Keep a later config flag when extra words are present.

A non-flag word no longer stops parsing, and a missing home directory refuses to create or rewrite a config instead of writing an empty log path.

Co-authored-by: Cursor <cursoragent@cursor.com>

app.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"context"
+	"fmt"
+	"io"
 
 	"gitea.neitzel.de/konrad/funknetz/audio"
 	"gitea.neitzel.de/konrad/funknetz/station"
@@ -51,3 +53,15 @@ func openStation(args []string) (*station.Station, error) {
 	}
 	return station.New(station.Options{ConfigPath: path})
 }
+
+// openStationReported opens the station from args. A flag or config failure is
+// one line on stderr and the returned error. The window is not opened.
+func openStationReported(args []string, stderr io.Writer) (*station.Station, error) {
+	st, err := openStation(args)
+	if err != nil {
+		// The returned error is the failure. A write error does not replace it.
+		_, _ = fmt.Fprintln(stderr, err.Error())
+		return nil, err
+	}
+	return st, nil
+}

config_path.go

@@ -24,8 +24,17 @@ func resolveConfigPath(args []string) (string, error) {
 	var config string
 	fs.StringVar(&config, "config", "", "path to the station config file")
 	fs.StringVar(&config, "c", "", "path to the station config file")
-	if err := fs.Parse(args); err != nil {
+	rest := args
-		return "", err
+	for {
+		if err := fs.Parse(rest); err != nil {
+			return "", err
+		}
+		rest = fs.Args()
+		if len(rest) == 0 {
+			break
+		}
+		// A non-flag word ends a parse. Skip it and keep later flags.
+		rest = rest[1:]
 	}
 	if config == "" {
 		path, err := defaultConfigPath()

config_path_test.go

@@ -3,11 +3,13 @@
 package main
 
 import (
+	"bytes"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
 
+	"encoding/json/v2"
 )
 
