fix: NoneType error on JSON output without position

.scripts/tests-e2e.sh

@@ -98,6 +98,8 @@ assertSuccess "$KOSMORRO_COMMAND --latitude=50.5876 --longitude=3.0624 -d 2020-0
 assertSuccess "$KOSMORRO_COMMAND --latitude=50.5876 --longitude=3.0624 -d 2020-01-27 --format=json"
 assertFailure "$KOSMORRO_COMMAND --latitude=50.5876 --longitude=3.0624 -d 2020-01-27 --format=pdf"
 
+assertSuccess "$KOSMORRO_COMMAND -d 2020-01-27 --format=json"
+
 # Environment variables
 assertSuccess "LATITUDE=50.5876 LONGITUDE=3.0624 TIMEZONE=1 kosmorro -d 2020-01-27"
 assertSuccess "LATITUDE=50.5876 LONGITUDE=3.0624 TIMEZONE=-1 kosmorro -d 2020-01-27"

_kosmorro/dumper.py

@@ -43,15 +43,23 @@
 
 
 class Dumper(ABC):
+    ephemerides: [AsterEphemerides]
+    moon_phase: MoonPhase
+    events: [Event]
+    date: datetime.date
+    timezone: int
+    with_colors: bool
+    show_graph: bool
+
     def __init__(
         self,
-        ephemerides: [AsterEphemerides] = None,
-        moon_phase: MoonPhase = None,
-        events: [Event] = None,
-        date: datetime.date = datetime.date.today(),
-        timezone: int = 0,
-        with_colors: bool = True,
-        show_graph: bool = False,
+        ephemerides: [AsterEphemerides],
+        moon_phase: MoonPhase,
+        events: [Event],
+        date: datetime.date,
+        timezone: int,
+        with_colors: bool,
+        show_graph: bool,
     ):
         self.ephemerides = ephemerides
         self.moon_phase = moon_phase
@@ -99,7 +107,7 @@ class TextDumper(Dumper):
     def to_string(self):
         text = [self.style(self.get_date_as_string(capitalized=True), "h1")]
 
-        if self.ephemerides is not None:
+        if len(self.ephemerides) > 0:
             text.append(self.stringify_ephemerides())
 
         text.append(self.get_moon(self.moon_phase))

_kosmorro/main.py

@@ -152,7 +152,7 @@ def get_information(
         except OutOfRangeDateError as error:
             raise DateRangeError(error.min_date, error.max_date)
     else:
-        eph = None
+        eph = []
 
     try:
         moon_phase = get_moon_phase(compute_date)