|
| 1 | +--- |
| 2 | +title: Devtools |
| 3 | +description: Enhance your Effect development experience with the Effect Language Service and official VS Code/Cursor extension for advanced diagnostics, refactors, and intelligent code completion. |
| 4 | +sidebar: |
| 5 | + order: 3 |
| 6 | +--- |
| 7 | + |
| 8 | +import { Aside, Steps, Tabs, TabItem } from "@astrojs/starlight/components" |
| 9 | + |
| 10 | +Effect provides powerful development tools to enhance your coding experience and help you write safer, more maintainable code. These tools integrate directly into your editor, providing real-time feedback, intelligent refactors, and helpful diagnostics. |
| 11 | + |
| 12 | +## Effect LSP |
| 13 | + |
| 14 | +The Effect LSP extends your editor with Effect-specific features. It analyzes your Effect code and provides intelligent assistance through diagnostics, quick info, completions, and automated refactors. |
| 15 | + |
| 16 | +It works in editors that supports the standard TypeScript LSP, such as Code, Cursor, Zed, NVim, etc. |
| 17 | + |
| 18 | +### Installation |
| 19 | + |
| 20 | +To install the Effect Language Service in your project: |
| 21 | + |
| 22 | +<Steps> |
| 23 | + |
| 24 | +1. Install the package as a development dependency: |
| 25 | + |
| 26 | + For monorepos, we suggest to install the language service at the root level. For single-package projects, install it in the package directory. |
| 27 | + |
| 28 | + <Tabs syncKey="package-manager"> |
| 29 | + |
| 30 | + <TabItem label="npm" icon="seti:npm"> |
| 31 | + |
| 32 | + ```sh showLineNumbers=false |
| 33 | + npm install @effect/language-service --save-dev |
| 34 | + ``` |
| 35 | + |
| 36 | + </TabItem> |
| 37 | + |
| 38 | + <TabItem label="pnpm" icon="pnpm"> |
| 39 | + |
| 40 | + ```sh showLineNumbers=false |
| 41 | + pnpm add -D @effect/language-service |
| 42 | + ``` |
| 43 | + |
| 44 | + </TabItem> |
| 45 | + |
| 46 | + <TabItem label="Yarn" icon="seti:yarn"> |
| 47 | + |
| 48 | + ```sh showLineNumbers=false |
| 49 | + yarn add --dev @effect/language-service |
| 50 | + ``` |
| 51 | + |
| 52 | + </TabItem> |
| 53 | + |
| 54 | + <TabItem label="Bun" icon="bun"> |
| 55 | + |
| 56 | + ```sh showLineNumbers=false |
| 57 | + bun add --dev @effect/language-service |
| 58 | + ``` |
| 59 | + |
| 60 | + </TabItem> |
| 61 | + |
| 62 | + </Tabs> |
| 63 | + |
| 64 | +2. Add the plugin to your `tsconfig.json`: |
| 65 | + |
| 66 | + ```json title="tsconfig.json" |
| 67 | + { |
| 68 | + "compilerOptions": { |
| 69 | + "plugins": [ |
| 70 | + { |
| 71 | + "name": "@effect/language-service" |
| 72 | + } |
| 73 | + ] |
| 74 | + } |
| 75 | + } |
| 76 | + ``` |
| 77 | + |
| 78 | +3. Ensure your editor uses the workspace TypeScript version: |
| 79 | + |
| 80 | + This step is critical for the language service to function properly. The plugin must run on the TypeScript version installed in your project, not the one bundled with your editor. |
| 81 | + |
| 82 | + <Aside type="tip"> |
| 83 | + In VS Code or Cursor, you can select the workspace TypeScript version by opening a TypeScript file, clicking on the TypeScript version number in the status bar, and selecting "Use Workspace Version". |
| 84 | + </Aside> |
| 85 | + |
| 86 | +4. You're ready to play! |
| 87 | + |
| 88 | + Writing the following code in a file.ts inside your project, should result in an error diagnostic appearing, saying that Effect's must be yielded or assigned to a variable: |
| 89 | + |
| 90 | + ```ts |
| 91 | + import { Effect } from "effect" |
| 92 | + |
| 93 | + Effect.log("Hello world!") |
| 94 | + // ^- should be run or assigned to a variable! |
| 95 | + ``` |
| 96 | + |
| 97 | +</Steps> |
| 98 | + |
| 99 | + |
| 100 | +### Features |
| 101 | + |
| 102 | +The Effect Language Service provides a comprehensive set of features to enhance your development workflow: |
| 103 | + |
| 104 | +#### Intelligent Quick Info |
| 105 | + |
