Merge pull request #41 from alexquick/document-write-dotenv

Document Marshal, Unmarshal, and Write

README.md

@@ -1,4 +1,4 @@
-# GoDotEnv [![Build Status](https://travis-ci.org/joho/godotenv.svg?branch=master)](https://travis-ci.org/joho/godotenv) [![Build status](https://ci.appveyor.com/api/projects/status/9v40vnfvvgde64u4?svg=true)](https://ci.appveyor.com/project/joho/godotenv)
+# GoDotEnv [![Build Status](https://travis-ci.org/joho/godotenv.svg?branch=master)](https://travis-ci.org/joho/godotenv) [![Build status](https://ci.appveyor.com/api/projects/status/9v40vnfvvgde64u4?svg=true)](https://ci.appveyor.com/project/joho/godotenv) [![Go Report Card](https://goreportcard.com/badge/github.com/joho/godotenv)](https://goreportcard.com/report/github.com/joho/godotenv)
 
 A Go (golang) port of the Ruby dotenv project (which loads env vars from a .env file)
 
@@ -96,6 +96,20 @@ myEnv, err := godotenv.Read()
 s3Bucket := myEnv["S3_BUCKET"]
 ```
 
+... or from an `io.Reader` instead of a local file
+
+```go
+reader := getRemoteFile()
+myEnv, err := godotenv.Parse(reader)
+```
+
+... or from a `string` if you so desire
+
+```go
+content := getRemoteFileContent()
+myEnv, err := godotenv.Unmarshal(content)
+```
+
 ### Command Mode
 
 Assuming you've installed the command as above and you've got `$GOPATH/bin` in your `$PATH`
@@ -106,6 +120,22 @@ godotenv -f /some/path/to/.env some_command with some args
 
 If you don't specify `-f` it will fall back on the default of loading `.env` in `PWD`
 
+### Writing Env Files
+
+Godotenv can also write a map representing the environment to a correctly-formatted and escaped file
+
+```go
+env, err := godotenv.Unmarshal("KEY=value")
+err := godotenv.Write(env, "./.env")
+```
+
+... or to a string
+
+```go
+env, err := godotenv.Unmarshal("KEY=value")
+content, err := godotenv.Marshal(env)
+```
+
 ## Contributing
 
 Contributions are most welcome! The parser itself is pretty stupidly naive and I wouldn't be surprised if it breaks with edge cases.
@@ -118,9 +148,15 @@ Contributions are most welcome! The parser itself is pretty stupidly naive and I
 4. Push to the branch (`git push origin my-new-feature`)
 5. Create new Pull Request
 
+## Releases
+
+Releases should follow [Semver](http://semver.org/) though the first couple of releases are `v1` and `v1.1`.
+
+Use [annotated tags for all releases](https://github.com/joho/godotenv/issues/30). Example `git tag -a v1.2.1`
+
 ## CI
 
-Linux: [![wercker status](https://app.wercker.com/status/507594c2ec7e60f19403a568dfea0f78/m "wercker status")](https://app.wercker.com/project/bykey/507594c2ec7e60f19403a568dfea0f78) Windows: [![Build status](https://ci.appveyor.com/api/projects/status/9v40vnfvvgde64u4)](https://ci.appveyor.com/project/joho/godotenv)
+Linux: [![Build Status](https://travis-ci.org/joho/godotenv.svg?branch=master)](https://travis-ci.org/joho/godotenv) Windows: [![Build status](https://ci.appveyor.com/api/projects/status/9v40vnfvvgde64u4)](https://ci.appveyor.com/project/joho/godotenv)
 
 ## Who?
 

godotenv.go

@@ -10,17 +10,23 @@
 //
 // 		godotenv.Load()
 //
-// and all the env vars declared in .env will be avaiable through os.Getenv("SOME_ENV_VAR")
+// and all the env vars declared in .env will be available through os.Getenv("SOME_ENV_VAR")
 package godotenv
 
 import (
 	"bufio"
 	"errors"
+	"fmt"
+	"io"
 	"os"
 	"os/exec"
+	"regexp"
+	"sort"
 	"strings"
 )
 
+const doubleQuoteSpecialChars = "\\\n\r\"!$`"
+
 // Load will read your env file(s) and load them into ENV for this process.
 //
 // Call this function as close as possible to the start of your program (ideally in main)
@@ -89,6 +95,39 @@ func Read(filenames ...string) (envMap map[string]string, err error) {
 	return
 }
 
+// Parse reads an env file from io.Reader, returning a map of keys and values.
+func Parse(r io.Reader) (envMap map[string]string, err error) {
+	envMap = make(map[string]string)
+
+	var lines []string
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+
+	if err = scanner.Err(); err != nil {
+		return
+	}
+
+	for _, fullLine := range lines {
