Suggest using go-toml v2

Refs #450

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,9 +1,18 @@
 ---
 name: Bug report
 about: Create a report to help us improve
-
 ---
 
+<!--
+‼️ Main development focus is on the upcoming go-toml v2 ⚠️
+
+As a result, v1.x bugs will likely not see a fix on a v1.x version.
+However, reporting the bug is the best way to ensure that it will be fixed in v2.
+
+See https://github.com/pelletier/go-toml/discussions/506.
+-->
+
+
 **Describe the bug**
 A clear and concise description of what the bug is.
 
@@ -14,7 +23,7 @@ Steps to reproduce the behavior. Including TOML files.
 A clear and concise description of what you expected to happen, if other than "should work".
 
 **Versions**
- - go-toml: version (git sha)
+ - go-toml: version (or git sha)
  - go: version
  - operating system: e.g. macOS, Windows, Linux
 

.github/dependabot.yml

@@ -0,0 +1,8 @@
+version: 2
+updates:
+- package-ecosystem: gomod
+  directory: "/"
+  schedule:
+    interval: daily
+    time: "13:00"
+  open-pull-requests-limit: 10

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,67 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master ]
+  schedule:
+    - cron: '26 19 * * 0'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

README.md

@@ -12,6 +12,31 @@ This library supports TOML version
 [![Go Report Card](https://goreportcard.com/badge/github.com/pelletier/go-toml)](https://goreportcard.com/report/github.com/pelletier/go-toml)
 [![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Fpelletier%2Fgo-toml.svg?type=shield)](https://app.fossa.io/projects/git%2Bgithub.com%2Fpelletier%2Fgo-toml?ref=badge_shield)
 
+
+## Development status
+
+**ℹ️ Consider go-toml v2!**
+
+The next version of go-toml is in [active development][v2-dev], and
+[nearing completion][v2-map].
+
+Though technically in beta, v2 is already more tested, [fixes bugs][v1-bugs],
+and [much faster][v2-bench]. If you only need reading and writing TOML documents
+(majority of cases), those features are implemented and the API unlikely to
+change.
+
+The remaining features (Document structure editing and tooling) will be added
+shortly. While pull-requests are welcome on v1, no active development is
+expected on it. When v2.0.0 is released, v1 will be deprecated.
+
+👉 [go-toml v2][v2]
+
+[v2]: https://github.com/pelletier/go-toml/tree/v2
+[v2-map]: https://github.com/pelletier/go-toml/discussions/506
+[v2-dev]: https://github.com/pelletier/go-toml/tree/v2
+[v1-bugs]: https://github.com/pelletier/go-toml/issues?q=is%3Aissue+is%3Aopen+label%3Av2-fixed
+[v2-bench]: https://github.com/pelletier/go-toml/tree/v2#benchmarks
+
 ## Features
 
 Go-toml provides the following features for using data parsed from TOML documents:
@@ -109,7 +134,7 @@ Go-toml provides three handy command line tools:
 
 ### Docker image
 
-Those tools are also availble as a Docker image from
+Those tools are also available as a Docker image from
 [dockerhub](https://hub.docker.com/r/pelletier/go-toml). For example, to
 use `tomljson`:
 

azure-pipelines.yml

@@ -12,9 +12,9 @@ stages:
       vmImage: ubuntu-latest
     steps:
     - task: GoTool@0
-      displayName: "Install Go 1.15"
+      displayName: "Install Go 1.16"
       inputs:
-        version: "1.15"
+        version: "1.16"
     - task: Go@0
       displayName: "go fmt ./..."
       inputs:
@@ -23,14 +23,13 @@ stages:
         arguments: './...'
   - job: coverage
     displayName: "coverage"
-    condition: ne(variables['Build.SourceBranchName'], 'master')
     pool:
       vmImage: ubuntu-latest
     steps:
     - task: GoTool@0
-      displayName: "Install Go 1.15"
+      displayName: "Install Go 1.16"
       inputs:
-        version: "1.15"
+        version: "1.16"
     - task: Go@0
       displayName: "Generate coverage"
       inputs:
@@ -48,9 +47,9 @@ stages:
       vmImage: ubuntu-latest
     steps:
     - task: GoTool@0
-      displayName: "Install Go 1.15"
+      displayName: "Install Go 1.16"
       inputs:
-        version: "1.15"
+        version: "1.16"
     - script: echo "##vso[task.setvariable variable=PATH]${PATH}:/home/vsts/go/bin/"
     - task: Bash@3
       inputs:
@@ -61,6 +60,15 @@ stages:
     displayName: "unit tests"
     strategy:
       matrix:
+        linux 1.16:
+          goVersion: '1.16'
+          imageName: 'ubuntu-latest'
+        mac 1.16:
+          goVersion: '1.16'
+          imageName: 'macOS-latest'
+        windows 1.16:
+          goVersion: '1.16'
+          imageName: 'windows-latest'
         linux 1.15:
           goVersion: '1.15'
           imageName: 'ubuntu-latest'
@@ -70,15 +78,6 @@ stages:
         windows 1.15:
           goVersion: '1.15'
           imageName: 'windows-latest'
-        linux 1.14:
-          goVersion: '1.14'
-          imageName: 'ubuntu-latest'
-        mac 1.14:
-          goVersion: '1.14'
-          imageName: 'macOS-latest'
-        windows 1.14:
-          goVersion: '1.14'
-          imageName: 'windows-latest'
     pool:
       vmImage: $(imageName)
     steps:
@@ -114,7 +113,7 @@ stages:
     - task: GoTool@0
       displayName: "Install Go"
       inputs:
-        version: 1.15
+        version: 1.16
     - task: Bash@3
       inputs:
         targetType: inline

