update github.com/pelletier/go-toml to 1.2.0

Rationale: github.com/pelletier/go-toml is the only package that currently
prevents the future vendoring of github.com/golang/dep as it depends on
functions introduced in 1.1.0.

The only consumers of this package are github.com/spf13/viper (used to run e2e
tests) and github.com/bazelbuild/bazel-gazelle (bazel helper), so that's a
pretty low-risk change.

vendor/github.com/pelletier/go-toml/tomltree_write.go

@@ -12,7 +12,41 @@ import (
 	"time"
 )
 
-// encodes a string to a TOML-compliant string value
+// Encodes a string to a TOML-compliant multi-line string value
+// This function is a clone of the existing encodeTomlString function, except that whitespace characters
+// are preserved. Quotation marks and backslashes are also not escaped.
+func encodeMultilineTomlString(value string) string {
+	var b bytes.Buffer
+
+	for _, rr := range value {
+		switch rr {
+		case '\b':
+			b.WriteString(`\b`)
+		case '\t':
+			b.WriteString("\t")
+		case '\n':
+			b.WriteString("\n")
+		case '\f':
+			b.WriteString(`\f`)
+		case '\r':
+			b.WriteString("\r")
+		case '"':
+			b.WriteString(`"`)
+		case '\\':
+			b.WriteString(`\`)
+		default:
+			intRr := uint16(rr)
+			if intRr < 0x001F {
+				b.WriteString(fmt.Sprintf("\\u%0.4X", intRr))
+			} else {
+				b.WriteRune(rr)
+			}
+		}
+	}
+	return b.String()
+}
+
+// Encodes a string to a TOML-compliant string value
 func encodeTomlString(value string) string {
 	var b bytes.Buffer
 
@@ -44,7 +78,16 @@ func encodeTomlString(value string) string {
 	return b.String()
 }
 
-func tomlValueStringRepresentation(v interface{}) (string, error) {
+func tomlValueStringRepresentation(v interface{}, indent string, 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)
+	if ok {
+		v = tv.value
+	} else {
+		tv = &tomlValue{}
+	}
+
 	switch value := v.(type) {
 	case uint64:
 		return strconv.FormatUint(value, 10), nil
@@ -54,14 +97,17 @@ func tomlValueStringRepresentation(v interface{}) (string, error) {
 		// Ensure a round float does contain a decimal point. Otherwise feeding
 		// the output back to the parser would convert to an integer.
 		if math.Trunc(value) == value {
-			return strconv.FormatFloat(value, 'f', 1, 32), nil
+			return strings.ToLower(strconv.FormatFloat(value, 'f', 1, 32)), nil
 		}
-		return strconv.FormatFloat(value, 'f', -1, 32), nil
+		return strings.ToLower(strconv.FormatFloat(value, 'f', -1, 32)), nil
 	case string:
+		if tv.multiline {
+			return "\"\"\"\n" + encodeMultilineTomlString(value) + "\"\"\"", nil
+		}
 		return "\"" + encodeTomlString(value) + "\"", nil
 	case []byte:
 		b, _ := v.([]byte)
-		return tomlValueStringRepresentation(string(b))
+		return tomlValueStringRepresentation(string(b), indent, arraysOneElementPerLine)
 	case bool:
 		if value {
 			return "true", nil
@@ -76,21 +122,38 @@ func tomlValueStringRepresentation(v interface{}) (string, error) {
 	rv := reflect.ValueOf(v)
 
 	if rv.Kind() == reflect.Slice {
-		values := []string{}
+		var values []string
 		for i := 0; i < rv.Len(); i++ {
 			item := rv.Index(i).Interface()
-			itemRepr, err := tomlValueStringRepresentation(item)
+			itemRepr, err := tomlValueStringRepresentation(item, indent, arraysOneElementPerLine)
 			if err != nil {
 				return "", err
 			}
 			values = append(values, itemRepr)
 		}
+		if arraysOneElementPerLine && len(values) > 1 {
+			stringBuffer := bytes.Buffer{}
+			valueIndent := indent + `  ` // TODO: move that to a shared encoder state
+
+			stringBuffer.WriteString("[\n")
+
+			for _, value := range values {
+				stringBuffer.WriteString(valueIndent)
+				stringBuffer.WriteString(value)
+				stringBuffer.WriteString(`,`)
+				stringBuffer.WriteString("\n")
+			}
+
+			stringBuffer.WriteString(indent + "]")
+
+			return stringBuffer.String(), nil
+		}
 		return "[" + strings.Join(values, ",") + "]", nil
 	}
 	return "", fmt.Errorf("unsupported value type %T: %v", v, v)
 }
 
