Report error when loading the lexer

caddyfile/dispenser.go

@@ -19,9 +19,10 @@ type Dispenser struct {
 
 // NewDispenser returns a Dispenser, ready to use for parsing the given input.
 func NewDispenser(filename string, input io.Reader) Dispenser {
+	tokens, _ := allTokens(input) // ignoring error because nothing to do with it
 	return Dispenser{
 		filename: filename,
-		tokens:   allTokens(input),
+		tokens:   tokens,
 		cursor:   -1,
 	}
 }

caddyfile/lexer.go

@@ -33,7 +33,10 @@ func (l *lexer) load(input io.Reader) error {
 
 	// discard byte order mark, if present
 	firstCh, _, err := l.reader.ReadRune()
-	if err == nil && firstCh != 0xFEFF {
+	if err != nil {
+		return err
+	}
+	if firstCh != 0xFEFF {
 		err := l.reader.UnreadRune()
 		if err != nil {
 			return err

caddyfile/parse.go

@@ -22,13 +22,17 @@ func Parse(filename string, input io.Reader, validDirectives []string) ([]Server
 // allTokens lexes the entire input, but does not parse it.
 // It returns all the tokens from the input, unstructured
 // and in order.
-func allTokens(input io.Reader) (tokens []Token) {
+func allTokens(input io.Reader) ([]Token, error) {
 	l := new(lexer)
-	l.load(input)
+	err := l.load(input)
+	if err != nil {
+		return nil, err
+	}
+	var tokens []Token
 	for l.next() {
 		tokens = append(tokens, l.token)
 	}
-	return
+	return tokens, nil
 }
 
 type parser struct {
@@ -294,7 +298,10 @@ func (p *parser) doSingleImport(importFile string) ([]Token, error) {
 		return nil, p.Errf("Could not import %s: is a directory", importFile)
 	}
 
-	importedTokens := allTokens(file)
+	importedTokens, err := allTokens(file)
+	if err != nil {
+		return nil, p.Errf("Could not read tokens while importing %s: %v", importFile, err)
+	}
 
 	// Tack the filename onto these tokens so errors show the imported file's name
 	filename := filepath.Base(importFile)

caddyfile/parse_test.go

@@ -9,8 +9,11 @@ import (
 func TestAllTokens(t *testing.T) {
 	input := strings.NewReader("a b c\nd e")
 	expected := []string{"a", "b", "c", "d", "e"}
-	tokens := allTokens(input)
+	tokens, err := allTokens(input)
 
+	if err != nil {
+		t.Fatalf("Expected no error, got %v", err)
+	}
 	if len(tokens) != len(expected) {
 		t.Fatalf("Expected %d tokens, got %d", len(expected), len(tokens))
 	}