diff --git a/ChangeLog.md b/ChangeLog.md
index 7e701fd..6c8d939 100755
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -3,6 +3,15 @@ JSON for the XP Framework ChangeLog
 
 ## ?.?.? / ????-??-??
 
+## 4.1.0 / 2021-04-18
+
+* Fixed up file-based input and output tests to clean up temporary files
+  they create as their fixture
+  (@thekid)
+* Made all of `text.json.Format`, `text.json.Input` and `text.json.Output`
+  implement `lang.Value` and provide string representations
+  (@thekid)
+
 ## 4.0.1 / 2020-12-27
 
 * Fixed warnings from *iconv* library on Un\*x systems - @thekid
diff --git a/src/main/php/text/json/FileInput.class.php b/src/main/php/text/json/FileInput.class.php
index 4efcdd8..7023bc1 100755
--- a/src/main/php/text/json/FileInput.class.php
+++ b/src/main/php/text/json/FileInput.class.php
@@ -54,4 +54,9 @@ public function close() {
 
   /** @return io.File */
   public function file() { return $this->file; }
+
+  /** @return string */
+  public function toString() {
+    return nameof($this).'(file= '.$this->file->toString().', encoding= '.$this->encoding.')';
+  }
 }
\ No newline at end of file
diff --git a/src/main/php/text/json/FileOutput.class.php b/src/main/php/text/json/FileOutput.class.php
index 29189a5..f3c73f7 100755
--- a/src/main/php/text/json/FileOutput.class.php
+++ b/src/main/php/text/json/FileOutput.class.php
@@ -52,4 +52,9 @@ public function close() {
 
   /** @return io.File */
   public function file() { return $this->file; }
+
+  /** @return string */
+  public function toString() {
+    return nameof($this).'(file= '.$this->file->toString().', format= '.$this->format->toString().')';
+  }
 }
\ No newline at end of file
diff --git a/src/main/php/text/json/Format.class.php b/src/main/php/text/json/Format.class.php
index 7163391..46887b6 100755
--- a/src/main/php/text/json/Format.class.php
+++ b/src/main/php/text/json/Format.class.php
@@ -1,13 +1,13 @@
 <?php namespace text\json;
 
-use lang\IllegalArgumentException;
+use lang\{IllegalArgumentException, Value};
 
 /**
  * JSON format
  *
  * @test  xp://text.json.unittest.FormatFactoryTest
  */
-abstract class Format {
+abstract class Format implements Value {
   const ESCAPE_SLASHES = -65;  // ~JSON_UNESCAPED_SLASHES
   const ESCAPE_UNICODE = -257; // ~JSON_UNESCAPED_UNICODE
   const ESCAPE_ENTITIES = 11;  // JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_QUOT
@@ -130,4 +130,20 @@ public function representationOf($value) {
       throw new IllegalArgumentException('Cannot represent instances of '.typeof($value));
     }
   }
+
+  /** @return string */
+  public function toString() { return nameof($this); }
+
+  /** @return string */
+  public function hashCode() { return spl_object_id($this); }
+
+  /**
+   * Comparison
+   *
+   * @param  var $value
+   * @return int
+   */
+  public function compareTo($value) {
+    return $value === $this ? 0 : 1;
+  }
 }
\ No newline at end of file
diff --git a/src/main/php/text/json/Input.class.php b/src/main/php/text/json/Input.class.php
index 2f3b4a0..c5b59ed 100755
--- a/src/main/php/text/json/Input.class.php
+++ b/src/main/php/text/json/Input.class.php
@@ -1,6 +1,6 @@
 <?php namespace text\json;
 
-use lang\FormatException;
+use lang\{FormatException, Value};
 use util\Objects;
 
 /**
@@ -9,7 +9,7 @@
  * @see  xp://text.json.JsonString
  * @see  xp://text.json.JsonStream
  */
-abstract class Input {
+abstract class Input implements Value {
   protected $bytes;
   protected $len;
   protected $pos;
@@ -284,6 +284,22 @@ public function close() {
     // Does nothing
   }
 
+  /** @return string */
+  public function toString() { return nameof($this).'(encoding= '.$this->encoding.')'; }
+
+  /** @return string */
+  public function hashCode() { return spl_object_id($this); }
+
+  /**
+   * Comparison
+   *
+   * @param  var $value
+   * @return int
+   */
+  public function compareTo($value) {
+    return $value === $this ? 0 : 1;
+  }
+
   /** @return void */
   public function __destruct() {
     $this->close();
diff --git a/src/main/php/text/json/Output.class.php b/src/main/php/text/json/Output.class.php
index e60092f..a706376 100755
--- a/src/main/php/text/json/Output.class.php
+++ b/src/main/php/text/json/Output.class.php
@@ -1,8 +1,8 @@
 <?php namespace text\json;
 
-use lang\IllegalArgumentException;
+use lang\{IllegalArgumentException, Value};
 
-abstract class Output {
+abstract class Output implements Value {
   public $format;
 
   /**
@@ -79,6 +79,22 @@ public function close() {
     // Does nothing
   }
 
+  /** @return string */
+  public function toString() { return nameof($this).'(format= '.$this->format->toString().')'; }
+
+  /** @return string */
+  public function hashCode() { return spl_object_id($this); }
+
+  /**
+   * Comparison
+   *
+   * @param  var $value
+   * @return int
+   */
+  public function compareTo($value) {
+    return $value === $this ? 0 : 1;
+  }
+
   /** @return void */
   public function __destruct() {
     $this->close();
diff --git a/src/main/php/text/json/StreamInput.class.php b/src/main/php/text/json/StreamInput.class.php
index fe64ac6..25329f6 100755
--- a/src/main/php/text/json/StreamInput.class.php
+++ b/src/main/php/text/json/StreamInput.class.php
@@ -173,6 +173,11 @@ public function nextToken() {
     return null;
   }
 
