Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v3...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
         os: [ ubuntu-latest, macOS-latest, windows-latest ]
     name: ${{ matrix.os }} Go ${{ matrix.go }} Tests
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup go
         uses: actions/setup-go@v4
         with:

.github/workflows/codeql-analysis.yml

@@ -38,7 +38,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Generate build files
         uses: thatisuday/go-cross-build@v1.0.2
         with:

cmd/godotenv/cmd.go

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

fixtures/substitutions.env

@@ -3,4 +3,3 @@ 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

@@ -207,21 +207,15 @@ 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, presets)
+	loadEnvAndCompareValues(t, Load, envFileName, expectedValues, noopPresets)
 }
 
 func TestExpanding(t *testing.T) {

parser.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"os"
 	"regexp"
 	"strings"
 	"unicode"
@@ -265,12 +264,6 @@ 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