slight alterative to keep the filename out

opts/envfile.go

@@ -1,6 +1,7 @@
 package opts
 
 import (
+	"fmt"
 	"os"
 )
 
@@ -18,5 +19,14 @@ import (
 // environment variables, that's why we just strip leading whitespace and
 // nothing more.
 func ParseEnvFile(filename string) ([]string, error) {
-	return parseKeyValueFile(filename, os.LookupEnv)
+	fh, err := os.Open(filename)
+	if err != nil {
+		return []string{}, err
+	}
+	out, err := parseKeyValueFile(fh, os.LookupEnv)
+	_ = fh.Close()
+	if err != nil {
+		return []string{}, fmt.Errorf("invalid env file (%s): %v", filename, err)
+	}
+	return out, nil
 }

opts/file.go

@@ -5,36 +5,30 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"os"
 	"strings"
 	"unicode"
 	"unicode/utf8"
 )
 
-const whiteSpaces = " \t"
-
-func parseKeyValueFile(filename string, lookupFn func(string) (string, bool)) ([]string, error) {
-	fh, err := os.Open(filename)
-	if err != nil {
-		return []string{}, err
-	}
-	defer fh.Close()
-	return ParseKeyValueFile(fh, filename, lookupFn)
-}
-
 // ParseKeyValueFile parse a file containing key,value pairs separated by equal sign
 // Lines starting with `#` are ignored
 // If a key is declared without a value (no equal sign), lookupFn is requested to provide value for the given key
 // value is returned as-is, without any kind of parsing but removal of leading whitespace
-func ParseKeyValueFile(r io.Reader, filename string, lookupFn func(string) (string, bool)) ([]string, error) {
+func ParseKeyValueFile(r io.Reader, lookupFn func(string) (string, bool)) ([]string, error) {
+	return parseKeyValueFile(r, lookupFn)
+}
+
+const whiteSpaces = " \t"
+
+func parseKeyValueFile(r io.Reader, lookupFn func(string) (string, bool)) ([]string, error) {
 	lines := []string{}
 	scanner := bufio.NewScanner(r)
 	currentLine := 0
 	utf8bom := []byte{0xEF, 0xBB, 0xBF}
 	for scanner.Scan() {
 		scannedBytes := scanner.Bytes()
 		if !utf8.Valid(scannedBytes) {
-			return []string{}, fmt.Errorf("env file %s contains invalid utf8 bytes at line %d: %v", filename, currentLine+1, scannedBytes)
+			return []string{}, fmt.Errorf("invalid utf8 bytes at line %d: %v", currentLine+1, scannedBytes)
 		}
 		// We trim UTF8 BOM
 		if currentLine == 0 {

opts/file_test.go

@@ -20,7 +20,7 @@ ZOT`)
 		return v, ok
 	}
 
-	got, err := ParseKeyValueFile(bytes.NewReader(b), "(inlined)", lookupFn)
+	got, err := ParseKeyValueFile(bytes.NewReader(b), lookupFn)
 	assert.NilError(t, err)
 	assert.DeepEqual(t, got, []string{"FOO=BAR", "ZOT=QIX"})
 }

opts/parse.go

@@ -2,6 +2,7 @@ package opts
 
 import (
 	"errors"
+	"fmt"
 	"os"
 	"strconv"
 	"strings"
@@ -25,9 +26,14 @@ func ReadKVEnvStrings(files []string, override []string) ([]string, error) {
 func readKVStrings(files []string, override []string, emptyFn func(string) (string, bool)) ([]string, error) {
 	var variables []string
 	for _, ef := range files {
-		parsedVars, err := parseKeyValueFile(ef, emptyFn)
+		fh, err := os.Open(ef)
 		if err != nil {
-			return nil, err
+			return []string{}, err
+		}
+		parsedVars, err := parseKeyValueFile(fh, emptyFn)
+		_ = fh.Close()
+		if err != nil {
+			return nil, fmt.Errorf("invalid env file (%s): %v", ef, err)
 		}
 		variables = append(variables, parsedVars...)
 	}