Better messages for "JSON node should (not) contain"

Author: jdeniau

src/Context/JsonContext.php

@@ -226,7 +226,13 @@ public function theJsonNodeShouldContain($node, $text): void
 
         $actual = $this->inspector->evaluate($json, $node);
 
-        $this->assertContains($text, (string) $actual);
+        $printedActual = strlen($actual) > 50 ? substr($actual, 0, 50) . '[…]' : $actual;
+
+        $this->assertContains(
+            $text,
+            (string) $actual, 
+            'The node "'.$node.'" does not contain the expected text "'.$text.'" (found "'.$printedActual.'")'
+        );
     }
 
     /**
@@ -252,7 +258,13 @@ public function theJsonNodeShouldNotContain($node, $text): void
 
         $actual = $this->inspector->evaluate($json, $node);
 
-        $this->assertNotContains($text, (string) $actual);
+        $printedActual = strlen($actual) > 50 ? substr($actual, 0, 50) . '[…]' : $actual;
+
+        $this->assertNotContains(
+            $text,
+            (string) $actual,
+            'The node "'.$node.'" does contain "'.$text.'" while it should not (found "'.$printedActual.'")'
+        );
     }
 
     /**