resource_transformers/tocss: Fixed hugo:vars casting

Variables passed via the hugo:vars function where passed as type string.
This caused problems when using the variables in sass functions because
these expect a specific type. Now we check if the passed variables have
to be quoted and therefore are of type string or if they should not be
quoted and let the type interpretation up to the sass compiler.

Fixes #10632

resources/resource_transformers/tocss/dartsass/integration_test.go

@@ -368,3 +368,55 @@ T1: {{ $r.Content }}
 
 	b.AssertFileContent("public/index.html", `T1: body body{background:url(images/hero.jpg) no-repeat center/cover}p{color:blue;font-size:24px}b{color:green}`)
 }
+
+func TestVarsCasting(t *testing.T) {
+	t.Parallel()
+	if !dartsass.Supports() {
+		t.Skip()
+	}
+
+	files := `
+-- config.toml --
+disableKinds = ["term", "taxonomy", "section", "page"]
+
+[params]
+[params.sassvars]
+color_hex = "#fff"
+color_rgb = "rgb(255, 255, 255)"
+color_hsl = "hsl(0, 0%, 100%)"
+dimension = "24px"
+percentage = "10%"
+flex = "5fr"
+-- assets/scss/main.scss --
+@use "hugo:vars";
+@use "sass:meta";
+
+@debug meta.type-of(vars.$color_hex);
+@debug meta.type-of(vars.$color_rgb);
+@debug meta.type-of(vars.$color_hsl);
+@debug meta.type-of(vars.$dimension);
+@debug meta.type-of(vars.$percentage);
+@debug meta.type-of(vars.$flex);
+-- layouts/index.html --
+{{ $vars := site.Params.sassvars}}
+{{ $cssOpts := (dict "transpiler" "dartsass" "vars" $vars ) }}
+{{ $r := resources.Get "scss/main.scss" |  toCSS $cssOpts }}
+T1: {{ $r.Content }}
+		`
+
+	b := hugolib.NewIntegrationTestBuilder(
+		hugolib.IntegrationTestConfig{
+			T:           t,
+			TxtarString: files,
+			NeedsOsFS:   true,
+			LogLevel:    jww.LevelInfo,
+		}).Build()
+
+	b.AssertLogMatches(`INFO.*Dart Sass: .*assets.*main.scss:3:0: color`)
+	b.AssertLogMatches(`INFO.*Dart Sass: .*assets.*main.scss:4:0: color`)
+	b.AssertLogMatches(`INFO.*Dart Sass: .*assets.*main.scss:5:0: color`)
+	b.AssertLogMatches(`INFO.*Dart Sass: .*assets.*main.scss:6:0: number`)
+	b.AssertLogMatches(`INFO.*Dart Sass: .*assets.*main.scss:7:0: number`)
+	b.AssertLogMatches(`INFO.*Dart Sass: .*assets.*main.scss:8:0: number`)
+
+}

resources/resource_transformers/tocss/internal/sass/cssValues.go

@@ -0,0 +1,79 @@
+// Copyright 2022 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sass
+
+type cssValue struct {
+	prefix []string
+	sufix  []string
+}
+
+var (
+	cssValues = cssValue{
+		prefix: []string{
+			"#",
+			"rgb(",
+			"hsl(",
+			"hwb(",
+			"lch(",
+			"lab(",
+			"calc(",
+			"min(",
+			"max(",
+			"minmax(",
+			"clamp(",
+			"attr(",
+		},
+		sufix: []string{
+			"em",
+			"ex",
+			"cap",
+			"ch",
+			"ic",
+			"rem",
+			"lh",
+			"rlh",
+			"vw",
+			"vh",
+			"vi",
+			"vb",
+			"vmin",
+			"vmax",
+			"cqw",
+			"cqh",
+			"cqi",
+			"cqb",
+			"cqmin",
+			"cqmax",
+			"cm",
+			"mm",
+			"Q",
+			"in",
+			"pc",
+			"pt",
+			"px",
+			"deg",
+			"grad",
+			"rad",
+			"turn",
+			"s",
+			"ms",
+			"fr",
+			"dpi",
+			"dpcm",
+			"dppx",
+			"x",
+			"%",
+		},
+	}
+)

resources/resource_transformers/tocss/internal/sass/helpers.go

@@ -38,11 +38,32 @@ func CreateVarsStyleSheet(vars map[string]string) string {
 		// These variables can be a combination of Sass identifiers (e.g. sans-serif), which
 		// should not be quoted, and URLs et, which should be quoted.
 		// unquote() is knowing what to do with each.
-		varsSlice = append(varsSlice, fmt.Sprintf("%s%s: unquote(%q);", prefix, k, v))
+		// Use quoteVar() to check if the variables should be quoted or not.
+		if quoteVar(v) {
+			varsSlice = append(varsSlice, fmt.Sprintf("%s%s: unquote(%q);", prefix, k, v))
+		} else {
+			varsSlice = append(varsSlice, fmt.Sprintf("%s%s: %s;", prefix, k, v))
+		}
 	}
 	sort.Strings(varsSlice)
 	varsStylesheet = strings.Join(varsSlice, "\n")
 
 	return varsStylesheet
 
 }
+
+func quoteVar(v string) bool {
+	v = strings.Trim(v, "\"")
+	for _, p := range cssValues.prefix {
+		if strings.HasPrefix(v, p) {
+			return false
+		}
+	}
+	for _, s := range cssValues.sufix {
+		if strings.HasSuffix(v, s) {
+			return false
+		}
+	}
+
+	return true
+}