Issue #8: Remove the space between elements.

spec/drupol/phptree/Exporter/TextSpec.php

@@ -5,7 +5,6 @@
 namespace spec\drupol\phptree\Exporter;
 
 use drupol\phptree\Exporter\Text;
-use drupol\phptree\Node\Node;
 use drupol\phptree\Node\ValueNode;
 use PhpSpec\ObjectBehavior;
 
@@ -28,22 +27,7 @@ public function it_can_export_to_text()
 
         $this
             ->export($tree)
-            ->shouldReturn('[root [A [C [G] [H]] [D [I] [J]]] [B [E] [F]]]');
-    }
-
-    public function it_can_throw_an_error_when_tree_is_not_a_valuenode()
-    {
-        $tree = new Node();
-
-        foreach (\range('A', 'Z') as $key => $value) {
-            $nodes[$value] = new Node();
-        }
-
-        $tree->add(...\array_values($nodes));
-
-        $this
-            ->shouldThrow(\InvalidArgumentException::class)
-            ->during('export', [$tree]);
+            ->shouldReturn('[root[A[C[G][H]][D[I][J]]][B[E][F]]]');
     }
 
     public function it_is_initializable()

spec/drupol/phptree/Node/ValueNodeSpec.php

@@ -45,11 +45,11 @@ public function it_can_be_manipulated_like_an_array()
 
         $tree[25] = new ValueNode('Foo');
 
-        $export = '[root [a] [b] [c] [d] [e] [f] [g] [h] [i] [j] [k] [l] [m] [n] [o] [p] [q] [r] [s] [t] [u] [v] [w] [x] [y] [Foo]]';
+        $export = '[root[a][b][c][d][e][f][g][h][i][j][k][l][m][n][o][p][q][r][s][t][u][v][w][x][y][Foo]]';
         $this->shouldHaveSameTextExport($export);
 
         unset($tree[25]);
-        $export = '[root [a] [b] [c] [d] [e] [f] [g] [h] [i] [j] [k] [l] [m] [n] [o] [p] [q] [r] [s] [t] [u] [v] [w] [x] [y]]';
+        $export = '[root[a][b][c][d][e][f][g][h][i][j][k][l][m][n][o][p][q][r][s][t][u][v][w][x][y]]';
         $this->shouldHaveSameTextExport($export);
 
         $this->shouldThrow(\OutOfBoundsException::class)->during('offsetSet', [30, new ValueNode('out')]);
@@ -103,7 +103,7 @@ public function it_can_have_children()
             $tree->add(new ValueNode($value, 3));
         }
 
-        $export = '[root [A [C [I] [J] [K]] [D [L] [M] [N]] [E [O] [P] [Q]]] [B [F [R] [S] [T]] [G [U] [V] [W]] [H [X] [Y] [Z]]]]';
+        $export = '[root[A[C[I][J][K]][D[L][M][N]][E[O][P][Q]]][B[F[R][S][T]][G[U][V][W]][H[X][Y][Z]]]]';
 
         $this->shouldHaveSameTextExport($export);
         $this->shouldHaveSameGraph($tree);
@@ -121,12 +121,12 @@ public function it_can_remove()
         $this
             ->add($node1, $node2);
 
-        $this->shouldHaveSameTextExport('[root [A] [B]]');
+        $this->shouldHaveSameTextExport('[root[A][B]]');
 
         $this
             ->remove($node2);
 
-        $this->shouldHaveSameTextExport('[root [A]]');
+        $this->shouldHaveSameTextExport('[root[A]]');
         $this
             ->count()
             ->shouldReturn(1);

src/Exporter/Text.php

@@ -17,18 +17,31 @@ class Text implements ExporterInterface
      */
     public function export(NodeInterface $node): string
     {
-        if (!($node instanceof ValueNodeInterface)) {
-            throw new \InvalidArgumentException('Must implements ValueNodeInterface');
-        }
-
         $children = [];
+
         /** @var ValueNodeInterface $child */
         foreach ($node->children() as $child) {
             $children[] = $this->export($child);
         }
 
         return [] === $children ?
-            \sprintf('[%s]', $node->getValue()) :
-            \sprintf('[%s %s]', $node->getValue(), \implode(' ', $children));
+            \sprintf('[%s]', $this->getNodeValue($node)) :
+            \sprintf('[%s%s]', $this->getNodeValue($node), \implode('', $children));
+    }
+
+    /**
+     * Get a string representation of a node.
+     *
+     * @param \drupol\phptree\Node\NodeInterface $node
+     *   The node.
+     *
+     * @return string
+     *   The string representation.
+     */
+    protected function getNodeValue(NodeInterface $node): string
+    {
+        return $node instanceof ValueNodeInterface ?
+            (string) $node->getValue() :
+            (string) \spl_object_hash($node);
     }
 }