From c36c9781daafc529a45f0676346c2ccb0652d978 Mon Sep 17 00:00:00 2001
From: Miorel-Lucian Palii <mlpalii@gmail.com>
Date: Sun, 22 Sep 2024 16:15:17 -0700
Subject: [PATCH] Have some fun with Yarn constraints

I recently learned about Yarn constraints (https://yarnpkg.com/features/constraints), so I've been yearning for a chance to try them.
---
 package.json    |  1 +
 yarn.config.cjs | 52 +++++++++++++++++++++++++++++++++++++++++++++++--
 yarn.lock       | 12 +++++++++++-
 3 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index 212862d4..a8eafa73 100644
--- a/package.json
+++ b/package.json
@@ -29,6 +29,7 @@
   },
   "devDependencies": {
     "@code-chronicles/eslint-config": "workspace:*",
+    "@yarnpkg/types": "4.0.0",
     "eslint": "9.11.0",
     "husky": "9.1.6",
     "lint-staged": "15.2.10",
diff --git a/yarn.config.cjs b/yarn.config.cjs
index 87010d06..b68732b7 100644
--- a/yarn.config.cjs
+++ b/yarn.config.cjs
@@ -1,7 +1,55 @@
-module.exports = {
+const { defineConfig } = require("@yarnpkg/types");
+
+module.exports = defineConfig({
   async constraints({ Yarn }) {
+    const rootWorkspace = Yarn.workspace({ cwd: "." });
+    if (rootWorkspace == null) {
+      Yarn.workspace().error("Didn't find a root workspace?!");
+      return;
+    }
+
+    // Use ESM everywhere.
     for (const workspace of Yarn.workspaces()) {
       workspace.set("type", "module");
     }
+
+    // Set a consistent repository for all workspaces.
+    if (rootWorkspace.manifest.repository == null) {
+      rootWorkspace.error("Missing repository specification!");
+    }
+    for (const workspace of Yarn.workspaces()) {
+      if (workspace.cwd !== ".") {
+        workspace.set("repository.directory", workspace.cwd);
+        workspace.set(
+          "repository.type",
+          rootWorkspace.manifest.repository.type,
+        );
+        workspace.set("repository.url", rootWorkspace.manifest.repository.url);
+      } else {
+        workspace.unset("repository.directory");
+      }
+    }
+
+    // Expect each workspace to either have a license or be private.
+    for (const workspace of Yarn.workspaces()) {
+      if (workspace.manifest.license == null && !workspace.manifest.private) {
+        // Don't default since we want a human to make the call.
+        workspace.error("Missing license for non-private workspace!");
+      }
+    }
+
+    // Expect each workspace to specify a version, except for the root.
+    for (const workspace of Yarn.workspaces()) {
+      if (workspace.cwd !== ".") {
+        workspace.set("version", workspace.manifest.version ?? "0.0.1");
+      } else {
+        workspace.unset("version");
+      }
+    }
+
+    // Explicitly specify whether the workspace is private or not.
+    for (const workspace of Yarn.workspaces()) {
+      workspace.set("private", !!workspace.manifest.private);
+    }
   },
-};
+});
diff --git a/yarn.lock b/yarn.lock
index 2c6a6f61..e41d8375 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2142,6 +2142,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@yarnpkg/types@npm:4.0.0":
+  version: 4.0.0
+  resolution: "@yarnpkg/types@npm:4.0.0"
+  dependencies:
+    tslib: "npm:^2.4.0"
+  checksum: 10c0/41f67a4aa5c414c1e228f51453451fa15e0dd70c5cf2b1ae1ca142a3f018f25e4a37e60372cd0f5970c755e1804a2e31e208bff427add1cf13f899b0b9adc1e0
+  languageName: node
+  linkType: hard
+
 "abbrev@npm:^2.0.0":
   version: 2.0.0
   resolution: "abbrev@npm:2.0.0"
@@ -6989,6 +6998,7 @@ __metadata:
   resolution: "root-workspace-0b6124@workspace:."
   dependencies:
     "@code-chronicles/eslint-config": "workspace:*"
+    "@yarnpkg/types": "npm:4.0.0"
     eslint: "npm:9.11.0"
     husky: "npm:9.1.6"
     lint-staged: "npm:15.2.10"
@@ -7682,7 +7692,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"tslib@npm:^2.6.2, tslib@npm:^2.6.3":
+"tslib@npm:^2.4.0, tslib@npm:^2.6.2, tslib@npm:^2.6.3":
   version: 2.7.0
   resolution: "tslib@npm:2.7.0"
   checksum: 10c0/469e1d5bf1af585742128827000711efa61010b699cb040ab1800bcd3ccdd37f63ec30642c9e07c4439c1db6e46345582614275daca3e0f4abae29b0083f04a6