Add tempDir() accessor

Author: thekid

ChangeLog.md

@@ -5,6 +5,8 @@ AWS Lambda change log
 
 ## 1.1.0 / 2021-08-28
 
+* Added accessor for temporary directory, `Environment::tempDir()`
+  (@thekid)
 * Added accessor for environment root path, `Environment::taskroot()`
   (@thekid)
 

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

@@ -27,6 +27,14 @@ public function taskroot(): Path { return new Path($this->root); }
   /** Returns a path inside this environment's root path */
   public function path(string $path): Path { return new Path($this->root, $path); }
 
+  /** Returns temporary directory */
+  public function tempDir(): Path {
+    foreach (['TEMP', 'TMP', 'TMPDIR', 'TEMPDIR'] as $variant) {
+      if (isset($_ENV[$variant])) return new Path($_ENV[$variant]);
+    }
+    return new Path(sys_get_temp_dir());
+  }
+
   /**
    * Writes a trace message
    *

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

@@ -25,6 +25,11 @@ public function path() {
     Assert::equals(new Path('./etc'), (new Environment('.'))->path('etc'));
   }
 
+  #[Test]
+  public function tempDir() {
+    Assert::instance(Path::class, (new Environment('.'))->tempDir());
+  }
+
   #[Test]
   public function trace() {
     $stream= new MemoryOutputStream();