 func TestResolveConfigPathDefaultIsHome(t *testing.T) {
@@ -122,3 +124,216 @@ func TestOpenStationUsesResolvedPath(t *testing.T) {
 		t.Fatalf("callsign = %q, want DL0FN-1", st.State().Callsign)
 	}
 }
+
+func TestConfigEqualsFlagSelectsTheFile(t *testing.T) {
+	abs := filepath.Join(t.TempDir(), "lab.json")
+	got, err := resolveConfigPath([]string{"--config=" + abs})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != abs {
+		t.Fatalf("--config= = %q, want %q", got, abs)
+	}
+}
+
+func TestCreatedFileViaFlagMatchesHomeTemplate(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "lab.json")
+	var stderr bytes.Buffer
+	st, err := openStationReported([]string{"-c", path}, &stderr)
+	if st != nil {
+		t.Fatal("station = non-nil, want nil before the window")
+	}
+	if err == nil {
+		t.Fatal("error = nil, want the file created")
+	}
+	if got, want := err.Error(), "created "+path; got != want {
+		t.Fatalf("error = %q, want %q", got, want)
+	}
+	if got, want := stderr.String(), err.Error()+"\n"; got != want {
+		t.Fatalf("stderr = %q, want %q", got, want)
+	}
+	info, err := os.Stat(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got, want := info.Mode().Perm(), os.FileMode(0o600); got != want {
+		t.Fatalf("mode = %o, want %o", got, want)
+	}
+	body, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got map[string]any
+	if err := json.Unmarshal(body, &got); err != nil {
+		t.Fatalf("created file is not JSON: %v\n%s", err, body)
+	}
+	if got["host"] != "" || got["callsign"] != "" || got["authKey"] != "" {
+		t.Fatalf("string fields = %#v, want empty host, callsign, and authKey", got)
+	}
+	if got["port"] != float64(0) || got["talkGroup"] != float64(0) {
+		t.Fatalf("numeric fields = %#v, want port and talkGroup at zero", got)
+	}
+	if got["enableLogging"] != false {
+		t.Fatalf("enableLogging = %#v, want false", got["enableLogging"])
+	}
+	home, err := os.UserHomeDir()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got["logFile"] != filepath.Join(home, "funknetz.log") {
+		t.Fatalf("logFile = %#v, want funknetz.log in the home directory", got["logFile"])
+	}
+}
+
+func TestLaterFlagSelectsTheFile(t *testing.T) {
+	dir := t.TempDir()
+	first := filepath.Join(dir, "first.json")
+	second := filepath.Join(dir, "second.json")
+
+	got, err := resolveConfigPath([]string{"-c", first, "--config", second})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != second {
+		t.Fatalf("later --config = %q, want %q", got, second)
+	}
+
+	got, err = resolveConfigPath([]string{"--config", first, "-c", second})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != second {
+		t.Fatalf("later -c = %q, want %q", got, second)
+	}
+}
+
+func TestEmptyConfigFlagUsesHomeFile(t *testing.T) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := filepath.Join(home, ".funknetz.json")
+	for _, args := range [][]string{
+		{"-c", ""},
+		{"--config", ""},
+		{"--config="},
+	} {
+		got, err := resolveConfigPath(args)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if got != want {
+			t.Fatalf("resolveConfigPath(%q) = %q, want %q", args, got, want)
+		}
+	}
+}
+
+func TestExtraWordsDoNotChangeTheSelectedFile(t *testing.T) {
+	abs := filepath.Join(t.TempDir(), "lab.json")
+	got, err := resolveConfigPath([]string{"-c", abs, "leftover"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != abs {
+		t.Fatalf("with leftover = %q, want %q", got, abs)
+	}
+
+	home, err := os.UserHomeDir()
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err = resolveConfigPath([]string{"note"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := filepath.Join(home, ".funknetz.json")
+	if got != want {
+		t.Fatalf("bare word = %q, want %q", got, want)
+	}
+
+	got, err = resolveConfigPath([]string{"note", "-c", abs})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != abs {
+		t.Fatalf("word before -c = %q, want %q", got, abs)
+	}
+
+	second := filepath.Join(filepath.Dir(abs), "second.json")
+	got, err = resolveConfigPath([]string{"-c", abs, "leftover", "--config", second})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != second {
+		t.Fatalf("flag after a word = %q, want %q", got, second)
+	}
+}
+
+func TestSelectedFileIsLeftByteForByte(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "lab.json")
+	original := []byte("{\"host\":\"127.0.0.1\",\"port\":5308,\"callsign\":\"DL1ABC\",\"authKey\":\"a b\",\"talkGroup\":20,\"enableLogging\":false,\"logFile\":\"/tmp/funknetz.log\"}\n")
+	if err := os.WriteFile(path, original, 0o640); err != nil {
+		t.Fatal(err)
+	}
+
+	st, err := openStation([]string{"--config", path})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if st.State().Callsign != "DL1ABC" {
+		t.Fatalf("callsign = %q, want DL1ABC", st.State().Callsign)
+	}
+	got, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(got) != string(original) {
+		t.Fatalf("file = %q, want %q", got, original)
+	}
+}
+
+func TestEmptyHostOnSelectedFileNamesHost(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "lab.json")
+	body := []byte("{\"host\":\"\",\"port\":5308,\"callsign\":\"DL1ABC\",\"authKey\":\"key\",\"talkGroup\":20,\"enableLogging\":false,\"logFile\":\"/tmp/funknetz.log\"}\n")
+	if err := os.WriteFile(path, body, 0o600); err != nil {
+		t.Fatal(err)
+	}
+	var stderr bytes.Buffer
+	st, err := openStationReported([]string{"-c", path}, &stderr)
+	if st != nil {
+		t.Fatal("station = non-nil, want nil")
+	}
+	if err == nil || !strings.Contains(err.Error(), "host") {
+		t.Fatalf("error = %v, want it to name host", err)
+	}
+	if stderr.String() != err.Error()+"\n" {
+		t.Fatalf("stderr = %q, want the error line", stderr.String())
+	}
+}
+
+func TestBadFlagPrintsParserError(t *testing.T) {
+	cases := []struct {
+		args []string
+		want string
+	}{
+		{[]string{"-not-a-flag"}, "flag provided but not defined: -not-a-flag\n"},
+		{[]string{"-c"}, "flag needs an argument: -c\n"},
+		{[]string{"--config"}, "flag needs an argument: -config\n"},
+	}
+	for _, tc := range cases {
+		var stderr bytes.Buffer
+		st, err := openStationReported(tc.args, &stderr)
+		if st != nil {
+			t.Fatal("station = non-nil, want nil")
+		}
+		if err == nil {
+			t.Fatal("error = nil, want a flag error")
+		}
+		if got := stderr.String(); got != tc.want {
+			t.Fatalf("stderr = %q, want %q", got, tc.want)
+		}
+		if strings.Contains(strings.ToLower(stderr.String()), "usage") {
+			t.Fatalf("stderr = %q, want no usage text", stderr.String())
+		}
+	}
+}

main.go

@@ -17,9 +17,8 @@ import (
 var assets embed.FS
 
 func main() {
-	st, err := openStation(os.Args[1:])
+	st, err := openStationReported(os.Args[1:], os.Stderr)
 	if err != nil {
-		fmt.Fprintln(os.Stderr, err.Error())
 		os.Exit(1)
 	}
 	app := &App{station: st}

