Fixed polarity bug getting 'Undefined offset: 1' when looking for the word 'of' after 'kind' where kind is the last word in the sentence

Author: Lars Hartmann

src/Sentiment/Vader.php

@@ -176,8 +176,9 @@ public function getPolarityScores(array $tokens) : array
         {
             $valence = 0.0;
             $lcToken = strtolower($tokens[$index]);
-            if( $lcToken === "kind" && strtolower($tokens[$index+1]) === 'of' ||
-                isset(self::$this->boosterDict[$lcToken]) ) {   
+            if( $lcToken === "kind" 
+            && (array_key_exists($index+1, $tokens) && strtolower($tokens[$index+1]) === 'of') ||
+                isset(self::$this->boosterDict[$lcToken]) ) { 
 
                 $sentiments[] = $valence;
             } else {

tests/TextAnalysis/Sentiment/VaderTest.php

@@ -97,7 +97,7 @@ public function testGetPolarityScores()
         $examples[] = ['sent' => "Make sure you :) or :D today!", 'neg'=> 0.0, 'neu'=> 0.294, 'pos'=> 0.706, 'compound'=> 0.8633];
         $examples[] = ['sent' => "Today SUX!", 'neg'=> 0.0, 'neg'=> 0.779, 'neu'=> 0.221, 'pos'=> 0.0, 'compound'=> -0.5461];
         $examples[] = ['sent' => "Today only kinda sux! But I'll get by, lol", 'neg'=> 0.179, 'neu'=> 0.569, 'pos'=> 0.251, 'compound'=> 0.2228];
-    
+        
         $vader = new Vader;
 
         foreach($examples as $test)
@@ -113,9 +113,20 @@ public function testIssue44OffsetError()
             return;
         }
 
-	$vader = new Vader;
+	    $vader = new Vader;
         $result = $vader->getPolarityScores([ 'great', 'for', 'the', 'jawbone']);
         $this->assertEquals(0.577, $result['pos']);
     }
+
+    public function testSentimentScoreKindOfCombo()
+    {
+        if( getenv('SKIP_TEST')) {
+            return;
+        }
+
+        $sentimentScores = vader(['kind']);
+
+        $this->assertEquals(0.6197, $sentimentScores['compound']);
+    }
 
 }