Project Configuration
Projects can be configured in package.json (if you use npm scripts and not Nx executors) and project.json (if you use task executors). Both package.json and project.json files are located in each project's folder. Nx merges the two files to get each project's configuration.
The following configuration creates build and test targets for Nx.
{
"name": "mylib",
"scripts": {
"test": "jest",
"build": "tsc -p tsconfig.lib.json" // the actual command here is arbitrary
}
}
You can invoke nx build mylib or nx test mylib without any extra configuration.
You can add Nx-specific configuration as follows:
{
"name": "mylib",
"scripts": {
"test": "jest",
"build": "tsc -p tsconfig.lib.json", // the actual command here is arbitrary
"ignored": "exit 1"
},
"nx": {
"namedInputs": {
"default": ["{projectRoot}/**/*"],
"production": ["!{projectRoot}/**/*.spec.tsx"]
},
"targets": {
"build": {
"inputs": ["production", "^production"],
"outputs": ["{workspaceRoot}/dist/libs/mylib"],
"dependsOn": ["^build"]
},
"test": {
"inputs": ["default", "^production"],
"outputs": [],
"dependsOn": ["build"]
}
},
"includedScripts": ["test", "build"] // If you want to limit the scripts Nx sees, you can specify a list here.
}
}
inputs & namedInputs
The inputs array tells Nx what to consider to determine whether a particular invocation of a script should be a cache hit or not. There are three types of inputs:
Filesets
Examples:
{projectRoot}/**.*.ts- same as
{fileset: "{projectRoot}/**/*.ts"} {workspaceRoot}/jest.config.ts- same as
{fileset: "{workspaceRoot}/jest.config.ts}
{projectRoot} is a key word that is replaced by the path to the current project's root directory. {workspaceRoot} is a key word that is replaced by the path to the workspace root directory.
Runtime Inputs
Examples:
{runtime: "node -v"}
Note the result value is hashed, so it is never displayed.
Env Variables
Examples:
{env: "MY_ENV_VAR"}
Note the result value is hashed, so it is never displayed.
Named Inputs
Examples:
inputs: ["production"]- same as
inputs: [{input: "production", projects: "self"}]
Often the same glob will appear in many places (e.g., prod fileset will exclude spec files for all projects). Because keeping them in sync is error-prone, we recommend defining namedInputs, which you can then reference in all of those places.
Using ^
Examples:
inputs: ["^production"]- same as
inputs: [{input: "production", projects: "dependencies"}]
Similar to dependsOn, the "^" symbols means "dependencies". This is a very important idea, so let's illustrate it with an example.
"test": {
"inputs": [ "default", "^production" ]
}
The configuration above means that the test target depends on all source files of a given project and only prod sources (non-test sources) of its dependencies. In other words, it treats test sources as private.
inputs and namedInputs are also described in the nx.json reference
This guide walks through a few examples of how to customize inputs and namedInputs
outputs
Targets may define outputs to tell Nx where the target is going to create file artifacts that Nx should cache. "outputs": ["{workspaceRoot}/dist/libs/mylib"] tells Nx where the build target is going to create file artifacts.
This configuration is usually not needed. Nx comes with reasonable defaults (imported in nx.json) which implement the configuration above.
Basic Example
Usually, a target writes to a specific directory or a file. The following instructs Nx to cache dist/libs/mylib and build/libs/mylib/main.js:
{
"build": {
"outputs": [
"{workspaceRoot}/dist/libs/mylib",
"{workspaceRoot}/build/libs/mylib/main.js"
]
}
}
Specifying Globs
Sometimes, multiple targets might write to the same directory. When possible it is recommended to direct these targets into separate directories.
{
"build-js": {
"outputs": ["{workspaceRoot}/dist/libs/mylib/js"]
},
"build-css": {
"outputs": ["{workspaceRoot}/dist/libs/mylib/css"]
}
}
But if the above is not possible, globs can be specified as outputs to only cache a set of files rather than the whole directory.
{
"build-js": {
"outputs": ["{workspaceRoot}/dist/libs/mylib/**/*.js"]
},
"build-css": {
"outputs": ["{workspaceRoot}/dist/libs/mylib/**/*.css"]
}
}
dependsOn
Targets can depend on other targets. This is the relevant portion of the configuration file:
"build": {
"dependsOn": ["^build"]
},
"test": {
"dependsOn": ["build"]
}
A common scenario is having to build dependencies of a project first before building the project. This is what the "dependsOn": ["^build"] property of the build target configures. It tells Nx that before it can build mylib it needs to make sure that mylib's dependencies are built as well. This doesn't mean Nx is going to rerun those builds. If the right artifacts are already in the right place, Nx will do nothing. If they aren't in the right place, but they are available in the cache, Nx will retrieve them from the cache.
Another common scenario is for a target to depend on another target of the same project. For instance, "dependsOn": ["build"] of the test target tells Nx that before it can test mylib it needs to make sure that mylib is built, which will result in mylib's dependencies being built as well.
You can also express the same configuration using:
"build": {
"dependsOn": [{ "projects": "dependencies", "target": "build" }]
},
"test": {
"dependsOn": [{ "projects": "self", "target": "build" }]
}
With the expanded syntax, you also have a third option available to configure how to handle the params passed to the target. You can either forward them or you can ignore them (default).
"build": {
// forward params passed to this target to the dependency targets
"dependsOn": [{ "projects": "dependencies", "target": "build", "params": "forward" }]
},
"test": {
// ignore params passed to this target, won't be forwarded to the dependency targets
"dependsOn": [{ "projects": "dependencies", "target": "build", "params": "ignore" }]
}
"lint": {
// ignore params passed to this target, won't be forwarded to the dependency targets
"dependsOn": [{ "projects": "dependencies", "target": "build" }]
}
Obviously this also works when defining a relation for the target of the project itself using "projects": "self":
"build": {
// forward params passed to this target to the project target
"dependsOn": [{ "projects": "self", "target": "pre-build", "params": "forward" }]
}
This configuration is usually not needed. Nx comes with reasonable defaults (imported in nx.json) which implement the configuration above.
tags
You can annotate your projects with tags as follows:
{
"name": "mylib",
"nx": {
"tags": ["scope:myteam"]
}
}
You can configure lint rules using these tags to, for instance, ensure that libraries belonging to myteam are not depended on by libraries belong to theirteam.
implicitDependencies
Nx uses powerful source-code analysis to figure out your workspace's project graph. Some dependencies cannot be deduced statically, so you can set them manually like this:
{
"name": "mylib",
"nx": {
"implicitDependencies": ["anotherlib"]
}
}
You can also remove a dependency as follows:
{
"name": "mylib",
"nx": {
"implicitDependencies": ["!anotherlib"] # regardless of what Nx thinks, "mylib" doesn't depend on "anotherlib"
}
}
Including package.json files as projects in the graph
Any package.json file that is referenced by the workspaces property in the root package.json file will be included as a project in the graph. If you are using Lerna, projects defined in lerna.json will be included. If you are using pnpm, projects defined in pnpm-workspace.yml will be included.
If you want to ignore a particular package.json file, exclude it from those tools. For example, you can add !packages/myproject to the workspaces property.
Ignoring package.json scripts
Nx merges package.json scripts with your targets that are defined in project.json. If you only wish for some scripts to be used as Nx targets, you can specify them in the includedScripts property of the project's package.json.
{
"name": "my-library",
"version": "0.0.1",
"scripts": {
"build": "tsc",
"postinstall": "node ./tasks/postinstall"
},
"nx": {
"includedScripts": ["build"]
}
}