add PaymentInformation to track pending payments

pickhardt-payments/src/test/java/de/cotto/lndmanagej/pickhardtpayments/model/PaymentInformationTest.java

@@ -0,0 +1,49 @@
+package de.cotto.lndmanagej.pickhardtpayments.model;
+
+import de.cotto.lndmanagej.model.Coins;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class PaymentInformationTest {
+    private static final PaymentInformation PAYMENT_INFORMATION =
+            new PaymentInformation(Coins.ofSatoshis(123), false, false);
+
+    @Test
+    void inFlight() {
+        assertThat(PAYMENT_INFORMATION.inFlight()).isEqualTo(Coins.ofSatoshis(123));
+    }
+
+    @Test
+    void settled() {
+        assertThat(PAYMENT_INFORMATION.settled()).isFalse();
+    }
+
+    @Test
+    void failed() {
+        assertThat(PAYMENT_INFORMATION.failed()).isFalse();
+    }
+
+    @Test
+    void withAdditionalInFlight() {
+        assertThat(PAYMENT_INFORMATION.withAdditionalInFlight(Coins.ofSatoshis(77)))
+                .isEqualTo(new PaymentInformation(Coins.ofSatoshis(200), false, false));
+    }
+
+    @Test
+    void withIsSettled() {
+        assertThat(PAYMENT_INFORMATION.withIsSettled())
+                .isEqualTo(new PaymentInformation(Coins.ofSatoshis(123), true, false));
+    }
+
+    @Test
+    void withIsFailed() {
+        assertThat(PAYMENT_INFORMATION.withIsFailed())
+                .isEqualTo(new PaymentInformation(Coins.ofSatoshis(123), false, true));
+    }
+
+    @Test
+    void default_values() {
+        assertThat(PaymentInformation.DEFAULT).isEqualTo(new PaymentInformation(Coins.NONE, false, false));
+    }
+}