Add support for log events (e.g. @debug)

go.mod

@@ -4,6 +4,6 @@ go 1.15
 
 require (
 	github.com/cli/safeexec v1.0.0
-	github.com/frankban/quicktest v1.11.2
+	github.com/frankban/quicktest v1.14.2
 	google.golang.org/protobuf v1.25.0
 )

go.sum

@@ -4,10 +4,13 @@ github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA
 github.com/cli/safeexec v1.0.0 h1:0VngyaIyqACHdcMNWfo6+KdUYnqEr2Sg+bSP1pdF+dI=
 github.com/cli/safeexec v1.0.0/go.mod h1:Z/D4tTN8Vs5gXYHDCbaM1S/anmEDnJb1iW0+EJ5zx3Q=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/frankban/quicktest v1.11.2 h1:mjwHjStlXWibxOohM7HYieIViKyh56mmt3+6viyhDDI=
 github.com/frankban/quicktest v1.11.2/go.mod h1:K+q6oSqb0W0Ininfk863uOk1lMy69l/P6txr3mVT54s=
+github.com/frankban/quicktest v1.14.2 h1:SPb1KFFmM+ybpEjPUhCCkZOM5xlovT5UbrMvWnXyBns=
+github.com/frankban/quicktest v1.14.2/go.mod h1:mgiwOwqx65TmIk1wJ6Q7wvnVMocbUorkibMOrVTHZps=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
@@ -25,12 +28,21 @@ github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.2 h1:X2ev0eStA3AbceY54o37/0PQ/UWqKEiiO2dKL5OPaFM=
 github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/rogpeppe/go-internal v1.6.1 h1:/FiVV8dS/e+YqF2JvO3yXRFbBLTIuSDkuC7aBOAvL+k=
+github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -70,5 +82,7 @@ google.golang.org/protobuf v1.22.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2
 google.golang.org/protobuf v1.23.1-0.20200526195155-81db48ad09cc/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
 google.golang.org/protobuf v1.25.0 h1:Ejskq+SyPohKW+1uil0JJMtmHCgJPJ/qWTxr8qp+R4c=
 google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlbajtzgsN7c=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

options.go

@@ -24,6 +24,32 @@ type Options struct {
 	// as running this code against the beta5 binary would hang
 	// on Execute.
 	Timeout time.Duration
+
+	// LogEventHandler will, if set, receive log events from Dart Sass,
+	// e.g. @debug and @warn log statements.
+	LogEventHandler func(LogEvent)
+}
+
+// LogEvent is a type of log event from Dart Sass.
+type LogEventType int
+
+const (
+	// Usually triggered by the @warn directive.
+	LogEventTypeWarning LogEventType = iota
+
+	// Events trigered for usage of deprecated Sass features.
+	LogEventTypeDeprecated
+
+	// Triggered by the @debug directive.
+	LogEventTypeDebug
+)
+
+type LogEvent struct {
+	// Type is the type of log event.
+	Type LogEventType
+
+	// Message on the form url:line:col message.
+	Message string
 }
 
 func (opts *Options) init() error {

transpiler.go

@@ -339,7 +339,29 @@ func (t *Transpiler) input() {
 				},
 			)
 		case *embeddedsass.OutboundMessage_LogEvent_:
-			// Drop these for now.
+			if t.opts.LogEventHandler != nil {
+				var logEvent LogEvent
+				e := c.LogEvent
+				if e.Span != nil {
+					url := e.Span.Url
+					if url == "" {
+						url = "stdin"
+					}
+					logEvent = LogEvent{
+						Type:    LogEventType(e.Type),
+						Message: fmt.Sprintf("%s:%d:%d: %s", url, e.Span.Start.Line, e.Span.Start.Column, c.LogEvent.GetMessage()),
+					}
+				} else {
+					logEvent = LogEvent{
+						Type:    LogEventType(e.Type),
+						Message: e.GetMessage(),
+					}
+				}
+
+				t.opts.LogEventHandler(logEvent)
+
+			}
+
 		case *embeddedsass.OutboundMessage_Error:
 			err = fmt.Errorf("SASS error: %s", c.Error.GetMessage())
 		default:

transpiler_test.go

@@ -99,6 +99,7 @@ body
 		{"Error in ImportResolver.Load", Options{}, Args{Source: "@import \"colors\";", ImportResolver: testImportResolver{name: "colors", failOnLoad: true}}, false},
 		{"Invalid OutputStyle", Options{}, Args{Source: "a", OutputStyle: "asdf"}, false},
 		{"Invalid SourceSyntax", Options{}, Args{Source: "a", SourceSyntax: "asdf"}, false},
+		{"Erro logging", Options{}, Args{Source: `@error "foo";`}, false},
 	} {
 
 		test := test
@@ -125,6 +126,43 @@ body
 	}
 }
 
+func TestDebugWarn(t *testing.T) {
+	c := qt.New(t)
+
+	args := Args{
+		Source: `
+$color: #333;
+body {
+	  color: $color;
+}
+
+ @debug "foo";
+@warn "bar";
+
+`,
+	}
+
+	var events []LogEvent
+	eventHandler := func(e LogEvent) {
+		events = append(events, e)
+	}
+
+	opts := Options{
+		LogEventHandler: eventHandler,
+	}
+
+	transpiler, clean := newTestTranspiler(c, opts)
+	defer clean()
+	result, err := transpiler.Execute(args)
+	c.Assert(err, qt.IsNil)
+
+	c.Assert(result.CSS, qt.Equals, "body {\n  color: #333;\n}")
+	c.Assert(events, qt.DeepEquals, []LogEvent{
+		{Type: 2, Message: "stdin:6:1: foo"},
+		{Type: 0, Message: "bar"},
+	})
+}
+
 func TestIncludePaths(t *testing.T) {
 	dir1, _ := ioutil.TempDir(os.TempDir(), "libsass-test-include-paths-dir1")
 	defer os.RemoveAll(dir1)