chore: further code health refactoring

jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/FieldScope.java

@@ -126,7 +126,8 @@ private MethodScope doFindGetter() {
         possibleGetterNames.add("get" + capitalisedFieldName);
         possibleGetterNames.add("is" + capitalisedFieldName);
         // @since 4.32.0 - for a field like "isBool" also consider "isBool()" as potential getter method
-        if (declaredName.startsWith("is") && declaredName.length() > 2 && Character.isUpperCase(declaredName.charAt(2))) {
+        boolean fieldNameStartsWithIs = declaredName.startsWith("is") && declaredName.length() > 2 && Character.isUpperCase(declaredName.charAt(2));
+        if (fieldNameStartsWithIs) {
             possibleGetterNames.add(declaredName);
         }
         ResolvedMethod[] methods = this.getDeclaringTypeMembers().getMemberMethods();

jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/MemberScope.java

@@ -445,9 +445,11 @@ public <A extends Annotation> A getContainerItemAnnotationConsideringFieldAndGet
         if (this.isFakeContainerItemScope()) {
             return this.getContainerItemAnnotationConsideringFieldAndGetter(annotationClass, considerOtherAnnotation);
         }
-        if (this.getOverriddenType() != null
-                && this.getDeclaredType().getErasedType() == Optional.class
-                && this.getOverriddenType().getErasedType() == this.getDeclaredType().getTypeParameters().get(0).getErasedType()) {
+        // in addition to an explicitly marked "faked container item scope", also support a type wrapped in an Optional
+        if (this.getOverriddenType() == null || this.getDeclaredType().getErasedType() != Optional.class) {
+            return null;
+        }
+        if (this.getOverriddenType().getErasedType() == this.getDeclaredType().getTypeParameters().get(0).getErasedType()) {
             return this.getContainerItemAnnotationConsideringFieldAndGetter(annotationClass, considerOtherAnnotation);
         }
         return null;

jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/MethodScope.java

@@ -126,17 +126,18 @@ public FieldScope findGetterField() {
      * @return associated field
      */
     private FieldScope doFindGetterField() {
-        if (this.getType() == null || !this.isPublic() || this.getArgumentCount() > 0) {
-            // void and non-public methods or those with arguments are not deemed to be getters
+        if (this.getType() == null || this.getArgumentCount() > 0) {
+            // void methods or those with arguments are not deemed to be getters
             return null;
         }
-        String methodName = this.getDeclaredName();
-        Set<String> possibleFieldNames = new HashSet<>(3);
-        if (methodName.startsWith("get")) {
-            getPossibleFieldNamesStartingWithGet(methodName, possibleFieldNames);
-        } else if (methodName.startsWith("is")) {
-            getPossibleFieldNamesStartingWithIs(methodName, possibleFieldNames);
+        if (!this.isPublic()) {
+            // only public methods are deemed eligible to be getters
+            return null;
         }
+        String methodName = this.getDeclaredName();
+        Set<String> possibleFieldNames = Stream.of("get", "is")
+                .flatMap(prefix -> getPossibleFieldNames(prefix, methodName))
+                .collect(Collectors.toSet());
         if (possibleFieldNames.isEmpty()) {
             // method name does not fall into getter conventions
             return null;
@@ -150,28 +151,25 @@ private FieldScope doFindGetterField() {
                 .orElse(null);
     }
 
-    private static void getPossibleFieldNamesStartingWithGet(String methodName, Set<String> possibleFieldNames) {
-        if (methodName.length() > 3 && Character.isUpperCase(methodName.charAt(3))) {
-            // ensure that the variable starts with a lower-case letter
-            possibleFieldNames.add(methodName.substring(3, 4).toLowerCase() + methodName.substring(4));
+    private static Stream<String> getPossibleFieldNames(String prefix, String methodName) {
+        if (!methodName.startsWith(prefix) || prefix.length() == methodName.length()) {
+            return Stream.of();
         }
-        // @since 4.32.0 - conforming with JavaBeans API specification edge case when second character in field name is in uppercase
-        if (methodName.length() > 4 && Character.isUpperCase(methodName.charAt(4))) {
-            possibleFieldNames.add(methodName.substring(3));
-        }
-    }
-
-    private static void getPossibleFieldNamesStartingWithIs(String methodName, Set<String> possibleFieldNames) {
-        if (methodName.length() > 2 && Character.isUpperCase(methodName.charAt(2))) {
+        Stream.Builder<String> possibleFieldNames = Stream.builder();
+        String methodNameWithoutPrefix = methodName.substring(prefix.length());
+        if (Character.isUpperCase(methodNameWithoutPrefix.charAt(0))) {
             // ensure that the variable starts with a lower-case letter
-            possibleFieldNames.add(methodName.substring(2, 3).toLowerCase() + methodName.substring(3));
-            // since 4.32.0: a method "isBool()" is considered a possible getter for a field "isBool" as well as for "bool"
-            possibleFieldNames.add(methodName);
+            possibleFieldNames.add(methodNameWithoutPrefix.substring(0, 1).toLowerCase() + methodNameWithoutPrefix.substring(1));
+            if ("is".equals(prefix)) {
+                // since 4.32.0: a method "isBool()" is considered a possible getter for a field "isBool" as well as for "bool"
+                possibleFieldNames.add(methodName);
+            }
         }
         // @since 4.32.0 - conforming with JavaBeans API specification edge case when second character in field name is in uppercase
-        if (methodName.length() > 3 && Character.isUpperCase(methodName.charAt(3))) {
-            possibleFieldNames.add(methodName.substring(2));
+        if (methodNameWithoutPrefix.length() > 1 && Character.isUpperCase(methodNameWithoutPrefix.charAt(1))) {
+            possibleFieldNames.add(methodNameWithoutPrefix);
         }
+        return possibleFieldNames.build();
     }
 
