diff --git a/docs/pages/repo/docs/core-concepts/caching.mdx b/docs/pages/repo/docs/core-concepts/caching.mdx index df638ed26d4bb..59a3ac82e9b37 100644 --- a/docs/pages/repo/docs/core-concepts/caching.mdx +++ b/docs/pages/repo/docs/core-concepts/caching.mdx @@ -83,6 +83,85 @@ turbo run build --force Note that `--force` disables cache reads but does not disable cache writes. If you want to disable cache writes, use the `--no-cache` flag. +## Handling Node.js versions + +To account for Node.js versions, use [the `engines` key in package.json](https://docs.npmjs.com/cli/v10/configuring-npm/package-json#engines). Turborepo will see the changes to your `package.json` and miss cache when the field is updated. + +## Handling platforms and other arbitrary hash contributors + +For advanced use cases, you may want the operating system (OS), architecture, or other external factors to contribute to your hash. You can do this in four quick steps. + +### 1. Write an arbitrary file to disk + +First, create a script that accounts for the hash contributors that you are interested in. For example, here is a Node.js script that looks at platform and architecture and writes those details to a file (`turbo-cache-key.json`): + +```js +#!/usr/bin/env node + +const { writeFileSync } = require('fs'); +const { join } = require('path'); + +const { platform, arch } = process; +const file = "turbo-cache-key.json"; +const str = JSON.stringify({ platform, arch }); +console.log(`Generating cache key: ${str}`); +writeFileSync(file, str); +``` + +### 2. Add the file to your .gitignore + +You won't want to commit this file to source control since it's dependent on environment. Add it to your `.gitignore`: + +```txt +// .gitignore + ++ turbo-cache-key.json +``` + +### 3. Add the file to the hash + +Now, make sure that `turbo` is aware of the file by adding it to task inputs. You can do this two ways: + +- **For specific tasks**: Include the file in [the `inputs` array](/repo/docs/reference/configuration#inputs) of the task(s): + +```json +{ + "$schema": "https://turbo.build/schema.json", + "pipelines": { + "build-for-platforms": { + "dependsOn": ["^build"], + "inputs": ["turbo-cache-key.json", ...] + } + } +} +``` + +- **For all tasks**: Add the file to [`globalDependencies`](/repo/docs/reference/configuration#globaldependencies) + +```json +{ + "$schema": "https://turbo.build/schema.json", + "globalDependencies": ["turbo-cache-key.json"], + "pipelines": { + ... + } +} +``` + +### 4. Generate the file before running `turbo` + +Last, you'll want to ensure that you run the script before running `turbo`. For example: + +```json +{ + "scripts": { + "build-for-platforms": "node ./scripts/create-turbo-cache-key.js && turbo run build" + } +} +``` + +`turbo run build` will now take into account the contents of `turbo-cache-key.json` when calculating the hash for the `build` task. + ## Logs Not only does `turbo` cache the output of your tasks, it also records the terminal output (i.e. combined `stdout` and `stderr`) to (`/.turbo/run-.log`). When `turbo` encounters a cached task, it will replay the output as if it happened again, but instantly, with the package name slightly dimmed.