Nx VS Lerna

Preface

NX and Lerna are both excellent monorepo tools.

This article compares the differences between the two.

https://nx.dev/

https://lerna.js.org/

Before comparing, you can read these two articles

to understand the basic usage of NX and Lerna:

一文学会用Lerna管理多个npm包

强大的构建系统：NX

Task Execution

Both NX and Lerna can execute tasks.

In fact, Lerna’s task execution uses NX under the hood.

Single Task Execution

# nx
nx run is-odd:build

# lerna
lerna run build --scope=is-odd

Multi-task Execution

# nx
nx run-many --target=build

# lerna
lerna run build

Local Caching

Lerna does not have local caching by default.

NX provides local caching by default.

Enable Local Caching in NX

Just add an nx.json to the project:

{
  "tasksRunnerOptions": {
    "default": {
      "runner": "nx/tasks-runners/default",
      "options": {
        "cacheableOperations": ["build", "test"]
      }
    }
  }
}

Enable Local Caching in Lerna

1. Add an nx.json to the project as above

2. Or use the CLI command:

lerna add-caching

Distributed Caching

Distributed caching is a capability provided by nx-cloud.

Simply put: one person builds, the whole team gets the cache.

Enable Distributed Caching in NX

The following command binds the local accessToken to your nx-cloud account.

For detailed usage, see this article: https://blog.insistime.com/nx

nx connect-to-nx-cloud

Enable Distributed Caching in Lerna

Since Lerna is based on NX, enabling distributed caching in Lerna is the same as NX:

nx connect-to-nx-cloud

After running the command above, the runner in nx.json will be changed to nx-cloud,

and an accessToken will be generated:

Then you can visit the URL shown below to bind with nx-cloud:

View Dependencies

Lerna does not have this feature.

You can use NX’s capability directly.

View Package Dependencies with NX

nx graph

Version Management

Task execution, local caching, and distributed caching are primarily NX capabilities.

Lerna’s main strengths are version management and publishing.

NX does not have version management capability.

Version Management with Lerna

lerna version

The result looks like this:

Its power lies in:

1. Managing versions across multiple packages

2. Including dependency versions between packages

For example, if package A depends on package B, and B’s version changes, A’s version will be updated accordingly.

Publishing to npm

Similarly, NX does not have publish capability.

Lerna has publish capability.

Publishing Packages with Lerna

lerna publish

The result looks like this:

Lerna’s publish power lies in being able to publish multiple packages to npm simultaneously,

which is very useful for monorepos managing many published npm packages.

NX vs Lerna

Here’s a simple summary of the differences:

In fact, Lerna uses NX under the hood. Using Lerna with NX is the best approach:

# Lerna uses NX to enable local caching
lerna add-caching

# Lerna uses NX to enable distributed caching
nx connect-to-nx-cloud

# Lerna uses NX to view dependencies
nx graph