Add precommit checks and format sources

AGENTS.md

@@ -0,0 +1,56 @@
+# Repository Guidelines
+
+## Project Structure & Module Organization
+
+This is an Elixir Mix library for sending encrypted Web Push notifications.
+Core source lives in `lib/`: `lib/web_push_elixir.ex` contains the public
+notification API and crypto/header logic, `lib/web_push_elixir/application.ex`
+starts supervision, and `lib/mix/tasks/generate_vapid_keys.ex` defines the VAPID
+key generator task. Runtime and test configuration are in `config/`. Tests live
+in `test/`, with shared local HTTP behavior in `test/support/mock_server.ex`.
+The browser demo and GitHub Pages assets are in `example/`.
+
+## Build, Test, and Development Commands
+
+- `mix deps.get` installs Hex dependencies.
+- `mix compile` compiles the library and checks for compile-time errors.
+- `mix test` runs the ExUnit suite; tests start a local Plug/Cowboy server on
+  port `4040`.
+- `mix coveralls.json` runs test coverage in the same format used by CI.
+- `mix format` formats all Elixir files according to Mix formatter defaults.
+- `mix generate.vapid.keys` generates sample VAPID keys for local configuration.
+- `mix precommit` checks formatting, compiles with warnings as errors, and runs
+  the test suite. Run this before every commit.
+
+## Coding Style & Naming Conventions
+
+Use standard Elixir formatting: two-space indentation, pipeline-friendly
+function chains, and `snake_case` for functions, variables, and test names.
+Modules use `PascalCase` under the `WebPushElixir` namespace, with Mix tasks
+under `Mix.Tasks.*`. Prefer pattern matching and tagged tuples such as
+`{:ok, response}` and `{:error, reason}` for control flow. Keep comments sparse;
+public behavior should be documented with `@doc` examples when helpful.
+
+## Testing Guidelines
+
+Tests use ExUnit and should be named `*_test.exs`. Add focused tests next to the
+behavior being changed, and use `test/support/mock_server.ex` for push-service
+HTTP responses instead of calling external services. When changing request
+headers, encryption payload behavior, or error handling, assert both return
+tuples and relevant response/request fields. Run `mix test` before submitting;
+run `mix coveralls.json` for changes that affect coverage-sensitive logic.
+
+## Commit & Pull Request Guidelines
+
+Recent history uses short imperative messages, often with Conventional Commit
+prefixes such as `build(deps): bump jason from 1.4.4 to 1.4.5`, `build: 0.8.0`,
+and `ci: revert test`. Run `mix precommit` before every commit, then keep
+commits scoped and descriptive. Pull requests should include a concise summary,
+test results, linked issues when applicable, and note any configuration or
+example asset changes. Screenshots are only useful for changes under `example/`.
+
+## Security & Configuration Tips
+
+Never commit real VAPID private keys. Use placeholders in docs and configure
+`vapid_public_key`, `vapid_private_key`, and `vapid_subject` through environment
+specific config or application runtime configuration.

config/config.exs

@@ -2,4 +2,4 @@ import Config
 
 if Mix.env() == :test do
   import_config "test.exs"
-end
+end

config/test.exs

@@ -1,6 +1,6 @@
 import Config
 
 config :web_push_elixir,
-       vapid_public_key: "someVapidPublicKey",
-       vapid_private_key: "someVapidPrivateKey",
-       vapid_subject: "mailto:admin@email.com"
+  vapid_public_key: "someVapidPublicKey",
+  vapid_private_key: "someVapidPrivateKey",
+  vapid_subject: "mailto:admin@email.com"

lib/mix/tasks/generate_vapid_keys.ex

@@ -11,6 +11,6 @@ defmodule Mix.Tasks.Generate.Vapid.Keys do
       vapid_private_key: Base.url_encode64(private_key, padding: false),
       vapid_subject: "mailto:admin@email.com"
     }
-    |> IO.inspect
+    |> IO.inspect()
   end
 end

lib/web_push_elixir.ex

@@ -147,7 +147,8 @@ defmodule WebPushElixir do
       {"content-encoding", "aesgcm"},
       {"content-length", "#{byte_size(encrypted_payload.ciphertext)}"},
       {"content-type", "application/octet-stream"},
-      {"crypto-key", "dh=#{url_encode(encrypted_payload.local_public_key)};p256ecdsa=#{url_encode(vapid_public_key)}"},
+      {"crypto-key",
+       "dh=#{url_encode(encrypted_payload.local_public_key)};p256ecdsa=#{url_encode(vapid_public_key)}"},
       {"encryption", "salt=#{url_encode(encrypted_payload.salt)}"},
       {"ttl", "#{ttl}"}
     ]
@@ -156,11 +157,11 @@ defmodule WebPushElixir do
     headers = if topic, do: [{"topic", topic} | headers], else: headers
 
     case Req.run(
-      method: :post,
-      url: endpoint,
-      body: encrypted_payload.ciphertext,
-      headers: headers
-    ) do
+           method: :post,
+           url: endpoint,
+           body: encrypted_payload.ciphertext,
+           headers: headers
+         ) do
       {request, %{status: status} = response} when status in 200..202 ->
         {:ok, Map.put(response, :request, request)}
 

mix.exs

@@ -9,6 +9,7 @@ defmodule WebPushElixir.MixProject do
       elixirc_paths: elixirc_paths(Mix.env()),
       start_permanent: Mix.env() == :prod,
       deps: deps(),
+      aliases: aliases(),
       description: "Simple web push for Elixir",
       package: [
         licenses: ["MIT"],
@@ -18,6 +19,12 @@ defmodule WebPushElixir.MixProject do
     ]
   end
 
