add bash (environment variable export) file format

internal/cnf/bash.go

@@ -0,0 +1,99 @@
+package cnf
+
+import (
+	lib "github.com/xdrm-brackets/nix-amer/internal/cnf/parser/bash"
+	"io"
+	"strings"
+)
+
+type bash struct {
+	data   *lib.File
+	parsed bool
+}
+
+// ReadFrom implements io.ReaderFrom
+func (d *bash) ReadFrom(_reader io.Reader) (int64, error) {
+
+	d.data = new(lib.File)
+
+	// 1. get bash decoder
+	decoder := lib.NewDecoder(_reader)
+	err := decoder.Decode(d.data)
+	if err != nil {
+		return 0, err
+	}
+
+	d.parsed = true
+	return 0, nil
+
+}
+
+// WriteTo implements io.WriterTo
+func (d *bash) WriteTo(_writer io.Writer) (int64, error) {
+	encoder := lib.NewEncoder(_writer)
+	return 0, encoder.Encode(d.data)
+}
+
+// browse returns the target of a dot-separated path (as an interface{} chain where the last is the target if found)
+// if <create> is true, create if does not exist
+func (d *bash) browse(_path string, create ...bool) (*lib.Line, bool) {
+
+	mustCreate := len(create) > 0 && create[0]
+
+	// 1. extract path
+	path := strings.Split(_path, ".")
+	field := path[len(path)-1]
+
+	// 2. nothing
+	if len(path) < 1 {
+		return &lib.Line{}, true
+	}
+
+	// 3. iterate over path / nested fields
+	for _, line := range d.data.Lines {
+		if line.Type == lib.ASSIGNMENT && len(line.Components) > 1 && line.Components[1] == field {
+			return line, true
+		}
+	}
+
+	// 4. create assignment
+	if mustCreate {
+		assignment := &lib.Line{
+			Type:       lib.ASSIGNMENT,
+			Components: []string{"", field, "", ""},
+		}
+		d.data.Lines = append(d.data.Lines, assignment)
+		return assignment, true
+	}
+
+	return nil, false
+}
+
+// Get returns the value of a dot-separated path, and if it exists
+func (d *bash) Get(_path string) (string, bool) {
+
+	// 1. browse path
+	last, found := d.browse(_path, true)
+	if !found {
+		return "", false
+	}
+
+	// 2. Get last field
+	return last.Components[2], true
+
+}
+
+// Set the value of a dot-separated path, and creates it if not found
+func (d *bash) Set(_path, _value string) bool {
+
+	// 1. browse path
+	last, found := d.browse(_path, true)
+	if !found {
+		return false
+	}
+
+	// 2. Set value
+	last.Components[2] = _value
+	return true
+
+}