+  /** @return string */
+  public function toString() {
+    return nameof($this).'(stream= '.$this->in->toString().', encoding= '.$this->encoding.')';
+  }
+
   /** @return void */
   public function close() { $this->in->close(); }
 }
\ No newline at end of file
diff --git a/src/main/php/text/json/StreamOutput.class.php b/src/main/php/text/json/StreamOutput.class.php
index c85c2de..74b2993 100755
--- a/src/main/php/text/json/StreamOutput.class.php
+++ b/src/main/php/text/json/StreamOutput.class.php
@@ -36,6 +36,11 @@ public function appendToken($bytes) {
     $this->stream->write($bytes);
   }
 
+  /** @return string */
+  public function toString() {
+    return nameof($this).'(stream= '.$this->stream->toString().', format= '.$this->format->toString().')';
+  }
+
   /** @return void */
   public function close() { $this->stream->close(); }
 
diff --git a/src/test/php/text/json/unittest/FileInputTest.class.php b/src/test/php/text/json/unittest/FileInputTest.class.php
index 2781036..29b4702 100755
--- a/src/test/php/text/json/unittest/FileInputTest.class.php
+++ b/src/test/php/text/json/unittest/FileInputTest.class.php
@@ -9,10 +9,18 @@
  * Tests the FileInput implementation
  */
 class FileInputTest extends JsonInputTest {
+  private $created= [];
 
   /** @param io.Path */
   private function tempName() {
-    return Path::compose([Environment::tempDir(), md5(uniqid()).'-xp.json']);
+    return $this->created[]= Path::compose([Environment::tempDir(), md5(uniqid()).'-xp.json']);
+  }
+
+  /** @return void */
+  public function tearDown() {
+    foreach ($this->created as $path) {
+      $path->exists() && $path->asFile()->unlink();
+    }
   }
 
   /**
@@ -97,4 +105,13 @@ public function is_reopened_when_reset() {
     $input->reset();
     $this->assertTrue($file->isOpen());
   }
+
+  #[Test]
+  public function string_representation() {
+    $file= $this->fileWith('{}', File::REWRITE);
+    $this->assertEquals(
+      'text.json.FileInput(file= '.$file->toString().', encoding= utf-8)',
+      (new FileInput($file))->toString()
+    );
+  }
 }
\ No newline at end of file
diff --git a/src/test/php/text/json/unittest/FileOutputTest.class.php b/src/test/php/text/json/unittest/FileOutputTest.class.php
index 5eb179b..64d1b00 100755
--- a/src/test/php/text/json/unittest/FileOutputTest.class.php
+++ b/src/test/php/text/json/unittest/FileOutputTest.class.php
@@ -3,13 +3,21 @@
 use io\{File, Path};
 use lang\Environment;
 use text\json\{FileOutput, Types};
-use unittest\Test;
+use unittest\{Test, AfterClass};
 
 class FileOutputTest extends JsonOutputTest {
+  private $created= [];
 
   /** @param io.Path */
   private function tempName() {
-    return Path::compose([Environment::tempDir(), md5(uniqid()).'-xp.json']);
+    return $this->created[]= Path::compose([Environment::tempDir(), md5(uniqid()).'-xp.json']);
+  }
+
+  /** @return void */
+  public function tearDown() {
+    foreach ($this->created as $path) {
+      $path->exists() && $path->asFile()->unlink();
+    }
   }
 
   /** @return text.json.Output */
@@ -72,4 +80,13 @@ public function open_files_are_not_closed() {
     (new FileOutput($file))->write('test');
     $this->assertTrue($file->isOpen());
   }
+
+  #[Test]
+  public function string_representation() {
+    $output= $this->output();
+    $this->assertEquals(
+      'text.json.FileOutput(file= '.$output->file()->toString().', format= text.json.DenseFormat)',
+      $output->toString()
+    );
+  }
 }
\ No newline at end of file
diff --git a/src/test/php/text/json/unittest/StreamInputTest.class.php b/src/test/php/text/json/unittest/StreamInputTest.class.php
index 318dca5..cf1a4f5 100755
--- a/src/test/php/text/json/unittest/StreamInputTest.class.php
+++ b/src/test/php/text/json/unittest/StreamInputTest.class.php
@@ -86,4 +86,12 @@ public function cannot_reset_unseekable() {
       // OK
     }
   }
+
+  #[Test]
+  public function string_representation() {
+    $this->assertEquals(
+      'text.json.StreamInput(stream= io.streams.MemoryInputStream(@2 of 2 bytes), encoding= utf-8)',
+      $this->input('{}')->toString()
+    );
+  }
 }
\ No newline at end of file
diff --git a/src/test/php/text/json/unittest/StreamOutputTest.class.php b/src/test/php/text/json/unittest/StreamOutputTest.class.php
index 18945bd..bfda900 100755
--- a/src/test/php/text/json/unittest/StreamOutputTest.class.php
+++ b/src/test/php/text/json/unittest/StreamOutputTest.class.php
@@ -17,4 +17,12 @@ protected function output() { return new StreamOutput(new MemoryOutputStream());
   protected function result($out) {
     return $out->stream()->getBytes();
   }
+
+  #[Test]
+  public function string_representation() {
+    $this->assertEquals(
+      'text.json.StreamOutput(stream= io.streams.MemoryOutputStream(@0 of 0 bytes), format= text.json.DenseFormat)',
+      $this->output()->toString()
+    );
+  }
 }
\ No newline at end of file