Move lock diff to TOML

* Expanded diff test case to verify that multiple projects
  are formatted properly

testdata/txn_writer/expected_diff_output.txt

@@ -1,34 +1,31 @@
 Memo: 595716d270828e763c811ef79c9c41f85b1d1bfbdfe85280036405c03772206c -> 2252a285ab27944a4d7adcba8dbd03980f59ba652f12db39fa93b927c345593e
-Add: [
-    {
-        "name": "github.com/stuff/realthing",
-        "version": "2.0.0",
-        "revision": "1f02e52d6bac308da54ab84a234c58a98ca82347",
-        "packages": [
-            "."
-        ]
-    }
-]
-Remove: [
-    {
-        "name": "github.com/stuff/placeholder",
-        "version": "2.0.0",
-        "revision": "6694017eeb4e20fd277b049bf29dba4895c97234",
-        "packages": [
-            "."
-        ]
-    }
-]
-Modify: [
-    {
-        "name": "github.com/foo/bar",
-        "source": "+ http://github.example.com/foo/bar",
-        "version": "+ 1.2.0",
-        "branch": "- master",
-        "revision": "f24338400f072ef18125ae0fbe6b06fe6d1783e7 -> 2a3a211e171803acb82d1d5d42ceb53228f51751",
-        "packages": [
-            "- placeholder",
-            "+ thing"
-        ]
-    }
-]
+
+Add:
+[[projects]]
+  name = "github.com/sdboyer/deptest"
+  packages = ["."]
+  revision = "ff2948a2ac8f538c4ecd55962e919d1e13e74baf"
+  version = "v1.0.0"
+
+[[projects]]
+  name = "github.com/stuff/realthing"
+  packages = ["."]
+  revision = "1f02e52d6bac308da54ab84a234c58a98ca82347"
+  version = "2.0.0"
+
+Remove:
+[[projects]]
+  name = "github.com/stuff/placeholder"
+  packages = ["."]
+  revision = "6694017eeb4e20fd277b049bf29dba4895c97234"
+  version = "2.0.0"
+
+Modify:
+[[projects]]
+  branch = "- master"
+  name = "github.com/foo/bar"
+  packages = ["- placeholder","+ thing"]
+  revision = "f24338400f072ef18125ae0fbe6b06fe6d1783e7 -> 2a3a211e171803acb82d1d5d42ceb53228f51751"
+  source = "+ http://github.example.com/foo/bar"
+  version = "+ 1.2.0"
+

testdata/txn_writer/original_lock.toml

@@ -6,7 +6,7 @@ memo = "595716d270828e763c811ef79c9c41f85b1d1bfbdfe85280036405c03772206c"
   revision = "f24338400f072ef18125ae0fbe6b06fe6d1783e7"
   packages = ["placeholder", "util"]
 
-[[packages]]
+[[projects]]
   name = "github.com/stuff/placeholder"
   version = "2.0.0"
   revision = "6694017eeb4e20fd277b049bf29dba4895c97234"

testdata/txn_writer/updated_lock.toml

@@ -7,8 +7,14 @@ memo = "2252a285ab27944a4d7adcba8dbd03980f59ba652f12db39fa93b927c345593e"
   revision = "2a3a211e171803acb82d1d5d42ceb53228f51751"
   packages = ["thing","util"]
 
-[[packages]]
+[[projects]]
   name = "github.com/stuff/realthing"
   version = "2.0.0"
   revision = "1f02e52d6bac308da54ab84a234c58a98ca82347"
   packages = ["."]
+
+[[projects]]
+  name = "github.com/sdboyer/deptest"
+  packages = ["."]
+  revision = "ff2948a2ac8f538c4ecd55962e919d1e13e74baf"
+  version = "v1.0.0"

txn_writer.go

@@ -7,7 +7,6 @@ package dep
 import (
 	"bytes"
 	"encoding/hex"
-	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -15,6 +14,7 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/pelletier/go-toml"
 	"github.com/pkg/errors"
 	"github.com/sdboyer/gps"
 )
@@ -67,40 +67,40 @@ func (diff *LockDiff) Format() (string, error) {
 	var buf bytes.Buffer
 
 	if diff.HashDiff != nil {
-		buf.WriteString(fmt.Sprintf("Memo: %s\n", diff.HashDiff))
+		buf.WriteString(fmt.Sprintf("Memo: %s\n\n", diff.HashDiff))
+	}
+
+	writeDiffs := func(diffs []LockedProjectDiff) error {
+		for i := 0; i < len(diffs); i++ {
+			chunk, err := diffs[i].MarshalTOML()
+			if err != nil {
+				return err
+			}
+			buf.WriteString(chunk)
+		}
+		buf.WriteString("\n")
+		return nil
 	}
 
 	if len(diff.Add) > 0 {
-		buf.WriteString("Add: ")
-
-		enc := json.NewEncoder(&buf)
-		enc.SetIndent("", "    ")
-		enc.SetEscapeHTML(false)
-		err := enc.Encode(diff.Add)
+		buf.WriteString("Add:")
+		err := writeDiffs(diff.Add)
 		if err != nil {
 			return "", errors.Wrap(err, "Unable to format LockDiff.Add")
 		}
 	}
 
