feat!: update to lerna v4

BREAKING CHANGE: upgrade to lerna v4

@commitlint/config-lerna-scopes/fixtures/basic/lerna.json

@@ -1,5 +1,5 @@
 {
-  "lerna": "3.22.1",
+  "lerna": "4",
   "version": "1.0.0",
   "packages": ["packages/*"]
 }

@commitlint/config-lerna-scopes/fixtures/basic/package.json

@@ -2,6 +2,6 @@
   "name": "basic",
   "version": "1.0.0",
   "devDependencies": {
-    "lerna": "^3.0.0"
+    "lerna": "^4.0.0"
   }
 }

@commitlint/config-lerna-scopes/fixtures/empty/lerna.json

@@ -1,5 +1,5 @@
 {
-  "lerna": "3.22.1",
+  "lerna": "4",
   "version": "1.0.0",
   "packages": ["packages/*"]
 }

@commitlint/config-lerna-scopes/fixtures/empty/package.json

@@ -2,6 +2,6 @@
   "name": "empty",
   "version": "1.0.0",
   "devDependencies": {
-    "lerna": "^3.0.0"
+    "lerna": "^4.0.0"
   }
 }

@commitlint/config-lerna-scopes/fixtures/lerna-two/lerna.json

@@ -1,5 +1,5 @@
 {
-  "lerna": "2.4.0",
+  "lerna": "4",
   "version": "1.0.0",
   "packages": ["packages/*"]
 }

@commitlint/config-lerna-scopes/fixtures/lerna-two/package.json

@@ -2,6 +2,6 @@
   "name": "version-mismatch",
   "version": "1.0.0",
   "devDependencies": {
-    "lerna": "^2.0.0"
+    "lerna": "^4.0.0"
   }
 }

@commitlint/config-lerna-scopes/fixtures/scoped/lerna.json

@@ -1,5 +1,5 @@
 {
-  "lerna": "3.22.1",
+  "lerna": "4",
   "version": "1.0.0",
   "packages": ["@packages/*"]
 }

@commitlint/config-lerna-scopes/fixtures/scoped/package.json

@@ -2,6 +2,6 @@
   "name": "scoped",
   "version": "1.0.0",
   "devDependencies": {
-    "lerna": "^3.0.0"
+    "lerna": "^4.0.0"
   }
 }

@commitlint/config-lerna-scopes/fixtures/yarn/package.json

@@ -2,7 +2,7 @@
   "name": "yarn",
   "version": "1.0.0",
   "devDependencies": {
-    "lerna": "^3.0.0"
+    "lerna": "^4.0.0"
   },
   "workspaces": [
     "@packages/*"

@commitlint/config-lerna-scopes/index.js

@@ -43,9 +43,8 @@ function getPackages(context) {
 				});
 			}
 
-			const Project = importFrom(cwd, '@lerna/project');
-			const project = new Project(cwd);
-			return project.getPackages();
+			const {getPackages} = importFrom(cwd, '@lerna/project');
+			return getPackages(cwd);
 		})
 		.then((packages) => {
 			return packages

@commitlint/config-lerna-scopes/package.json

@@ -26,7 +26,7 @@
   },
   "homepage": "https://github.com/conventional-changelog/commitlint#readme",
   "peerDependencies": {
-    "lerna": "^3.22.1"
+    "lerna": "^4.0.0"
   },
   "engines": {
     "node": ">=v10"

@packages/test/src/lerna.ts

@@ -1,5 +1,5 @@
-import path from 'path';
 import fs from 'fs-extra';
+import path from 'path';
 import resolvePkg from 'resolve-pkg';
 import * as fix from './fix';
 
@@ -10,11 +10,7 @@ export async function bootstrap(
 	directory: string
 ): Promise<string> {
 	const cwd = await fix.bootstrap(`fixtures/${fixture}`, directory);
-	// this used to test lerna v2 and v3
-	// the v2 option is removed here, lerna version tests as well
-	// all the code to test differnt version is still in place
-	// cause i'm not sure how to remove this properly
-	const lerna = 'lerna-v3';
+	const lerna = 'lerna';
 	await fs.mkdirp(path.join(cwd, 'node_modules', '@lerna'));
 	await fs.symlink(
 		resolvePkg('@lerna/project')!,

lerna.json

@@ -1,5 +1,5 @@
 {
-  "lerna": "3",
+  "lerna": "4",
   "npmClient": "yarn",
   "useWorkspaces": true,
   "version": "12.0.1"

package.json

@@ -97,8 +97,7 @@
     "eslint-plugin-jest": "^24.0.0",
     "husky": "^5.1.1",
     "jest": "26.6.3",
-    "lerna": "^3.22.1",
-    "lerna-v3": "npm:lerna@3",
+    "lerna": "^4.0.0",
     "lint-staged": "10.5.4",
     "prettier": "^2.0.5",
     "ts-jest": "26.5.2",