Migrate from Yarn v1 to Yarn v3

The package manager used has been upgraded from Yarn v1 to Yarn v3. All
of the steps in the migration guide [1] have been followed. Effectively
everything should work the same way it did before.

Closes #847

[1]: https://yarnpkg.com/getting-started/migration

.gitattributes

@@ -1,3 +1,8 @@
 * text=auto
 
 yarn.lock linguist-generated=false
+
+# yarn v3
+# See: https://yarnpkg.com/getting-started/qa#which-files-should-be-gitignored
+/.yarn/releases/** binary
+/.yarn/plugins/** binary

.github/workflows/build-lint-test.yml

@@ -20,7 +20,7 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
       - name: Get Yarn cache directory
-        run: echo "::set-output name=YARN_CACHE_DIR::$(yarn cache dir)"
+        run: echo "::set-output name=YARN_CACHE_DIR::$(yarn config get cacheFolder)"
         id: yarn-cache-dir
       - name: Get Yarn version
         run: echo "::set-output name=YARN_VERSION::$(yarn --version)"
@@ -30,7 +30,7 @@ jobs:
         with:
           path: ${{ steps.yarn-cache-dir.outputs.YARN_CACHE_DIR }}
           key: yarn-cache-${{ runner.os }}-${{ steps.yarn-version.outputs.YARN_VERSION }}-${{ hashFiles('yarn.lock') }}
-      - run: yarn --frozen-lockfile
+      - run: yarn --immutable
       - run: yarn allow-scripts
       - run: yarn build
       - run: yarn lint

.gitignore

@@ -1,8 +1,6 @@
 # node
 npm-debug.log
 yarn-error.log
-npm-debug.log
-yarn-error.log
 node_modules
 package-lock.json
 
@@ -16,3 +14,13 @@ package-lock.json
 coverage
 dist
 docs
+
+# yarn v3 (w/o zero-install)
+# See: https://yarnpkg.com/getting-started/qa#which-files-should-be-gitignored
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/sdks
+!.yarn/versions

.yarnrc.yml

@@ -0,0 +1,9 @@
+# We use allow-scripts to manually enable scripts and then run them
+enableScripts: false
+
+# This ensures Yarn still uses a `node_modules` directory, which is required
+# right now for TypeScript to find @types/* packages
+nodeLinker: node-modules
+
+# The current version of Yarn we're using
+yarnPath: .yarn/releases/yarn-3.2.1.cjs

README.md

@@ -259,7 +259,7 @@ console.log(datamodel.flatState); // {infura: {...}, contractExchangeRates: [...
 
 - Install [Node.js](https://nodejs.org) version 12
   - If you are using [nvm](https://github.com/creationix/nvm#installation) (recommended) running `nvm use` will automatically choose the right node version for you.
-- Install [Yarn v1](https://yarnpkg.com/en/docs/install)
+- Install [Yarn v3](https://yarnpkg.com/getting-started/install)
 - Run `yarn setup` to install dependencies and run any requried post-install scripts
   - **Warning:** Do not use the `yarn` / `yarn install` command directly. Use `yarn setup` instead. The normal install command will skip required post-install scripts, leaving your development environment in an invalid state.
 

package.json

@@ -29,7 +29,7 @@
     "lint:eslint": "eslint . --cache --ext js,ts",
     "lint:fix": "yarn lint:eslint --fix && yarn lint:misc --write",
     "lint:misc": "prettier '**/*.json' '**/*.md' '!CHANGELOG.md' '**/*.yml' --ignore-path .gitignore",
-    "prepublishOnly": "yarn build",
+    "prepack": "yarn build",
     "setup": "yarn install && yarn allow-scripts",
     "test": "jest",
     "test:watch": "jest --watch"
@@ -110,6 +110,7 @@
     "typedoc-plugin-missing-exports": "^0.22.6",
     "typescript": "~4.6.3"
   },
+  "packageManager": "[email protected]",
   "engines": {
     "node": ">=12.0.0"
   },