+		if !isIgnoredLine(fullLine) {
+			var key, value string
+			key, value, err = parseLine(fullLine)
+
+			if err != nil {
+				return
+			}
+			envMap[key] = value
+		}
+	}
+	return
+}
+
+//Unmarshal reads an env file from a string, returning a map of keys and values.
+func Unmarshal(str string) (envMap map[string]string, err error) {
+	return Parse(strings.NewReader(str))
+}
+
 // Exec loads env vars from the specified filenames (empty map falls back to default)
 // then executes the cmd specified.
 //
@@ -106,6 +145,31 @@ func Exec(filenames []string, cmd string, cmdArgs []string) error {
 	return command.Run()
 }
 
+// Write serializes the given environment and writes it to a file
+func Write(envMap map[string]string, filename string) error {
+	content, error := Marshal(envMap)
+	if error != nil {
+		return error
+	}
+	file, error := os.Create(filename)
+	if error != nil {
+		return error
+	}
+	_, err := file.WriteString(content)
+	return err
+}
+
+// Marshal outputs the given environment as a dotenv-formatted environment file.
+// Each line is in the format: KEY="VALUE" where VALUE is backslash-escaped.
+func Marshal(envMap map[string]string) (string, error) {
+	lines := make([]string, 0, len(envMap))
+	for k, v := range envMap {
+		lines = append(lines, fmt.Sprintf(`%s="%s"`, k, doubleQuoteEscape(v)))
+	}
+	sort.Strings(lines)
+	return strings.Join(lines, "\n"), nil
+}
+
 func filenamesOrDefault(filenames []string) []string {
 	if len(filenames) == 0 {
 		return []string{".env"}
@@ -142,30 +206,7 @@ func readFile(filename string) (envMap map[string]string, err error) {
 	}
 	defer file.Close()
 
-	envMap = make(map[string]string)
+	return Parse(file)
-
-	var lines []string
-	scanner := bufio.NewScanner(file)
-	for scanner.Scan() {
-		lines = append(lines, scanner.Text())
-	}
-
-	if err = scanner.Err(); err != nil {
-		return
-	}
-
-	for _, fullLine := range lines {
-		if !isIgnoredLine(fullLine) {
-			var key, value string
-			key, value, err = parseLine(fullLine)
-
-			if err != nil {
-				return
-			}
-			envMap[key] = value
-		}
-	}
-	return
 }
 
 func parseLine(line string) (key string, value string, err error) {
@@ -197,11 +238,11 @@ func parseLine(line string) (key string, value string, err error) {
 		line = strings.Join(segmentsToKeep, "#")
 	}
 
-	// now split key from value
+	firstEquals := strings.Index(line, "=")
+	firstColon := strings.Index(line, ":")
 	splitString := strings.SplitN(line, "=", 2)
-
+	if firstColon != -1 && (firstColon < firstEquals || firstEquals == -1) {
-	if len(splitString) != 2 {
+		//this is a yaml-style line
-		// try yaml mode!
 		splitString = strings.SplitN(line, ":", 2)
 	}
 
@@ -218,30 +259,56 @@ func parseLine(line string) (key string, value string, err error) {
 	key = strings.Trim(key, " ")
 
 	// Parse the value
-	value = splitString[1]
+	value = parseValue(splitString[1])
+	return
+}
+
+func parseValue(value string) string {
 
 	// trim
 	value = strings.Trim(value, " ")
 
-	// check if we've got quoted values
+	// check if we've got quoted values or possible escapes
-	if value != "" {
+	if len(value) > 1 {
 		first := string(value[0:1])
 		last := string(value[len(value)-1:])
 		if first == last && strings.ContainsAny(first, `"'`) {
 			// pull the quotes off the edges
-			value = strings.Trim(value, `"'`)
+			value = value[1 : len(value)-1]
-
+			// handle escapes
-			// expand quotes
+			escapeRegex := regexp.MustCompile(`\\.`)
-			value = strings.Replace(value, `\"`, `"`, -1)
+			value = escapeRegex.ReplaceAllStringFunc(value, func(match string) string {
-			// expand newlines
+				c := strings.TrimPrefix(match, `\`)
-			value = strings.Replace(value, `\n`, "\n", -1)
+				switch c {
+				case "n":
+					return "\n"
+				case "r":
+					return "\r"
+				default:
+					return c
+				}
+			})
 		}
 	}
 
-	return
+	return value
 }
 
 func isIgnoredLine(line string) bool {
 	trimmedLine := strings.Trim(line, " \n\t")
 	return len(trimmedLine) == 0 || strings.HasPrefix(trimmedLine, "#")
 }
+
+func doubleQuoteEscape(line string) string {
+	for _, c := range doubleQuoteSpecialChars {
