[errors] Remove Fix(), move MultiErrorFromErrors().

common/sync/parallel/multierror_test.go

Index: common/sync/parallel/multierror_test.go
diff --git a/common/errors/multierror_test.go b/common/sync/parallel/multierror_test.go
similarity index 50%
copy from common/errors/multierror_test.go
copy to common/sync/parallel/multierror_test.go
index 5d1363d03dcdaf806b2db67ed9520a1a219cec25..f5dd7276d4d325b8d3a718370040b8d79aa3f74c 100644
--- a/common/errors/multierror_test.go
+++ b/common/sync/parallel/multierror_test.go
@@ -2,13 +2,13 @@
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
-package errors
+package parallel
 
 import (
-	"errors"
 	"fmt"
 	"testing"
 
+	"github.com/luci/luci-go/common/errors"
 	. "github.com/smartystreets/goconvey/convey"
 )
 
@@ -20,10 +20,6 @@ func TestMultiError(t *testing.T) {
 	t.Parallel()
 
 	Convey("MultiError works", t, func() {
-		var me error = MultiError{fmt.Errorf("hello"), fmt.Errorf("bob")}
-
-		So(me.Error(), ShouldEqual, `hello (and 1 other error)`)
-
 		Convey("MultiErrorFromErrors with errors works", func() {
 			mec := make(chan error, 4)
 			mec <- nil
@@ -52,59 +48,14 @@ func TestMultiError(t *testing.T) {
 	})
 }
 
-func TestUpstreamErrors(t *testing.T) {
-	t.Parallel()
-
-	Convey("Test MultiError", t, func() {
-		Convey("nil", func() {
-			me := MultiError(nil)
-			So(me.Error(), ShouldEqual, "(0 errors)")
-			Convey("single", func() {
-				So(SingleError(error(me)), ShouldBeNil)
-			})
-		})
-		Convey("one", func() {
-			me := MultiError{errors.New("sup")}
-			So(me.Error(), ShouldEqual, "sup")
-		})
-		Convey("two", func() {
-			me := MultiError{errors.New("sup"), errors.New("what")}
-			So(me.Error(), ShouldEqual, "sup (and 1 other error)")
-		})
-		Convey("more", func() {
-			me := MultiError{errors.New("sup"), errors.New("what"), errors.New("nerds")}
-			So(me.Error(), ShouldEqual, "sup (and 2 other errors)")
-
-			Convey("single", func() {
-				So(SingleError(error(me)), ShouldResemble, errors.New("sup"))
-			})
-		})
-	})
-
-	Convey("SingleError passes through", t, func() {
-		e := errors.New("unique")
-		So(SingleError(e), ShouldEqual, e)
-	})
-
-	Convey("Test MultiError Conversion", t, func() {
-		ome := otherMEType{errors.New("sup")}
-		So(Fix(ome), ShouldHaveSameTypeAs, MultiError{})
-	})
-
-	Convey("Fix passes through", t, func() {
-		e := errors.New("unique")
-		So(Fix(e), ShouldEqual, e)
-	})
-}
-
-func ExampleMultiError() {
+func ExampleMultiErrorFromErrors() {
 	errCh := make(chan error, 10)
 	errCh <- nil // nils are ignored
 	errCh <- fmt.Errorf("what")
 	close(errCh)
 
 	err := MultiErrorFromErrors(errCh)
-	fmt.Printf("got: %s len=%d\n", err, len(err.(MultiError)))
+	fmt.Printf("got: %s len=%d\n", err, len(err.(errors.MultiError)))
 
 	errCh = make(chan error, 10)
 	errCh <- nil // and if the channel only has nils