 	if len(diff.Remove) > 0 {
-		buf.WriteString("Remove: ")
-
-		enc := json.NewEncoder(&buf)
-		enc.SetIndent("", "    ")
-		enc.SetEscapeHTML(false)
-		err := enc.Encode(diff.Remove)
+		buf.WriteString("Remove:")
+		err := writeDiffs(diff.Remove)
 		if err != nil {
 			return "", errors.Wrap(err, "Unable to format LockDiff.Remove")
 		}
 	}
 
 	if len(diff.Modify) > 0 {
-		buf.WriteString("Modify: ")
-
-		enc := json.NewEncoder(&buf)
-		enc.SetIndent("", "    ")
-		enc.SetEscapeHTML(false)
-		err := enc.Encode(diff.Modify)
+		buf.WriteString("Modify:")
+		err := writeDiffs(diff.Modify)
 		if err != nil {
 			return "", errors.Wrap(err, "Unable to format LockDiff.Modify")
 		}
@@ -113,12 +113,52 @@ func (diff *LockDiff) Format() (string, error) {
 // Fields are only populated when there is a difference, otherwise they are empty.
 // TODO(carolynvs) this should be moved to gps
 type LockedProjectDiff struct {
-	Name     gps.ProjectRoot `json:"name"`
-	Source   *StringDiff     `json:"source,omitempty"`
-	Version  *StringDiff     `json:"version,omitempty"`
-	Branch   *StringDiff     `json:"branch,omitempty"`
-	Revision *StringDiff     `json:"revision,omitempty"`
-	Packages []StringDiff    `json:"packages,omitempty"`
+	Name     gps.ProjectRoot
+	Source   *StringDiff
+	Version  *StringDiff
+	Branch   *StringDiff
+	Revision *StringDiff
+	Packages []StringDiff
+}
+
+func (diff *LockedProjectDiff) MarshalTOML() (string, error) {
+	prj := make(map[string]interface{})
+	prj["name"] = string(diff.Name)
+
+	if diff.Source != nil {
+		prj["source"] = diff.Source.String()
+	}
+
+	if diff.Version != nil {
+		prj["version"] = diff.Version.String()
+	}
+
+	if diff.Branch != nil {
+		prj["branch"] = diff.Branch.String()
+	}
+
+	if diff.Revision != nil {
+		prj["revision"] = diff.Revision.String()
+	}
+
+	if len(diff.Packages) > 0 {
+		p := make([]interface{}, len(diff.Packages))
+		for i := 0; i < len(diff.Packages); i++ {
+			p[i] = diff.Packages[i].String()
+		}
+		prj["packages"] = p
+	}
+
+	m := make(map[string]interface{})
+	m["projects"] = []map[string]interface{}{prj}
+
+	t, err := toml.TreeFromMap(m)
+	if err != nil {
+		return "", errors.Wrap(err, "Unable to marshal lock diff to TOML tree")
+	}
+
+	result, err := t.ToTomlString()
+	return result, errors.Wrap(err, "Unable to marshal lock diff to TOML string")
 }
 
 type StringDiff struct {
@@ -142,15 +182,6 @@ func (diff StringDiff) String() string {
 	return diff.Current
 }
 
-func (diff StringDiff) MarshalJSON() ([]byte, error) {
-	var buf bytes.Buffer
-	enc := json.NewEncoder(&buf)
-	enc.SetEscapeHTML(false)
-	err := enc.Encode(diff.String())
-
-	return buf.Bytes(), err
-}
-
 // VendorBehavior defines when the vendor directory should be written.
 type VendorBehavior int
 

txn_writer_test.go

@@ -518,12 +518,16 @@ func TestSafeWriter_DiffLocks(t *testing.T) {
 		t.Fatalf("Expected the lock diff to contain the updated hash: expected %s, got %s", pc.Project.Lock.Memo, updatedLock.Memo)
 	}
 
-	if len(diff.Add) != 1 {
-		t.Fatalf("Expected the lock diff to contain 1 added project, got %d", len(diff.Add))
+	if len(diff.Add) != 2 {
+		t.Fatalf("Expected the lock diff to contain 2 added projects, got %d", len(diff.Add))
 	} else {
-		add := diff.Add[0]
-		if add.Name != "github.com/stuff/realthing" {
-			t.Errorf("expected new project github.com/stuff/realthing, got %s", add.Name)
+		add1 := diff.Add[0]
+		if add1.Name != "github.com/sdboyer/deptest" {
+			t.Errorf("expected new project[0] github.com/sdboyer/deptest, got %s", add1.Name)
+		}
+		add2 := diff.Add[1]
+		if add2.Name != "github.com/stuff/realthing" {
+			t.Errorf("expected new project[1] github.com/stuff/realthing, got %s", add2.Name)
 		}
 	}