feat(parser): add AST manipulation functions for inserting, replacing, and exporting AST as JSON (#24)

* Add convert_ast_to_estree

* Add estree function and tests inside elixir part

* Add insert_ast_at_index and replace_ast_at_index rust

* Add some docs for rust functions

* Update formatter.rs

* Add nif functions

* Add functions insert_at_index and replace_at_index inside elixir without testing

* Add some tests

* Change indexing of insert_at_index function

* Update ast.rs

* Delete -1 from docs

Author: shahryarjb

lib/igniter_js/native.ex

@@ -53,6 +53,12 @@ defmodule IgniterJs.Native do
 
   def format_css_nif(_file_content), do: error()
 
+  def convert_ast_to_estree_nif(_file_content), do: error()
+
+  def insert_ast_at_index_nif(_file_content, _insert_code, _index), do: error()
+
+  def replace_ast_at_index_nif(_file_content, _replace_code, _index), do: error()
+
   def is_css_formatted_nif(_file_content), do: error()
 
   defp error, do: :erlang.nif_error(:nif_not_loaded)

lib/igniter_js/parsers/javascript/parser.ex

@@ -295,4 +295,109 @@ defmodule IgniterJs.Parsers.Javascript.Parser do
       type
     )
   end
+
+  @doc """
+  Converts a JavaScript AST into the ESTree format.
+
+  This function takes either a file path or raw JavaScript content, processes it
+  and returns the resulting ESTree Map structure.
+
+  ```elixir
+  alias IgniterJs.Parsers.Javascript.Parser
+  Parser.ast_to_estree(js_content)
+  Parser.ast_to_estree("/path/to/file.js", :path)
+  ```
+  """
+  def ast_to_estree(file_path_or_content, type \\ :content) do
+    call_nif_fn(
+      file_path_or_content,
+      __ENV__.function,
+      fn file_content ->
+        Native.convert_ast_to_estree_nif(file_content)
+      end,
+      type
+    )
+    |> case do
+      {:ok, _, output} ->
+        {:ok, :ast_to_estree, Jason.decode!(output)}
+
+      {:error, :ast_to_estree, error} ->
+        {:error, :ast_to_estree, error}
+    end
+  end
+
+  @doc """
+    Inserts a JavaScript AST at the specified index within an existing AST.
+
+    This function takes either a file path or raw JavaScript content, along with the
+    JavaScript code to be inserted and the target index. It processes the AST and inserts
+    the new code at the specified position.
+
+
+    ```elixir
+    alias IgniterJs.Parsers.Javascript.Parser
+
+    # Insert after index 1
+    Parser.insert_at_index(js_content, "function newFunc() {}", 1)
+
+    # Insert before all code
+    Parser.insert_at_index(js_content, "function newFunc() {}", 0)
+
+    # Insert using a file path
+    Parser.insert_at_index("/path/to/file.js", "function newFunc() {}", 2, :path)
+    ```
+  """
+  def insert_at_index(
+        file_path_or_content,
+        insert_code,
+        index,
+        type \\ :content
+      ) do
+    call_nif_fn(
+      file_path_or_content,
+      __ENV__.function,
+      fn file_content ->
+        Native.insert_ast_at_index_nif(file_content, insert_code, index)
+      end,
+      type
+    )
+  end
+
+  @doc """
+  Replaces a JavaScript AST node at the specified index with new JavaScript code.
+
+  This function takes either a file path or raw JavaScript content, along with the
+  JavaScript code that should replace an existing node at the given index. It processes
+  the AST and replaces the target node while preserving the surrounding structure.
+
+  If the `index` is out of bounds, an error is returned.
+
+  ```elixir
+  alias IgniterJs.Parsers.Javascript.Parser
+
+  # Replace node at index 1
+  Parser.replace_at_index(js_content, "function newFunc() {}", 1)
+
+  # Replace node at index 0 (first item)
+  Parser.replace_at_index(js_content, "function newFunc() {}", 0)
+
+  # Replace using a file path
+  Parser.replace_at_index("/path/to/file.js", "function newFunc() {}", 2, :path)
+  ```
+  """
+  def replace_at_index(
+        file_path_or_content,
+        replace_code,
+        index,
+        type \\ :content
+      ) do
+    call_nif_fn(
+      file_path_or_content,
+      __ENV__.function,
+      fn file_content ->
+        Native.replace_ast_at_index_nif(file_content, replace_code, index)
+      end,
+      type
+    )
+  end
 end

mix.exs

@@ -106,6 +106,7 @@ defmodule IgniterJs.MixProject do
   defp deps do
     [
       {:rustler, "~> 0.36.1", optional: true},
+      {:jason, "~> 1.4"},
       {:rustler_precompiled, "~> 0.8"},
       {:ex_doc, "~> 0.35", only: [:dev, :test], runtime: false},
       {:ex_check, "~> 0.12", only: [:dev, :test]},