+  def cli do
+    [
+      preferred_envs: [precommit: :test]
+    ]
+  end
+
   # Run "mix help compile.app" to learn about applications.
   def application do
     [
@@ -42,4 +49,10 @@ defmodule WebPushElixir.MixProject do
       {:plug_cowboy, "~> 2.0", only: :test}
     ]
   end
+
+  defp aliases do
+    [
+      precommit: ["format --check-formatted", "compile --warnings-as-errors", "test"]
+    ]
+  end
 end

test/web_push_elixir_test.exs

@@ -4,25 +4,26 @@ defmodule WebPushElixirTest do
   @test_subscription %{
     "endpoint" => "http://localhost:4040/some-push-service",
     "keys" => %{
-      "p256dh" => "BNcRdreALRFXTkOOUHK1EtK2wtaz5Ry4YfYCA_0QTpQtUbVlUls0VJXg7A8u-Ts1XbjhazAkj7I99e8QcYP7DkM=",
+      "p256dh" =>
+        "BNcRdreALRFXTkOOUHK1EtK2wtaz5Ry4YfYCA_0QTpQtUbVlUls0VJXg7A8u-Ts1XbjhazAkj7I99e8QcYP7DkM=",
       "auth" => "tBHItJI5svbpez7KI4CCXg=="
-      }
     }
+  }
 
   test "it should send notification" do
     subscription = Jason.encode!(@test_subscription)
 
     {:ok, response} = WebPushElixir.send_notification(subscription, "some message")
 
     assert %{
-              "authorization" => ["WebPush " <> <<_jwt::binary>>],
-              "content-encoding" => ["aesgcm"],
-              "content-length" => ["30"],
-              "content-type" => ["application/octet-stream"],
-              "crypto-key" => ["dh=" <> <<_crypto_keys::binary>>],
-              "encryption" => ["salt=" <> <<_salt::binary>>],
-              "ttl" => ["60"]
-            } = response.request.headers
+             "authorization" => ["WebPush " <> <<_jwt::binary>>],
+             "content-encoding" => ["aesgcm"],
+             "content-length" => ["30"],
+             "content-type" => ["application/octet-stream"],
+             "crypto-key" => ["dh=" <> <<_crypto_keys::binary>>],
+             "encryption" => ["salt=" <> <<_salt::binary>>],
+             "ttl" => ["60"]
+           } = response.request.headers
 
     assert response.status in 200..202
   end
@@ -38,30 +39,35 @@ defmodule WebPushElixirTest do
   test "it should send the urgency parameter" do
     subscription = Jason.encode!(@test_subscription)
 
-    {:ok, response} = WebPushElixir.send_notification(subscription, "some message", urgency: :high)
+    {:ok, response} =
+      WebPushElixir.send_notification(subscription, "some message", urgency: :high)
 
     assert ["high"] = Map.get(response.request.headers, "urgency")
   end
 
   test "it should set the topic if it is provided" do
     subscription = Jason.encode!(@test_subscription)
 
-    {:ok, response} = WebPushElixir.send_notification(subscription, "some message", topic: "some-test-topic")
+    {:ok, response} =
+      WebPushElixir.send_notification(subscription, "some message", topic: "some-test-topic")
 
     assert ["some-test-topic"] = Map.get(response.request.headers, "topic")
   end
 
   test "it should return expired" do
-    expired_subscription = Jason.encode!(%{@test_subscription | "endpoint" => "http://localhost:4040/gone"})
+    expired_subscription =
+      Jason.encode!(%{@test_subscription | "endpoint" => "http://localhost:4040/gone"})
 
     assert {:error, :expired} = WebPushElixir.send_notification(expired_subscription, "message")
   end
 
   test "it should return http error" do
+    error_subscription =
+      Jason.encode!(%{@test_subscription | "endpoint" => "http://localhost:4040/error"})
 
-    error_subscription = Jason.encode!(%{@test_subscription | "endpoint" => "http://localhost:4040/error"})
+    assert {:error, {:http_error, status, _body}} =
+             WebPushElixir.send_notification(error_subscription, "message")
 
-    assert {:error, {:http_error, status, _body}} = WebPushElixir.send_notification(error_subscription, "message")
     assert status != 200..202
   end
 end