make it work for monorepos

Author: hipstersmoothie

plugins/update-repo/src/index.ts

@@ -6,16 +6,30 @@ import path from "path";
 import parseGitHubUrl from "parse-github-url";
 import * as t from "io-ts";
 
+/** Determine if the current directory is an NPM package */
+const isNpmPackage = (dir?: string) =>
+  fs.existsSync(dir ? path.join(dir, "package.json") : "package.json");
+
+/** Determine if the current directory is an lerna monorepo */
+const isLernaMonorepo = (dir?: string) =>
+  fs.existsSync(dir ? path.join(dir, "package.json") : "package.json");
+
+/** Read a NPM package.json */
+const readPackageJson = (dir?: string) =>
+  JSON.parse(
+    fs.readFileSync(dir ? path.join(dir, "package.json") : "package.json", {
+      encoding: "utf-8",
+    })
+  );
+
 /** Update package in an npm package */
 const updateNpmPackage = (
   dir: string,
   name: string,
   version: string,
   isYarn: boolean
 ) => {
-  const { dependencies, devDependencies } = JSON.parse(
-    fs.readFileSync(path.join(dir, "package.json"), { encoding: "utf-8" })
-  );
+  const { dependencies, devDependencies } = readPackageJson(dir);
 
   const isDep = Boolean(dependencies[name]);
   const isDevDep = Boolean(devDependencies[name]);
@@ -30,21 +44,65 @@ const updateNpmPackage = (
   }
 };
 
+/** Update a dependency in a monorepo */
+const updateLernaMonorepo = (dir: string, name: string, version: string) =>
+  execSync(
+    `npx lernaupdate --non-interactive --dependency ${name}@${version}`,
+    { cwd: dir }
+  );
+
+/** Update a dependency in a JS project */
+const updateJsProject = (dir: string, name: string, version: string) => {
+  if (isLernaMonorepo()) {
+    updateLernaMonorepo(dir, name, version);
+  } else {
+    const hasLock = fs.existsSync("yarn.lock");
+    updateNpmPackage(dir, name, version, hasLock);
+  }
+};
+
+interface LernaPackage {
+  /** The name of the package */
+  name: string;
+  /** The current version of the package */
+  version: string;
+  /** Whether the package is private */
+  private: boolean;
+}
+
 /** Get a package name + updater to use with updateRepo */
-function getUpdater(): [string, (dir: string) => void] | undefined {
-  if (fs.existsSync("package.json")) {
-    const { name, version } = JSON.parse(
-      fs.readFileSync("package.json", { encoding: "utf-8" })
+async function getUpdater(
+  auto: Auto
+): Promise<[string, (dir: string) => void] | undefined> {
+  // We are in a lerna monorepo so we should try to make updates for all of the
+  // packages in it. We assume that the thing we are updating is also a JS project
+  if (isLernaMonorepo()) {
+    const { name } = readPackageJson();
+    // Since we have already tagged the release we need to calculate from the previous tag
+    const lastRelease = await auto.git!.getPreviousTagInBranch();
+    const changedPackages: LernaPackage[] = JSON.parse(
+      execSync(`lerna ls --json --since ${lastRelease}`, { encoding: "utf8" })
     );
 
     return [
       name,
       (dir) => {
-        const hasLock = fs.existsSync("yarn.lock");
-        updateNpmPackage(dir, name, version, hasLock);
+        changedPackages.forEach((p) => {
+          if (p.private) {
+            return;
+          }
+
+          updateJsProject(dir, p.name, p.version);
+        });
       },
     ];
   }
+
+  // We are in NPM package. We assume that the thing we are updating is also a JS project.
+  if (isNpmPackage()) {
+    const { name, version } = readPackageJson();
+    return [name, (dir) => updateJsProject(dir, name, version)];
+  }
 }
 
 const optionalOptions = t.interface({
@@ -102,14 +160,15 @@ export default class UpdateRepoPlugin implements IPlugin {
         }
 
         for await (const config of this.options) {
-          await this.updateRepo(newVersion, releaseNotes, config);
+          await this.updateRepo(auto, newVersion, releaseNotes, config);
         }
       }
     );
   }
 
   /** Open a pr with a dependency update */
   private async updateRepo(
+    auto: Auto,
     newVersion: string,
     releaseNotes: string,
     config: UpdateRepoConfiguration
@@ -122,7 +181,7 @@ export default class UpdateRepoPlugin implements IPlugin {
       );
     }
 
-    const updater = getUpdater();
+    const updater = await getUpdater(auto);
 
     if (!updater) {
       throw new Error(