Improve README

README.md

@@ -1,16 +1,138 @@
-# AbsintheHelpers
+Here’s the full README with consistent formatting and no title case for headings:
 
-Adds support for schema constraints, type coercions, and other custom transformations.
+---
+
+# Absinthe Helpers
+
+This package provides two key features:
+
+1. **constraints**: enforce validation rules (like `min`, `max`, etc.) on fields and arguments in your schema.
+2. **transforms**: apply custom transformations (like `Trim`, `ToInteger`, etc.) to input fields and arguments.
 
 ## Installation
 
-If [available in Hex](https://hex.pm/docs/publish), the package can be installed
-by adding `absinthe_helpers` to your list of dependencies in `mix.exs`:
+Add `absinthe_helpers` to your list of dependencies in `mix.exs`:
 
 ```elixir
 def deps do
   [
-     {:absinthe_helpers, "~> 0.1.0", organization: "fresha"}
+    {:absinthe_helpers, "~> 0.1.0", organization: "fresha"}
   ]
 end
 ```
+
+Then, run:
+
+```bash
+mix deps.get
+```
+
+### Setup: adding constraints and transforms to your Absinthe pipeline
+
+To set up both **constraints** and **transforms**, follow these steps:
+
+1. Add constraints and transforms to your Absinthe pipeline:
+
+```elixir
+forward "/graphql",
+    to: Absinthe.Plug,
+    init_opts: [
+      schema: MyProject.Schema,
+      pipeline: {__MODULE__, :absinthe_pipeline},
+    ]
+
+def absinthe_pipeline(config, opts) do
+  config
+  |> Absinthe.Plug.default_pipeline(opts)
+  |> AbsintheHelpers.Phases.ApplyConstraints.add_to_pipeline(opts)
+  |> AbsintheHelpers.Phases.ApplyTransforms.add_to_pipeline(opts)
+end
+```
+
+2. Add constraints to your schema:
+
+```elixir
+defmodule MyApp.Schema do
+  use Absinthe.Schema
+  @prototype_schema AbsintheHelpers.Directives.Constraints
+  # ...
+end
+```
+
+---
+
+## Constraints
+
+The `constraints` directive allows you to enforce validation rules on fields and arguments in your GraphQL schema. Constraints are applied at the schema level and are visible in the GraphQL schema, making them accessible to the frontend.
+
+### Example: graphql schema with constraints
+
+```graphql
+"Overrides for location-specific service pricing."
+input LocationOverrideInput {
+  duration: Int @constraints(min: 300, max: 43200)
+  price: Decimal @constraints(min: 0, max: 100000000)
+  priceType: ServicePriceType
+  locationId: ID!
+}
+```
+
+### How to use constraints
+
+1. Apply constraints to a field or argument:
+
+```elixir
+field :my_list, list_of(:integer) do
+  directive(:constraints, [min_items: 2, max_items: 5, min: 1, max: 100])
+
+  resolve(&MyResolver.resolve/3)
+end
+
+field :my_field, :integer do
+  arg :my_arg, non_null(:string), directives: [constraints: [min: 10]]
+
+  resolve(&MyResolver.resolve/3)
+end
+```
+
+---
+
+## Transforms
+
+Transforms allow you to modify or coerce input values at runtime. You can apply these transformations to individual fields, lists, or arguments in your Absinthe schema.
+
+### Example: applying transforms in your schema
+
+1. Apply transforms directly to a field:
+
+```elixir
+alias AbsintheHelpers.Transforms.ToInteger
+alias AbsintheHelpers.Transforms.Trim
+alias AbsintheHelpers.Transforms.Increment
+
+field :employee_id, :id do
+  meta transforms: [Trim, ToInteger, {Increment, 3}]
+end
+```
+
+2. Apply transforms to a list of values:
+
+```elixir
+field :employee_ids, non_null(list_of(non_null(:id))) do
+  meta transforms: [Trim, ToInteger, {Increment, 3}]
+end
+```
+
+3. Apply transforms to an argument:
+
+```elixir
+field(:create_booking, :string) do
+  arg(:employee_id, non_null(:id),
+    __private__: [meta: [transforms: [Trim, ToInteger, {Increment, 3}]]]
+  )
+
+  resolve(&TestResolver.run/3)
+end
+```
+
+In this example, the `Trim`, `ToInteger`, and `Increment` transformations will be applied to the `employee_id` argument, ensuring that the input data is processed according to the specified logic.