Update go-toml for nested custom Marshaler support

Author: carolynvs

fs.go

@@ -13,15 +13,9 @@ import (
 	"syscall"
 
 	"github.com/pkg/errors"
+	"github.com/pelletier/go-toml"
 )
 
-// tomlMarshaler is the interface implemented by types that
-// can marshal themselves into valid TOML.
-// TODO(carolynvs) Add this (and an unmarshaler) to go-toml, implemented using the same patterns in encoding/json
-type tomlMarshaler interface {
-	MarshalTOML() ([]byte, error)
-}
-
 func IsRegular(name string) (bool, error) {
 	// TODO: lstat?
 	fi, err := os.Stat(name)
@@ -65,7 +59,7 @@ func IsNonEmptyDir(name string) (bool, error) {
 	return len(files) != 0, nil
 }
 
-func writeFile(path string, in tomlMarshaler) error {
+func writeFile(path string, in toml.Marshaler) error {
 	f, err := os.Create(path)
 	if err != nil {
 		return err

lock.toml

@@ -27,7 +27,7 @@ memo = "31a7162c06758e4619ed89b91e1f48bf94ad14f394bbee79299ed0bb5150e409"
 [[projects]]
   branch = "master"
   name = "github.com/pelletier/go-toml"
-  revision = "e32a2e04744250647a72bf17da1b09befc03b6b1"
+  revision = "fe206efb84b2bc8e8cfafe6b4c1826622be969e3"
   packages = ["."]
 
 [[projects]]

txn_writer.go

@@ -59,6 +59,10 @@ type LockDiff struct {
 	Modify   []LockedProjectDiff
 }
 
+type rawLockedProjectDiffs struct {
+	Projects []LockedProjectDiff `toml:"projects"`
+}
+
 func (diff *LockDiff) Format() (string, error) {
 	if diff == nil {
 		return "", nil
@@ -71,13 +75,12 @@ func (diff *LockDiff) Format() (string, error) {
 	}
 
 	writeDiffs := func(diffs []LockedProjectDiff) error {
-		for i := 0; i < len(diffs); i++ {
-			chunk, err := toml.Marshal(diffs[i])
-			if err != nil {
-				return err
-			}
-			buf.Write(chunk)
+		raw := rawLockedProjectDiffs{diffs}
+		chunk, err := toml.Marshal(raw)
+		if err != nil {
+			return err
 		}
+		buf.Write(chunk)
 		buf.WriteString("\n")
 		return nil
 	}
@@ -114,11 +117,11 @@ func (diff *LockDiff) Format() (string, error) {
 // TODO(carolynvs) this should be moved to gps
 type LockedProjectDiff struct {
 	Name     gps.ProjectRoot `toml:"name"`
-	Source   *StringDiff     `toml:"source"`
-	Version  *StringDiff     `toml:"version"`
-	Branch   *StringDiff     `toml:"branch"`
-	Revision *StringDiff     `toml:"revision"`
-	Packages []StringDiff    `toml:"packages"`
+	Source   *StringDiff     `toml:"source,omitempty"`
+	Version  *StringDiff     `toml:"version,omitempty"`
+	Branch   *StringDiff     `toml:"branch,omitempty"`
+	Revision *StringDiff     `toml:"revision,omitempty"`
+	Packages []StringDiff    `toml:"packages,omitempty"`
 }
 
 type StringDiff struct {
@@ -142,6 +145,10 @@ func (diff StringDiff) String() string {
 	return diff.Current
 }
 
+func (diff StringDiff) MarshalTOML() ([]byte, error) {
+	return []byte(diff.String()), nil
+}
+
 // VendorBehavior defines when the vendor directory should be written.
 type VendorBehavior int