From c9281dadcb72d96ffd8014dd66d4576671717d21 Mon Sep 17 00:00:00 2001
From: Erick Velez <erickvelez7@gmail.com>
Date: Wed, 26 Nov 2025 22:28:10 -0800
Subject: [PATCH] [clang-doc] Add Mustache case to assets test

Mustache wasn't tested in the assets lit test, which tests if
user-supplied assets are copied correctly. The Mustache HTML backend
initialy failed this test because it expected every asset, which
included Mustache templates, to be supplied. For now, we just expect
either CSS or JS to be supplied and use the default if one of them isn't
given.

We can allow custom templates in the future using the same checks.
---
 clang-tools-extra/clang-doc/support/Utils.cpp | 20 +++++++++++++------
 .../clang-doc/tool/ClangDocMain.cpp           |  5 +++--
 clang-tools-extra/test/clang-doc/assets.cpp   |  4 ++++
 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/clang-tools-extra/clang-doc/support/Utils.cpp b/clang-tools-extra/clang-doc/support/Utils.cpp
index 6ed56033738b5..897a7ad0adb79 100644
--- a/clang-tools-extra/clang-doc/support/Utils.cpp
+++ b/clang-tools-extra/clang-doc/support/Utils.cpp
@@ -33,8 +33,20 @@ void getMustacheHtmlFiles(StringRef AssetsPath,
   assert(!AssetsPath.empty());
   assert(sys::fs::is_directory(AssetsPath));
 
-  SmallString<128> DefaultStylesheet =
-      appendPathPosix(AssetsPath, "clang-doc-mustache.css");
+  // TODO: Allow users to override default templates with their own. We would
+  // similarly have to check if a template file already exists in CDCtx.
+  if (CDCtx.UserStylesheets.empty()) {
+    SmallString<128> DefaultStylesheet =
+        appendPathPosix(AssetsPath, "clang-doc-mustache.css");
+    CDCtx.UserStylesheets.insert(CDCtx.UserStylesheets.begin(),
+                                 DefaultStylesheet.c_str());
+  }
+
+  if (CDCtx.JsScripts.empty()) {
+    SmallString<128> IndexJS = appendPathPosix(AssetsPath, "mustache-index.js");
+    CDCtx.JsScripts.insert(CDCtx.JsScripts.begin(), IndexJS.c_str());
+  }
+
   SmallString<128> NamespaceTemplate =
       appendPathPosix(AssetsPath, "namespace-template.mustache");
   SmallString<128> ClassTemplate =
@@ -45,11 +57,7 @@ void getMustacheHtmlFiles(StringRef AssetsPath,
       appendPathPosix(AssetsPath, "function-template.mustache");
   SmallString<128> CommentTemplate =
       appendPathPosix(AssetsPath, "comment-template.mustache");
-  SmallString<128> IndexJS = appendPathPosix(AssetsPath, "mustache-index.js");
 
-  CDCtx.JsScripts.insert(CDCtx.JsScripts.begin(), IndexJS.c_str());
-  CDCtx.UserStylesheets.insert(CDCtx.UserStylesheets.begin(),
-                               DefaultStylesheet.c_str());
   CDCtx.MustacheTemplates.insert(
       {"namespace-template", NamespaceTemplate.c_str()});
   CDCtx.MustacheTemplates.insert({"class-template", ClassTemplate.c_str()});
diff --git a/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp b/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
index 62fa6a17df2ee..8de7c8ad6f000 100644
--- a/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
+++ b/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
@@ -151,6 +151,7 @@ static std::string getExecutablePath(const char *Argv0, void *MainAddr) {
   return llvm::sys::fs::getMainExecutable(Argv0, MainAddr);
 }
 
+// TODO: Rename this, since it only gets custom CSS/JS
 static llvm::Error getAssetFiles(clang::doc::ClangDocContext &CDCtx) {
   using DirIt = llvm::sys::fs::directory_iterator;
   std::error_code FileErr;
@@ -221,8 +222,8 @@ static llvm::Error getMustacheHtmlFiles(const char *Argv0,
     llvm::outs() << "Asset path supply is not a directory: " << UserAssetPath
                  << " falling back to default\n";
   if (IsDir) {
-    getMustacheHtmlFiles(UserAssetPath, CDCtx);
-    return llvm::Error::success();
+    if (auto Err = getAssetFiles(CDCtx))
+      return Err;
   }
   void *MainAddr = (void *)(intptr_t)getExecutablePath;
   std::string ClangDocPath = getExecutablePath(Argv0, MainAddr);
diff --git a/clang-tools-extra/test/clang-doc/assets.cpp b/clang-tools-extra/test/clang-doc/assets.cpp
index c5933e504f6b9..9acb64a10b4fe 100644
--- a/clang-tools-extra/test/clang-doc/assets.cpp
+++ b/clang-tools-extra/test/clang-doc/assets.cpp
@@ -1,9 +1,13 @@
 // RUN: rm -rf %t && mkdir %t
 // RUN: clang-doc --format=html --output=%t --asset=%S/Inputs/test-assets --executor=standalone %s --base base_dir
+// RUN: clang-doc --format=mustache --output=%t --asset=%S/Inputs/test-assets --executor=standalone %s --base base_dir
 // RUN: FileCheck %s -input-file=%t/index.html -check-prefix=INDEX
 // RUN: FileCheck %s -input-file=%t/test.css -check-prefix=CSS
 // RUN: FileCheck %s -input-file=%t/test.js -check-prefix=JS
 
+// RUN: FileCheck %s -input-file=%t/html/test.css -check-prefix=CSS
+// RUN: FileCheck %s -input-file=%t/html/test.js -check-prefix=JS
+
 // INDEX: <!DOCTYPE html>
 // INDEX-NEXT: <meta charset="utf-8"/>
 // INDEX-NEXT: <title>Index</title>