Add automatic function discovery (#11)

* add: automatic function discovery

* fix: typo

* Fix: lint

* fix:test

* fix: functions disovery test

* minor changes

Author: hiiambhanu

README.md

@@ -11,17 +11,17 @@ It detects any changes to a function by bundling it into a single minified file,
 
 ## Usage
 
-- Create a `.differspec.json` file in the directory containing your Firebase Functions:
+-   Create a `.differspec.json` file in the directory containing your Firebase Functions:
 
 ```shell
 my-firebase-project
     ├── firebase.json
     ├── functions
         ├── src
-        └── .differspec.json 
+        └── .differspec.json
 ```
 
-- Specify your function names and their paths in `.differspec.json`:
+-   Specify your function names and their paths in `.differspec.json`:
 
 ```json
 {
@@ -32,14 +32,14 @@ my-firebase-project
 }
 ```
 
-- Run `functions-differ` in the directory containing `.differspec.json`
+-   Run `functions-differ` in the directory containing `.differspec.json`
 
 ```shell
 cd my-firebase-project/functions
 functions-differ
 ```
 
-- `functions-differ` will then output a list of functions that need to be (re)deployed. This includes any functions that were changed or added since its last invocation.
+-   `functions-differ` will then output a list of functions that need to be (re)deployed. This includes any functions that were changed or added since its last invocation.
 
 ```shell
 > functions-differ
@@ -52,13 +52,17 @@ The default output is suitable for passing to `firebase deploy --only` command.
 
 `functions-differ` supports the following options:
 
-| Name    | Alias | Description                                      | Default                     |
-| ------- | ----- | ------------------------------------------------ | --------------------------- |
-| dir     | d     | The directory containing `.differspec.json` file | (current working directory) |
-| write   | w     | Write output to `.differspec.json` file or not   | true                        |
-| verbose | v     | Output verbose logs                              | false                       |
-| prefix  |       | Prefix for each function name output             | `functions:`                |
-| sep     |       | Separator for each output function               | `,`                         |
+| Name          | Alias | Description                                                                                                  | Default                                 |
+| ------------- | ----- | ------------------------------------------------------------------------------------------------------------ | --------------------------------------- |
+| dir           | d     | The directory containing `.differspec.json` file                                                             | (current working directory)             |
+| write         | w     | Write output to `.differspec.json` file or not                                                               | true                                    |
+| verbose       | v     | Output verbose logs                                                                                          | false                                   |
+| prefix        |       | Prefix for each function name output                                                                         | `functions:`                            |
+| sep           |       | Separator for each output function                                                                           | `,`                                     |
+| bundlerConfig |       | Path to the bundler config file which would be passed to esbuild                                             |                                         |
+| concurrency   |       | Number to control the concurrency of the bundling process. Useful in CI/CD flows with limited memory            | Number of functions in .differspec.json |
+| discover      |       | Flag indicating whether to use automatic function path discovery                                             | false                                   |
+| indexFilePath |       | Location of the index.ts file which exports all the functions. Optional. Only used if used with `--discover` | `src/index.ts`                          |
 
 ## .differspec.json
 
@@ -70,14 +74,14 @@ The default output is suitable for passing to `firebase deploy --only` command.
 | `hashes`    | (**AUTOGENERATED, DO NOT MODIFY**) JSON object containing hashes of all functions in the `functions` property                 |
 | `lastDiff`  | (**AUTOGENERATED, DO NOT MODIFY**) JSON object containing the results of the last successful invocation of `functions-differ` |
 
-- The `functions` property serves as an index of all functions present in your repository. `functions-differ` does not support automatic discovery of functions in the project (yet), and therefore this property is required.
-- The `hashes` and `lastDiff` properties are autogenerated by `functions-differ`, and should not be created/edited manually.
+-   The `functions` property serves as an index of all functions present in your repository. `functions-differ` does not support automatic discovery of functions in the project (yet), and therefore this property is required.
+-   The `hashes` and `lastDiff` properties are autogenerated by `functions-differ`, and should not be created/edited manually.
 
 ## Contributions
 
 Please discuss bugs, feature requests, and help in Github Issues. Pull requests are welcome, but please make sure to open an issue for your changes first.
 
-## Installation 
+## Installation
 
 Install the package with `npm`: