Add B2B

[IvanBila]

Summary

This PR adds B2B support to the library

[thatfiredev]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds B2B payment support by introducing a new intiate_b2b function. The implementation is straightforward, but I've provided a suggestion to improve the new function. The feedback focuses on fixing a typo in the function name, adhering to common JavaScript naming conventions for parameters, improving code clarity with modern syntax like template literals, and ensuring consistency with the existing codebase.

[gemini-code-assist]

This new function has a few areas for improvement regarding consistency, conventions, and clarity.

• Typo: There's a typo in the function name (intiate_b2b). It should be initiate_b2b to match other functions.
• Parameter Naming: The parameter names (e.g., input_Amount) are inconsistent with JavaScript's camelCase convention. The input_ prefix is also redundant.
• Code Clarity:
  • The response variable can be declared with const as it's not reassigned.
  • Using template literals for URL and Authorization header strings is cleaner.
  • Explicitly converting input_Amount to a string with String() is more readable than using + "".
• Consistency: The function definition is missing a semicolon at the end, which is present on other similar functions in this file.

Here is a refactored version that addresses all these points:

module.exports.initiate_b2b = async function (amount, transactionReference, thirdPartyReference, primaryPartyCode, receiverPartyCode) {
    initialize_api_from_dotenv();
    try {
        const response = await axios({
            method: 'post',
            url: `https://${mpesaConfig.baseUrl}:18349/ipg/v1x/b2bPayment/`,
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${_getBearerToken(mpesaConfig.publicKey, mpesaConfig.apiKey)}`,
                'Origin': mpesaConfig.origin
            },
            data: {
                "input_TransactionReference": transactionReference,
                "input_Amount": String(amount),
                "input_ThirdPartyReference": thirdPartyReference,
                "input_PrimaryPartyCode": primaryPartyCode,
                "input_ReceiverPartyCode": receiverPartyCode
            }
        });
        return response.data;
    } catch (e) {
        if (e.response && e.response.data) {
            throw e.response.data;
        } else {
            throw e;
        }
    }
};