feat: implement ParseDotEnv function to parse .env file content and add unit tests

Author: flarco

core/env/envfile.go

@@ -142,8 +142,24 @@ func LoadDotEnvSling() map[string]string {
 		return dotEnvMap.Items() // file doesn't exist or can't be read
 	}
 
-	for _, line := range strings.Split(string(bytes), "\n") {
-		line = strings.TrimSpace(line)
+	for key, val := range ParseDotEnv(string(bytes)) {
+		// don't overwrite existing env vars
+		if _, exists := os.LookupEnv(key); !exists {
+			dotEnvMap.Set(key, val)
+			os.Setenv(key, val)
+		}
+	}
+	return dotEnvMap.Items()
+}
+
+// ParseDotEnv parses a .env file content into key-value pairs.
+// It supports single-line and multi-line values enclosed in matching quotes (' or ").
+func ParseDotEnv(content string) map[string]string {
+	result := map[string]string{}
+	lines := strings.Split(content, "\n")
+
+	for i := 0; i < len(lines); i++ {
+		line := strings.TrimSpace(lines[i])
 		if line == "" || strings.HasPrefix(line, "#") {
 			continue
 		}
@@ -156,21 +172,36 @@ func LoadDotEnvSling() map[string]string {
 		key = strings.TrimSpace(key)
 		val = strings.TrimSpace(val)
 
-		// remove surrounding quotes
-		if len(val) >= 2 {
-			if (val[0] == '"' && val[len(val)-1] == '"') ||
-				(val[0] == '\'' && val[len(val)-1] == '\'') {
+		// check for quoted multi-line values
+		if len(val) >= 1 && (val[0] == '\'' || val[0] == '"') {
+			quote := val[0]
+
+			// check if closing quote is on the same line
+			if len(val) >= 2 && val[len(val)-1] == quote {
+				// single-line quoted value
 				val = val[1 : len(val)-1]
+			} else {
+				// multi-line: accumulate lines until we find the closing quote
+				var buf strings.Builder
+				buf.WriteString(val[1:]) // content after opening quote
+				for i++; i < len(lines); i++ {
+					raw := lines[i]
+					trimmed := strings.TrimRight(raw, " \t")
+					if len(trimmed) > 0 && trimmed[len(trimmed)-1] == quote {
+						buf.WriteByte('\n')
+						buf.WriteString(trimmed[:len(trimmed)-1])
+						break
+					}
+					buf.WriteByte('\n')
+					buf.WriteString(raw)
+				}
+				val = buf.String()
 			}
 		}
 
-		// don't overwrite existing env vars
-		if _, exists := os.LookupEnv(key); !exists {
-			dotEnvMap.Set(key, val)
-			os.Setenv(key, val)
-		}
+		result[key] = val
 	}
-	return dotEnvMap.Items()
+	return result
 }
 
 func UnsetEnvKeys(keys []string) {

core/env/envfile_test.go

@@ -0,0 +1,138 @@
+package env
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseDotEnv(t *testing.T) {
+	tests := []struct {
+		name     string
+		content  string
+		expected map[string]string
+	}{
+		{
+			name:    "simple key=value",
+			content: "FOO=bar",
+			expected: map[string]string{
+				"FOO": "bar",
+			},
+		},
+		{
+			name:    "single-line single-quoted JSON",
+			content: `KEY='{"a": "b"}'`,
+			expected: map[string]string{
+				"KEY": `{"a": "b"}`,
+			},
+		},
+		{
+			name:    "single-line double-quoted JSON",
+			content: `KEY="{\"a\": \"b\"}"`,
+			expected: map[string]string{
+				"KEY": `{\"a\": \"b\"}`,
+			},
+		},
+		{
+			name: "multi-line single-quoted JSON",
+			content: `KEY='{
+  "a": "b"
+}'`,
+			expected: map[string]string{
+				"KEY": "{\n  \"a\": \"b\"\n}",
+			},
+		},
+		{
+			name: "multi-line double-quoted value",
+			content: "KEY=\"hello\nworld\"",
+			expected: map[string]string{
+				"KEY": "hello\nworld",
+			},
+		},
+		{
+			name: "multi-line with multiple keys",
+			content: `BEFORE=hello
+JSON_VAL='{
+  "key": "value",
+  "num": 42
+}'
+AFTER=world`,
+			expected: map[string]string{
+				"BEFORE":   "hello",
+				"JSON_VAL": "{\n  \"key\": \"value\",\n  \"num\": 42\n}",
+				"AFTER":    "world",
+			},
+		},
+		{
+			name: "comments and blank lines are skipped",
+			content: `# this is a comment
+FOO=bar
+
+# another comment
+BAZ=qux`,
+			expected: map[string]string{
+				"FOO": "bar",
+				"BAZ": "qux",
+			},
+		},
+		{
+			name:    "value with equals sign",
+			content: `CONN=postgres://user:pass@host/db?sslmode=require`,
+			expected: map[string]string{
+				"CONN": "postgres://user:pass@host/db?sslmode=require",
+			},
+		},
+		{
+			name: "multi-line with nested braces",
+			content: `CONFIG='{
+  "database": {
+    "host": "localhost",
+    "port": 5432
+  }
+}'`,
+			expected: map[string]string{
+				"CONFIG": "{\n  \"database\": {\n    \"host\": \"localhost\",\n    \"port\": 5432\n  }\n}",
+			},
+		},
+		{
+			name:    "unquoted value",
+			content: `KEY=some value here`,
+			expected: map[string]string{
+				"KEY": "some value here",
+			},
+		},
+		{
+			name:    "empty value",
+			content: `KEY=`,
+			expected: map[string]string{
+				"KEY": "",
+			},
+		},
+		{
+			name: "double-quoted value with single quotes inside",
+			content: `KEY="{'a': 'b'}"`,
+			expected: map[string]string{
+				"KEY": "{'a': 'b'}",
+			},
+		},
+		{
+			name: "multi-line double-quoted with single quotes inside",
+			content: "KEY=\"{\n  'a': 'b'\n}\"",
+			expected: map[string]string{
+				"KEY": "{\n  'a': 'b'\n}",
+			},
+		},
+		{
+			name:    "line without equals is skipped",
+			content: "NOPE",
+			expected: map[string]string{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := ParseDotEnv(tt.content)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}