annot: flag @mc* setters which have a non-void return type as an error #2862 (#2864)

Author: christiangoerdes

annot/src/main/java/com/predic8/membrane/annot/SpringConfigurationXSDGeneratingAnnotationProcessor.java

@@ -461,6 +461,7 @@ private void scan(MainInfo main, ElementInfo ii, TypeElement te) {
             scan(main, ii, (TypeElement) ((DeclaredType) superclass).asElement());
 
         for (Element e2 : te.getEnclosedElements()) {
+            validateMcSetterReturnType(e2);
             MCAttribute a = e2.getAnnotation(MCAttribute.class);
             if (a != null) {
                 AttributeInfo ai = new AttributeInfo();
@@ -530,6 +531,28 @@ private void scan(MainInfo main, ElementInfo ii, TypeElement te) {
         Collections.sort(ii.getChildElementSpecs());
     }
 
+    private void validateMcSetterReturnType(Element e2) {
+        if (!(e2 instanceof ExecutableElement executableElement))
+            return;
+        String annotationName = getMcSetterAnnotationName(e2);
+        if (annotationName == null)
+            return;
+        if (executableElement.getReturnType().getKind() != TypeKind.VOID)
+            throw new ProcessingException("Setter annotated with @" + annotationName + " must return void.", e2);
+    }
+
+    private String getMcSetterAnnotationName(Element e2) {
+        if (e2.getAnnotation(MCAttribute.class) != null)
+            return "MCAttribute";
+        if (e2.getAnnotation(MCChildElement.class) != null)
+            return "MCChildElement";
+        if (e2.getAnnotation(MCTextContent.class) != null)
+            return "MCTextContent";
+        if (e2.getAnnotation(MCOtherAttributes.class) != null)
+            return "MCOtherAttributes";
+        return null;
+    }
+
     private boolean isRequired(Element e2) {
         for (AnnotationMirror am : e2.getAnnotationMirrors())
             if (((TypeElement) am.getAnnotationType().asElement()).getQualifiedName().toString().equals(REQUIRED))
@@ -581,4 +604,4 @@ private void validateEnumConstantsUppercase(TypeElement enumType) {
             }
         }
     }
-}
+}

annot/src/test/java/com/predic8/membrane/annot/SpringConfigXSDErrorsTest.java

@@ -355,4 +355,22 @@ public class Child2 extends AbstractDemoChildElement {
         ), result);
     }
 
+    @Test
+    public void mcSetterMustReturnVoid() {
+        var sources = splitSources(MC_MAIN_DEMO + """
+        package com.predic8.membrane.demo;
+        import com.predic8.membrane.annot.*;
+        @MCElement(name="demo")
+        public class DemoElement {
+            @MCAttribute
+            public String setName(String name) { return name; }
+        }
+        """);
+        var result = CompilerHelper.compile(sources, false);
+
+        assertCompilerResult(false, of(
+                error("Setter annotated with @MCAttribute must return void.")
+        ), result);
+    }
+
 }

core/src/main/java/com/predic8/membrane/core/interceptor/jwt/HeaderJwtRetriever.java

@@ -51,18 +51,16 @@ public String getHeader() {
 
     @Required
     @MCAttribute
-    public HeaderJwtRetriever setHeader(String header) {
+    public void setHeader(String header) {
         this.header = header;
-        return this;
     }
 
     public String getRemoveFromValue() {
         return removeFromValue;
     }
 
     @MCAttribute
-    public HeaderJwtRetriever setRemoveFromValue(String removeFromValue) {
+    public void setRemoveFromValue(String removeFromValue) {
         this.removeFromValue = removeFromValue;
-        return this;
     }
 }

core/src/main/java/com/predic8/membrane/core/interceptor/jwt/Jwks.java

@@ -100,13 +100,12 @@ public List<Jwk> getJwks() {
     }
 
     @MCChildElement
-    public Jwks setJwks(List<Jwk> jwks) {
+    public void setJwks(List<Jwk> jwks) {
         if (router != null) {  // set in init, so we can't update prior to that call
             if (jwks == null) throw new ConfigurationException("JWKs list must not be null.");
             this.keysByKid = buildKeyMap(jwks);
         }
         this.jwks = (jwks == null) ? emptyList() : jwks;  // unnecessary, mainly for consistency when debugging
-        return this;
     }
 
     public String getJwksUris() {
@@ -232,9 +231,8 @@ public String getKid() {
         }
 
         @MCAttribute
-        public Jwk setKid(String kid) {
+        public void setKid(String kid) {
             this.kid = kid;
-            return this;
         }
 
         /**

core/src/main/java/com/predic8/membrane/core/interceptor/jwt/JwtAuthInterceptor.java

@@ -197,9 +197,8 @@ public String getExpectedTid() {
      * <p>Use "any!!" to allow any audience value. This is strongly discouraged.</p>
      */
     @MCAttribute
-    public JwtAuthInterceptor setExpectedAud(String expectedAud) {
+    public void setExpectedAud(String expectedAud) {
         this.expectedAud = expectedAud;
-        return this;
     }
 
     /**
@@ -209,9 +208,8 @@ public JwtAuthInterceptor setExpectedAud(String expectedAud) {
      * @example 67c869d3-0cd4-4a99-86db-088bed1a9601
      */
     @MCAttribute
-    public JwtAuthInterceptor setExpectedTid(String expectedTid) {
+    public void setExpectedTid(String expectedTid) {
         this.expectedTid = expectedTid;
-        return this;
     }
 
     @Override

core/src/main/java/com/predic8/membrane/core/interceptor/ntlm/NtlmInterceptor.java

@@ -156,9 +156,8 @@ private void prepareStreamByEmptyingIt(Exchange exc) {
     }
 
     @MCChildElement(order = 1)
-    public NtlmInterceptor setNTLMRetriever(NTLMRetriever NTLMRetriever) {
+    public void setNTLMRetriever(NTLMRetriever NTLMRetriever) {
         this.NTLMRetriever = NTLMRetriever;
-        return this;
     }
 
     public NTLMRetriever getNTLMRetriever() {

core/src/main/java/com/predic8/membrane/core/interceptor/session/SessionManager.java

@@ -437,9 +437,8 @@ public boolean isSecure() {
      * @default false
      */
     @MCAttribute
-    public SessionManager setSecure(boolean secure) {
+    public void setSecure(boolean secure) {
         this.secure = secure;
-        return this;
     }
 
     public boolean isSessionCookie() {
@@ -451,9 +450,8 @@ public boolean isSessionCookie() {
      * @default false
      */
     @MCAttribute
-    public SessionManager setSessionCookie(boolean sessionCookie) {
+    public void setSessionCookie(boolean sessionCookie) {
         this.sessionCookie = sessionCookie;
-        return this;
     }
 
     protected String getKeyOfCookie(String validCookie) {