Output multi-element TOML arrays on newlines

CHANGELOG.md

@@ -7,6 +7,7 @@ NEW FEATURES:
 * Allow override of cache directory location using environment variable
 `DEPCACHEDIR`. ([#1234](https://github.com/golang/dep/pull/1234))
 * Add support for template output in `dep status`. (#1389)
+* Each element in a multi-item TOML array is output on its own line. (#1461)
 
 BUG FIXES:
 

cmd/dep/testdata/harness_tests/init/glide/case1/final/Gopkg.toml

@@ -1,4 +1,7 @@
-ignored = ["github.com/golang/notexist/samples","github.com/sdboyer/dep-test"]
+ignored = [
+  "github.com/golang/notexist/samples",
+  "github.com/sdboyer/dep-test"
+]
 
 [[constraint]]
   name = "github.com/sdboyer/deptestdos"

cmd/dep/testdata/harness_tests/init/govendor/case1/final/Gopkg.toml

@@ -1,4 +1,7 @@
-ignored = ["github.com/golang/notexist/samples*","github.com/sdboyer/dep-test*"]
+ignored = [
+  "github.com/golang/notexist/samples*",
+  "github.com/sdboyer/dep-test*"
+]
 
 [[constraint]]
   name = "github.com/sdboyer/deptestdos"

lock.go

@@ -173,8 +173,10 @@ func (l *Lock) toRaw() rawLock {
 // MarshalTOML serializes this lock into TOML via an intermediate raw form.
 func (l *Lock) MarshalTOML() ([]byte, error) {
 	raw := l.toRaw()
-	result, err := toml.Marshal(raw)
-	return result, errors.Wrap(err, "Unable to marshal lock to TOML string")
+	var buf bytes.Buffer
+	enc := toml.NewEncoder(&buf).ArraysWithOneElementPerLine(true)
+	err := enc.Encode(raw)
+	return buf.Bytes(), errors.Wrap(err, "Unable to marshal lock to TOML string")
 }
 
 // LockFromSolution converts a gps.Solution to dep's representation of a lock.

manifest.go

@@ -454,8 +454,10 @@ func toProject(raw rawProject) (n gps.ProjectRoot, pp gps.ProjectProperties, err
 // MarshalTOML serializes this manifest into TOML via an intermediate raw form.
 func (m *Manifest) MarshalTOML() ([]byte, error) {
 	raw := m.toRaw()
-	result, err := toml.Marshal(raw)
-	return result, errors.Wrap(err, "unable to marshal the lock to a TOML string")
+	var buf bytes.Buffer
+	enc := toml.NewEncoder(&buf).ArraysWithOneElementPerLine(true)
+	err := enc.Encode(raw)
+	return buf.Bytes(), errors.Wrap(err, "unable to marshal the lock to a TOML string")
 }
 
 // toRaw converts the manifest into a representation suitable to write to the manifest file