Add Result.swap support (#6)

Signed-off-by: David Greven <[email protected]> Signed-off-by: Sebastian Becker <[email protected]>
carbynestack · Nov 15, 2021 · f60395b · f60395b
1 parent 135764e
commit f60395b
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diff --git a/common-testing/src/test/java/io/carbynestack/common/result/FailureTest.java b/common-testing/src/test/java/io/carbynestack/common/result/FailureTest.java
@@ -131,6 +131,11 @@ void orNullPointerException() {
                 .isExactlyInstanceOf(NullPointerException.class);
     }
 
+    @Test
+    void swap() {
+        assertThat(result.swap()).hasValue(reason);
+    }
+
     @Test
     void toOptional() {
         assertThat(result.toOptional()).isEmpty();

diff --git a/common-testing/src/test/java/io/carbynestack/common/result/SuccessTest.java b/common-testing/src/test/java/io/carbynestack/common/result/SuccessTest.java
@@ -132,6 +132,11 @@ void orNullPointerException() {
                 .isExactlyInstanceOf(NullPointerException.class);
     }
 
+    @Test
+    void swap() {
+        assertThat(result.swap()).hasReason(value);
+    }
+
     @Test
     void toOptional() {
         assertThat(result.toOptional()).hasValue(value);

diff --git a/common-types/src/main/java/io/carbynestack/common/result/Failure.java b/common-types/src/main/java/io/carbynestack/common/result/Failure.java
@@ -198,6 +198,17 @@ public Result<S, F> or(Supplier<? extends Result<? extends S, F>> supplier) {
         return (Result<S, F>) requireNonNull(supplier.get());
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     * @return a {@code Result} with swapped content
+     * @since 0.1.0
+     */
+    @Override
+    public Result<F, S> swap() {
+        return new Success<>(this.reason());
+    }
+
     /**
      * {@inheritDoc}
      *

diff --git a/common-types/src/main/java/io/carbynestack/common/result/Result.java b/common-types/src/main/java/io/carbynestack/common/result/Result.java
@@ -181,6 +181,14 @@ default boolean isFailure() {
      */
     Result<S, F> or(Supplier<? extends Result<? extends S, F>> supplier);
 
+    /**
+     * Swaps the {@code Result} success value with the failure reason or vise versa.
+     *
+     * @return a {@code Result} with swapped content
+     * @since 0.1.0
+     */
+    Result<F, S> swap();
+
     /**
      * If the {@code Result} is a {@link Success}, returns an {@link Optional}
      * for the {@link Success#value()}. Otherwise, an empty {@code Optional} is

diff --git a/common-types/src/main/java/io/carbynestack/common/result/Success.java b/common-types/src/main/java/io/carbynestack/common/result/Success.java
@@ -198,6 +198,17 @@ public Result<S, F> or(Supplier<? extends Result<? extends S, F>> supplier) {
         return this;
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     * @return a {@code Result} with swapped content
+     * @since 0.1.0
+     */
+    @Override
+    public Result<F, S> swap() {
+        return new Failure<>(this.value());
+    }
+
     /**
      * {@inheritDoc}
      *

diff --git a/common-types/src/main/java17/io/carbynestack/common/result/Failure.java b/common-types/src/main/java17/io/carbynestack/common/result/Failure.java
@@ -168,6 +168,17 @@ public Result<S, F> or(Supplier<? extends Result<? extends S, F>> supplier) {
         return (Result<S, F>) requireNonNull(supplier.get());
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     * @return a {@code Result} with swapped content
+     * @since 0.1.0
+     */
+    @Override
+    public Result<F, S> swap() {
+        return new Success<>(this.reason());
+    }
+
     /**
      * {@inheritDoc}
      *

diff --git a/common-types/src/main/java17/io/carbynestack/common/result/Result.java b/common-types/src/main/java17/io/carbynestack/common/result/Result.java
@@ -181,6 +181,14 @@ default boolean isFailure() {
      */
     Result<S, F> or(Supplier<? extends Result<? extends S, F>> supplier);
 
+    /**
+     * Swaps the {@code Result} success value with the failure reason or vise versa.
+     *
+     * @return a {@code Result} with swapped content
+     * @since 0.1.0
+     */
+    Result<F, S> swap();
+
     /**
      * If the {@code Result} is a {@link Success}, returns an {@link Optional}
      * for the {@link Success#value()}. Otherwise, an empty {@code Optional} is

diff --git a/common-types/src/main/java17/io/carbynestack/common/result/Success.java b/common-types/src/main/java17/io/carbynestack/common/result/Success.java
@@ -168,6 +168,17 @@ public Result<S, F> or(Supplier<? extends Result<? extends S, F>> supplier) {
         return this;
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     * @return a {@code Result} with swapped content
+     * @since 0.1.0
+     */
+    @Override
+    public Result<F, S> swap() {
+        return new Failure<>(this.value());
+    }
+
     /**
      * {@inheritDoc}
      *

diff --git a/common-types/src/test/java/io/carbynestack/common/result/ResultTest.java b/common-types/src/test/java/io/carbynestack/common/result/ResultTest.java
@@ -73,4 +73,13 @@ void result() {
         assertThat(res.toOptional()).isEmpty();
         assertThat(res.stream().toList()).isEmpty();
     }
+
+    @Test
+    void swap() {
+        var value = 12;
+        var res = new Success<Integer, Integer>(value);
+        assertThat(res.<Integer>fold(r -> -1, identity())).isEqualTo(value);
+        assertThat(res.swap().<Integer>fold(r -> -1, identity())).isEqualTo(-1);
+        assertThat(res.swap().swap().<Integer>fold(r -> -1, identity())).isEqualTo(value);
+    }
 }