Add method to run basic request diagnostics

README.md

@@ -203,6 +203,7 @@ Curl::call()
 Curl::close()
 Curl::complete($callback)
 Curl::delete($url, $query_parameters = [], $data = [])
+Curl::diagnose()
 Curl::disableTimeout()
 Curl::download($url, $mixed_filename)
 Curl::error($callback)

TROUBLESHOOTING.md

@@ -1,5 +1,13 @@
 # Troubleshooting
 
+### Debug using the diagnose method
+
+```php
+$curl = new Curl();
+$curl->get('https://www.example.com/');
+$curl->diagnose(); // <-- HERE
+```
+
 ### Debug the entire curl instance
 
 ```php

src/Curl/Curl.php

@@ -1432,6 +1432,89 @@ class Curl
         $this->setOpt(CURLOPT_STDERR, $output);
     }
 
+    /**
+     * Diagnose
+     *
+     * @access public
+     */
+    public function diagnose()
+    {
+        echo "\n";
+        echo '--- Begin PHP Curl Class diagnostic output ---' . "\n";
+        echo 'PHP Curl Class version: ' . self::VERSION . "\n";
+        echo 'PHP version: ' . PHP_VERSION . "\n";
+
+        $curl_version = curl_version();
+        echo 'Curl version: ' . $curl_version['version'] . "\n";
+
+        if ($this->attempts === 0) {
+            echo 'No HTTP requests have been made.' . "\n";
+        } else {
+            $request_method = $this->getOpt(CURLOPT_CUSTOMREQUEST);
+            $request_url = $this->getOpt(CURLOPT_URL);
+            $request_headers_count = count($this->requestHeaders);
+            $request_body_empty = empty($this->getOpt(CURLOPT_POSTFIELDS));
+            $response_length = isset($this->responseHeaders['Content-Length']) ?
+                $this->responseHeaders['Content-Length'] : '(not specified in response)';
+            $response_headers_count = count($this->responseHeaders);
+
+            echo
+                'Sent an HTTP '   . $request_method . ' request to "' . $request_url . '".' . "\n" .
+                'Request contained ' . (
+                    $request_headers_count === 1 ? 'no headers.' :
+                    $request_headers_count . ' headers:'
+                ) . "\n";
+            if ($this->requestHeaders !== null) {
+                $i = 1;
+                foreach ($this->requestHeaders as $key => $value) {
+                    echo '    ' . $i . ' ' . $key . ': ' . $value . "\n";
+                    $i += 1;
+                }
+            }
+
+            echo 'Request contained ' . ($request_body_empty ? 'no body' : 'a body') . '.' . "\n";
+
+            echo
+                'Received response containing ' . (
+                    $response_headers_count === 1 ? 'no headers.' :
+                    $response_headers_count . ' headers:'
+                ) . "\n";
+            if ($this->responseHeaders !== null) {
+                $i = 1;
+                foreach ($this->responseHeaders as $key => $value) {
+                    echo '    ' . $i . ' ' . $key . ': ' . $value . "\n";
+                    $i += 1;
+                }
+            }
+
+            if ($this->curlError) {
+                echo
+                    'A curl error (' . $this->curlErrorCode . ') occurred ' .
+                    'with message "' . $this->curlErrorMessage . '".' . "\n";
+            }
+            if (!empty($this->httpStatusCode)) {
+                echo 'Received an HTTP status code of ' . $this->httpStatusCode . '.' . "\n";
+            }
+            if ($this->httpError) {
+                echo
+                    'Received an HTTP ' . $this->httpStatusCode . ' error response ' .
+                    'with message "' . $this->httpErrorMessage . '".' . "\n";
+            }
+
+            if ($this->response === null) {
+                echo 'Received no response body.' . "\n";
+            } elseif ($this->response === '') {
+                echo 'Received an empty response body.' . "\n";
+            } else {
+                echo 'Received a non-empty response body.' . "\n";
+                echo 'Response content length: ' . $response_length . "\n";
+            }
+        }
+
+        echo '--- End PHP Curl Class diagnostic output ---' . "\n";
+        echo "\n";
+    }
+
     /**
      * Reset
      *

tests/PHPCurlClass/PHPCurlClassTest.php

@@ -4027,4 +4027,28 @@ class CurlTest extends \PHPUnit\Framework\TestCase
         $curl->setMaximumRedirects(3);
         $this->assertEquals(3, $curl->getOpt(CURLOPT_MAXREDIRS));
     }
+
+    public function testDiagnose()
+    {
+        $test = new Test();
+        $test->server('error_message', 'GET');
+
+        ob_start();
+        $test->curl->diagnose();
+        $output = ob_get_contents();
+        ob_end_clean();
+
+        $this->assertStringContainsString('--- Begin PHP Curl Class diagnostic output ---', $output);
+        $this->assertStringContainsString('PHP Curl Class version: ' . Curl::VERSION, $output);
+        $this->assertStringContainsString('PHP version: ' . PHP_VERSION, $output);
+        $this->assertStringContainsString('Sent an HTTP GET request ', $output);
+        $this->assertStringContainsString('Request contained no body.', $output);
+        $this->assertStringContainsString('Received an HTTP status code of 401.', $output);
+        $this->assertStringContainsString(
+            'Received an HTTP 401 error response with message "HTTP/1.1 401 Unauthorized".',
+            $output
+        );
+        $this->assertStringContainsString('Received an empty response body.', $output);
+        $this->assertStringContainsString('--- End PHP Curl Class diagnostic output ---', $output);
+    }
 }