Add Deferred::isResolved() and StreamSource::isComplete()

lib/Deferred.php

@@ -23,6 +23,7 @@ final class Deferred
             use Internal\Placeholder {
                 resolve as public;
                 fail as public;
+                isResolved as public;
             }
         };
 
@@ -37,6 +38,14 @@ final class Deferred
         return $this->promise;
     }
 
+    /**
+     * @return bool True if the contained promise has been resolved.
+     */
+    public function isResolved(): bool
+    {
+        return $this->resolver->isResolved();
+    }
+
     /**
      * Fulfill the promise with the given value.
      *

lib/Internal/EmitSource.php

@@ -218,6 +218,14 @@ final class EmitSource
         return $deferred->promise();
     }
 
+    /**
+     * @return bool True if the stream has been completed or failed.
+     */
+    public function isComplete(): bool
+    {
+        return $this->completed;
+    }
+
     /**
      * Completes the stream.
      **

lib/Internal/Placeholder.php

@@ -89,6 +89,11 @@ trait Placeholder
         }
     }
 
+    private function isResolved(): bool
+    {
+        return $this->resolved;
+    }
+
     /**
      * @param mixed $value
      *

lib/Stream.php

@@ -10,7 +10,7 @@ namespace Amp;
 interface Stream
 {
     /**
-     * Succeeds with the yielded value if the stream has yielded a value or null if the stream has completed.
+     * Succeeds with the emitted value if the stream has emitted a value or null if the stream has completed.
      * If the stream fails, the returned promise will fail with the same exception.
      *
      * @return Promise<mixed|null> Resolves with null if the stream has completed.

lib/StreamSource.php

@@ -48,6 +48,14 @@ final class StreamSource
         return $this->source->emit($value);
     }
 
+    /**
+     * @return bool True if the stream has been completed or failed.
+     */
+    public function isComplete(): bool
+    {
+        return $this->source->isComplete();
+    }
+
     /**
      * Completes the stream.
      *

test/DeferredTest.php

@@ -29,6 +29,8 @@ class DeferredTest extends BaseTest
         $value = "Resolution value";
         $promise = $this->deferred->promise();
 
+        $this->assertFalse($this->deferred->isResolved());
+
         $invoked = false;
         $promise->onResolve(function ($exception, $value) use (&$invoked, &$result) {
             $invoked = true;
@@ -37,6 +39,7 @@ class DeferredTest extends BaseTest
 
         $this->deferred->resolve($value);
 
+        $this->assertTrue($this->deferred->isResolved());
         $this->assertTrue($invoked);
         $this->assertSame($value, $result);
     }

test/StreamSourceTest.php

@@ -3,20 +3,20 @@
 namespace Amp\Test;
 
 use Amp\DisposedException;
-use Amp\Internal\EmitSource;
 use Amp\PHPUnit\AsyncTestCase;
 use Amp\Promise;
+use Amp\StreamSource;
 use Amp\Success;
 
-class EmitSourceTest extends AsyncTestCase
+class StreamSourceTest extends AsyncTestCase
 {
-    /** @var EmitSource */
+    /** @var StreamSource */
     private $source;
 
     public function setUp()
     {
         parent::setUp();
-        $this->source = new EmitSource;
+        $this->source = new StreamSource;
     }
 
     public function testEmit()
@@ -33,11 +33,30 @@ class EmitSourceTest extends AsyncTestCase
         $this->assertInstanceOf(Promise::class, $promise);
         $this->assertNull(yield $promise);
 
+        $this->assertFalse($this->source->isComplete());
+
         $this->source->complete();
 
+        $this->assertTrue($this->source->isComplete());
+
         $this->assertNull(yield $continue);
     }
 
+    public function testFail()
+    {
+        $this->assertFalse($this->source->isComplete());
+        $this->source->fail($exception = new \Exception);
+        $this->assertTrue($this->source->isComplete());
+
+        $stream = $this->source->stream();
+
+        try {
+            yield $stream->continue();
+        } catch (\Exception $caught) {
+            $this->assertSame($exception, $caught);
+        }
+    }
+
     /**
      * @depends testEmit
      */
@@ -53,7 +72,7 @@ class EmitSourceTest extends AsyncTestCase
     /**
      * @depends testEmit
      */
-    public function testEmitingNull()
+    public function testEmittingNull()
     {
         $this->expectException(\TypeError::class);
         $this->expectExceptionMessage('Streams cannot emit NULL');
@@ -64,7 +83,7 @@ class EmitSourceTest extends AsyncTestCase
     /**
      * @depends testEmit
      */
-    public function testEmitingPromise()
+    public function testEmittingPromise()
     {
         $this->expectException(\TypeError::class);
         $this->expectExceptionMessage('Streams cannot emit promises');