[rush-lib] prevent workspace dependencies in decoupledLocalDependencies

common/changes/@microsoft/rush/jmaher-prevent-decoupled-workspace-deps_2024-07-30-15-46.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "prevent workspace deps in decoupledLocalDependencies",
+      "type": "none",
+      "packageName": "@microsoft/rush"
+    }
+  ],
+  "packageName": "@microsoft/rush",
+  "email": "jamesmaher-dd@users.noreply.github.com"
+}

libraries/rush-lib/src/logic/installManager/WorkspaceInstallManager.ts

@@ -279,7 +279,25 @@ export class WorkspaceInstallManager extends BaseInstallManager {
             shrinkwrapIsUpToDate = false;
             continue;
           }
-        } else if (dependencySpecifier.specifierType === DependencySpecifierType.Workspace) {
+        } else if (
+          dependencySpecifier.specifierType === DependencySpecifierType.Workspace &&
+          rushProject.decoupledLocalDependencies.has(name)
+        ) {
+          // If the dependency is a local project that is decoupled, then we need to ensure that it is not specified
+          // as a workspace project. If it is, then we need to update the package.json to remove the workspace notation.
+          // eslint-disable-next-line no-console
+          console.log();
+          // eslint-disable-next-line no-console
+          console.log(
+            Colorize.red(
+              `"${rushProject.packageName}" depends on package ${name}@${version}, but also lists it in` +
+                `its "decoupledLocalDependencies" array. Either update the host project's package.json to use ` +
+                `a version from an external feed instead of "workspace:" notation, or remove the dependency from the ` +
+                `host project's "decoupledLocalDependencies" array in rush.json.`
+            )
+          );
+          throw new AlreadyReportedError();
+        } else if (!rushProject.decoupledLocalDependencies.has(name)) {
           // Already specified as a local project. Allow the package manager to validate this
           continue;
         }