fix: if a line contains multiple # characters, there will be issues w… (#238)

* fix: if a line contains multiple # characters, there will be issues when traversing from back to front

* fix: typo

cmd/godotenv/cmd.go

@@ -4,7 +4,6 @@ import (
 	"flag"
 	"fmt"
 	"log"
-
 	"strings"
 
 	"github.com/joho/godotenv"

fixtures/comments.env

@@ -1,4 +1,7 @@
 # Full line comment
+qux=thud # fred # other
+thud=fred#qux # other
+fred=qux#baz # other # more
 foo=bar # baz
 bar=foo#baz
 baz="foo"#bar

fixtures/substitutions.env

@@ -3,3 +3,4 @@ OPTION_B=${OPTION_A}
 OPTION_C=$OPTION_B
 OPTION_D=${OPTION_A}${OPTION_B}
 OPTION_E=${OPTION_NOT_DEFINED}
+OPTION_F=${GLOBAL_OPTION}

godotenv_test.go

@@ -207,15 +207,21 @@ func TestLoadQuotedEnv(t *testing.T) {
 
 func TestSubstitutions(t *testing.T) {
 	envFileName := "fixtures/substitutions.env"
+
+	presets := map[string]string{
+		"GLOBAL_OPTION": "global",
+	}
+
 	expectedValues := map[string]string{
 		"OPTION_A": "1",
 		"OPTION_B": "1",
 		"OPTION_C": "1",
 		"OPTION_D": "11",
 		"OPTION_E": "",
+		"OPTION_F": "global",
 	}
 
-	loadEnvAndCompareValues(t, Load, envFileName, expectedValues, noopPresets)
+	loadEnvAndCompareValues(t, Load, envFileName, expectedValues, presets)
 }
 
 func TestExpanding(t *testing.T) {
@@ -471,6 +477,9 @@ func TestErrorParsing(t *testing.T) {
 func TestComments(t *testing.T) {
 	envFileName := "fixtures/comments.env"
 	expectedValues := map[string]string{
+		"qux":  "thud",
+		"thud": "fred#qux",
+		"fred": "qux#baz",
 		"foo":  "bar",
 		"bar":  "foo#baz",
 		"baz":  "foo",

parser.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"os"
 	"regexp"
 	"strings"
 	"unicode"
@@ -142,9 +143,9 @@ func extractVarValue(src []byte, vars map[string]string) (value string, rest []b
 		}
 
 		// Work backwards to check if the line ends in whitespace then
-		// a comment (ie asdasd # some comment)
-		for i := endOfVar - 1; i >= 0; i-- {
-			if line[i] == charComment && i > 0 {
+		// a comment, ie: foo=bar # baz # other
+		for i := 0; i < endOfVar; i++ {
+			if line[i] == charComment && i < endOfVar {
 				if isSpace(line[i-1]) {
 					endOfVar = i
 					break
@@ -264,6 +265,12 @@ func expandVariables(v string, m map[string]string) string {
 		if submatch[1] == "\\" || submatch[2] == "(" {
 			return submatch[0][1:]
 		} else if submatch[4] != "" {
+			if val, ok := m[submatch[4]]; ok {
+				return val
+			}
+			if val, ok := os.LookupEnv(submatch[4]); ok {
+				return val
+			}
 			return m[submatch[4]]
 		}
 		return s