Add when and unless to partial tag

src/Tags/Partial.php

@@ -15,6 +15,10 @@ public function wildcard($tag)
 
     protected function render($partial)
     {
+        if (! $this->shouldRender()) {
+            return;
+        }
+
         $variables = array_merge($this->context->all(), $this->params->all(), [
             '__frontmatter' => $this->params->all(),
             'slot' => $this->isPair ? trim($this->parse()) : null,
@@ -25,6 +29,19 @@ protected function render($partial)
             ->render();
     }
 
+    protected function shouldRender(): bool
+    {
+        if ($this->params->has('when')) {
+            return $this->params->bool('when');
+        }
+
+        if ($this->params->has('unless')) {
+            return ! $this->params->bool('unless');
+        }
+
+        return true;
+    }
+
     protected function viewName($partial)
     {
         $partial = str_replace('/', '.', $partial);

tests/Tags/PartialTagsTest.php

@@ -101,4 +101,48 @@ public function parameter_will_override_partial_front_matter()
             $this->partialTag('mypartial', 'foo="baz"')
         );
     }
+
+    /** @test */
+    public function it_doesnt_render_partial_if_when_condition_is_false()
+    {
+        $this->viewShouldReturnRaw('mypartial', "---\nfoo: bar\n---\nthe partial content with {{ foo }}");
+
+        $this->assertEquals(
+            '',
+            $this->partialTag('mypartial', 'foo="baz" when="false"')
+        );
+    }
+
+    /** @test */
+    public function it_renders_partial_if_when_condition_is_true()
+    {
+        $this->viewShouldReturnRaw('mypartial', "---\nfoo: bar\n---\nthe partial content with {{ foo }}");
+
+        $this->assertEquals(
+            'the partial content with baz',
+            $this->partialTag('mypartial', 'foo="baz" when="true"')
+        );
+    }
+
+    /** @test */
+    public function it_doesnt_render_partial_if_unless_condition_is_true()
+    {
+        $this->viewShouldReturnRaw('mypartial', "---\nfoo: bar\n---\nthe partial content with {{ foo }}");
+
+        $this->assertEquals(
+            '',
+            $this->partialTag('mypartial', 'foo="baz" unless="true"')
+        );
+    }
+
+    /** @test */
+    public function it_renders_partial_if_unless_condition_is_false()
+    {
+        $this->viewShouldReturnRaw('mypartial', "---\nfoo: bar\n---\nthe partial content with {{ foo }}");
+
+        $this->assertEquals(
+            'the partial content with baz',
+            $this->partialTag('mypartial', 'foo="baz" unless="false"')
+        );
+    }
 }