benchmark/go.sum

@@ -1,7 +1,5 @@
 github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=

go.mod

@@ -1,5 +1,3 @@
 module github.com/pelletier/go-toml
 
 go 1.12
-
-require github.com/davecgh/go-spew v1.1.1

go.sum

@@ -1,2 +0,0 @@
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

marshal.go

@@ -18,6 +18,7 @@ const (
 	tagFieldComment = "comment"
 	tagCommented    = "commented"
 	tagMultiline    = "multiline"
+	tagLiteral      = "literal"
 	tagDefault      = "default"
 )
 
@@ -27,6 +28,7 @@ type tomlOpts struct {
 	comment      string
 	commented    bool
 	multiline    bool
+	literal      bool
 	include      bool
 	omitempty    bool
 	defaultValue string
@@ -46,6 +48,7 @@ type annotation struct {
 	comment      string
 	commented    string
 	multiline    string
+	literal      string
 	defaultValue string
 }
 
@@ -54,15 +57,16 @@ var annotationDefault = annotation{
 	comment:      tagFieldComment,
 	commented:    tagCommented,
 	multiline:    tagMultiline,
+	literal:      tagLiteral,
 	defaultValue: tagDefault,
 }
 
-type marshalOrder int
+type MarshalOrder int
 
 // Orders the Encoder can write the fields to the output stream.
 const (
 	// Sort fields alphabetically.
-	OrderAlphabetical marshalOrder = iota + 1
+	OrderAlphabetical MarshalOrder = iota + 1
 	// Preserve the order the fields are encountered. For example, the order of fields in
 	// a struct.
 	OrderPreserve
@@ -254,11 +258,12 @@ type Encoder struct {
 	w io.Writer
 	encOpts
 	annotation
-	line        int
-	col         int
-	order       marshalOrder
-	promoteAnon bool
-	indentation string
+	line            int
+	col             int
+	order           MarshalOrder
+	promoteAnon     bool
+	compactComments bool
+	indentation     string
 }
 
 // NewEncoder returns a new encoder that writes to w.
@@ -317,7 +322,7 @@ func (e *Encoder) ArraysWithOneElementPerLine(v bool) *Encoder {
 }
 
 // Order allows to change in which order fields will be written to the output stream.
-func (e *Encoder) Order(ord marshalOrder) *Encoder {
+func (e *Encoder) Order(ord MarshalOrder) *Encoder {
 	e.order = ord
 	return e
 }
@@ -365,6 +370,12 @@ func (e *Encoder) PromoteAnonymous(promote bool) *Encoder {
 	return e
 }
 
+// CompactComments removes the new line before each comment in the tree.
+func (e *Encoder) CompactComments(cc bool) *Encoder {
+	e.compactComments = cc
+	return e
+}
+
 func (e *Encoder) marshal(v interface{}) ([]byte, error) {
 	// Check if indentation is valid
 	for _, char := range e.indentation {
@@ -404,7 +415,7 @@ func (e *Encoder) marshal(v interface{}) ([]byte, error) {
 	}
 
 	var buf bytes.Buffer
-	_, err = t.writeToOrdered(&buf, "", "", 0, e.arraysOneElementPerLine, e.order, e.indentation, false)
+	_, err = t.writeToOrdered(&buf, "", "", 0, e.arraysOneElementPerLine, e.order, e.indentation, e.compactComments, false)
 
 	return buf.Bytes(), err
 }
@@ -442,6 +453,7 @@ func (e *Encoder) valueToTree(mtype reflect.Type, mval reflect.Value) (*Tree, er
 							Comment:   opts.comment,
 							Commented: opts.commented,
 							Multiline: opts.multiline,
+							Literal:   opts.literal,
 						}, val)
 					}
 				}
@@ -586,6 +598,7 @@ func (e *Encoder) wrapTomlValue(val interface{}, parent *Tree) interface{} {
 	_, isTree := val.(*Tree)
 	_, isTreeS := val.([]*Tree)
 	if isTree || isTreeS {
+		e.line++
 		return val
 	}
 
