vendor go-dotenv (#955)

* vendor go-dotenv

This makes it easier for Debian to package direnv. See #951

Repo: https://github.com/direnv/go-dotenv
Commit ID: 872ea3db4cb52bd8f1ae6690593f5d20c221c35b

* dotenv: fix linter warnings

default.nix

@@ -12,7 +12,7 @@ buildGoModule rec {
   version = lib.fileContents ./version.txt;
   subPackages = [ "." ];
 
-  vendorSha256 = "sha256-gFGGnnR1UNT4MYC411X8NwIqVJZqhnmUlVR+XAnrKY8=";
+  vendorSha256 = "sha256-u/LukIOYRudFYOrrlZTMtDAlM3+WjoSBiueR7aySSVU=";
 
   src = builtins.fetchGit ./.;
 

go.mod

@@ -4,7 +4,6 @@ go 1.16
 
 require (
 	github.com/BurntSushi/toml v1.1.0
-	github.com/direnv/go-dotenv v0.0.0-20220613081022-872ea3db4cb5
 	github.com/mattn/go-isatty v0.0.14
 	golang.org/x/mod v0.5.1
 	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect

go.sum

@@ -1,7 +1,5 @@
 github.com/BurntSushi/toml v1.1.0 h1:ksErzDEI1khOiGPgpwuI7x2ebx/uXQNw7xJpn9Eq1+I=
 github.com/BurntSushi/toml v1.1.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
-github.com/direnv/go-dotenv v0.0.0-20220613081022-872ea3db4cb5 h1:lMrU+5WHwaPfmvp+CIxUi2ujVJSu/mYh1Rcu23n7HaY=
-github.com/direnv/go-dotenv v0.0.0-20220613081022-872ea3db4cb5/go.mod h1:K5R9ofHu1mQRwNWMZgDnr0s1Ca1nkvz9r09NN/U2UyM=
 github.com/mattn/go-isatty v0.0.14 h1:yVuAays6BHfxijgZPzw+3Zlu5yQgKGP2/hcQbHb7S9Y=
 github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=

internal/cmd/cmd_dotenv.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"io/ioutil"
 
-	"github.com/direnv/go-dotenv"
+	"github.com/direnv/direnv/v2/pkg/dotenv"
 )
 
 // CmdDotEnv is `direnv dotenv [SHELL [PATH_TO_DOTENV]]`

pkg/dotenv/README.md

@@ -0,0 +1,29 @@
+# go-dotenv
+
+Go parsing library for the dotenv format.
+
+There is no formal definition of the dotenv format but it has been introduced
+by https://github.com/bkeepers/dotenv which is thus canonical. This library is a port of that.
+
+This library was developed specifically for [direnv](https://direnv.net).
+
+## Features
+
+* `k=v` format
+* bash `export k=v` format
+* yaml `k: v` format
+* variable expansion, including default values as in `${FOO:-default}`
+* comments
+
+## Missing
+
+* probably needs API breakage
+
+## Alternatives
+
+Some other good alternatives with various variations.
+
+* https://github.com/joho/godotenv
+* https://github.com/lazureykis/dotenv
+* https://github.com/subosito/gotenv
+

pkg/dotenv/parse.go

@@ -0,0 +1,150 @@
+// Package dotenv implements the parsing of the .env format.
+//
+// There is no formal definition of the format but it has been introduced by
+// https://github.com/bkeepers/dotenv which is thus canonical.
+package dotenv
+
+import (
+	"fmt"
+	"os"
+	"regexp"
+	"strings"
+)
+
+// LINE is the regexp matching a single line
+const LINE = `
+\A
+\s*
+(?:|#.*|          # comment line
+(?:export\s+)?    # optional export
+([\w\.]+)         # key
+(?:\s*=\s*|:\s+?) # separator
+(                 # optional value begin
+  '(?:\'|[^'])*'  #   single quoted value
+  |               #   or
+  "(?:\"|[^"])*"  #   double quoted value
+  |               #   or
+  [^\s#\n]+       #   unquoted value
+)?                # value end
+\s*
+(?:\#.*)?         # optional comment
+)
+\z
+`
+
+var linesRe = regexp.MustCompile("[\\r\\n]+")
+var lineRe = regexp.MustCompile(
+	regexp.MustCompile("\\s+").ReplaceAllLiteralString(
+		regexp.MustCompile("\\s+# .*").ReplaceAllLiteralString(LINE, ""), ""))
+
+// Parse reads a string in the .env format and returns a map of the extracted key=values.
+//
+// Ported from https://github.com/bkeepers/dotenv/blob/84f33f48107c492c3a99bd41c1059e7b4c1bb67a/lib/dotenv/parser.rb
+func Parse(data string) (map[string]string, error) {
+	var dotenv = make(map[string]string)
+
+	for _, line := range linesRe.Split(data, -1) {
+		if !lineRe.MatchString(line) {
+			return nil, fmt.Errorf("invalid line: %s", line)
+		}
+
+		match := lineRe.FindStringSubmatch(line)
+		// commented or empty line
+		if len(match) == 0 {
+			continue
+		}
+		if len(match[1]) == 0 {
+			continue
+		}
+
+		key := match[1]
+		value := match[2]
+
+		parseValue(key, value, dotenv)
+	}
+
+	return dotenv, nil
+}
+
+// MustParse works the same as Parse but panics on error
+func MustParse(data string) map[string]string {
+	env, err := Parse(data)
+	if err != nil {
+		panic(err)
+	}
+	return env
+}
+
+func parseValue(key string, value string, dotenv map[string]string) {
+	if len(value) <= 1 {
+		dotenv[key] = value
+		return
+	}
+
+	singleQuoted := false
+
+	if value[0:1] == "'" && value[len(value)-1:] == "'" {
+		// single-quoted string, do not expand
+		singleQuoted = true
+		value = value[1 : len(value)-1]
+	} else if value[0:1] == `"` && value[len(value)-1:] == `"` {
+		value = value[1 : len(value)-1]
+		value = expandNewLines(value)
+		value = unescapeCharacters(value)
+	}
+
+	if !singleQuoted {
+		value = expandEnv(value, dotenv)
+	}
+
+	dotenv[key] = value
+}
+
+var escRe = regexp.MustCompile("\\\\([^$])")
+
+func unescapeCharacters(value string) string {
+	return escRe.ReplaceAllString(value, "$1")
+}
+
+func expandNewLines(value string) string {
+	value = strings.Replace(value, "\\n", "\n", -1)
+	value = strings.Replace(value, "\\r", "\r", -1)
+	return value
+}
+
+func expandEnv(value string, dotenv map[string]string) string {
+	expander := func(value string) string {
+		envKey, defaultValue, hasDefault := splitKeyAndDefault(value, ":-")
+		expanded, found := lookupDotenv(envKey, dotenv)
+
+		if found {
+			return expanded
+		}
+		return getFromEnvOrDefault(envKey, defaultValue, hasDefault)
+	}
+
+	return os.Expand(value, expander)
+}
+
+func splitKeyAndDefault(value string, sep string) (string, string, bool) {
+	var i = strings.Index(value, sep)
+
+	if i == -1 {
+		return value, "", false
+	}
+	return value[0:i], value[i+len(sep):], true
+}
+
+func lookupDotenv(value string, dotenv map[string]string) (string, bool) {
+	retval, ok := dotenv[value]
+	return retval, ok
+}
+
+func getFromEnvOrDefault(envKey string, defaultValue string, hasDefault bool) string {
+	var envValue = os.Getenv(envKey)
+
+	if len(envValue) == 0 && hasDefault {
+		return defaultValue
+	}
+	return envValue
+}