     /**
@@ -213,7 +211,9 @@ public <A extends Annotation> A getAnnotationConsideringFieldAndGetter(Class<A>
         A annotation = this.getAnnotation(annotationClass, considerOtherAnnotation);
         if (annotation == null) {
             MemberScope<?, ?> associatedField = this.findGetterField();
-            annotation = associatedField == null ? null : associatedField.getAnnotation(annotationClass, considerOtherAnnotation);
+            if (associatedField != null) {
+                annotation = associatedField.getAnnotation(annotationClass, considerOtherAnnotation);
+            }
         }
         return annotation;
     }
@@ -224,7 +224,9 @@ public <A extends Annotation> A getContainerItemAnnotationConsideringFieldAndGet
         A annotation = this.getContainerItemAnnotation(annotationClass, considerOtherAnnotation);
         if (annotation == null) {
             MemberScope<?, ?> associatedField = this.findGetterField();
-            annotation = associatedField == null ? null : associatedField.getContainerItemAnnotation(annotationClass, considerOtherAnnotation);
+            if (associatedField != null) {
+                annotation = associatedField.getContainerItemAnnotation(annotationClass, considerOtherAnnotation);
+            }
         }
         return annotation;
     }
@@ -239,21 +241,19 @@ public <A extends Annotation> A getContainerItemAnnotationConsideringFieldAndGet
     @Override
     protected String doGetSchemaPropertyName() {
         String result = this.getName();
-        if (this.getContext().isDerivingFieldsFromArgumentFreeMethods() && this.getArgumentCount() == 0) {
-            if (this.getOverriddenName() == null) {
-                // remove the "get"/"is" prefix from non-overridden method names
-                if (result.startsWith("get") && result.length() > 3) {
-                    result = Character.toLowerCase(result.charAt(3)) + result.substring(4);
-                } else if (result.startsWith("is") && result.length() > 2) {
-                    result = Character.toLowerCase(result.charAt(2)) + result.substring(3);
-                } else {
-                    result += "()";
-                }
-            }
-        } else {
+        if (!this.getContext().isDerivingFieldsFromArgumentFreeMethods() || this.getArgumentCount() > 0) {
             result += this.getArgumentTypes().stream()
                     .map(this.getContext()::getMethodPropertyArgumentTypeDescription)
                     .collect(Collectors.joining(", ", "(", ")"));
+        } else if (this.getOverriddenName() == null) {
+            // remove the "get"/"is" prefix from non-overridden method names
+            if (result.startsWith("get") && result.length() > 3) {
+                result = Character.toLowerCase(result.charAt(3)) + result.substring(4);
+            } else if (result.startsWith("is") && result.length() > 2) {
+                result = Character.toLowerCase(result.charAt(2)) + result.substring(3);
+            } else {
+                result += "()";
+            }
         }
         return result;
     }

jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/TypeContext.java

@@ -32,6 +32,7 @@
 import java.util.List;
 import java.util.Optional;
 import java.util.WeakHashMap;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -188,10 +189,15 @@ public TypeScope createTypeScope(ResolvedType type) {
      */
     public ResolvedType getTypeParameterFor(ResolvedType type, Class<?> erasedSuperType, int parameterIndex) {
         List<ResolvedType> typeParameters = type.typeParametersFor(erasedSuperType);
-        if (typeParameters == null
-                || (!typeParameters.isEmpty() && typeParameters.size() <= parameterIndex)
-                || (typeParameters.isEmpty() && erasedSuperType.getTypeParameters().length <= parameterIndex)) {
-            // given type is not a super type of the type in scope or given index is out of bounds
+        if (typeParameters == null) {
+            // given type is not a super type of the type in scope
+            return null;
+        }
+        if (!typeParameters.isEmpty() && typeParameters.size() <= parameterIndex) {
+            // given index is out of bounds for the specific type
+        }
+        if (typeParameters.isEmpty() && erasedSuperType.getTypeParameters().length <= parameterIndex) {
+            // given index is out of bounds for the designated super type
             return null;
         }
         if (typeParameters.isEmpty()) {
@@ -441,4 +447,27 @@ private String getTypeDescription(ResolvedType type, boolean simpleClassNames) {
     public String getMethodPropertyArgumentTypeDescription(ResolvedType type) {
         return this.getSimpleTypeDescription(type);
     }
+
+    /**
+     * Helper function to write generic code that targets either a {@link FieldScope} or {@link MethodScope}.
+     *
+     * @param <R> type of expected return value
+     * @param member field or method being targeted
+     * @param fieldAction action to perform in case the given member is a {@link FieldScope}
+     * @param methodAction action to perform in case the given member is a {@link MethodScope}
+     * @return value returned by the performed action
+     * @throws IllegalStateException if given member is neither a {@link FieldScope} or {@link MethodScope}
+     */
+    public <R> R performActionOnMember(MemberScope<?, ?> member, Function<FieldScope, R> fieldAction,
+            Function<MethodScope, R> methodAction) {
+        R result;
+        if (member instanceof FieldScope) {
+            result = fieldAction.apply((FieldScope) member);
+        } else if (member instanceof MethodScope) {
+            result = methodAction.apply((MethodScope) member);
+        } else {
+            throw new IllegalStateException("Unsupported member scope of type: " + member.getClass());
+        }
+        return result;
+    }
 }