test: cover RouterConstraintsTest

test/test_router_mount.rb

@@ -0,0 +1,55 @@
+require 'minitest/autorun'
+require 'prism'
+
+class RouterMountTest < Minitest::Test
+  def setup
+    @router = Prism::Router.new
+  end
+
+  def test_finds_mount_for_exact_prefix
+    app = Object.new
+    @router.mount('/admin', app)
+    prefix, found = @router.find_mount('/admin')
+    assert_equal '/admin', prefix
+    assert_same app, found
+  end
+
+  def test_finds_mount_for_nested_path
+    app = Object.new
+    @router.mount('/admin', app)
+    prefix, found = @router.find_mount('/admin/users/1')
+    assert_equal '/admin', prefix
+    assert_same app, found
+  end
+
+  def test_does_not_match_sibling_path_with_shared_prefix
+    app = Object.new
+    @router.mount('/admin', app)
+    assert_nil @router.find_mount('/administrator')
+  end
+
+  def test_returns_nil_when_no_mount_matches
+    assert_nil @router.find_mount('/nowhere')
+  end
+
+  def test_trailing_slash_on_prefix_is_normalized
+    app = Object.new
+    @router.mount('/admin/', app)
+    prefix, found = @router.find_mount('/admin/users')
+    assert_equal '/admin', prefix
+    assert_same app, found
+  end
+
+  def test_longest_matching_prefix_wins_when_mounts_overlap
+    outer = Object.new
+    inner = Object.new
+    @router.mount('/api', outer)
+    @router.mount('/api/v2', inner)
+
+    _, found = @router.find_mount('/api/v2/widgets')
+    assert_same inner, found
+
+    _, found = @router.find_mount('/api/v1/widgets')
+    assert_same outer, found
+  end
+end