resources: Address Dart Sass deprecation of global built-in functions

See https://github.com/sass/dart-sass/releases/tag/1.80.0

Fixes #12961

4 files changed, 22 insertions, 7 deletions

diff --git a/resources/resource_transformers/tocss/dartsass/transform.go b/resources/resource_transformers/tocss/dartsass/transform.go
index f0bd6634a..d8b6ae5b4 100644
--- a/resources/resource_transformers/tocss/dartsass/transform.go
+++ b/resources/resource_transformers/tocss/dartsass/transform.go
@@ -29,7 +29,7 @@ import (
 	"github.com/gohugoio/hugo/resources"
 
 	"github.com/gohugoio/hugo/resources/internal"
-	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/internal/sass"
+	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/sass"
 
 	"github.com/spf13/afero"
 
@@ -85,7 +85,7 @@ func (t *transform) Transform(ctx *resources.ResourceTransformationCtx) error {
 			c:                 t.c,
 			dependencyManager: ctx.DependencyManager,
 
-			varsStylesheet: godartsass.Import{Content: sass.CreateVarsStyleSheet(opts.Vars)},
+			varsStylesheet: godartsass.Import{Content: sass.CreateVarsStyleSheet(sass.TranspilerDart, opts.Vars)},
 		},
 		OutputStyle:             godartsass.ParseOutputStyle(opts.OutputStyle),
 		EnableSourceMap:         opts.EnableSourceMap,
diff --git a/resources/resource_transformers/tocss/internal/sass/helpers.go b/resources/resource_transformers/tocss/sass/helpers.go
index c1cef141e..d4091a39c 100644
--- a/resources/resource_transformers/tocss/internal/sass/helpers.go
+++ b/resources/resource_transformers/tocss/sass/helpers.go
@@ -24,9 +24,14 @@ import (
 
 const (
 	HugoVarsNamespace = "hugo:vars"
+	// Transpiler implementation can be controlled from the client by
+	// setting the 'transpiler' option.
+	// Default is currently 'libsass', but that may change.
+	TranspilerDart    = "dartsass"
+	TranspilerLibSass = "libsass"
 )
 
-func CreateVarsStyleSheet(vars map[string]any) string {
+func CreateVarsStyleSheet(transpiler string, vars map[string]any) string {
 	if vars == nil {
 		return ""
 	}
@@ -49,12 +54,22 @@ func CreateVarsStyleSheet(vars map[string]any) string {
 				varsSlice = append(varsSlice, fmt.Sprintf("%s%s: %v;", prefix, k, v))
 			} else {
 				// unquote will preserve quotes around URLs etc. if needed.
-				varsSlice = append(varsSlice, fmt.Sprintf("%s%s: unquote(%q);", prefix, k, v))
+				if transpiler == TranspilerDart {
+					varsSlice = append(varsSlice, fmt.Sprintf("%s%s: string.unquote(%q);", prefix, k, v))
+				} else {
+					varsSlice = append(varsSlice, fmt.Sprintf("%s%s: unquote(%q);", prefix, k, v))
+				}
 			}
 		}
 	}
 	sort.Strings(varsSlice)
-	varsStylesheet = strings.Join(varsSlice, "\n")
+
+	if transpiler == TranspilerDart {
+		varsStylesheet = `@use "sass:string";` + "\n" + strings.Join(varsSlice, "\n")
+	} else {
+		varsStylesheet = strings.Join(varsSlice, "\n")
+	}
+
 	return varsStylesheet
 }
 
diff --git a/resources/resource_transformers/tocss/internal/sass/helpers_test.go b/resources/resource_transformers/tocss/sass/helpers_test.go
index ef31fdd8f..ef31fdd8f 100644
--- a/resources/resource_transformers/tocss/internal/sass/helpers_test.go
+++ b/resources/resource_transformers/tocss/sass/helpers_test.go
diff --git a/resources/resource_transformers/tocss/scss/tocss.go b/resources/resource_transformers/tocss/scss/tocss.go
index 36ef2a77d..4b9c51ce0 100644
--- a/resources/resource_transformers/tocss/scss/tocss.go
+++ b/resources/resource_transformers/tocss/scss/tocss.go
@@ -31,7 +31,7 @@ import (
 	"github.com/gohugoio/hugo/identity"
 	"github.com/gohugoio/hugo/media"
 	"github.com/gohugoio/hugo/resources"
-	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/internal/sass"
+	"github.com/gohugoio/hugo/resources/resource_transformers/tocss/sass"
 )
 
 // Used in tests. This feature requires Hugo to be built with the extended tag.
@@ -64,7 +64,7 @@ func (t *toCSSTransformation) Transform(ctx *resources.ResourceTransformationCtx
 		}
 	}
 
-	varsStylesheet := sass.CreateVarsStyleSheet(options.from.Vars)
+	varsStylesheet := sass.CreateVarsStyleSheet(sass.TranspilerLibSass, options.from.Vars)
 
 	// To allow for overrides of SCSS files anywhere in the project/theme hierarchy, we need
 	// to help libsass revolve the filename by looking in the composite filesystem first.