From 387dc077587cfb5fe1bb02a02a0e3e1282ff931b Mon Sep 17 00:00:00 2001
From: Christophe Dervieux <christophe.dervieux@gmail.com>
Date: Mon, 26 May 2025 12:57:42 +0200
Subject: [PATCH] make the whole projectContext still a reference after
 safeCloneDeep

projectContext should not be deep cloned. Only reference needs to be passed in the codebase.
---
 src/core/safe-clone-deep.ts                  | 2 ++
 src/project/project-context.ts               | 3 +++
 src/project/types.ts                         | 3 ++-
 src/project/types/single-file/single-file.ts | 1 +
 4 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/core/safe-clone-deep.ts b/src/core/safe-clone-deep.ts
index c9fd00dd5c..41e63a7f45 100644
--- a/src/core/safe-clone-deep.ts
+++ b/src/core/safe-clone-deep.ts
@@ -6,6 +6,8 @@
  * Copyright (C) 2025 Posit Software, PBC
  */
 
+// This is used to create new interfaces that extend the Cloneable interface
+// to make the object having a clone method for specific cloning behavior in safeCloneDeep.
 export interface Cloneable<T> {
   clone(): T;
 }
diff --git a/src/project/project-context.ts b/src/project/project-context.ts
index b661c56b01..4348e57eeb 100644
--- a/src/project/project-context.ts
+++ b/src/project/project-context.ts
@@ -275,6 +275,7 @@ export async function projectContext(
         });
         const fileInformationCache = new FileInformationCacheMap();
         const result: ProjectContext = {
+          clone: () => result,
           resolveBrand: async (fileName?: string) =>
             projectResolveBrand(result, fileName),
           resolveFullMarkdownForFile: (
@@ -371,6 +372,7 @@ export async function projectContext(
         });
         const fileInformationCache = new FileInformationCacheMap();
         const result: ProjectContext = {
+          clone: () => result,
           resolveBrand: async (fileName?: string) =>
             projectResolveBrand(result, fileName),
           resolveFullMarkdownForFile: (
@@ -446,6 +448,7 @@ export async function projectContext(
           });
           const fileInformationCache = new FileInformationCacheMap();
           const context: ProjectContext = {
+            clone: () => context,
             resolveBrand: async (fileName?: string) =>
               projectResolveBrand(context, fileName),
             resolveFullMarkdownForFile: (
diff --git a/src/project/types.ts b/src/project/types.ts
index 74b682e37c..7f456d2ae0 100644
--- a/src/project/types.ts
+++ b/src/project/types.ts
@@ -22,6 +22,7 @@ import {
 import { ProjectEnvironment } from "./project-environment-types.ts";
 import { ProjectCache } from "../core/cache/cache-types.ts";
 import { TempContext } from "../core/temp-types.ts";
+import { Cloneable } from "../core/safe-clone-deep.ts";
 
 export {
   type NavigationItem as NavItem,
@@ -58,7 +59,7 @@ export type FileInformation = {
   brand?: LightDarkBrand;
 };
 
-export interface ProjectContext {
+export interface ProjectContext extends Cloneable<ProjectContext> {
   dir: string;
   engines: string[];
   files: ProjectFiles;
diff --git a/src/project/types/single-file/single-file.ts b/src/project/types/single-file/single-file.ts
index cd5b6c0e28..9f4f415f43 100644
--- a/src/project/types/single-file/single-file.ts
+++ b/src/project/types/single-file/single-file.ts
@@ -41,6 +41,7 @@ export async function singleFileProjectContext(
   const projectCacheBaseDir = temp.createDir();
 
   const result: ProjectContext = {
+    clone: () => result,
     resolveBrand: (fileName?: string) => projectResolveBrand(result, fileName),
     dir: normalizePath(dirname(source)),
     engines: [],