Issue #140, #246: Improved exception handling and added PHPUnit test

src/PhpImap/ConnectionException.php

@@ -0,0 +1,8 @@
+<?php
+namespace PhpImap\Exceptions;
+
+/**
+ * @see https://github.com/barbushin/php-imap
+ * @author Barbushin Sergey http://linkedin.com/in/barbushin
+ */
+class ConnectionException extends Exception {}

src/PhpImap/Mailbox.php

@@ -1,6 +1,9 @@
-<?php namespace PhpImap;
+<?php
+namespace PhpImap;
 
 use stdClass;
+use Exception;
+use PhpImap\Exceptions\ConnectionException;
 
 /**
  * @see https://github.com/barbushin/php-imap
@@ -789,8 +792,13 @@ protected function initMailPart(IncomingMail $mail, $partStructure, $partNum, $m
 	 * @param string $string
 	 * @param string $toEncoding
 	 * @return string Converted string if conversion was successful, or the original string if not
+	 * @throws Exception
 	 */
 	public function decodeMimeStr($string, $toCharset = 'utf-8') {
+		if(empty(trim($string))) {
+			throw new Exception('decodeMimeStr() Can not decode an empty string!');
+		}
+
 		$newString = '';
 		foreach(imap_mime_header_decode($string) as $element) {
 			if(isset($element->text)) {
@@ -988,11 +996,3 @@ public function imap($methodShortName, $args = [], $prependConnectionAsFirstArg
 		return $result;
 	}
 }
-
-class Exception extends \Exception {
-
-}
-
-class ConnectionException extends Exception {
-
-}

tests/unit/MailboxTest.php

@@ -6,8 +6,8 @@
 * @author    Sebastian Kraetzig <sebastian-kraetzig@gmx.de>
 */
 
-use DateTime;
 use PhpImap\Mailbox;
+use PhpImap\Exceptions\ConnectionException;
 use PHPUnit\Framework\TestCase;
 
 final class MailboxTest extends TestCase
@@ -340,13 +340,19 @@ public function testMimeEncoding() {
 			'=?iso-8859-1?Q?Sebastian_Kr=E4tzig?=' => 'Sebastian Krätzig',
 			'sebastian.kraetzig' => 'sebastian.kraetzig',
 			'=?US-ASCII?Q?Keith_Moore?= <km@ab.example.edu>' => 'Keith Moore <km@ab.example.edu>',
+			'   ' => '',
 			'=?ISO-8859-1?Q?Max_J=F8rn_Simsen?= <max.joern.s@example.dk>' => 'Max Jørn Simsen <max.joern.s@example.dk>',
 			'=?ISO-8859-1?Q?Andr=E9?= Muster <andre.muster@vm1.ulg.ac.be>' => 'André Muster <andre.muster@vm1.ulg.ac.be>',
 			'=?ISO-8859-1?B?SWYgeW91IGNhbiByZWFkIHRoaXMgeW8=?= =?ISO-8859-2?B?dSB1bmRlcnN0YW5kIHRoZSBleGFtcGxlLg==?=' => 'If you can read this you understand the example.'
 		);
 
 		foreach($test_strings as $str => $expected) {
-			$this->assertEquals($this->mailbox->decodeMimeStr($str), $expected);
+			if(empty($expected)) {
+				$this->expectException(Exception::class);
+				$this->mailbox->decodeMimeStr($str);
+			} else {
+				$this->assertEquals($this->mailbox->decodeMimeStr($str), $expected);
+			}
 		}
 	}
 }