[infra] Use npm workspaces instead of lerna (#3112)

This PR removes Lerna entirely. Now we just use npm workspaces + wireit.

### Benefits

- No more `npm run bootstrap`, just `npm ci`.
- To upgrade or add a dependency, edit the `package.json` and `npm i` from the root.
- Cuts around 30s off install time in CI.
- Only one `package-lock.json` file for the whole monorepo.

### Tricky parts

- npm workspaces hoists packages to the top-level `node_modules/` folder whenever possible. This is different to Lerna, which always put all the dependencies in each package's own `node_modules/` folder. Only if there is a conflicting version would there now be a `node_modules/` folder inside a workspace package.

  - This required updating various paths to reach further up the file system.
 
  - In a couple of cases, this caused issues with conflicting `@types` packages for TypeScript, because while previously only the local version was available, now multiple versions could be. This is because TypeScript by default ambiently loads all `node_modules/@types/*` packages from _all recursive parent directories_. The solution to these cases are to specify that only the immediate `node_modules/` folder should be consulted through the `typeRoots` setting.

  - This required changing the tachometer server root directory as well, which ended up being more complicated than it should be, because of the way tachometer was treating paths in config files as relative to the current working directory, instead of the config file path. In google/tachometer#237 I changed that behavior, so this also bumps the tachometer version and updates the configs accordingly.

Fixes #3093

.changeset/few-monkeys-reply.md

@@ -0,0 +1,2 @@
+---
+---

.eslintignore

@@ -4,7 +4,6 @@
 ############################################
 
 node_modules/
-lerna-debug.log
 *.tgz
 *.tsbuildinfo
 .DS_Store

.github/workflows/benchmarks.yml

@@ -18,16 +18,13 @@ jobs:
         with:
           node-version: 16
           cache: 'npm'
-          cache-dependency-path: '**/package-lock.json'
+          cache-dependency-path: package-lock.json
 
       - uses: google/wireit@setup-github-actions-caching/v1
 
       - name: NPM install
         run: npm ci
 
-      - name: Lerna bootstrap
-        run: npm run bootstrap
-
       - name: Build
         run: npm run build
 

.github/workflows/sauce-ie11.yaml

@@ -22,16 +22,13 @@ jobs:
         with:
           node-version: 16
           cache: 'npm'
-          cache-dependency-path: '**/package-lock.json'
+          cache-dependency-path: package-lock.json
 
       - uses: google/wireit@setup-github-actions-caching/v1
 
       - name: NPM install
         run: npm ci
 
-      - name: Lerna bootstrap
-        run: npm run bootstrap
-
       - name: Build
         run: npm run build
 
@@ -49,4 +46,4 @@ jobs:
           SAUCE_ACCESS_KEY: ${{ secrets.SAUCE_ACCESS_KEY }}
         run: |
           cd packages/labs/ssr
-          npm run test:integration
+          npm run test:integration

.github/workflows/sauce.yaml

@@ -22,16 +22,13 @@ jobs:
         with:
           node-version: 16
           cache: 'npm'
-          cache-dependency-path: '**/package-lock.json'
+          cache-dependency-path: package-lock.json
 
       - uses: google/wireit@setup-github-actions-caching/v1
 
       - name: NPM install
         run: npm ci
 
-      - name: Lerna bootstrap
-        run: npm run bootstrap
-
       - name: Build
         run: npm run build
 

.github/workflows/tests.yml

@@ -17,9 +17,7 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: 16
-          # Note: we do not cache here because we're not running lerna
-          # bootstrap, so the ~/.npm dir won't have all dependencies, and if
-          # this job finishes first then we'll only cache root dependencies.
+          cache-dependency-path: package-lock.json
 
       - name: NPM install
         run: |
@@ -45,7 +43,7 @@ jobs:
         with:
           node-version: 16
           cache: 'npm'
-          cache-dependency-path: '**/package-lock.json'
+          cache-dependency-path: package-lock.json
 
       - uses: google/wireit@setup-github-actions-caching/v1
 
@@ -55,9 +53,6 @@ jobs:
       - name: NPM install
         run: npm ci
 
-      - name: Lerna bootstrap
-        run: npm run bootstrap
-
       - name: Build
         run: npm run build
 
@@ -79,16 +74,13 @@ jobs:
           # TODO(augustinekim) Unpin when latest node installed by action includes fixed npm
           node-version: 16.15.0
           cache: 'npm'
-          cache-dependency-path: '**/package-lock.json'
+          cache-dependency-path: package-lock.json
 
       - uses: google/wireit@setup-github-actions-caching/v1
 
       - name: NPM install
         run: npm ci
 
-      - name: Lerna bootstrap
-        run: npm run bootstrap
-
       - name: Test
         env:
           RUN_BROWSER_TESTS: false

.gitignore

@@ -1,5 +1,4 @@
 node_modules/
-lerna-debug.log
 *.tgz
 *.tsbuildinfo
 .DS_Store

.prettierignore

@@ -4,7 +4,6 @@
 ############################################
 
 node_modules/
-lerna-debug.log
 *.tgz
 *.tsbuildinfo
 .DS_Store

CONTRIBUTING.md

@@ -95,8 +95,7 @@ If you've already signed a CLA but are still getting bothered by the awfully ins
 ```bash
 git clone https://github.com/lit/lit.git
 cd lit
-npm install
-npm run bootstrap
+npm ci
 npm run build
 ```