From 197fd94c0097c569bb3a6f9eaf662eaa1a08760d Mon Sep 17 00:00:00 2001
From: Natalie Weizenbaum <nweiz@google.com>
Date: Wed, 15 May 2024 15:31:18 -0700
Subject: [PATCH] Add tests for underscores where hyphens aren't allowed

---
 spec/directives/function.hrx | 62 ++++++++++++++++++++++++++++++++++++
 spec/directives/mixin.hrx    | 33 +++++++++++++++++++
 2 files changed, 95 insertions(+)

diff --git a/spec/directives/function.hrx b/spec/directives/function.hrx
index 472d9f973..7c8c99308 100644
--- a/spec/directives/function.hrx
+++ b/spec/directives/function.hrx
@@ -30,3 +30,65 @@ For details, see https://sass-lang.com/d/css-function-mixin
 1 | @function --a() {@return 1}
   |           ^^^
   '
+
+<===>
+================================================================================
+<===> double_underscore_name/input.scss
+@function __a() {@return 1}
+b {c: __a()}
+
+<===> double_underscore_name/output.css
+b {
+  c: 1;
+}
+
+<===>
+================================================================================
+<===> custom_ident_call/input.scss
+@function __a() {@return 1}
+b {c: --a()}
+
+<===> custom_ident_call/output.css
+b {
+  c: 1;
+}
+
+<===> custom_ident_call/warning
+DEPRECATION WARNING: Sass @function names beginning with -- are deprecated for forward-compatibility with plain CSS functions.
+
+For details, see https://sass-lang.com/d/css-function-mixin
+
+  ,
+2 | b {c: --a()}
+  |       ^^^
+  '
+    input.scss 2:7  root stylesheet
+
+<===>
+================================================================================
+<===> vendor_like_underscore/README.md
+Function names like `-moz-calc()` aren't allowed, but they are with underscores.
+
+<===>
+================================================================================
+<===> vendor_like_underscore/start/input.scss
+@function _moz-calc() {@return 1}
+b {c: _moz-calc()}
+
+<===> vendor_like_underscore/start/output.css
+b {
+  c: 1;
+}
+
+<===>
+================================================================================
+<===> vendor_like_underscore/middle/input.scss
+@function -moz_calc() {@return 1}
+b {c: -moz_calc()}
+
+<===> vendor_like_underscore/middle/output.css
+b {
+  c: 1;
+}
+
+
diff --git a/spec/directives/mixin.hrx b/spec/directives/mixin.hrx
index 9f65b2262..93e356864 100644
--- a/spec/directives/mixin.hrx
+++ b/spec/directives/mixin.hrx
@@ -16,3 +16,36 @@ For details, see https://sass-lang.com/d/css-function-mixin
 1 | @mixin --a {b: c}
   |        ^^^
   '
+
+<===>
+================================================================================
+<===> double_underscore_name/input.scss
+@mixin __a() {b: c}
+d {@include __a}
+
+<===> double_underscore_name/output.css
+d {
+  b: c;
+}
+
+<===>
+================================================================================
+<===> custom_ident_include/input.scss
+@mixin __a() {b: c}
+d {@include --a}
+
+<===> custom_ident_include/output.css
+d {
+  b: c;
+}
+
+<===> custom_ident_include/warning
+DEPRECATION WARNING: Sass @mixin names beginning with -- are deprecated for forward-compatibility with plain CSS mixins.
+
+For details, see https://sass-lang.com/d/css-function-mixin
+
+  ,
+2 | d {@include --a}
+  |             ^^^
+  '
+    input.scss 2:13  root stylesheet