Editor page + reanalyze guide

data/sidebar_manual_v1200.json

@@ -67,7 +67,8 @@
     "warning-numbers"
   ],
   "Guides": [
-    "converting-from-js"
+    "converting-from-js",
+    "editor-code-analysis"
   ],
   "Extra": [
     "newcomer-examples",

pages/docs/manual/v12.0.0/editor-code-analysis.mdx

@@ -0,0 +1,158 @@
+---
+title: "Editor"
+metaTitle: "Editor"
+description: "Documentation about ReScript editor plugins and code analysis"
+canonical: "/docs/manual/v12.0.0/editor-plugins"
+---
+
+# Guide: Dead Code Analysis in ReScript
+
+This guide provides a detailed walkthrough on how to leverage ReScript’s powerful dead code analysis tools to maintain a clean, efficient, and distraction-free codebase.
+
+Dead code refers to code that's present in your codebase but is never executed. It can lead to:
+
+- Increased compilation times
+- Confusion during development
+- Misleading assumptions about functionality
+
+ReScript’s language design allows for accurate and efficient dead code analysis using the **ReScript Code Analyzer**, available via the official VSCode extension.
+
+### Prerequisites
+
+- ReScript VSCode extension (v1.8.2 or higher)
+
+### Activation
+
+1. Open the Command Palette: `Cmd/Ctrl + P`
+2. Run: `> ReScript: Start Code Analyzer`
+
+### Deactivation
+
+- Run: `> ReScript: Stop Code Analyzer` 
+- Or click “Stop Code Analyzer” in the status bar
+
+### Result
+
+- The “Problems” pane populates with dead code warnings and suggestions.
+
+## Real-World Use Cases
+
+### 1. **Unused Record Fields**
+
+```rescript
+type useReturn = {
+  items: array<item>,
+  toggleItemChecked: string => unit, // ← Never used
+  setCheckedOnItem: (string, bool) => unit,
+  checkAll: unit => unit,
+  uncheckAll: unit => unit,
+}
+```
+
+Remove unused fields to simplify code.
+
+### 2. **Unused Variant Cases**
+
+```rescript
+type textType =
+  | Text(string)
+  | TextWithIcon({icon: React.element, text: string})
+  | Render(React.element) // ← Never constructed
+```
+
+Removing unused variants allows simplifying rendering logic.
+
+### 3. **Unused Parts of State**
+
+```rescript
+type validationState = Idle | Invalid | Valid
+
+type state = {
+  oldPassword: string,
+  newPassword: string,
+  newPasswordRepeated: string,
+  validationState: validationState, // ← Never read
+}
+```
+
+Old validation logic might remain after refactors—clean it up.
+
+### 4. **Unnecessary Interface Exposure**
+
+```rescript
+// DrilldownTarget.resi
+MetricParam.parse // ← Never used
+MetricParam.serialize // ← Never used
+```
+
+Keep interfaces minimal by removing unused exports.
+
+### 5. **Unused Functions**
+
+```rescript
+let routerUrlToPath = ... // ← Never used
+let routeUrlStartsWith = ... // ← Never used
+```
+
+Removing these often uncovers further unused logic.
+
+### 6. **Unused Components**
+
+Components never referenced in production should be removed, unless explicitly preserved.
+
+
+## Keeping Some Dead Code
+
+### Use `@dead` and `@live`
+
+#### `@dead`
+
+Suppresses warnings but notifies if code becomes alive again.
+
+```rescript
+type user = {
+  name: string,
+  @dead age: int,
+}
+```
+
+#### `@live`
+
+Permanently marks code as alive (no future warnings).
+
+```rescript
+@live
+let getUserName = user => user.name
+```
+
+## Configuration
+
+Add to your `rescript.json`:
+
+```json
+"reanalyze": {
+  "analysis": ["dce"],
+  "suppress": ["src/bindings", "src/stories", "src/routes"],
+  "unsuppress": [],
+  "transitive": false
+}
+```
+
+### Options:
+
+- **analysis**: Enables dead code analysis (`"dce"`)
+- **suppress**: Silences reporting for paths (still analyzes)
+- **unsuppress**: Re-enables reports within suppressed paths
+- **transitive**: Controls reporting of indirectly dead code
+
+**Recommendation:** Set `transitive: false` for incremental cleanup.
+
+## Summary
+
+ReScript’s dead code analyzer helps you:
+
+- Incrementally clean up your codebase
+- Avoid confusion and complexity
+- Improve long-term maintainability
+
+Use it regularly for the best results.

pages/docs/manual/v12.0.0/editor-plugins.mdx

@@ -1,19 +1,52 @@
 ---
-title: "Editor Plugins"
-description: "List of ReScript editor plugins"
+title: "Editor"
+metaTitle: "Editor"
+description: "Documentation about ReScript editor plugins and code analysis"
 canonical: "/docs/manual/v12.0.0/editor-plugins"
 ---
 
-# Editor Plugins
+# Editor
+
+This section is about the editor plugin for ReScript. It adds syntax highlighting, autocomplete, type hints, formatting, code navigation, code analysis for `.res` and `.resi` files.
+
+
+## Plugins
 
 - [VSCode](https://marketplace.visualstudio.com/items?itemName=chenglou92.rescript-vscode)
 - [Sublime Text](https://github.com/rescript-lang/rescript-sublime)
 - [Vim/Neovim](https://github.com/rescript-lang/vim-rescript)
 
-## Community Supported
+### Community Supported
 
 We don't officially support these; use them at your own risk!
 
 - [Neovim Tree-sitter](https://github.com/nkrkv/nvim-treesitter-rescript)
 - [IDEA](https://github.com/reasonml-editor/reasonml-idea-plugin)
 - [Emacs](https://github.com/jjlee/rescript-mode)
+
+
+## Code analysis
+
+The code analysis provides extra checks for your ReScript project, such as detecting dead code and unhandled exceptions. It's powered by [reanalyze](https://github.com/rescript-association/reanalyze), which is built into the extension—no separate install required.
+
+### How to Use
+
+- Open the command palette and run:  
+  `ReScript: Start Code Analyzer`
+- Warnings like dead code will show inline in the editor.
+- Suppression actions are available where applicable.
+- To stop analysis, click **Stop Code Analyzer** in the status bar.
+
+### Configuration
+
+Add a `reanalyze` section to your `rescript.json` to control what the analyzer checks or ignores. You’ll get autocomplete for config options in the editor.  
+More details: [reanalyze config docs](https://github.com/rescript-association/reanalyze#configuration-via-bsconfigjson)
+
+### Guide
+
+Look [here](editor-code-analysis) for a more detailed guide about how to use the code analysis tool.
+
+### Caveats
+
+- Doesn't support cross-package dead code analysis in monorepos. Run it per package instead.
+