From 8ec002633b742f27af81cf49f988f41d3e42f354 Mon Sep 17 00:00:00 2001
From: Aaron Piotrowski <aaron@trowski.com>
Date: Sun, 14 Oct 2018 23:24:35 -0500
Subject: [PATCH] Return promise from Process::start(); int from
 Process::getPid()

---
 lib/Process.php      | 25 +++++++++++++++++--------
 test/ProcessTest.php | 16 +++++-----------
 2 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/lib/Process.php b/lib/Process.php
index 2e7a8cd..a3cade8 100644
--- a/lib/Process.php
+++ b/lib/Process.php
@@ -9,6 +9,7 @@ use Amp\Process\Internal\ProcessRunner;
 use Amp\Process\Internal\ProcessStatus;
 use Amp\Process\Internal\Windows\Runner as WindowsProcessRunner;
 use Amp\Promise;
+use function Amp\call;
 
 class Process
 {
@@ -30,6 +31,9 @@ class Process
     /** @var ProcessHandle */
     private $handle;
 
+    /** @var int|null */
+    private $pid;
+
     /**
      * @param   string|string[] $command Command to run.
      * @param   string|null     $cwd Working directory or use an empty string to use the working directory of the
@@ -90,15 +94,20 @@ class Process
     /**
      * Start the process.
      *
+     * @return Promise<int> Resolves with the PID.
+     *
      * @throws StatusError If the process has already been started.
      */
-    public function start()
+    public function start(): Promise
     {
         if ($this->handle) {
             throw new StatusError("Process has already been started.");
         }
 
-        $this->handle = $this->processRunner->start($this->command, $this->cwd, $this->env, $this->options);
+        return call(function () {
+            $this->handle = $this->processRunner->start($this->command, $this->cwd, $this->env, $this->options);
+            return $this->pid = yield $this->handle->pidDeferred->promise();
+        });
     }
 
     /**
@@ -152,17 +161,17 @@ class Process
     /**
      * Returns the PID of the child process.
      *
-     * @return Promise<int>
+     * @return int
      *
-     * @throws StatusError If the process has not started.
+     * @throws StatusError If the process has not started or has not completed starting.
      */
-    public function getPid(): Promise
+    public function getPid(): int
     {
-        if (!$this->handle) {
-            throw new StatusError("Process has not been started.");
+        if (!$this->pid) {
+            throw new StatusError("Process has not been started or has not completed starting.");
         }
 
-        return $this->handle->pidDeferred->promise();
+        return $this->pid;
     }
 
     /**
diff --git a/test/ProcessTest.php b/test/ProcessTest.php
index 4f757a1..3dbc2f7 100644
--- a/test/ProcessTest.php
+++ b/test/ProcessTest.php
@@ -8,7 +8,6 @@ use Amp\Loop;
 use Amp\Process\Process;
 use Amp\Process\ProcessInputStream;
 use Amp\Process\ProcessOutputStream;
-use Amp\Promise;
 use PHPUnit\Framework\TestCase;
 
 class ProcessTest extends TestCase
@@ -60,9 +59,7 @@ class ProcessTest extends TestCase
     {
         Loop::run(function () {
             $process = new Process(self::CMD_PROCESS);
-            $process->start();
-
-            $this->assertInternalType('int', yield $process->getPid());
+            $this->assertInternalType('int', yield $process->start());
             $this->assertSame(0, yield $process->join());
         });
     }
@@ -75,9 +72,8 @@ class ProcessTest extends TestCase
 
         Loop::run(function () {
             $process = new Process(self::CMD_PROCESS_SLOW);
-            $process->start();
+            yield $process->start();
             $process->signal(0);
-            $this->assertInstanceOf(Promise::class, $process->getPid());
             $this->assertSame(0, yield $process->join());
         });
     }
@@ -249,14 +245,12 @@ class ProcessTest extends TestCase
 
     /**
      * @expectedException \Amp\Process\StatusError
-     * @expectedExceptionMessage Process has not been started.
+     * @expectedExceptionMessage Process has not been started or has not completed starting.
      */
     public function testProcessHasNotBeenStartedWithGetPid()
     {
-        Loop::run(function () {
-            $process = new Process(self::CMD_PROCESS);
-            yield $process->getPid();
-        });
+        $process = new Process(self::CMD_PROCESS);
+        $process->getPid();
     }
 
     /**