feat: add regex pattern constraint (#4)

lib/absinthe_constraints/directive.ex

@@ -24,39 +24,36 @@ defmodule AbsintheConstraints.Directive do
   alias Absinthe.Blueprint.TypeReference.List
   alias Absinthe.Blueprint.TypeReference.NonNull
 
-  @string_args [:min_length, :max_length, :format]
+  @string_args [:min_length, :max_length, :format, :pattern]
   @number_args [:min, :max]
   @list_args [:min_items, :max_items]
 
   directive :constraints do
     on([:argument_definition, :field_definition])
 
-    arg(:min, non_null(:integer), description: "Ensure value is greater than or equal to")
-    arg(:max, non_null(:integer), description: "Ensure value is less than or equal to")
+    arg(:min, :integer, description: "Ensure value is greater than or equal to")
+    arg(:max, :integer, description: "Ensure value is less than or equal to")
 
-    arg(:format, non_null(:string), description: "Restricts the string to a specific format")
+    arg(:format, :string, description: "Restricts the string to a specific format")
+    arg(:pattern, :string, description: "Ensure value matches regex")
 
-    arg(:min_length, non_null(:integer), description: "Restrict to a minimum length")
-    arg(:max_length, non_null(:integer), description: "Restrict to a maximum length")
+    arg(:min_length, :integer, description: "Restrict to a minimum length")
+    arg(:max_length, :integer, description: "Restrict to a maximum length")
 
-    arg(:min_items, non_null(:integer), description: "Restrict to a minimum number of items")
-    arg(:max_items, non_null(:integer), description: "Restrict to a maximum number of items")
+    arg(:min_items, :integer, description: "Restrict to a minimum number of items")
+    arg(:max_items, :integer, description: "Restrict to a maximum number of items")
 
     expand(&__MODULE__.expand_constraints/2)
   end
 
-  def expand_constraints(args, %{type: %List{}} = node),
-    do: do_expand(args, node, get_args(:list))
-
-  def expand_constraints(args, %{type: %NonNull{of_type: type}} = node),
+  def expand_constraints(args, %{type: type} = node),
     do: do_expand(args, node, get_args(type))
 
-  def expand_constraints(args, %{type: type} = node), do: do_expand(args, node, get_args(type))
-
   defp get_args(:string), do: @string_args
   defp get_args(:integer), do: @number_args
   defp get_args(:float), do: @number_args
-  defp get_args(:list), do: @list_args
+  defp get_args(%List{}), do: @list_args
+  defp get_args(%NonNull{of_type: of_type}), do: get_args(of_type)
   defp get_args(type), do: raise("Unsupported type: #{inspect(type)}")
 
   defp do_expand(args, node, args_list) do

lib/absinthe_constraints/validator.ex

@@ -53,4 +53,10 @@ defmodule AbsintheConstraints.Validator do
       do: [],
       else: ["must be a valid email address"]
   end
+
+  def handle_constraint({:pattern, regex}, value) do
+    if String.match?(value, Regex.compile!(regex)),
+      do: [],
+      else: ["must match regular expression `#{regex}`"]
+  end
 end

mix.exs

@@ -23,11 +23,7 @@ defmodule AbsintheConstraints.MixProject do
 
   defp deps do
     [
-      # We require this version for a fix introduced in master that is not yet released.
-      {:absinthe,
-       github: "absinthe-graphql/absinthe",
-       ref: "a0afbe1aa3d7e2d47a88370b78d62fa9c002e72c",
-       override: true},
+      {:absinthe, ">= 1.7.6"},
       {:elixir_uuid, ">= 1.2.1"},
       {:ex_doc, "~> 0.14", only: :dev, runtime: false},
       {:dialyxir, "~> 1.3", only: [:dev], runtime: false}

