feat(dns): added support for a custom lookup function; (#5339)

[MitchLewis930]

User description

PR_026

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PR Type

Enhancement

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Description

• Added support for custom DNS lookup functions in HTTP adapter

• Supports both callback-based and async lookup functions

• Implemented callbackify helper to convert async functions to callbacks

• Added family option for IPv4/IPv6 selection

• Comprehensive test coverage and TypeScript type definitions

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Diagram Walkthrough

flowchart LR
  A["HTTP Adapter Config"] -->|lookup option| B["Callbackify Helper"]
  B -->|converts async| C["Callback Function"]
  C -->|passes to| D["Node.js HTTP Options"]
  A -->|family option| D
  E["Utils Functions"] -->|isAsyncFn detection| B

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File Walkthrough

	Relevant files
Enhancement	http.js Integrated custom DNS lookup support                                          lib/adapters/http.js Imported callbackify helper for async function conversion Extracted lookup and family from config parameters Added logic to detect and convert async lookup functions to callbacks Passed lookup and family to Node.js HTTP request options +15/-1    callbackify.js New async-to-callback converter utility                                    lib/helpers/callbackify.js New helper file that converts async functions to callback-based functions Supports optional reducer function for transforming return values Handles error propagation from async functions to callbacks +16/-0    utils.js Added function type detection utilities                                    lib/utils.js Added isAsyncFn function to detect async functions Added isGeneratorFn and isAsyncGeneratorFn for generator detection Added isPlainFunction to identify regular functions Added isThenable to detect promise-like objects Exported all new utility functions +15/-1
Tests	http.js Added comprehensive DNS lookup tests                                          test/unit/adapters/http.js Added SERVER_HANDLER_STREAM_ECHO constant for test server Added DNS test suite with three test cases Tests cover callback-based lookup, async lookup, and async lookup returning only IP Verifies lookup function is called and request succeeds +61/-0
Documentation	index.d.ts Added DNS lookup TypeScript definitions                                    index.d.ts Added family option typed as 4 | 6 | undefined for IPv4/IPv6 selection Added lookup option with dual signatures for callback and async functions Fixed formatting in beforeRedirect type definition +4/-1      index.d.cts Added DNS lookup CommonJS type definitions                              index.d.cts Added family option typed as 4 | 6 | undefined Added lookup option with callback and async function signatures +3/-0      index.ts Added DNS lookup TypeScript usage examples                              test/module/typings/esm/index.ts Added example usage of callback-based lookup function Added example usage of async lookup function Demonstrates both function signatures for TypeScript validation +14/-0
Formatting	CHANGELOG.md Fixed file formatting                                                                        CHANGELOG.md Fixed newline at end of file +1/-1

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[qodo-code-review]

PR Compliance Guide 🔍

Below is a summary of compliance checks for this PR:

Security Compliance
🟢	No security concerns identified No security vulnerabilities detected by AI analysis. Human verification advised for critical code.
Ticket Compliance
⚪	🎫 No ticket provided Create ticket/issue
Codebase Duplication Compliance
⚪	Codebase context is not defined Follow the guide to enable codebase context checks.
Custom Compliance
🟢	Generic: Comprehensive Audit Trails Objective: To create a detailed and reliable record of critical system actions for security analysis and compliance. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Meaningful Naming and Self-Documenting Code Objective: Ensure all identifiers clearly express their purpose and intent, making code self-documenting Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Error Handling Objective: To prevent the leakage of sensitive system information through error messages while providing sufficient detail for internal debugging. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Secure Logging Practices Objective: To ensure logs are useful for debugging and auditing without exposing sensitive information like PII, PHI, or cardholder data. Status: Passed Learn more about managing compliance generic rules or creating your own custom rules
⚪	Generic: Robust Error Handling and Edge Case Management Objective: Ensure comprehensive error handling that provides meaningful context and graceful degradation Status: Lookup return validation: The async lookup normalization validates the return is an array but does not validate array length/value types (e.g., [address, family]), which may lead to unclear downstream failures for malformed returns. Referred Code let {data, lookup, family} = config; const {responseType, responseEncoding} = config; const method = config.method.toUpperCase(); let isDone; let rejected = false; let req; if (lookup && utils.isAsyncFn(lookup)) { lookup = callbackify(lookup, (entry) => { if(utils.isString(entry)) { entry = [entry, entry.indexOf('.') < 0 ? 6 : 4] } else if (!utils.isArray(entry)) { throw new TypeError('lookup async function must return an array [ip: string, family: number]]') } return entry; }) } Learn more about managing compliance generic rules or creating your own custom rules
	Generic: Security-First Input Validation and Data Handling Objective: Ensure all data inputs are validated, sanitized, and handled securely to prevent vulnerabilities Status: Unvalidated family value: The family option from config is forwarded into Node request options without runtime validation (expected 4 | 6), which could cause unexpected behavior or errors if user-provided input is malformed. Referred Code let {data, lookup, family} = config; const {responseType, responseEncoding} = config; Learn more about managing compliance generic rules or creating your own custom rules

Compliance status legend

🟢 - Fully Compliant
🟡 - Partial Compliant
🔴 - Not Compliant
⚪ - Requires Further Human Verification
🏷️ - Compliance label

[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
Possible issue	Use net.isIP() for IP validation Replace the naive IP family detection logic with Node.js's net.isIP() function for accurate and reliable validation of IP addresses returned by the lookup function. lib/adapters/http.js [159-163] if(utils.isString(entry)) { - entry = [entry, entry.indexOf('.') < 0 ? 6 : 4] + const family = net.isIP(entry); + if (family === 0) { + throw new TypeError('lookup async function must return a valid IP address string'); + } + entry = [entry, family]; } else if (!utils.isArray(entry)) { - throw new TypeError('lookup async function must return an array [ip: string, family: number]]') + throw new TypeError('lookup async function must return an array [ip: string, family: number] or an IP address string.') } Apply / Chat Suggestion importance[1-10]: 8 __ Why: The suggestion correctly identifies that the IP family detection logic is flawed and proposes using the robust net.isIP() function, which fixes a correctness bug and improves validation.	Medium
General	Fix typo in error message Fix a typo in the TypeError message by removing an extra closing bracket. lib/adapters/http.js [162] -throw new TypeError('lookup async function must return an array [ip: string, family: number]]') +throw new TypeError('lookup async function must return an array [ip: string, family: number]') Apply / Chat Suggestion importance[1-10]: 2 __ Why: This suggestion corrects a minor typo in an error message, which improves developer experience but has no impact on runtime behavior.	Low
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