station/config.go

@@ -62,7 +62,11 @@ func loadConfig(path string) (loaded, error) {
 }
 
 func writeTemplate(path string) error {
-	body, err := jsonv2.Marshal(templateFile{LogFile: defaultLogPath()})
+	logFile, err := defaultLogPath()
+	if err != nil {
+		return err
+	}
+	body, err := jsonv2.Marshal(templateFile{LogFile: logFile})
 	if err != nil {
 		return err
 	}
@@ -99,7 +103,11 @@ func parseConfig(path string, body []byte) (loaded, error) {
 		if !operationalKindsOK(shape) {
 			return parseOperational(shape)
 		}
-		shape = withLogDefaults(shape)
+		var err error
+		shape, err = withLogDefaults(shape)
+		if err != nil {
+			return loaded{}, err
+		}
 		if err := rewriteConfig(path, shape); err != nil {
 			return loaded{}, fmt.Errorf("the file could not be read: %w", err)
 		}
@@ -189,12 +197,14 @@ func intField(name string, v jsontext.Value, min, max int) (int, error) {
 	return n, nil
 }
 
-func defaultLogPath() string {
+var userHomeDir = os.UserHomeDir
-	home, err := os.UserHomeDir()
+
+func defaultLogPath() (string, error) {
+	home, err := userHomeDir()
 	if err != nil {
-		return ""
+		return "", fmt.Errorf("config path: %w", err)
 	}
-	return filepath.Join(home, "funknetz.log")
+	return filepath.Join(home, "funknetz.log"), nil
 }
 
 func present(v jsontext.Value) bool { return len(v) > 0 }
@@ -243,7 +253,7 @@ func blockedLog(shape fileShape) (block bool, notice string) {
 	return true, ""
 }
 
-func withLogDefaults(shape fileShape) fileShape {
+func withLogDefaults(shape fileShape) (fileShape, error) {
 	shape.Host = rawOr(shape.Host, `""`)
 	shape.Port = rawOr(shape.Port, "0")
 	shape.Callsign = rawOr(shape.Callsign, `""`)
@@ -251,13 +261,17 @@ func withLogDefaults(shape fileShape) fileShape {
 	shape.TalkGroup = rawOr(shape.TalkGroup, "0")
 	shape.EnableLogging = rawOr(shape.EnableLogging, "false")
 	if !present(shape.LogFile) {
-		raw, err := jsonv2.Marshal(defaultLogPath())
+		logFile, err := defaultLogPath()
 		if err != nil {
-			raw = []byte(`""`)
+			return fileShape{}, err
+		}
+		raw, err := jsonv2.Marshal(logFile)
+		if err != nil {
+			return fileShape{}, err
 		}
 		shape.LogFile = jsontext.Value(raw)
 	}
-	return shape
+	return shape, nil
 }
 
 func rawOr(v jsontext.Value, fallback string) jsontext.Value {

station/home_test.go

@@ -0,0 +1,52 @@
+package station
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestMissingHomeDoesNotCreateConfig(t *testing.T) {
+	orig := userHomeDir
+	t.Cleanup(func() { userHomeDir = orig })
+	userHomeDir = func() (string, error) {
+		return "", errors.New("no home")
+	}
+
+	path := filepath.Join(t.TempDir(), "lab.json")
+	_, err := New(Options{ConfigPath: path})
+	if err == nil || !strings.HasPrefix(err.Error(), "config path:") {
+		t.Fatalf("New() error = %v, want a config path failure", err)
+	}
+	if _, statErr := os.Stat(path); !errors.Is(statErr, fs.ErrNotExist) {
+		t.Fatalf("stat = %v, want the file absent", statErr)
+	}
+}
+
+func TestMissingHomeDoesNotRewriteConfig(t *testing.T) {
+	orig := userHomeDir
+	t.Cleanup(func() { userHomeDir = orig })
+	userHomeDir = func() (string, error) {
+		return "", errors.New("no home")
+	}
+
+	path := filepath.Join(t.TempDir(), "lab.json")
+	original := []byte("{\"host\":\"127.0.0.1\",\"port\":5308,\"callsign\":\"DL1ABC\",\"authKey\":\"key\",\"talkGroup\":20}\n")
+	if err := os.WriteFile(path, original, 0o640); err != nil {
+		t.Fatal(err)
+	}
+	_, err := New(Options{ConfigPath: path})
+	if err == nil || !strings.HasPrefix(err.Error(), "config path:") {
+		t.Fatalf("New() error = %v, want a config path failure", err)
+	}
+	got, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(got) != string(original) {
+		t.Fatalf("file = %q, want %q", got, original)
+	}
+}