add set-clock!

Author: Vadim Platonov

CHANGELOG.md

@@ -4,6 +4,13 @@
 
 ### New Features
 
+* `zone-id?` predicate
+* `set-clock!` - sets the mocked clock value to the supplied instant
+
+## 0.3.1
+
+### New Features
+
 * `clock?` predicate
 * `mock-clock` - returns a mocked instance of `java.time.Clock`.
 

README.md

@@ -443,6 +443,13 @@ can be very handy in testing:
 (with-clock clock
   (j/instant))
 => #object[java.time.Instant "1970-01-01T05:20:00Z"]
+
+(set-clock! clock 0)
+=> nil
+
+(with-clock clock
+  (j/instant))
+=> #object[java.time.Instant "1970-01-01T00:00:00Z"]
 ```
 
 Clock overrides works for all of the date-time types.

src/java_time.clj

@@ -44,7 +44,7 @@
    with-zone-same-instant with-offset with-offset-same-instant]
 
   [java-time.mock
-   mock-clock advance-clock!]
+   mock-clock advance-clock! set-clock!]
 
   [java-time.convert
    as-map convert-amount to-java-date to-sql-date to-sql-timestamp

src/java_time/mock.clj

@@ -1,5 +1,6 @@
 (ns java-time.mock
   (:require [java-time
+             [amount :as amount]
              [core :as core]
              [temporal :as temporal]
              [zone :as zone]])
@@ -55,3 +56,13 @@
   This mutates the mock clock."
   [^IMockClock clock amount]
   (.advanceClock clock amount))
+
+(defn set-clock!
+  "Sets the `clock` to the given `time`.
+
+  This mutates the mock clock."
+  [^Clock clock time]
+  (let [current (.instant clock)]
+    (->> (core/time-between :millis current (temporal/instant time))
+         (amount/millis)
+         (advance-clock! clock))))

test/java_time_test.clj

@@ -467,17 +467,28 @@
 
         (testing "by negative amount"
           (j/advance-clock! clock (j/millis -1))
-          (is (= 0 (j/value clock))))
+          (is (= 0 (j/value clock))))))
 
-        (testing "clone with a different zone"
-          (let [cloned-clock (j/with-zone clock "GMT")]
-            (is (not (identical? clock cloned-clock)))
-            (is (= (j/zone-id "GMT") (j/zone-id cloned-clock)))
-            (is (= (j/value cloned-clock) (j/value clock)))
+    (testing "clone with a different zone"
+      (let [clock (utc-clock 0)
+            cloned-clock (j/with-zone clock "GMT")]
+        (is (not (identical? clock cloned-clock)))
+        (is (= (j/zone-id "GMT") (j/zone-id cloned-clock)))
+        (is (= (j/value cloned-clock) (j/value clock)))
 
-            (j/advance-clock! cloned-clock (j/seconds 1))
-            (is (= 1000 (j/value cloned-clock)))
-            (is (not= (j/value cloned-clock) (j/value clock)))))))))
+        (j/advance-clock! cloned-clock (j/seconds 1))
+        (is (= 1000 (j/value cloned-clock)))
+        (is (not= (j/value cloned-clock) (j/value clock)))))
+
+    (testing "set"
+      (let [clock (utc-clock 0)]
+        (testing "into future"
+          (j/set-clock! clock 100)
+          (is (= 100 (j/value clock))))
+
+        (testing "into past"
+          (j/set-clock! clock 0)
+          (is (= 0 (j/value clock))))))))
 
 (deftest properties
   (testing "units"