WIP: first fluent checker tests

jollyday-tests/src/test/java/de/focus_shift/jollyday/tests/HolidayCheckerApi.java

@@ -0,0 +1,33 @@
+package de.focus_shift.jollyday.tests;
+
+import de.focus_shift.jollyday.core.HolidayCalendar;
+import de.focus_shift.jollyday.core.HolidayType;
+
+import java.time.Month;
+import java.time.Year;
+
+public interface HolidayCheckerApi {
+
+  interface Holiday {
+    Between isFixedHoliday(final String propertyKey, final Month month, final int day);
+    Between isFixedHoliday(final String propertyKey, final Month month, final int day, final HolidayType type);
+
+    Between christian(final String propertyKey);
+    Between christian(final String propertyKey, final HolidayType type);
+
+    Between isIslamicHoliday(final String propertyKey);
+    Between isIslamicHoliday(final String propertyKey, final HolidayType type);
+  }
+
+  interface Between {
+    Between between(Year from, Year to);
+
+    Holiday and();
+
+    void check();
+  }
+
+  static HolidayCheckerFluent assertFor(final HolidayCalendar calendar) {
+    return new HolidayCheckerFluent(calendar);
+  }
+}