Instead of throwing an exception, we instead load out handler script …

…'script_not_found.php' to correctly write a message to STDERR and throw an exit code of 127 (command not found). This works around PHP Bug https://bugs.php.net/bug.php?id=64882 whereby the 'Could not open input file' error message goes to STDOUT which triggers an exception in the STDIN stream handler

bin/script_not_found.php

@@ -0,0 +1,4 @@
+<?php declare(strict_types=1);
+
+fprintf(STDERR, 'Unable to run PHP script. Script not found');
+exit(127);

src/functions.php

@@ -24,6 +24,7 @@
 use function function_exists;
 use function fwrite;
 use function json_encode;
+use function realpath;
 use function register_shutdown_function;
 use function set_exception_handler;
 use const PHP_BINARY;
@@ -92,7 +93,7 @@ function checkpoint($checkpoint)
     function php_cmd(string $filename): string
     {
         if (!file_exists($filename)) {
-            throw new ScriptNotFound("$filename not found");
+            $filename = realpath(__DIR__ . '/../bin/script_not_found.php');
         }
         return escapeshellarg(PHP_BINARY) . " -f " . escapeshellarg($filename) . " --";
     }
@@ -102,9 +103,9 @@ function php_cmd(string $filename): string
     function wrap_source_php_cmd(string $filename): string
     {
         if (!file_exists($filename)) {
-            throw new ScriptNotFound("$filename not found");
+            $filename = realpath(__DIR__ . '/../bin/script_not_found.php');
         }
-        $prepend_file = __DIR__ . '/../bin/source_prepend.php';
+        $prepend_file = realpath(__DIR__ . '/../bin/source_prepend.php');
         return escapeshellarg(PHP_BINARY) . " -d auto_prepend_file=" . escapeshellarg($prepend_file) . " -f " . escapeshellarg($filename) . " --";
     }
 }

tests/process_failure.php

@@ -0,0 +1,30 @@
+<?php declare(strict_types=1);
+
+use function EdgeTelemetrics\EventCorrelation\php_cmd;
+use function EdgeTelemetrics\EventCorrelation\wrap_source_php_cmd;
+
+include __DIR__ . '/../vendor/autoload.php';
+
+$ping = new React\ChildProcess\Process(php_cmd('unknownfile.php'));
+$ping->start();
+
+$ping->on('exit', function($code, $term) {
+    if ($code === 127) {
+        echo "Command not found. Test Pass" . PHP_EOL;
+    }
+    if ($code !== 0) {
+        echo "Process Failure code $code" . PHP_EOL;
+    }
+});
+
+$ping->stderr->on('data', function ($chunk) {
+    error_log('stderr: '. $chunk);
+});
+
+$ping->stdout->on('data', function ($chunk) {
+    error_log('stdout:' . $chunk);
+});
+
+React\EventLoop\Loop::get()->run();
+
+echo "Process Failure Test Completed" . PHP_EOL;