internal/cnf/bash_test.go

@@ -0,0 +1,219 @@
+package cnf
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestBashGet(t *testing.T) {
+
+	tests := []struct {
+		raw string
+		key string
+	}{
+		{"key=value;\n", "key"},
+		{"  \t key=value;\n", "key"},
+		{"key=value; #comment\n", "key"},
+		{"\t   key=value; #comment\n", "key"},
+		{"key=value; # comment\n", "key"},
+		{"\t \tkey=value; # comment\n", "key"},
+	}
+
+	for i, test := range tests {
+
+		parser := new(bash)
+		reader := bytes.NewBufferString(test.raw)
+
+		// try to extract value
+		_, err := parser.ReadFrom(reader)
+		if err != nil {
+			t.Errorf("[%d] parse error: %s", i, err)
+			continue
+		}
+
+		// extract value
+		value, found := parser.Get(test.key)
+		if !found {
+			t.Errorf("[%d] expected a result, got none", i)
+			continue
+		}
+
+		// check value
+		if value != "value" {
+			t.Errorf("[%d] expected 'value' got '%s'", i, value)
+		}
+
+	}
+
+}
+
+func TestBashSetPathExists(t *testing.T) {
+
+	tests := []struct {
+		raw   string
+		key   string
+		value string
+	}{
+
+		{"key=value;\n", "key", "newvalue"},
+		{"  \t key=value;\n", "key", "newvalue"},
+		{"key=value; #comment\n", "key", "newvalue"},
+		{"\t   key=value; #comment\n", "key", "newvalue"},
+		{"key=value; # comment\n", "key", "newvalue"},
+		{"\t \tkey=value; # comment\n", "key", "newvalue"},
+	}
+
+	for i, test := range tests {
+
+		parser := new(bash)
+		reader := bytes.NewBufferString(test.raw)
+
+		// try to extract value
+		_, err := parser.ReadFrom(reader)
+		if err != nil {
+			t.Errorf("[%d] parse error: %s", i, err)
+			continue
+		}
+
+		// update value
+		if !parser.Set(test.key, test.value) {
+			t.Errorf("[%d] cannot set '%s' to '%s'", i, test.key, test.value)
+			continue
+		}
+
+		// check new value
+		value, found := parser.Get(test.key)
+		if !found {
+			t.Errorf("[%d] expected a result, got none", i)
+			continue
+		}
+
+		// check value
+		if value != test.value {
+			t.Errorf("[%d] expected '%s' got '%s'", i, test.value, value)
+		}
+
+	}
+
+}
+
+func TestBashSetCreatePath(t *testing.T) {
+
+	tests := []struct {
+		raw    string
+		key    string
+		ignore string // path to field that must be present after transformation
+		value  string
+	}{
+		{"ignore=xxx;\n", "key", "ignore", "newvalue"},
+		{"unknown-line\nignore=xxx;\n", "key", "ignore", "newvalue"},
+	}
+
+	for i, test := range tests {
+
+		parser := new(bash)
+		reader := bytes.NewBufferString(test.raw)
+
+		// try to extract value
+		_, err := parser.ReadFrom(reader)
+		if err != nil {
+			t.Errorf("[%d] parse error: %s", i, err)
+			continue
+		}
+
+		// update value
+		if !parser.Set(test.key, test.value) {
+			t.Errorf("[%d] cannot set '%s' to '%s'", i, test.key, test.value)
+			continue
+		}
+
+		// check new value
+		value, found := parser.Get(test.key)
+		if !found {
+			t.Errorf("[%d] expected a result, got none", i)
+			continue
+		}
+
+		// check value
+		if value != test.value {
+			t.Errorf("[%d] expected '%s' got '%s'", i, test.value, value)
+			continue
+		}
+
+		// check that ignore field is still there
+		value, found = parser.Get(test.ignore)
+		if !found {
+			t.Errorf("[%d] expected ignore field, got none", i)
+			continue
+		}
+
+		// check value
+		if value != "xxx" {
+			t.Errorf("[%d] expected ignore value to be '%s' got '%s'", i, "xxx", value)
+			continue
+		}
+	}
+
+}
+
+func TestBashSetCreateEncode(t *testing.T) {
+
+	tests := []struct {
+		raw     string
+		key     string
+		value   string
+		encoded string
+	}{
+		{"ignore=xxx;\n", "key", `"newvalue"`, "ignore=xxx;\nkey=\"newvalue\";\n"},
+	}
+
+	for i, test := range tests {
+
+		parser := new(bash)
+		r, w := bytes.NewBufferString(test.raw), new(bytes.Buffer)
+
+		// try to extract value
+		_, err := parser.ReadFrom(r)
+		if err != nil {
+			t.Errorf("[%d] parse error: %s", i, err)
+			continue
+		}
+
+		// update value
+		if !parser.Set(test.key, test.value) {
+			t.Errorf("[%d] cannot set '%s' to '%s'", i, test.key, test.value)
+			continue
+		}
+
+		// check new value
+		value, found := parser.Get(test.key)
+		if !found {
+			t.Errorf("[%d] expected a result, got none", i)
+			continue
+		}
+
+		// check value
+		if value != test.value {
+			t.Errorf("[%d] expected '%s' got '%s'", i, test.value, value)
+			continue
+		}
+
+		// writeToBuffer
+		_, err = parser.WriteTo(w)
+		if err != nil {
+			t.Errorf("[%d] unexpected write error <%s>", i, err)
+			continue
+		}
+
+		encoded := w.String()
+
+		// check value
+		if encoded != test.encoded {
+			t.Errorf("[%d] wrong encoded value \n-=-=-= HAVE =-=-=-\n%s\n-=-=-= WANT =-=-=-\n%s\n-=-=-=-=-=\n", i, escape(test.encoded), escape(encoded))
+			continue
+		}
+
+		// try to write
+	}
+
+}

internal/cnf/loader.go

@@ -70,6 +70,8 @@ func loadFromExtension(ext string) ConfigurationFormat {
 		return new(yaml)
 	case ".nginx":
 		return new(nginx)
+	case ".sh":
+		return new(bash)
 	default:
 		return nil
 	}
@@ -86,7 +88,7 @@ func loadFromContent(path string) (ConfigurationFormat, error) {
 	defer file.Close()
 
 	// extensions ordered by strictness of the language's syntax
-	extensions := []string{".json", ".nginx", ".ini", ".yaml"}
+	extensions := []string{".json", ".nginx", ".ini", ".sh", ".yaml"}
 