@@ -1168,6 +1181,7 @@ func tomlOptions(vf reflect.StructField, an annotation) tomlOpts {
 	}
 	commented, _ := strconv.ParseBool(vf.Tag.Get(an.commented))
 	multiline, _ := strconv.ParseBool(vf.Tag.Get(an.multiline))
+	literal, _ := strconv.ParseBool(vf.Tag.Get(an.literal))
 	defaultValue := vf.Tag.Get(tagDefault)
 	result := tomlOpts{
 		name:         vf.Name,
@@ -1175,6 +1189,7 @@ func tomlOptions(vf reflect.StructField, an annotation) tomlOpts {
 		comment:      comment,
 		commented:    commented,
 		multiline:    multiline,
+		literal:      literal,
 		include:      true,
 		omitempty:    false,
 		defaultValue: defaultValue,

marshal_test.go

@@ -1294,6 +1294,32 @@ NonCommented = "Not commented line"
 	}
 }
 
+func TestMarshalMultilineLiteral(t *testing.T) {
+	type Doc struct {
+		Value string `multiline:"true" literal:"true"`
+	}
+
+	d := Doc{
+		Value: "hello\nworld\ttest\nend",
+	}
+
+	expected := []byte(`Value = '''
+hello
+world	test
+end
+'''
+`)
+
+	b, err := Marshal(d)
+	if err != nil {
+		t.Fatal("unexpected error")
+	}
+
+	if !bytes.Equal(b, expected) {
+		t.Errorf("Bad marshal: expected\n-----\n%s\n-----\ngot\n-----\n%s\n-----\n", expected, b)
+	}
+}
+
 func TestMarshalNonPrimitiveTypeCommented(t *testing.T) {
 	expectedToml := []byte(`
 # [CommentedMapField]
@@ -1450,6 +1476,47 @@ commented out"""
 	}
 }
 
+func TestCompactComments(t *testing.T) {
+	expected := []byte(`
+[first-section]
+  # comment for first-key
+  first-key = 1
+  # comment for second-key
+  second-key = "value"
+  # comment for commented third-key
+  # third-key = []
+
+[second-section]
+  # comment for first-key
+  first-key = 2
+  # comment for second-key
+  second-key = "another value"
+  # comment for commented third-key
+  # third-key = ["value1", "value2"]
+`)
+	type Settings struct {
+		FirstKey  int      `toml:"first-key" comment:"comment for first-key"`
+		SecondKey string   `toml:"second-key" comment:"comment for second-key"`
+		ThirdKey  []string `toml:"third-key" comment:"comment for commented third-key" commented:"true"`
+	}
+	type Config struct {
+		FirstSection  Settings `toml:"first-section"`
+		SecondSection Settings `toml:"second-section"`
+	}
+	data := Config{
+		FirstSection:  Settings{1, "value", []string{}},
+		SecondSection: Settings{2, "another value", []string{"value1", "value2"}},
+	}
+	buf := new(bytes.Buffer)
+	if err := NewEncoder(buf).CompactComments(true).Encode(data); err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(expected, buf.Bytes()) {
+		t.Errorf("Bad marshal: expected\n-----\n%s\n-----\ngot\n-----\n%s\n-----\n", expected, buf.Bytes())
+	}
+}
+
 type mapsTestStruct struct {
 	Simple map[string]string
 	Paths  map[string]string

parser_test.go

@@ -6,8 +6,6 @@ import (
 	"reflect"
 	"testing"
 	"time"
-
-	"github.com/davecgh/go-spew/spew"
 )
 
 func assertSubTree(t *testing.T, path []string, tree *Tree, err error, ref map[string]interface{}) {
@@ -39,7 +37,7 @@ func assertSubTree(t *testing.T, path []string, tree *Tree, err error, ref map[s
 }
 
 func assertTree(t *testing.T, tree *Tree, err error, ref map[string]interface{}) {
-	t.Log("Asserting tree:\n", spew.Sdump(tree))
+	t.Logf("Asserting tree:\n (%T)(%p)(%+v)", tree, tree, tree)
 	assertSubTree(t, []string{}, tree, err, ref)
 	t.Log("Finished tree assertion.")
 }

toml.go

@@ -15,6 +15,7 @@ type tomlValue struct {
 	comment   string
 	commented bool
 	multiline bool
+	literal   bool
 	position  Position
 }
 
