Add Url to main entry + imports

To get proper source references in source maps.

Also clean up the scheme logic.

options.go

@@ -31,9 +31,14 @@ func (opts *Options) init() error {
 }
 
 // ImportResolver allows custom import resolution.
+//
 // CanonicalizeURL should create a canonical version of the given URL if it's
 // able to resolve it, else return an empty string.
-// Include scheme if relevant, e.g. 'file://foo/bar.scss'.
+//
+// A canonicalized URL should include a scheme, e.g. 'file:///foo/bar.scss',
+// if applicable, see:
+//     https://en.wikipedia.org/wiki/File_URI_scheme
+//
 // Importers   must ensure that the same canonical URL
 // always refers to the same stylesheet.
 //
@@ -49,6 +54,12 @@ type Args struct {
 	// The input source.
 	Source string
 
+	// The URL of the Source.
+	// Leave empty if it's unknown.
+	// Must include a scheme, e.g. 'file:///myproject/main.scss'
+	// See https://en.wikipedia.org/wiki/File_URI_scheme
+	URL string
+
 	// Defaults is SCSS.
 	SourceSyntax SourceSyntax
 

transpiler.go

@@ -8,8 +8,8 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"regexp"
 	"runtime"
-	"strings"
 	"sync"
 
 	"github.com/cli/safeexec"
@@ -21,9 +21,6 @@ import (
 var defaultDartSassEmbeddedFilename = "dart-sass-embedded"
 
 const (
-	// Dart Sass requires a schema of some sort, add this
-	// if the resolver does not.
-	dummyImportSchema = "godartimport:"
 
 	// There is only one, and this number is picked out of a hat.
 	importerID = 5679
@@ -113,6 +110,7 @@ func (t *Transpiler) Execute(args Args) (Result, error) {
 				String_: &embeddedsass.InboundMessage_CompileRequest_StringInput{
 					Syntax: args.sassSourceSyntax,
 					Source: args.Source,
+					Url:    args.URL,
 				},
 			},
 			SourceMap: args.EnableSourceMap,
@@ -186,10 +184,6 @@ func (t *Transpiler) input() {
 		case *embeddedsass.OutboundMessage_CanonicalizeRequest_:
 			var url *embeddedsass.InboundMessage_CanonicalizeResponse_Url
 			if resolved := t.opts.ImportResolver.CanonicalizeURL(c.CanonicalizeRequest.GetUrl()); resolved != "" {
-				if !strings.Contains(resolved, ":") {
-					// Add a dummy schema.
-					resolved = dummyImportSchema + ":" + resolved
-				}
 				url = &embeddedsass.InboundMessage_CanonicalizeResponse_Url{
 					Url: resolved,
 				}
@@ -209,12 +203,24 @@ func (t *Transpiler) input() {
 			)
 
 		case *embeddedsass.OutboundMessage_ImportRequest_:
+			url := c.ImportRequest.GetUrl()
+			var sourceMapURL string
+			// Dart Sass expect a browser-accessible URL or an empty string.
+			// If no URL is supplied, a `data:` URL wil be generated
+			// automatically from `contents`
+			// The hasSchema function may be too coarse grained, but we
+			// need to test this in real life situations.
+			if hasSchema(url) {
+				sourceMapURL = url
+			}
+
 			response := &embeddedsass.InboundMessage_ImportResponse_{
 				ImportResponse: &embeddedsass.InboundMessage_ImportResponse{
 					Id: c.ImportRequest.GetId(),
 					Result: &embeddedsass.InboundMessage_ImportResponse_Success{
 						Success: &embeddedsass.InboundMessage_ImportResponse_ImportSuccess{
-							Contents: t.opts.ImportResolver.Load(strings.TrimPrefix(c.ImportRequest.GetUrl(), dummyImportSchema)),
+							Contents:     t.opts.ImportResolver.Load(url),
+							SourceMapUrl: sourceMapURL,
 						},
 					},
 				},
@@ -319,3 +325,9 @@ func (call *call) done() {
 func isWindows() bool {
 	return runtime.GOOS == "windows"
 }
+
+var hasSchemaRe = regexp.MustCompile("^[a-z]*:")
+
+func hasSchema(s string) bool {
+	return hasSchemaRe.MatchString(s)
+}

transpiler_test.go

@@ -1,6 +1,7 @@
 package godartsass
 
 import (
+	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -41,7 +42,7 @@ func (t testImportResolver) CanonicalizeURL(url string) string {
 		return ""
 	}
 