 	// try to load each available extension
 	for _, ext := range extensions {

internal/cnf/parser/bash/bash.go

@@ -0,0 +1,20 @@
+package bash
+
+import (
+	"io"
+)
+
+// File represents a bash file
+type File struct {
+	Lines []*Line
+}
+
+// NewDecoder implements parser.T
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{reader: r}
+}
+
+// NewEncoder implements parser.T
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{writer: w}
+}

internal/cnf/parser/bash/decoder.go

@@ -0,0 +1,72 @@
+package bash
+
+import (
+	"bufio"
+	"io"
+	"regexp"
+	"strings"
+)
+
+// Decoder implements parser.Decoder
+type Decoder struct{ reader io.Reader }
+
+// Decode is the main function of the parser.Decoder interface
+func (d *Decoder) Decode(v interface{}) error {
+
+	// check 'v'
+	if v == nil {
+		return ErrNullReceiver
+	}
+	vcast, ok := v.(*File)
+	if !ok {
+		return ErrInvalidReceiver
+	}
+	vcast.Lines = make([]*Line, 0)
+
+	r := bufio.NewReader(d.reader)
+	n := -1 // line number
+
+	// regexes
+	reAssign := regexp.MustCompile(`(?m)^(\s*)([A-Za-z0-9_]+)=([^;]+);?\s*(#.+)?$`)
+	eof := false
+
+	for {
+		n++
+		if eof {
+			break
+		}
+
+		l := &Line{Type: ANY}
+
+		// 1. read line
+		line, err := r.ReadString('\n')
+		if err == io.EOF {
+			if len(line) > 0 {
+				eof = true
+			} else {
+				break
+			}
+		} else if err != nil {
+			return &LineError{n, err}
+		}
+		line = strings.Trim(line, "\r\n")
+
+		// 2. ignore empty
+		if len(strings.Trim(line, " \t\r\n")) < 1 {
+			continue
+		}
+
+		// 3. assignment
+		match := reAssign.FindStringSubmatch(line)
+		if match != nil {
+			l.Type = ASSIGNMENT
+			l.Components = match[1:]
+		}
+
+		// 4. add to file
+		vcast.Lines = append(vcast.Lines, l)
+
+	}
+
+	return nil
+}

internal/cnf/parser/bash/encoder.go

@@ -0,0 +1,59 @@
+package bash
+
+import (
+	"fmt"
+	"io"
+	"strings"
+)
+
+// Encoder implements parser.Encoder
+type Encoder struct {
+	writer io.Writer
+	prefix []byte
+	indent []byte
+}
+
+// Encode is the main function of the parser.Encoder interface
+func (e *Encoder) Encode(v interface{}) error {
+
+	// check 'v'
+	vcast, ok := v.(*File)
+	if !ok {
+		return ErrInvalidReceiver
+	}
+
+	// empty config
+	if len(vcast.Lines) < 1 {
+		return nil
+	}
+
+	for _, line := range vcast.Lines {
+
+		// line representation
+		repr := ""
+
+		// ASSIGNMENT
+		if line.Type == ASSIGNMENT {
+			repr = fmt.Sprintf("%s%s=%s;", line.Components[0], line.Components[1], line.Components[2])
+
+			// optional comment
+			if len(line.Components[3]) > 0 {
+				repr += fmt.Sprintf(" #%s", line.Components[3])
+			}
+
+			// ANY
+		} else {
+			repr = strings.Join(line.Components, "")
+		}
+
+		repr += "\n"
+
+		_, err := e.writer.Write([]byte(repr))
+		if err != nil {
+			return err
+		}
+
+	}
+
+	return nil
+}

internal/cnf/parser/bash/errors.go

@@ -0,0 +1,23 @@
+package bash
+
+import (
+	"fmt"
+	"github.com/xdrm-brackets/nix-amer/internal/clifmt"
+)
+
+// ErrNullReceiver is raised when a null receiver is provided
+var ErrNullReceiver = fmt.Errorf("receiver must not be null")
+
+// ErrInvalidReceiver is raised when an invalid receiver is provided
+var ErrInvalidReceiver = fmt.Errorf("receiver must be compatible with *File")
+
+// LineError wraps errors with a line index
+type LineError struct {
+	Line int
+	Err  error
+}
+
+// Error implements Error
+func (le LineError) Error() string {
+	return fmt.Sprintf(":%d %s", le.Line, clifmt.Color(31, le.Err.Error()))
+}

internal/cnf/parser/bash/line.go

@@ -0,0 +1,26 @@
+package bash
+
+// LineType enumerates available line types
+type LineType byte
+
+const (
+	// ANY is the default line type (all except assignments)
+	ANY LineType = iota
+	// ASSIGNMENT line
+	ASSIGNMENT
+)
+
+// Line represents a meaningful line
+type Line struct {
+	// Type of line
+	Type LineType
+
+	// Components of the line
+	//
+	// When Type = ASSIGNMENT :
+	//  [0] = indentation (spaces and tabs)
+	//  [1] = variable name
+	//  [2] = variable value
+	//  [3] = comment (optional)
+	Components []string
+}