@@ -314,6 +315,7 @@ type SetOptions struct {
 	Comment   string
 	Commented bool
 	Multiline bool
+	Literal   bool
 }
 
 // SetWithOptions is the same as Set, but allows you to provide formatting
@@ -362,12 +364,14 @@ func (t *Tree) SetPathWithOptions(keys []string, opts SetOptions, value interfac
 		v.comment = opts.Comment
 		v.commented = opts.Commented
 		v.multiline = opts.Multiline
+		v.literal = opts.Literal
 		toInsert = v
 	default:
 		toInsert = &tomlValue{value: value,
 			comment:   opts.Comment,
 			commented: opts.Commented,
 			multiline: opts.Multiline,
+			literal:   opts.Literal,
 			position:  Position{Line: subtree.position.Line + len(subtree.values) + 1, Col: subtree.position.Col}}
 	}
 

toml_testgen_support_test.go

@@ -8,8 +8,6 @@ import (
 	"reflect"
 	"testing"
 	"time"
-
-	"github.com/davecgh/go-spew/spew"
 )
 
 func testgenInvalid(t *testing.T, input string) {
@@ -56,7 +54,7 @@ func testgenValid(t *testing.T, input string, jsonRef string) {
 	}
 
 	if !reflect.DeepEqual(jsonExpected, jsonTest) {
-		t.Logf("Diff:\n%s", spew.Sdump(jsonExpected, jsonTest))
+		t.Logf("Diff:\n%#+v\n%#+v", jsonExpected, jsonTest)
 		t.Fatal("parsed TOML tree is different than expected structure")
 	}
 }

tomltree_write.go

@@ -103,7 +103,7 @@ func encodeTomlString(value string) string {
 	return b.String()
 }
 
-func tomlTreeStringRepresentation(t *Tree, ord marshalOrder) (string, error) {
+func tomlTreeStringRepresentation(t *Tree, ord MarshalOrder) (string, error) {
 	var orderedVals []sortNode
 	switch ord {
 	case OrderPreserve:
@@ -126,7 +126,7 @@ func tomlTreeStringRepresentation(t *Tree, ord marshalOrder) (string, error) {
 	return "{ " + strings.Join(values, ", ") + " }", nil
 }
 
-func tomlValueStringRepresentation(v interface{}, commented string, indent string, ord marshalOrder, arraysOneElementPerLine bool) (string, error) {
+func tomlValueStringRepresentation(v interface{}, commented string, indent string, ord MarshalOrder, arraysOneElementPerLine bool) (string, error) {
 	// this interface check is added to dereference the change made in the writeTo function.
 	// That change was made to allow this function to see formatting options.
 	tv, ok := v.(*tomlValue)
@@ -158,7 +158,15 @@ func tomlValueStringRepresentation(v interface{}, commented string, indent strin
 		return strings.ToLower(strconv.FormatFloat(value, 'f', -1, bits)), nil
 	case string:
 		if tv.multiline {
-			return "\"\"\"\n" + encodeMultilineTomlString(value, commented) + "\"\"\"", nil
+			if tv.literal {
+				b := strings.Builder{}
+				b.WriteString("'''\n")
+				b.Write([]byte(value))
+				b.WriteString("\n'''")
+				return b.String(), nil
+			} else {
+				return "\"\"\"\n" + encodeMultilineTomlString(value, commented) + "\"\"\"", nil
+			}
 		}
 		return "\"" + encodeTomlString(value) + "\"", nil
 	case []byte:
@@ -218,7 +226,9 @@ func tomlValueStringRepresentation(v interface{}, commented string, indent strin
 }
 
 func getTreeArrayLine(trees []*Tree) (line int) {
-	// get lowest line number that is not 0
+	// Prevent returning 0 for empty trees
+	line = int(^uint(0) >> 1)
+	// get lowest line number >= 0
 	for _, tv := range trees {
 		if tv.position.Line < line || line == 0 {
 			line = tv.position.Line
@@ -307,10 +317,10 @@ func sortAlphabetical(t *Tree) (vals []sortNode) {
 }
 
 func (t *Tree) writeTo(w io.Writer, indent, keyspace string, bytesCount int64, arraysOneElementPerLine bool) (int64, error) {
-	return t.writeToOrdered(w, indent, keyspace, bytesCount, arraysOneElementPerLine, OrderAlphabetical, "  ", false)
+	return t.writeToOrdered(w, indent, keyspace, bytesCount, arraysOneElementPerLine, OrderAlphabetical, "  ", false, false)
 }
 
