Error on nonexistent sources instead of returning nothing

cmd/feed.go

@@ -48,6 +48,10 @@ func feed(
 	var items []core.Item
 	var err error
 	if source != "" {
+		if exists, err := core.SourceExists(db, source); !exists || err != nil {
+			log.Fatalf("error: no such source %s", source)
+		}
+
 		if showInactive {
 			items, err = core.GetAllItemsForSource(db, source)
 		} else {

core/source.go

@@ -39,6 +39,13 @@ func GetSources(db DB) ([]string, error) {
 	return names, nil
 }
 
+func SourceExists(db DB, source string) (bool, error) {
+	row := db.QueryRow("select count(*) from sources where name = ?", source)
+	var c int
+	err := row.Scan(&c)
+	return c > 0, err
+}
+
 func DeleteSource(db DB, name string) error {
 	_, err := db.Exec(`
 		delete from sources

core/source_test.go

@@ -14,9 +14,16 @@ import (
 func TestCreateSource(t *testing.T) {
 	db := EphemeralDb(t)
 
+	if exists, err := SourceExists(db, "one"); exists || err != nil {
+		t.Fatal(err)
+	}
 	if err := AddSource(db, "one"); err != nil {
 		t.Fatal(err)
 	}
+	if exists, err := SourceExists(db, "one"); !exists || err != nil {
+		t.Fatal(err)
+	}
+
 	if err := AddSource(db, "two"); err != nil {
 		t.Fatal(err)
 	}

web/source.go

@@ -10,12 +10,11 @@ import (
 
 func (env *Env) getSource(writer http.ResponseWriter, req *http.Request) {
 	source := req.PathValue("source")
-	if source == "" {
+	if exists, err := core.SourceExists(env.db, source); !exists || err != nil {
 		http.NotFound(writer, req)
 		return
 	}
 
-	// TODO this needs to properly error if the source doesn't exist instead of just returning []
 	var items []core.Item
 	var err error
 	inactive := req.URL.Query().Get("inactive") == "1"