Improve exception messages

Author: colinodell

src/Data.php

@@ -84,7 +84,7 @@ public function set(string $key, $value = null): void
                 $currentValue[$currentKey] = [];
             }
             if (!is_array($currentValue[$currentKey])) {
-                throw new DataException("Key path at $currentKey of $key cannot be indexed into (is not an array)");
+                throw new DataException(sprintf('Key path "%s" within "%s" cannot be indexed into (is not an array)', $currentKey, self::formatPath($key)));
             }
             $currentValue =& $currentValue[$currentKey];
         }
@@ -166,7 +166,7 @@ public function getData(string $key): DataInterface
             return new Data($value);
         }
 
-        throw new DataException("Value at '$key' could not be represented as a DataInterface");
+        throw new DataException(sprintf('Value at "%s" could not be represented as a DataInterface', self::formatPath($key)));
     }
 
     /**
@@ -248,4 +248,20 @@ protected static function keyToPathArray(string $path): array
 
         return \explode('.', $path);
     }
+
+    /**
+     * @param string|string[] $path
+     *
+     * @return string
+     *
+     * @psalm-pure
+     */
+    protected static function formatPath($path): string
+    {
+        if (is_string($path)) {
+            $path = self::keyToPathArray($path);
+        }
+
+        return implode(' » ', $path);
+    }
 }

tests/DataTest.php

@@ -65,6 +65,7 @@ protected function runSampleDataTests(DataInterface $data)
         $this->assertEquals($data->get('f/g/h/i', 'default-value-2'), 'default-value-2');
 
         $this->expectException(InvalidPathException::class);
+        $this->expectExceptionMessage('Path cannot be an empty string');
         $data->get('', 'broken');
     }
 
@@ -93,7 +94,7 @@ public function testAppend()
         $this->assertEquals(['L'], $data->get('i.k.l'));
 
         $this->expectException(InvalidPathException::class);
-
+        $this->expectExceptionMessage('Path cannot be an empty string');
         $data->append('', 'broken');
     }
 
@@ -116,7 +117,7 @@ public function testSet()
         $this->assertEquals(['e' => ['f' => 'F', 'g' => 'G']], $data->get('d'));
 
         $this->expectException(InvalidPathException::class);
-
+        $this->expectExceptionMessage('Path cannot be an empty string');
         $data->set('', 'broken');
     }
 
@@ -127,7 +128,7 @@ public function testSetClobberStringInPath()
         $data->set('a.b.c', 'Should not be able to write to a.b.c.d.e');
 
         $this->expectException(DataException::class);
-
+        $this->expectExceptionMessage('Key path "c" within "a » b » c » d » e" cannot be indexed into (is not an array)');
         $data->set('a.b.c.d.e', 'broken');
     }
 
@@ -149,7 +150,7 @@ public function testRemove()
         $this->assertEquals('D2', $data->get('b.d.d2'));
 
         $this->expectException(InvalidPathException::class);
-
+        $this->expectExceptionMessage('Path cannot be an empty string');
         $data->remove('', 'broken');
     }
 
@@ -177,6 +178,7 @@ public function testHas()
         }
 
         $this->expectException(InvalidPathException::class);
+        $this->expectExceptionMessage('Path cannot be an empty string');
         $data->has('', 'broken');
     }
 
@@ -200,8 +202,7 @@ public function testGetDataOnNonArrayValue()
         ]);
 
         $this->expectException(DataException::class);
-        $this->expectExceptionMessageRegExp('/could not be represented as a DataInterface/');
-
+        $this->expectExceptionMessage('Value at "foo" could not be represented as a DataInterface');
         $data->getData('foo');
     }
 
@@ -287,7 +288,7 @@ public function testOffsetSet()
         $this->assertEquals(['e' => ['f' => 'F', 'g' => 'G']], $data['d']);
 
         $this->expectException(InvalidPathException::class);
-
+        $this->expectExceptionMessage('Path cannot be an empty string');
         $data->set('', 'broken');
     }
 
@@ -309,7 +310,7 @@ public function testOffsetUnset()
         $this->assertEquals('D2', $data['b.d.d2']);
 
         $this->expectException(InvalidPathException::class);
-
+        $this->expectExceptionMessage('Path cannot be an empty string');
         unset($data['']);
     }
 }