| 106 | +Hover over Effect values to see extended type information and detailed insights: |
| 107 | + |
| 108 | +- **Effect Types**: See comprehensive type information for Effect values |
| 109 | +- **Generator Parameters**: When hovering over `yield*` in `Effect.gen`, view detailed information about the yielded value |
| 110 | +- **Layer Composition**: Visualize layer dependencies with interactive graphs showing how layers compose together |
| 111 | +- **Service Dependencies**: Understand service requirements and their relationships at a glance |
| 112 | + |
| 113 | +#### Real-time Diagnostics |
| 114 | + |
| 115 | +Catch common mistakes and potential issues as you write code: |
| 116 | + |
| 117 | +- **Floating Effects**: Detect Effect values that aren't assigned or yielded, preventing silent bugs |
| 118 | +- **Layer Issues**: Catch layer requirement leaks and scope violations before runtime |
| 119 | +- **Unnecessary Code**: Identify redundant `Effect.gen` or `pipe()` calls |
| 120 | +- **Error Handling**: Detect misuse of catch functions on Effects that cannot fail |
| 121 | +- **Version Conflicts**: Detect when multiple Effect versions are present in your project |
| 122 | + |
| 123 | +#### Smart Completions |
| 124 | + |
| 125 | +Speed up your coding with context-aware suggestions: |
| 126 | + |
| 127 | +- **Generator Boilerplate**: Quickly scaffold `Effect.gen` functions |
| 128 | +- **Scaffolds**: For `Effect.Service`, `Data.TaggedError` and friends. |
| 129 | +- **Self Parameters**: Auto-complete for `Self` parameters in service declarations |
| 130 | + |
| 131 | +#### Powerful Refactors |
| 132 | + |
| 133 | +Transform your code with intelligent automated refactors: |
| 134 | + |
| 135 | +- **Async to Effect**: Convert async functions to Effect using `gen` or `fn` syntax |
| 136 | +- **Error Generation**: Generate tagged errors from promise-based code |
| 137 | +- **Service Accessors**: Automatically implement service accessor functions |
| 138 | +- **Pipe Conversion**: Transform function calls to pipe syntax |
| 139 | +- **Pipe Styles**: Toggle between different pipe style formats |
| 140 | +- **Layer Magic**: Automatically compose layers with correct dependencies |
| 141 | + |
| 142 | +### Configuration |
| 143 | + |
| 144 | +The Effect LSP provides also lots of configuration options such as changing severity or disabling diagnostic messages. |
| 145 | + |
| 146 | +To see the full list of options and features, please visit the [README from the LSP repository](https://github.com/Effect-TS/language-service). |
| 147 | + |
| 148 | +### Build-Time Diagnostics |
| 149 | + |
| 150 | +While LSPs only activate during editing sessions, you may want to catch diagnostics during your build process. |
| 151 | + |
| 152 | +Usually that's done through linting rules, but since almost all of the Effect diagnostics relies on types, that would mean enabling type-aware linting, which means performing type checking again on the project files. |
| 153 | + |
| 154 | +To solve this, the Effect Language Service allows you to patch your local TypeScript installation, so diagnostics are emitted while performing type checking. |
| 155 | + |
| 156 | +To enable it run the following command to modify your local TypeScript installation: |
| 157 | + |
| 158 | +```sh showLineNumbers=false |
| 159 | +effect-language-service patch |
| 160 | +``` |
| 161 | + |
| 162 | +To make this automatic for all developers, add it to your `package.json`: |
| 163 | + |
| 164 | +```json title="package.json" |
| 165 | +{ |
| 166 | + "scripts": { |
| 167 | + "prepare": "effect-language-service patch" |
| 168 | + } |
| 169 | +} |
| 170 | +``` |
| 171 | + |
| 172 | +This ensures the language service runs during compilation with the standard `tsc` command. |
| 173 | + |
| 174 | + |
| 175 | +## VS Code / Cursor Extension |
| 176 | + |
| 177 | +<Aside type="caution"> |
