1 files changed, 23 insertions, 0 deletions
diff --git a/packages/taler-util/src/time.ts b/packages/taler-util/src/time.ts
index 3d7d80485..cf370fdad 100644
--- a/packages/taler-util/src/time.ts
+++ b/packages/taler-util/src/time.ts
@@ -216,6 +216,29 @@ export namespace Duration {
     };
   }
 
+  /**
+   * Compare two durations.  Returns 0 when equal, -1 when a < b
+   * and +1 when a > b.
+   */
+  export function cmp(d1: Duration, d2: Duration): 1 | 0 | -1 {
+    if (d1.d_ms === "forever") {
+      if (d2.d_ms === "forever") {
+        return 0;
+      }
+      return 1;
+    }
+    if (d2.d_ms === "forever") {
+      return -1;
+    }
+    if (d1.d_ms == d2.d_ms) {
+      return 0;
+    }
+    if (d1.d_ms > d2.d_ms) {
+      return 1;
+    }
+    return -1;
+  }
+
   export function max(d1: Duration, d2: Duration): Duration {
     return durationMax(d1, d2);
   }