Dendron is setup as a monorepo utilizing lerna and yarn workspace. This means ALL dependencies are pulled to the top of the repo in a global node_modules folder. This helps dedup dependencies but can lead to bugs because imports that might work in development will NOT work in production if that dependency isn't in the package.json of the respective package.

Some common pitfalls:

  • vscode cannot be imported in any package besides Plugin Core
  • you cannot do relative imports of other packages in the monorepo
    • eg
      • bad: import {foo} from "../lib/@dendronhq/common-all"
      • good: import {foo} from "@dendronhq/common-all"


These are common operations that you might need to do during development

Install All dependencies

echo "install workspace dependencies..."
echo "install package dependencies..."
yarn setup
echo "done"

Watching all dependencies

  • NOTE: typescript is a compiled language which means that the executable won't be updated unless you compile. The watch script will auto-compile all code on change
# watch all dependencies

Pulling from master when there is a new dependency

Sometimes when you pull from master, there will be a new dependency added and running Watching all dependencies might fail. In these cases, you want to run the following to install all dependencies before running watch

lerna bootstrap
  • NOTE: in the rare case that this does not work, you can rebuild yourn workspace by running yarn setup


These are less common tasks that you might need to do in the monorepo

Remove all build artifacts

This cleans up all node_modules and build artifacts. Useful if you think theres some stale local dependency that is causing issues


Install a new package

Because Dendron is packaged as a mono repo managed using lerna, you can't just do a regular yarn add to install new packages. This is because lerna symlinks mono-repo dependencies together and a yarn add would override that. Instead, use the following command:

lerna add {package-to-install} --scope @dendronhq/{package-to-install-into}

Because this is typescript, don't forget to also install the @types package if it exists

lerna add @types/{package-to-install} --scope @dendronhq/{package-to-install-into}
  • NOTE: watch out that you are installing dependencies in the right package. Missing dependencies will appear to work in development if that dependency is present in any of the other packages. The reason things work is because of the way the nodejs module resolution works and that we're in a monorepo. Dependencies are installed at the root of the monorepo and will be found there when the package doesn't have them. When we publish them as npm packages, these dependencies will show up as missing in their respective packages if its not included in the dependencies

Removing a package

When removing a package, execute the following steps

cd packages/{PROJECT_NAME}
yarn remove {DEPENDENCY_NAME}
  • TIP: to remove the same dependency from all packages, use lerna
 lerna exec -- yarn remove {DEPENDENCY_NAME}

Pinning a dependency

Sometimes, its necessary to pin dependencies to prevent accidental updates (usually because the next version forces an incompatible node version). This usually comes to light when upgrading dependencies or when we follow the Removing a package cookbook. When you find a dependency is incompatible, you can pin it by removing the ^ sign infront of the dependency in the respective package.json.

When you do so, be sure to also add that dependency in Pinned Dependencies

Publish a new monorepo package

  • WARNING: you should almost never need to do this. consult with #dendron-team (Private) before trying to publish

  • initialize repo

cd {workspace_dir}
cp -R /path/to/dendron-yeoman/node-ts packages/{new-package}
  • update package.json

    • change project name
  • publish the repo (needs to be done initially before running lerna publish)

npm publish --access public


Build is failing

For 99% of cases, running the two steps below will help fix all build issues

Investigating a build step

yarn setup runs the following commands. If you want to dive into a specific build step that is failing, run the steps serially in your shell

npx lerna run build --scope @dendronhq/common-all
npx lerna run build --scope @dendronhq/common-server
npx lerna run build --scope @dendronhq/engine-server
npx lerna run build --scope @dendronhq/pods-core
npx lerna run build --parallel --scope "@dendronhq/{common-test-utils,api-server,common-assets}"
npx lerna run build --parallel --scope "@dendronhq/{common-frontend,dendron-cli}"
npx lerna run build --scope "@dendronhq/{engine-test-utils,dendron-next-server}"
npx lerna run build --scope "@dendronhq/dendron-plugin-views"
npx lerna run build --scope "@dendronhq/plugin-core"
npx yarn dendron dev sync_assets --fast

  1. Advanced Cookbook