[perf] rephrase some egregious ld.cloneDeep calls

Author: cscheid

src/command/render/render-contexts.ts

@@ -756,20 +756,17 @@ export async function projectMetadataForInputFile(
   input: string,
   project: ProjectContext,
 ): Promise<Metadata> {
-  // don't mutate caller
-  project = ld.cloneDeep(project) as ProjectContext;
-
   if (project.dir && project.config) {
     // If there is directory and configuration information
     // process paths
     return toInputRelativePaths(
       projectType(project.config?.project?.[kProjectType]),
       project.dir,
       dirname(input),
-      project.config,
+      ld.cloneDeep(project.config),
     ) as Metadata;
   } else {
     // Just return the config or empty metadata
-    return project.config || {};
+    return ld.cloneDeep(project.config) || {};
   }
 }

src/project/project-context.ts

@@ -653,11 +653,15 @@ async function resolveProjectExtension(
   return projectConfig;
 }
 
+// migrate 'site' to 'website'
+// TODO make this a deprecation warning
 function migrateProjectConfig(projectConfig: ProjectConfig) {
-  projectConfig = ld.cloneDeep(projectConfig);
-
-  // migrate 'site' to 'website'
   const kSite = "site";
+  if (projectConfig[kSite] === undefined) {
+    return projectConfig;
+  }
+
+  projectConfig = ld.cloneDeep(projectConfig);
   if (projectConfig.project[kProjectType] === kSite) {
     projectConfig.project[kProjectType] = kWebsite;
   }