-	return url
+	return filepath.Clean("file:/myproject/scss/" + url + "_myfile.scss")
 }
 
 func (t testImportResolver) Load(url string) string {
@@ -66,7 +67,7 @@ func TestTranspilerVariants(t *testing.T) {
 		expect interface{}
 	}{
 		{"Output style compressed", Options{}, Args{Source: "div { color: #ccc; }", OutputStyle: OutputStyleCompressed}, Result{CSS: "div{color:#ccc}"}},
-		{"Enable Source Map", Options{}, Args{Source: "div{color:blue;}", OutputStyle: OutputStyleCompressed, EnableSourceMap: true}, Result{CSS: "div{color:blue}", SourceMap: "{\"version\":3,\"sourceRoot\":\"\",\"sources\":[\"data:;charset=utf-8,div%7Bcolor:blue;%7D\"],\"names\":[],\"mappings\":\"AAAA\"}"}},
+		{"Enable Source Map", Options{}, Args{Source: "div{color:blue;}", URL: "file://myproject/main.scss", OutputStyle: OutputStyleCompressed, EnableSourceMap: true}, Result{CSS: "div{color:blue}", SourceMap: "{\"version\":3,\"sourceRoot\":\"\",\"sources\":[\"file://myproject/main.scss\"],\"names\":[],\"mappings\":\"AAAA\"}"}},
 		{"Sass syntax", Options{}, Args{
 			Source: `$font-stack:    Helvetica, sans-serif
 $primary-color: #333
@@ -79,6 +80,7 @@ body
 			SourceSyntax: SourceSyntaxSASS,
 		}, Result{CSS: "body{font:100% Helvetica,sans-serif;color:#333}"}},
 		{"Import resolver", Options{ImportResolver: colorsResolver}, Args{Source: "@import \"colors\";\ndiv { p { color: $white; } }"}, Result{CSS: "div p {\n  color: #ffff;\n}"}},
+		{"Import resolver with source map", Options{ImportResolver: colorsResolver}, Args{Source: "@import \"colors\";\ndiv { p { color: $white; } }", EnableSourceMap: true}, Result{CSS: "div p {\n  color: #ffff;\n}", SourceMap: "{\"version\":3,\"sourceRoot\":\"\",\"sources\":[\"data:;charset=utf-8,@import%20%22colors%22;%0Adiv%20%7B%20p%20%7B%20color:%20$white;%20%7D%20%7D\",\"file:///myproject/scss/colors_myfile.scss\"],\"names\":[],\"mappings\":\"AACM;EAAI,OCDC\"}"}},
 
 		// Error cases
 		{"Invalid syntax", Options{}, Args{Source: "div { color: $white; }"}, false},
@@ -102,7 +104,9 @@ body
 			} else {
 				expectedResult := test.expect.(Result)
 				c.Assert(err, qt.IsNil)
+				//printJSON(result.SourceMap)
 				c.Assert(result, qt.Equals, expectedResult)
+
 			}
 		})
 
@@ -250,6 +254,16 @@ func BenchmarkTranspiler(b *testing.B) {
 	})
 }
 
+func TestHasSchema(t *testing.T) {
+	c := qt.New(t)
+
+	c.Assert(hasSchema("file:foo"), qt.Equals, true)
+	c.Assert(hasSchema("http:foo"), qt.Equals, true)
+	c.Assert(hasSchema("123:foo"), qt.Equals, false)
+	c.Assert(hasSchema("foo"), qt.Equals, false)
+
+}
+
 func newTestTranspiler(c *qt.C, opts Options) (*Transpiler, func()) {
 	opts.DartSassEmbeddedFilename = getSassEmbeddedFilename()
 	transpiler, err := Start(opts)
@@ -268,3 +282,12 @@ func getSassEmbeddedFilename() string {
 
 	return defaultDartSassEmbeddedFilename
 }
+
+// used for debugging
+func printJSON(s string) {
+	m := make(map[string]interface{})
+	json.Unmarshal([]byte(s), &m)
+	b, _ := json.MarshalIndent(m, "", "  ")
+	fmt.Printf("%s", b)
+
+}