+		toReplace := "\\" + string(c)
+		if c == '\n' {
+			toReplace = `\n`
+		}
+		if c == '\r' {
+			toReplace = `\r`
+		}
+		line = strings.Replace(line, string(c), toReplace, -1)
+	}
+	return line
+}

godotenv_test.go

@@ -1,7 +1,10 @@
 package godotenv
 
 import (
+	"bytes"
+	"fmt"
 	"os"
+	"reflect"
 	"testing"
 )
 
@@ -94,6 +97,23 @@ func TestReadPlainEnv(t *testing.T) {
 	}
 }
 
+func TestParse(t *testing.T) {
+	envMap, err := Parse(bytes.NewReader([]byte("ONE=1\nTWO='2'\nTHREE = \"3\"")))
+	expectedValues := map[string]string{
+		"ONE":   "1",
+		"TWO":   "2",
+		"THREE": "3",
+	}
+	if err != nil {
+		t.Fatalf("error parsing env: %v", err)
+	}
+	for key, value := range expectedValues {
+		if envMap[key] != value {
+			t.Errorf("expected %s to be %s, got %s", key, value, envMap[key])
+		}
+	}
+}
+
 func TestLoadDoesNotOverride(t *testing.T) {
 	envFileName := "fixtures/plain.env"
 
@@ -199,9 +219,18 @@ func TestParsing(t *testing.T) {
 	// parses escaped double quotes
 	parseAndCompare(t, `FOO="escaped\"bar"`, "FOO", `escaped"bar`)
 
+	// parses single quotes inside double quotes
+	parseAndCompare(t, `FOO="'d'"`, "FOO", `'d'`)
+
 	// parses yaml style options
 	parseAndCompare(t, "OPTION_A: 1", "OPTION_A", "1")
 
+	//parses yaml values with equal signs
+	parseAndCompare(t, "OPTION_A: Foo=bar", "OPTION_A", "Foo=bar")
+
+	// parses non-yaml options with colons
+	parseAndCompare(t, "OPTION_A=1:B", "OPTION_A", "1:B")
+
 	// parses export keyword
 	parseAndCompare(t, "export OPTION_A=2", "OPTION_A", "2")
 	parseAndCompare(t, `export OPTION_B='\n'`, "OPTION_B", "\n")
@@ -238,6 +267,15 @@ func TestParsing(t *testing.T) {
 	parseAndCompare(t, `FOO="ba#r"`, "FOO", "ba#r")
 	parseAndCompare(t, "FOO='ba#r'", "FOO", "ba#r")
 
+	//newlines and backslashes should be escaped
+	parseAndCompare(t, `FOO="bar\n\ b\az"`, "FOO", "bar\n baz")
+	parseAndCompare(t, `FOO="bar\\\n\ b\az"`, "FOO", "bar\\\n baz")
+	parseAndCompare(t, `FOO="bar\\r\ b\az"`, "FOO", "bar\\r baz")
+
+	parseAndCompare(t, `="value"`, "", "value")
+	parseAndCompare(t, `KEY="`, "KEY", "\"")
+	parseAndCompare(t, `KEY="value`, "KEY", "\"value")
+
 	// it 'throws an error if line format is incorrect' do
 	// expect{env('lol$wut')}.to raise_error(Dotenv::FormatError)
 	badlyFormattedLine := "lol$wut"
@@ -290,3 +328,50 @@ func TestErrorParsing(t *testing.T) {
 		t.Errorf("Expected error, got %v", envMap)
 	}
 }
+
+func TestWrite(t *testing.T) {
+	writeAndCompare := func(env string, expected string) {
+		envMap, _ := Unmarshal(env)
+		actual, _ := Marshal(envMap)
+		if expected != actual {
+			t.Errorf("Expected '%v' (%v) to write as '%v', got '%v' instead.", env, envMap, expected, actual)
+		}
+	}
+	//just test some single lines to show the general idea
+	//TestRoundtrip makes most of the good assertions
+
+	//values are always double-quoted
+	writeAndCompare(`key=value`, `key="value"`)
+	//double-quotes are escaped
+	writeAndCompare(`key=va"lu"e`, `key="va\"lu\"e"`)
+	//but single quotes are left alone
+	writeAndCompare(`key=va'lu'e`, `key="va'lu'e"`)
+	// newlines, backslashes, and some other special chars are escaped
+	writeAndCompare(`foo="$ba\n\r\\r!"`, `foo="\$ba\n\r\\r\!"`)
+	// lines should be sorted
+	writeAndCompare("foo=bar\nbaz=buzz", "baz=\"buzz\"\nfoo=\"bar\"")
+
+}
+
+func TestRoundtrip(t *testing.T) {
+	fixtures := []string{"equals.env", "exported.env", "plain.env", "quoted.env"}
+	for _, fixture := range fixtures {
+		fixtureFilename := fmt.Sprintf("fixtures/%s", fixture)
+		env, err := readFile(fixtureFilename)
+		if err != nil {
+			t.Errorf("Expected '%s' to read without error (%v)", fixtureFilename, err)
+		}
+		rep, err := Marshal(env)
+		if err != nil {
+			t.Errorf("Expected '%s' to Marshal (%v)", fixtureFilename, err)
+		}
+		roundtripped, err := Unmarshal(rep)
+		if err != nil {
+			t.Errorf("Expected '%s' to Mashal and Unmarshal (%v)", fixtureFilename, err)
+		}
+		if !reflect.DeepEqual(env, roundtripped) {
+			t.Errorf("Expected '%s' to roundtrip as '%v', got '%v' instead", fixtureFilename, env, roundtripped)
+		}
+
+	}
+}