Consume one chunk on decoding errors if regex did not match

Author: inouire

src/ChunkDecoder/MetarChunkDecoder.php

@@ -27,4 +27,5 @@ public function consume($remaining_metar)
             'remaining' => $new_remaining_metar,
         );
     }
+
 }

src/Exception/ChunkDecoderException.php

@@ -38,12 +38,32 @@ public function getChunk()
     /**
      * Get remaining metar after the chunk decoder consumed it
      * In the cases where the exception is triggered because
-      * chunk's regexp didn't match, it will be the same.
-      * For other cases it won't, and having this information
-      * will allow to continue decoding
+      * chunk's regexp didn't match, one chunk will be eaten
+      * with whitespace separator.
+      * Having this information can allow the decoding to continue
+      */
+    public function getFreshRemainingMetar()
+    {
+        if(trim($this->remaining_metar) == $this->metar_chunk){
+          return $this->consumeOneChunk($this->remaining_metar);
+        } else {
+          return $this->remaining_metar;
+        }
+    }
+
+
+    /**
+     * Consume one chunk blindly, without looking for the specific pattern
+     * (only whitespace)
      */
-    public function getRemainingMetar()
+    private static function consumeOneChunk($remaining_metar)
     {
-        return $this->remaining_metar;
+        $next_space = strpos($remaining_metar, ' ');
+        if($next_space > 0){
+            return substr($remaining_metar, $next_space + 1);
+        } else {
+            return $remaining_metar;
+        }
+
     }
 }

src/MetarDecoder.php

@@ -26,6 +26,8 @@ class MetarDecoder
 
     protected $global_strict_parsing = false;
 
+    protected $discard_faulty_part_on_error = true;
+
     public function __construct()
     {
         $this->decoder_chain = array(
@@ -116,14 +118,16 @@ private function parseWithMode($raw_metar, $strict)
                 // update remaining metar for next round
                 $remaining_metar = $decoded['remaining_metar'];
             } catch (ChunkDecoderException $cde) {
-                // log error in decoded metar and abort decoding if in strict mode
+                // log error in decoded metar
                 $decoded_metar->addDecodingException($cde);
+
                 // abort decoding if strict mode is activated, continue otherwise
                 if ($strict) {
                     break;
                 }
+
                 // update remaining metar for next round
-                $remaining_metar = $cde->getRemainingMetar();
+                $remaining_metar = $cde->getFreshRemainingMetar();
             }
 
             // hook for report status decoder, abort if nil, but decoded metar is valid though
@@ -141,4 +145,5 @@ private function parseWithMode($raw_metar, $strict)
 
         return $decoded_metar;
     }
+
 }

tests/ChunkDecoder/SurfaceWindChunkDecoderTest.php

@@ -73,7 +73,7 @@ public function testEmptyInformationChunk()
             $this->decoder->parse('/////KT PPP');
             $this->fail('An exception should have been thrown here');
         } catch (ChunkDecoderException $cde) {
-            $this->assertEquals('PPP', $cde->getRemainingMetar());
+            $this->assertEquals('PPP', $cde->getFreshRemainingMetar());
         }
     }
 

tests/Exception/ChunkDecoderExceptionTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace MetarDecoder\Test\ChunkDecoder;
+
+use MetarDecoder\ChunkDecoder\ReportStatusChunkDecoder;
+use MetarDecoder\Exception\ChunkDecoderException;
+
+class ChunkDecoderExceptionTest extends \PHPUnit_Framework_TestCase
+{
+
+    /**
+     * Test handling of remaining metar
+     */
+    public function testFreshRemainingMetar()
+    {
+        $chunk_decoder = new ReportStatusChunkDecoder();
+
+        // with regex match
+        $exception  = new ChunkDecoderException("FAULTY_PART AAA BBB CC-D ", "BBB CC-D ", "This is an error message", $chunk_decoder);
+        $this->assertEquals("BBB CC-D ", $exception->getFreshRemainingMetar());
+        $this->assertEquals("ReportStatusChunkDecoder", $exception->getChunkDecoder());
+        $this->assertEquals("FAULTY_PART AAA BBB CC-D", $exception->getChunk());
+
+        // no regex match, consume one chunk blindly
+        $exception  = new ChunkDecoderException("FAULTY_PART AAA BBB CC-D ", "FAULTY_PART AAA BBB CC-D ", "This is an error message", $chunk_decoder);
+        $this->assertEquals("AAA BBB CC-D ", $exception->getFreshRemainingMetar());
+    }
+
+}

tests/MetarDecoderTest.php

@@ -117,6 +117,7 @@ public function testParseInvalid()
     {
         // launch decoding
         $d = $this->decoder->parseNotStrict('METAR LFPB 190730Z AUTOPP 17005KT 6000 OVC024 02/00 Q10032 ');
+        //                                                     here ^                              ^ and here
 
         // compare results
         $this->assertFalse($d->isValid());
@@ -139,6 +140,36 @@ public function testParseInvalid()
         $this->assertEquals(2, $d->getAirTemperature()->getValue());
         $this->assertEquals(0, $d->getDewPointTemperature()->getValue());
         $this->assertNull($d->getPressure());
+
+    }
+
+    /**
+     * Test parsing of an invalid METAR, where parsing can continue normally without strict option activated
+     */
+    public function testParseInvalidPart()
+    {
+        // launch decoding
+        $d = $this->decoder->parseNotStrict('METAR LFPB 190730Z AUTOP X17005KT 6000 OVC024 02/00 Q1032 ');
+        //                                                     here ^ ^ and here
+
+        // compare results
+        $this->assertFalse($d->isValid());
+        $this->assertEquals(2, count($d->getDecodingExceptions()));
+        $this->assertEquals('METAR', $d->getType());
+        $this->assertEquals('LFPB', $d->getIcao());
+        $this->assertEquals(19, $d->getDay());
+        $this->assertEquals('07:30 UTC', $d->getTime());
+        $this->assertNull($d->getStatus());
+        $this->assertNull($d->getSurfaceWind());
+        $v = $d->getVisibility();
+        $this->assertEquals(6000, $v->getVisibility()->getValue());
+        $cs = $d->getClouds();
+        $c = $cs[0];
+        $this->assertEquals('OVC', $c->getAmount());
+        $this->assertEquals(2400, $c->getBaseHeight()->getValue());
+        $this->assertEquals(2, $d->getAirTemperature()->getValue());
+        $this->assertEquals(0, $d->getDewPointTemperature()->getValue());
+        $this->assertEquals(1032, $d->getPressure()->getValue());
     }
 
     /**