feat: support FC22 in servers

[yguyot]

Problem

• FC22 is supported by the client but not by the servers.

Solution

• Add FC22 support to TCP and RTU servers.
• Add setRegisterMask to the server vector.
• Support synchronous, callback, and Promise handlers.
• Handle invalid requests and vector errors.

Tests

• Add TCP and RTU coverage.
• Cover success and error scenarios.
• Lint and full test suite passing.

Documentation

• Update TypeScript declarations.
• Update the server examples.
• Update the README with the new server vector method.

Summary by CodeRabbit

• New Features
  • Added Modbus Function Code 22 (Mask Write Register) handling on both TCP and serial servers.
  • Supports callback-, Promise-, and synchronous-style setRegisterMask implementations.
  • Returns correct FC22 responses and Modbus exceptions for unsupported or failing requests.
• Documentation
  • Updated the ModbusTCP server README example and added public type declarations for setRegisterMask.
• Tests
  • Added FC22 test coverage across TCP variants and serial, including success, malformed requests, and failure/exception scenarios.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: c9f54ad2-bbc1-421b-be6d-09336a969ea5

📥 Commits

Reviewing files that changed from the base of the PR and between 131c2fa and 8a76a2e.

📒 Files selected for processing (1)

• examples/server.js

🚧 Files skipped from review as they are similar to previous changes (1)

• examples/server.js

---

📝 Walkthrough

Walkthrough

Modbus serial and TCP servers now support Modbus function code 22, including typed vector handlers, callback/Promise/synchronous execution, response generation, error handling, examples, and protocol tests.

Changes

Modbus FC22 mask-write support

Layer / File(s)	Summary
FC22 contract and handler ServerTCP.d.ts, servers/servertcp_handler.js, servers/serverserial.js, servers/servertcp.js	Adds the optional setRegisterMask API, dispatches function code 22, parses mask parameters, invokes supported handler styles, and returns echoed responses or Modbus errors.
Serial and TCP behavior coverage test/servers/serverserial.test.js, test/servers/servertcp*.test.js	Tests successful masking, response frames, synchronous/callback/Promise failures, missing handlers, short requests, and unit IDs.
Example vector support README.md, examples/server.js	Adds setRegisterMask logging callbacks to the server examples.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant ModbusClient
  participant ModbusServer
  participant maskWriteRegister
  participant setRegisterMask
  ModbusClient->>ModbusServer: Send FC22 request
  ModbusServer->>maskWriteRegister: Dispatch request
  maskWriteRegister->>setRegisterMask: Pass address and masks
  setRegisterMask-->>maskWriteRegister: Complete or return error
  maskWriteRegister-->>ModbusClient: Echo response or exception

Loading

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: adding FC22 support to the servers.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 ESLint

If the error stems from missing dependencies, add them to the package.json file. For unrecoverable errors (e.g., due to private dependencies), disable the tool in the CodeRabbit configuration.

ESLint install timed out. The project may have too many dependencies for the sandbox.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@examples/server.js`:
- Line 25: Update the setRegisterMask function signature in the example to
accept unitID as the fourth parameter after addr, andMask, and orMask, and
include it in the existing log output so the example matches the FC22 invocation
contract.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: a81a4d26-580e-43e2-bc6b-8a4a31656b4e

📥 Commits

Reviewing files that changed from the base of the PR and between 3200f11 and 131c2fa.

📒 Files selected for processing (10)

• README.md
• ServerTCP.d.ts
• examples/server.js
• servers/serverserial.js
• servers/servertcp.js
• servers/servertcp_handler.js
• test/servers/serverserial.test.js
• test/servers/servertcp.test.js
• test/servers/servertcpCallback.test.js
• test/servers/servertcpPromise.test.js

[yaacov]

Thank you for the pull request 💚

please address the automatic comment

[yguyot]

Is it possible to get a npm release ? Thanks