Create initial project structure with tests and reader

test/challenge_test.clj

@@ -0,0 +1,47 @@
+(ns challenge-test
+  (:require [challenge.core :refer [difference]]
+            [challenge.readers]
+            [clojure.test :refer [deftest is testing]]))
+
+(def week0 #st/local-date-range "2024-01-01/P7D")
+(def week1 #st/local-date-range "2024-01-08/P7D")
+(def week2 #st/local-date-range "2024-01-15/P7D")
+(def week3 #st/local-date-range "2024-01-22/P7D")
+(def extra #st/local-date-range "2024-01-29/P3D")
+(def month0 #st/local-date-range "2024-01-01/P1M")
+
+(deftest unary
+  (is (= #{week0}
+         (difference #{week0})))
+  (testing "compresses results"
+    (is (= #{month0}
+           (difference #{week0 week1 week2 week3 extra})))))
+
+(deftest binary
+  (testing "equals"
+    (is (= #{}
+           (difference #{week0} #{week0})))
+    (is (= #{}
+           (difference #{week0 week1} #{week0 week1}))))
+  (testing "overlapped by"
+    (is (= #{#st/local-date-range "2024-01-01/P4D"}
+           (difference #{week0}
+                       #{#st/local-date-range "2024-01-05/P10D"})))
+    (is (= #{#st/local-date-range "2024-01-01/P4D"}
+           (difference #{week0 week1}
+                       #{#st/local-date-range "2024-01-05/P10D"}))))
+  (testing "met by"
+    (is (= #{week0}
+           (difference #{week0} #{week1}))))
+  (testing "contains"
+    (is (= #{week0 #st/local-date-range "2024-01-15/P17D"}
+           (difference #{month0} #{week1}))))
+  (testing "during"
+    (is (= #{}
+           (difference #{week1} #{month0})))))
+
+(deftest variadic
+  (is (= #{week0 extra}
+         (difference #{month0}
+                     #{week1}
+                     #{week2 week3}))))