chore(nix): remove redundant tsgolint and add nix-workflow rule (#297)

* chore(nix): remove redundant tsgolint package

The tsgolint binary is bundled with the oxlint package in nixpkgs,
so specifying it separately is unnecessary. This removes the duplicate
from both flake.nix and CI workflow.

* docs(rules): add nix-workflow rule

Add comprehensive documentation for Nix usage in the project:
- Development environment setup with flake.nix
- CI workflow using nix profile install via setup-nix action
- Tool configuration and adding new packages
- Build flags for local development

This helps maintain consistency when modifying Nix configuration.

* chore(ci): remove unused similarity and nixfmt from lint job

These tools are not used by pnpm lint (only oxfmt, oxlint, knip).

* chore(nix): update flake.lock

Author: ryoppippi

.claude/rules/nix-workflow.md

@@ -0,0 +1,88 @@
+# Nix Workflow
+
+This rule provides guidance on Nix usage in the StackOne SDK.
+
+## Development Environment
+
+The project uses `flake.nix` to define the development environment with `nix develop`.
+
+### Adding Development Tools
+
+To add a new tool to the development environment, add it to `buildInputs` in `flake.nix`:
+
+```nix
+buildInputs = with pkgs; [
+  # runtime
+  nodejs_24
+  pnpm_10
+
+  # formatting and linting tools
+  oxlint  # includes tsgolint
+  oxfmt
+
+  # your new tool here
+  new-tool
+];
+```
+
+## CI Workflow
+
+CI uses `nix profile install` via the `.github/actions/setup-nix/action.yaml` composite action.
+
+### Adding Tools to CI Jobs
+
+Specify tools in the `tools` input of the setup-nix action:
+
+```yaml
+- name: Setup Nix
+  uses: ./.github/actions/setup-nix
+  with:
+    tools: nodejs_24 pnpm_10 oxlint oxfmt
+```
+
+The action installs packages using:
+
+```bash
+nix profile install --inputs-from . nixpkgs#tool1 nixpkgs#tool2
+```
+
+### CI Tool Configuration
+
+- **Default tools**: `nodejs_24 pnpm_10` (defined in action.yaml)
+- **Skip pnpm install**: Set `skip-pnpm-install: 'true'` for jobs that don't need node dependencies
+
+### Example: Adding a New Tool to Lint Job
+
+```yaml
+lint:
+  runs-on: ubuntu-latest
+  steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+    - name: Setup Nix
+      uses: ./.github/actions/setup-nix
+      with:
+        tools: nodejs_24 pnpm_10 oxlint oxfmt new-tool
+    - name: Run Lint
+      run: pnpm run lint
+```
+
+## Build Flags
+
+Always use these flags when running Nix build commands locally:
+
+```bash
+--print-build-logs --show-trace
+```
+
+Example:
+
+```bash
+nix build --print-build-logs --show-trace
+nix flake check --print-build-logs --show-trace
+```
+
+## Notes
+
+- Some packages bundle multiple tools (e.g., `oxlint` includes `tsgolint`)
+- Check nixpkgs for package contents before adding redundant dependencies

.github/workflows/ci.yaml

@@ -41,7 +41,7 @@ jobs:
       - name: Setup Nix
         uses: ./.github/actions/setup-nix
         with:
-          tools: nodejs_24 pnpm_10 oxlint oxfmt similarity nixfmt tsgolint
+          tools: nodejs_24 pnpm_10 oxlint oxfmt
       - name: Run Lint
         run: pnpm run lint
 

CLAUDE.md

@@ -15,6 +15,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 | **pnpm-usage**           | All files      | pnpm commands and troubleshooting                  |
 | **git-workflow**         | All files      | Commit conventions, branch strategy, PR guidelines |
 | **development-workflow** | All files      | Code style, file naming, project conventions       |
+| **nix-workflow**         | All files      | Nix development environment and CI setup           |
 | **typescript-patterns**  | `**/*.ts`      | Type safety, exhaustiveness checks, clean code     |
 | **typescript-testing**   | `**/*.test.ts` | Vitest, MSW mocking, fs-fixture                    |
 | **file-operations**      | `**/*.ts`      | Native fetch API patterns and error handling       |

flake.lock

@@ -31,7 +31,6 @@
               # formatting and linting tools
               similarity
               nixfmt
-              tsgolint
               oxlint
               oxfmt