+  }
+
   #[Test]
   public function credentials() {
     $env= [