| 178 | +The editor extension does not include the Effect LSP! Installation of that should be performed per-project, this allows fine grained control on when to load it, for which projects and with a version pinned with your repository lockfile. |
| 179 | +</Aside> |
| 180 | + |
| 181 | +The editor extension provides utilities in helping you debug your Effect applications. |
| 182 | + |
| 183 | +At the moment only Code and Code forks like Cursor are supported. |
| 184 | + |
| 185 | +### Installation |
| 186 | + |
| 187 | +The extension can be installed by searching directly in your editor extension page or from the [Code Marketplace](https://marketplace.visualstudio.com/items?itemName=effectful-tech.effect-vscode) or the [Open VSX Marketplace](https://open-vsx.org/extension/effectful-tech/effect-vscode). |
| 188 | + |
| 189 | +### Debugger Features |
| 190 | + |
| 191 | +With the Effect Extension, you'll find couple of new sections inside the Debug section of your editor that, once you pause execution, will . |
| 192 | + |
| 193 | +- **Context**: Allows you to inspect the context of the currently paused Effect Fiber. |
| 194 | +- **Span Stack**: Shows you the stack of telemetry spans that lead you into the execution of the currently paused Effect. |
| 195 | +- **Fibers**: List all the Effect Fibers running in your application, allows you to inspect informations such as interrupt-ability and allows to request interruption of them. |
| 196 | +- **Breakpoints**: Allows to enable "pause on defect"; letting your debugger pause when a Effect Fiber fails with a defect. |
| 197 | + |
| 198 | +### Built-in Tracer and Metrics |
| 199 | + |
| 200 | +The built-in tracer and metrics view allows to quickly see Effect Spans and Metrics of your app without spinning up an entire telemetry service. |
| 201 | + |
| 202 | +To enable it, you need to install the following dependency in your project: |
| 203 | + |
| 204 | +<Tabs syncKey="package-manager"> |
| 205 | + |
| 206 | +<TabItem label="npm" icon="seti:npm"> |
| 207 | + |
| 208 | +```sh showLineNumbers=false |
| 209 | +npm install @effect/experimental |
| 210 | +``` |
| 211 | + |
| 212 | +</TabItem> |
| 213 | + |
| 214 | +<TabItem label="pnpm" icon="pnpm"> |
| 215 | + |
| 216 | +```sh showLineNumbers=false |
| 217 | +pnpm install @effect/experimental |
| 218 | +``` |
| 219 | + |
| 220 | +</TabItem> |
| 221 | + |
| 222 | +<TabItem label="Yarn" icon="seti:yarn"> |
| 223 | + |
| 224 | +```sh showLineNumbers=false |
| 225 | +yarn add @effect/experimental |
| 226 | +``` |
| 227 | + |
| 228 | +</TabItem> |
| 229 | + |
| 230 | +<TabItem label="Bun" icon="bun"> |
| 231 | + |
| 232 | +```sh showLineNumbers=false |
| 233 | +bun add @effect/experimental |
| 234 | +``` |
| 235 | + |
| 236 | +</TabItem> |
| 237 | + |
| 238 | +</Tabs> |
| 239 | + |
| 240 | +You can then import and use the DevTools module in your Effect app: |
| 241 | + |
| 242 | +```ts |
| 243 | +import { DevTools } from "@effect/experimental" |
| 244 | +import { NodeRuntime, NodeSocket } from "@effect/platform-node" |
| 245 | +import { Effect, Layer } from "effect" |
| 246 | + |
| 247 | +const program = Effect.log("Hello!").pipe( |
| 248 | + Effect.delay(2000), |
| 249 | + Effect.withSpan("Hi", { attributes: { foo: "bar" } }), |
| 250 | + Effect.forever, |
| 251 | +) |
| 252 | +const DevToolsLive = DevTools.layer() |
| 253 | + |
| 254 | +program.pipe(Effect.provide(DevToolsLive), NodeRuntime.runMain) |
| 255 | +``` |
| 256 | + |
| 257 | +If you are using `@effect/opentelemetry` in your project, then it is important that you provide the DevTools layer before your tracing layers, so the tracer is patched correctly. |
| 258 | + |
| 259 | +Now start both your editor and your app. Inside the Effect panel, in the clients section you'll see a newly connected client. |
| 260 | + |
| 261 | +In the bottom of your editor, near your terminal, a new tab "Effect Tracer" will appear as well, showing visually your spans as they happen in real time. |
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