From e4e62da7405f53288d64416d2835ac69cc11986f Mon Sep 17 00:00:00 2001
From: Ulli Hafner <ullrich.hafner@gmail.com>
Date: Wed, 7 Apr 2021 17:44:18 +0200
Subject: [PATCH] Add an architecture test that checks exception raising.

When a new exception is raised then the no-arg constructor
of the exception must never be called. Otherwise the context
of the failure is missing.
---
 .../edu/hm/hafner/util/ArchitectureRules.java | 21 +++++++++++++++++++
 .../edu/hm/hafner/util/ArchitectureTest.java  |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/src/test/java/edu/hm/hafner/util/ArchitectureRules.java b/src/test/java/edu/hm/hafner/util/ArchitectureRules.java
index c081d3c2..45a4494c 100644
--- a/src/test/java/edu/hm/hafner/util/ArchitectureRules.java
+++ b/src/test/java/edu/hm/hafner/util/ArchitectureRules.java
@@ -8,7 +8,9 @@
 import org.junit.jupiter.params.ParameterizedTest;
 
 import com.tngtech.archunit.base.DescribedPredicate;
+import com.tngtech.archunit.core.domain.AccessTarget.ConstructorCallTarget;
 import com.tngtech.archunit.core.domain.JavaCall;
+import com.tngtech.archunit.core.domain.JavaConstructorCall;
 import com.tngtech.archunit.core.domain.JavaModifier;
 import com.tngtech.archunit.core.domain.properties.CanBeAnnotated;
 import com.tngtech.archunit.junit.ArchTest;
@@ -27,6 +29,10 @@ private ArchitectureRules() {
         // prevents instantiation
     }
 
+    /** Never create exception without any context. */
+    public static final ArchRule NO_EXCEPTIONS_WITH_NO_ARG_CONSTRUCTOR =
+            noClasses().should().callConstructorWhere(new ExceptionHasNoContext());
+
     /** Junit 5 test classes should not be public. */
     public static final ArchRule NO_PUBLIC_TEST_CLASSES =
             noClasses().that().haveSimpleNameEndingWith("Test")
@@ -124,4 +130,19 @@ public boolean apply(final JavaCall<?> input) {
                     && !"assertTimeoutPreemptively".equals(input.getName());
         }
     }
+
+    private static class ExceptionHasNoContext extends DescribedPredicate<JavaConstructorCall> {
+        ExceptionHasNoContext() {
+            super("exception context is missing");
+        }
+
+        @Override
+        public boolean apply(final JavaConstructorCall javaConstructorCall) {
+            ConstructorCallTarget target = javaConstructorCall.getTarget();
+            if (target.getRawParameterTypes().size() > 0) {
+                return false;
+            }
+            return target.getOwner().isAssignableTo(Throwable.class);
+        }
+    }
 }
diff --git a/src/test/java/edu/hm/hafner/util/ArchitectureTest.java b/src/test/java/edu/hm/hafner/util/ArchitectureTest.java
index 7af1d4e5..ec37de92 100644
--- a/src/test/java/edu/hm/hafner/util/ArchitectureTest.java
+++ b/src/test/java/edu/hm/hafner/util/ArchitectureTest.java
@@ -32,4 +32,7 @@ class ArchitectureTest {
 
     @ArchTest
     static final ArchRule NO_FORBIDDEN_ANNOTATION_USED = ArchitectureRules.NO_FORBIDDEN_ANNOTATION_USED;
+
+    @ArchTest
+    static final ArchRule NO_EXCEPTIONS_WITH_NO_ARG_CONSTRUCTOR = ArchitectureRules.NO_EXCEPTIONS_WITH_NO_ARG_CONSTRUCTOR;
 }