added epoch

internal/exercises/catalog.yaml

@@ -177,3 +177,11 @@ projects:
   hints:
     - Implement an in-memory key-value store with basic CRUD operations and optional persistence.
 
+- slug: 36_epoch
+  title: "Epoch Conversion"
+  difficulty: beginner
+  topics: ["time", "epoch", "unix"]
+  hints:
+    - "Use Go's `time.Unix()` to convert an epoch to time."
+    - "Use `t.Unix()` to convert time back to epoch."
+    - "Remember Go’s `time.Parse` can help parse date strings."

internal/exercises/templates/36_epoch/epoch.go

@@ -0,0 +1,15 @@
+package epoch
+
+// TODO: Implement these functions so tests pass
+
+// EpochToTime converts a unix epoch (seconds) into a formatted time string "2006-01-02 15:04:05".
+func EpochToTime(epoch int64) string {
+	// Intentionally wrong to simulate failing exercise
+	return ""
+}
+
+// TimeToEpoch converts a formatted time string "2006-01-02 15:04:05" into a unix epoch (seconds).
+func TimeToEpoch(input string) int64 {
+	// Intentionally wrong to simulate failing exercise
+	return 0
+}

internal/exercises/templates/36_epoch/epoch_test.go

@@ -0,0 +1,20 @@
+package epoch
+
+import "testing"
+
+func TestEpochToTime(t *testing.T) {
+	const want = "2021-10-01 00:00:00"
+	const epoch = int64(1633046400) // 2021-10-01 00:00:00 UTC
+	got := EpochToTime(epoch)
+	if got != want {
+		t.Fatalf("EpochToTime(%d) = %q, want %q", epoch, got, want)
+	}
+}
+func TestTimeToEpoch(t *testing.T) {
+	const input = "2021-10-01 00:00:00"
+	const want = int64(1633046400)
+	got := TimeToEpoch(input)
+	if got != want {
+		t.Fatalf("TimeToEpoch(%q) = %d, want %d", input, got, want)
+	}
+}