OAuth Configuration Validator

Build a command-line tool that validates OAuth 2.0 client configuration files and generates authorization URLs for Google API access.

Requirements

Your tool should:

1. Accept a path to a JSON client secrets file as a command-line argument
2. Load and validate the client configuration from the file
3. Create an OAuth 2.0 flow with the specified scopes: https://www.googleapis.com/auth/drive.readonly and https://www.googleapis.com/auth/userinfo.email
4. Generate an authorization URL that requests offline access
5. Output the authorization URL and state parameter to stdout in the format:

   Authorization URL: <url>
   State: <state>

6. Handle errors gracefully, printing error messages to stderr and exiting with code 1 on failure

Implementation

Create a Python script oauth_validator.py that implements the above requirements. The script should accept a single command-line argument for the client secrets file path.

Dependencies { .dependencies }

google-auth-oauthlib { .dependency }

Provides OAuth 2.0 authorization flow support for Google APIs.

Test Cases

Test 1: Valid Configuration { @test }

Given a valid client secrets file test_client_secrets.json:

{
  "installed": {
    "client_id": "test_client_id.apps.googleusercontent.com",
    "client_secret": "test_secret",
    "auth_uri": "https://accounts.google.com/o/oauth2/auth",
    "token_uri": "https://oauth2.googleapis.com/token",
    "redirect_uris": ["http://localhost"]
  }
}

When running: python oauth_validator.py test_client_secrets.json

The output should contain:

• A line starting with "Authorization URL: https://accounts.google.com/o/oauth2/auth"
• A line starting with "State: " followed by a non-empty string
• The authorization URL should include parameters for the requested scopes and offline access

Test 2: Missing File { @test }

When running: python oauth_validator.py nonexistent.json

The script should:

• Print an error message to stderr
• Exit with code 1

Test 3: Multiple Scopes in URL { @test }

Using the same valid configuration from Test 1, verify that the generated authorization URL includes both requested scopes in the URL parameters.