-func (t *Tree) writeTo(w io.Writer, indent, keyspace string, bytesCount int64) (int64, error) {
+func (t *Tree) writeTo(w io.Writer, indent, keyspace string, bytesCount int64, arraysOneElementPerLine bool) (int64, error) {
 	simpleValuesKeys := make([]string, 0)
 	complexValuesKeys := make([]string, 0)
 
@@ -113,12 +176,29 @@ func (t *Tree) writeTo(w io.Writer, indent, keyspace string, bytesCount int64) (
 			return bytesCount, fmt.Errorf("invalid value type at %s: %T", k, t.values[k])
 		}
 
-		repr, err := tomlValueStringRepresentation(v.value)
+		repr, err := tomlValueStringRepresentation(v, indent, arraysOneElementPerLine)
 		if err != nil {
 			return bytesCount, err
 		}
 
-		writtenBytesCount, err := writeStrings(w, indent, k, " = ", repr, "\n")
+		if v.comment != "" {
+			comment := strings.Replace(v.comment, "\n", "\n"+indent+"#", -1)
+			start := "# "
+			if strings.HasPrefix(comment, "#") {
+				start = ""
+			}
+			writtenBytesCountComment, errc := writeStrings(w, "\n", indent, start, comment, "\n")
+			bytesCount += int64(writtenBytesCountComment)
+			if errc != nil {
+				return bytesCount, errc
+			}
+		}
+
+		var commented string
+		if v.commented {
+			commented = "# "
+		}
+		writtenBytesCount, err := writeStrings(w, indent, commented, k, " = ", repr, "\n")
 		bytesCount += int64(writtenBytesCount)
 		if err != nil {
 			return bytesCount, err
@@ -132,28 +212,48 @@ func (t *Tree) writeTo(w io.Writer, indent, keyspace string, bytesCount int64) (
 		if keyspace != "" {
 			combinedKey = keyspace + "." + combinedKey
 		}
+		var commented string
+		if t.commented {
+			commented = "# "
+		}
 
 		switch node := v.(type) {
 		// node has to be of those two types given how keys are sorted above
 		case *Tree:
-			writtenBytesCount, err := writeStrings(w, "\n", indent, "[", combinedKey, "]\n")
+			tv, ok := t.values[k].(*Tree)
+			if !ok {
+				return bytesCount, fmt.Errorf("invalid value type at %s: %T", k, t.values[k])
+			}
+			if tv.comment != "" {
+				comment := strings.Replace(tv.comment, "\n", "\n"+indent+"#", -1)
+				start := "# "
+				if strings.HasPrefix(comment, "#") {
+					start = ""
+				}
+				writtenBytesCountComment, errc := writeStrings(w, "\n", indent, start, comment)
+				bytesCount += int64(writtenBytesCountComment)
+				if errc != nil {
+					return bytesCount, errc
+				}
+			}
+			writtenBytesCount, err := writeStrings(w, "\n", indent, commented, "[", combinedKey, "]\n")
 			bytesCount += int64(writtenBytesCount)
 			if err != nil {
 				return bytesCount, err
 			}
-			bytesCount, err = node.writeTo(w, indent+"  ", combinedKey, bytesCount)
+			bytesCount, err = node.writeTo(w, indent+"  ", combinedKey, bytesCount, arraysOneElementPerLine)
 			if err != nil {
 				return bytesCount, err
 			}
 		case []*Tree:
 			for _, subTree := range node {
-				writtenBytesCount, err := writeStrings(w, "\n", indent, "[[", combinedKey, "]]\n")
+				writtenBytesCount, err := writeStrings(w, "\n", indent, commented, "[[", combinedKey, "]]\n")
 				bytesCount += int64(writtenBytesCount)
 				if err != nil {
 					return bytesCount, err
 				}
 
-				bytesCount, err = subTree.writeTo(w, indent+"  ", combinedKey, bytesCount)
+				bytesCount, err = subTree.writeTo(w, indent+"  ", combinedKey, bytesCount, arraysOneElementPerLine)
 				if err != nil {
 					return bytesCount, err
 				}
@@ -179,7 +279,7 @@ func writeStrings(w io.Writer, s ...string) (int, error) {
 // WriteTo encode the Tree as Toml and writes it to the writer w.
 // Returns the number of bytes written in case of success, or an error if anything happened.
 func (t *Tree) WriteTo(w io.Writer) (int64, error) {
-	return t.writeTo(w, "", "", 0)
+	return t.writeTo(w, "", "", 0, false)
 }
 
 // ToTomlString generates a human-readable representation of the current tree.