treat symlinks as redirects

closes #7

incorporealcms/pages.py

@@ -22,7 +22,8 @@ def display_page(path):
     """Get the file contents of the requested path and render the file."""
     try:
         resolved_path, render_type = request_path_to_instance_resource_path(path)
-        logger.debug("received request for path '%s', resolved to '%s'", path, resolved_path)
+        logger.debug("received request for path '%s', resolved to '%s', type '%s'",
+                     path, resolved_path, render_type)
     except PermissionError:
         abort(400)
     except IsADirectoryError:
@@ -32,6 +33,8 @@ def display_page(path):
 
     if render_type == 'file':
         return send_from_directory(app.instance_path, resolved_path)
+    elif render_type == 'symlink':
+        return redirect(instance_resource_path_to_request_path(resolved_path), code=301)
     elif render_type == 'markdown':
         try:
             with app.open_instance_resource(resolved_path, 'r') as entry_file:
@@ -77,6 +80,15 @@ def request_path_to_instance_resource_path(path):
         logger.warning("client tried to request a path '%s' outside of the base_dir!", path)
         raise PermissionError
 
+    # if this is a (valid) symlink, find what it's pointed to and redirect the user
+    if os.path.islink(os.path.join(base_dir, path)):
+        logger.info("client requested a path '%s' that is actually a symlink to file '%s'", path, resolved_path)
+        return resolved_path.replace(f'{app.instance_path}{os.path.sep}', ''), 'symlink'
+    elif os.path.islink(os.path.join(base_dir, f'{path}.md')):
+        resolved_path = os.path.realpath(os.path.join(base_dir, f'{path}.md'))
+        logger.info("client requested a path '%s' that is actually a symlink to file '%s'", path, resolved_path)
+        return resolved_path.replace(f'{app.instance_path}{os.path.sep}', ''), 'symlink'
+
     # if this is a file-like requset but actually a directory, redirect the user
     if os.path.isdir(resolved_path) and not path.endswith('/'):
         logger.info("client requested a path '%s' that is actually a directory", path)

tests/functional_tests.py

@@ -108,6 +108,21 @@ def test_that_page_request_redirects_to_directory(client):
     """
     response = client.get('/subdir')
     assert response.status_code == 301
+    assert response.location == 'http://localhost/subdir/'
+
+
+def test_that_request_to_symlink_redirects_markdown(client):
+    """Test that a request to /foo redirects to /what-foo-points-at."""
+    response = client.get('/symlink-to-no-title')
+    assert response.status_code == 301
+    assert response.location == 'http://localhost/no-title'
+
+
+def test_that_request_to_symlink_redirects_file(client):
+    """Test that a request to /foo.txt redirects to /what-foo-points-at.txt."""
+    response = client.get('/symlink-to-foo.txt')
+    assert response.status_code == 301
+    assert response.location == 'http://localhost/foo.txt'
 
 
 def test_that_dir_request_does_not_redirect(client):

tests/instance/pages/symlink-to-foo.txt

@@ -0,0 +1 @@
+foo.txt

tests/instance/pages/symlink-to-no-title.md

@@ -0,0 +1 @@
+no-title.md

tests/test_pages.py

@@ -132,6 +132,20 @@ def test_request_path_to_instance_resource_path_actual_file(app):
                 ('pages/bss-square-no-bg.png', 'file'))
 
 
+def test_request_path_to_instance_resource_path_markdown_symlink(app):
+    """Test that a request for e.g. '/foo' when foo.md is a symlink to another .md file redirects."""
+    with app.test_request_context():
+        assert (request_path_to_instance_resource_path('symlink-to-no-title') ==
+                ('pages/no-title.md', 'symlink'))
+
+
+def test_request_path_to_instance_resource_path_file_symlink(app):
+    """Test that a request for e.g. '/foo' when foo.txt is a symlink to another .txt file redirects."""
+    with app.test_request_context():
+        assert (request_path_to_instance_resource_path('symlink-to-foo.txt') ==
+                ('pages/foo.txt', 'symlink'))
+
+
 def test_request_path_to_instance_resource_path_nonexistant_file_errors(app):
     """Test that a request for something not on disk errors."""
     with app.test_request_context():