-func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount int64, arraysOneElementPerLine bool, ord marshalOrder, indentString string, parentCommented bool) (int64, error) {
+func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount int64, arraysOneElementPerLine bool, ord MarshalOrder, indentString string, compactComments, parentCommented bool) (int64, error) {
 	var orderedVals []sortNode
 
 	switch ord {
@@ -360,7 +370,7 @@ func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount i
 				if err != nil {
 					return bytesCount, err
 				}
-				bytesCount, err = node.writeToOrdered(w, indent+indentString, combinedKey, bytesCount, arraysOneElementPerLine, ord, indentString, parentCommented || t.commented || tv.commented)
+				bytesCount, err = node.writeToOrdered(w, indent+indentString, combinedKey, bytesCount, arraysOneElementPerLine, ord, indentString, compactComments, parentCommented || t.commented || tv.commented)
 				if err != nil {
 					return bytesCount, err
 				}
@@ -376,7 +386,7 @@ func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount i
 						return bytesCount, err
 					}
 
-					bytesCount, err = subTree.writeToOrdered(w, indent+indentString, combinedKey, bytesCount, arraysOneElementPerLine, ord, indentString, parentCommented || t.commented || subTree.commented)
+					bytesCount, err = subTree.writeToOrdered(w, indent+indentString, combinedKey, bytesCount, arraysOneElementPerLine, ord, indentString, compactComments, parentCommented || t.commented || subTree.commented)
 					if err != nil {
 						return bytesCount, err
 					}
@@ -404,7 +414,14 @@ func (t *Tree) writeToOrdered(w io.Writer, indent, keyspace string, bytesCount i
 				if strings.HasPrefix(comment, "#") {
 					start = ""
 				}
-				writtenBytesCountComment, errc := writeStrings(w, "\n", indent, start, comment, "\n")
+				if !compactComments {
+					writtenBytesCountComment, errc := writeStrings(w, "\n")
+					bytesCount += int64(writtenBytesCountComment)
+					if errc != nil {
+						return bytesCount, errc
+					}
+				}
+				writtenBytesCountComment, errc := writeStrings(w, indent, start, comment, "\n")
 				bytesCount += int64(writtenBytesCountComment)
 				if errc != nil {
 					return bytesCount, errc

tomltree_write_test.go

@@ -364,6 +364,55 @@ c = nan`
 	}
 }
 
+func TestOrderedEmptyTrees(t *testing.T) {
+	type val struct {
+		Key string `toml:"key"`
+	}
+	type structure struct {
+		First val   `toml:"first"`
+		Empty []val `toml:"empty"`
+	}
+	input := structure{First: val{Key: "value"}}
+	buf := new(bytes.Buffer)
+	err := NewEncoder(buf).Order(OrderPreserve).Encode(input)
+	if err != nil {
+		t.Fatal("failed to encode input")
+	}
+	expected := `
+[first]
+  key = "value"
+`
+	if expected != buf.String() {
+		t.Fatal("expected and encoded body aren't equal: ", expected, buf.String())
+	}
+}
+
+func TestOrderedNonIncreasedLine(t *testing.T) {
+	type NiceMap map[string]string
+	type Manifest struct {
+		NiceMap `toml:"dependencies"`
+		Build   struct {
+			BuildCommand string `toml:"build-command"`
+		} `toml:"build"`
+	}
+
+	test := &Manifest{}
+	test.Build.BuildCommand = "test"
+	buf := new(bytes.Buffer)
+	if err := NewEncoder(buf).Order(OrderPreserve).Encode(test); err != nil {
+		panic(err)
+	}
+	expected := `
+[dependencies]
+
+[build]
+  build-command = "test"
+`
+	if expected != buf.String() {
+		t.Fatal("expected and encoded body aren't equal: ", expected, buf.String())
+	}
+}
+
 func TestIssue290(t *testing.T) {
 	tomlString :=
 		`[table]

tomltree_writepub.go

@@ -0,0 +1,6 @@
+package toml
+
+// ValueStringRepresentation transforms an interface{} value into its toml string representation.
+func ValueStringRepresentation(v interface{}, commented string, indent string, ord MarshalOrder, arraysOneElementPerLine bool) (string, error) {
+	return tomlValueStringRepresentation(v, commented, indent, ord, arraysOneElementPerLine)
+}