mix.lock

@@ -1,5 +1,5 @@
 %{
-  "absinthe": {:git, "https://github.com/absinthe-graphql/absinthe.git", "a0afbe1aa3d7e2d47a88370b78d62fa9c002e72c", [ref: "a0afbe1aa3d7e2d47a88370b78d62fa9c002e72c"]},
+  "absinthe": {:hex, :absinthe, "1.7.6", "0b897365f98d068cfcb4533c0200a8e58825a4aeeae6ec33633ebed6de11773b", [:mix], [{:dataloader, "~> 1.0.0 or ~> 2.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}, {:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}, {:opentelemetry_process_propagator, "~> 0.2.1", [hex: :opentelemetry_process_propagator, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "e7626951ca5eec627da960615b51009f3a774765406ff02722b1d818f17e5778"},
   "dialyxir": {:hex, :dialyxir, "1.3.0", "fd1672f0922b7648ff9ce7b1b26fcf0ef56dda964a459892ad15f6b4410b5284", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "00b2a4bcd6aa8db9dcb0b38c1225b7277dca9bc370b6438715667071a304696f"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.33", "3c3fd9673bb5dcc9edc28dd90f50c87ce506d1f71b70e3de69aa8154bc695d44", [:mix], [], "hexpm", "2d526833729b59b9fdb85785078697c72ac5e5066350663e5be6a1182da61b8f"},
   "elixir_uuid": {:hex, :elixir_uuid, "1.2.1", "dce506597acb7e6b0daeaff52ff6a9043f5919a4c3315abb4143f0b00378c097", [:mix], [], "hexpm", "f7eba2ea6c3555cea09706492716b0d87397b88946e6380898c2889d68585752"},

test/absinthe_constraints/validator_test.exs

@@ -49,6 +49,14 @@ defmodule AbsintheConstraints.ValidatorTest do
       assert handle_constraint({:format, "email"}, "[email protected]") == []
     end
 
+    test "should validate regex pattern" do
+      assert handle_constraint({:pattern, "^[A-Z]*$"}, "asdf") == [
+               "must match regular expression `^[A-Z]*$`"
+             ]
+
+      assert handle_constraint({:pattern, "^[A-Z]*$"}, "ASDF") == []
+    end
+
     test "should validate min_items" do
       assert handle_constraint({:min_items, 5}, ["1", "2", "3", "4"]) == [
                "must have at least 5 items"

test/integration/api_test.exs

@@ -13,8 +13,16 @@ defmodule AbsintheConstraints.Integration.APITest do
 
       query do
         field :test, non_null(:string) do
-          arg(:list, list_of(:integer), directives: [constraints: [min_items: 2]])
+          arg(:list, non_null(list_of(non_null(:integer))),
+            directives: [constraints: [min_items: 2]]
+          )
+
           arg(:number, :integer, directives: [constraints: [min: 2]])
+
+          arg(:regex_field, non_null(:string),
+            directives: [constraints: [pattern: "^[A-Z][0-9a-z]*$"]]
+          )
+
           resolve(fn _, _ -> {:ok, "test_result"} end)
         end
       end
@@ -39,7 +47,7 @@ defmodule AbsintheConstraints.Integration.APITest do
 
     test "should return success on valid query arguments" do
       assert {:ok, %{data: %{"test" => "test_result"}}} ==
-               TestSchema.run_query("{ test(list: [1, 3], number: 5) }")
+               TestSchema.run_query("{ test(list: [1, 3], number: 5, regexField: \"A123aa\") }")
     end
 
     test "should return errors on invalid query arguments" do
@@ -53,10 +61,14 @@ defmodule AbsintheConstraints.Integration.APITest do
                   %{
                     message: "\"number\" must be greater than or equal to 2",
                     locations: [%{line: 1, column: 19}]
+                  },
+                  %{
+                    message: "\"regexField\" must match regular expression `^[A-Z][0-9a-z]*$`",
+                    locations: [%{line: 1, column: 30}]
                   }
                 ]
               }} ==
-               TestSchema.run_query("{ test(list: [1], number: 1) }")
+               TestSchema.run_query("{ test(list: [1], number: 1, regexField: \"invalid\") }")
     end
 
     test "should return errors on valid mutation arguments" do