Using Executors / Builders

Executors perform actions on your code. This can include building, linting, testing, serving and many other actions.

Executors can be written using @nrwl/devkit or @angular-devkit. Executors written with the @angular-devkit are called Builders.

There are two main differences between an executor and a shell script or an npm script:

  1. Executors encourage a consistent methodology for performing similar actions on unrelated projects. i.e. A developer switching between teams can be confident that nx build project2 will build project2 with the default settings, just like nx build project1 built project1.
  2. Nx can leverage this consistency to perform the same executor across multiple projects. i.e. nx affected --target==test will run the test executor on every project that is affected by the current code change.

Executor Definitions

The executors that are available for each project are defined and configured in the /workspace.json file.

2  "projects": {
3    "cart": {
4      "root": "apps/cart",
5      "sourceRoot": "apps/cart/src",
6      "projectType": "application",
7      "generators": {},
8      "targets": {
9        "build": {
10          "executor": "@nrwl/web:build",
11          "options": {
12            "outputPath": "dist/apps/cart",
13            ...
14          },
15          "configurations": {
16            "production": {
17              "sourceMap": false,
18              ...
19            }
20          }
21        },
22        "test": {
23          "executor": "@nrwl/jest:jest",
24          "options": {
25            ...
26          }
27        }
28      }
29    }
30  }

Note: There are a few property keys in workspace.json that have interchangeable aliases. You can replace generators with schematics, targets with architect or executor with builder.

Each project has its executors defined in the targets property. In this snippet, cart has two executors defined - build and test.

Note: build and test can be any strings you choose. For the sake of consistency, we make test run unit tests for every project and build produce compiled code for the projects which can be built.

Each executor definition has an executor property and, optionally, an options and a configurations property.

  • executor is a string of the from [package name]:[executor name]. For the build executor, the package name is @nrwl/web and the executor name is build.
  • options is an object that contains any configuration defaults for the executor. These options vary from executor to executor.
  • configurations allows you to create presets of options for different scenarios. All the configurations start with the properties defined in options as a baseline and then overwrite those options. In the example, there is a production configuration that overrides the default options to set sourceMap to false.

Running Executors

The nx run cli command (or the shorthand versions) can be used to run executors.

nx run [project]:[command]
nx run cart:build

As long as your command name doesn't conflict with an existing nx cli command, you can use this short hand:

nx [command] [project]
nx build cart

You can also use a specific configuration preset like this:

nx [command] [project] --configuration=[configuration]
nx build cart --configuration=production

Or you can overwrite individual executor options like this:

nx [command] [project] --[optionNameInCamelCase]=[value]
nx build cart --outputPath=some/other/path

See Also