Vendor extensions support

Author: quen2404

README.md

@@ -129,6 +129,11 @@ try {
 }
 ```
 
+### Extensions
+This project uses Java Service Provider Inteface (SPI) so additional extensions can be added. 
+
+To build your own extension, you simply need to create a `src/main/resources/META-INF/services/com.qdesrame.openapi.diff.compare.ExtensionDiff` file with the full classname of your implementation.  Your class must also implement the `com.qdesrame.openapi.diff.compare.ExtensionDiff` interface.  Then, including your library with the `openapi-diff` module will cause it to be triggered automatically.
+
 # Example
 ### CLI Output
 

src/main/java/com/qdesrame/openapi/diff/compare/ExtensionDiff.java

@@ -0,0 +1,15 @@
+package com.qdesrame.openapi.diff.compare;
+
+import com.qdesrame.openapi.diff.model.Changed;
+import com.qdesrame.openapi.diff.model.DiffContext;
+
+import java.util.Optional;
+
+public interface ExtensionDiff {
+
+    ExtensionDiff setOpenApiDiff(OpenApiDiff openApiDiff);
+
+    String getName();
+
+    Optional<Changed> diff(Object left, Object right, DiffContext context);
+}

src/main/java/com/qdesrame/openapi/diff/compare/ExtensionsDiff.java

@@ -0,0 +1,43 @@
+package com.qdesrame.openapi.diff.compare;
+
+import com.qdesrame.openapi.diff.model.DiffContext;
+import com.qdesrame.openapi.diff.model.schema.ChangedExtensions;
+
+import java.util.*;
+
+import static com.qdesrame.openapi.diff.utils.ChangedUtils.isChanged;
+
+public class ExtensionsDiff {
+    private final OpenApiDiff openApiDiff;
+
+    private ServiceLoader<ExtensionDiff> extensionsLoader = ServiceLoader.load(ExtensionDiff.class);
+    private List<ExtensionDiff> extensionsDiff = new ArrayList<>();
+
+    public ExtensionsDiff(OpenApiDiff openApiDiff) {
+        this.openApiDiff = openApiDiff;
+        this.extensionsLoader.reload();
+        for (ExtensionDiff anExtensionsLoader : this.extensionsLoader) {
+            extensionsDiff.add(anExtensionsLoader);
+        }
+    }
+
+    public Optional<ChangedExtensions> diff(Map<String, Object> left, Map<String, Object> right, DiffContext context) {
+        if (null == left) left = new HashMap<>();
+        if (null == right) right = new HashMap<>();
+        ChangedExtensions changedExtensions = new ChangedExtensions(left, new HashMap<>(right), context);
+        changedExtensions.getIncreased().putAll(right);
+        for (String key : left.keySet()) {
+            if (changedExtensions.getIncreased().containsKey(key)) {
+                Optional<ExtensionDiff> extensionDiff = extensionsDiff.stream()
+                        .filter(diff -> ("x-" + diff.getName()).equals(key)).findFirst();
+                Object leftValue = left.get(key);
+                Object rightValue = changedExtensions.getIncreased().remove(key);
+                extensionDiff.ifPresent(diff -> diff.setOpenApiDiff(openApiDiff).diff(leftValue, rightValue, context)
+                        .ifPresent(changed -> changedExtensions.getChanged().put(key, changed)));
+            } else {
+                changedExtensions.getMissing().put(key, left.get(key));
+            }
+        }
+        return isChanged(changedExtensions);
+    }
+}

src/main/java/com/qdesrame/openapi/diff/compare/OpenApiDiff.java

@@ -40,6 +40,7 @@ public class OpenApiDiff {
     private SecuritySchemeDiff securitySchemeDiff;
     private OAuthFlowsDiff oAuthFlowsDiff;
     private OAuthFlowDiff oAuthFlowDiff;
+    private ExtensionsDiff extensionsDiff;
 
     private OpenAPI oldSpecOpenApi;
     private OpenAPI newSpecOpenApi;
@@ -84,6 +85,7 @@ private void initializeFields() {
         this.securitySchemeDiff = new SecuritySchemeDiff(this);
         this.oAuthFlowsDiff = new OAuthFlowsDiff(this);
         this.oAuthFlowDiff = new OAuthFlowDiff(this);
+        this.extensionsDiff = new ExtensionsDiff(this);
     }
 
     private ChangedOpenApi compare() {
@@ -201,6 +203,10 @@ public OAuthFlowDiff getoAuthFlowDiff() {
         return oAuthFlowDiff;
     }
 
+    public ExtensionsDiff getExtensionsDiff() {
+        return extensionsDiff;
+    }
+
     public OpenAPI getOldSpecOpenApi() {
         return oldSpecOpenApi;
     }

src/main/java/com/qdesrame/openapi/diff/compare/schemadiffresult/SchemaDiffResult.java

@@ -5,6 +5,7 @@
 import com.qdesrame.openapi.diff.model.ChangedSchema;
 import com.qdesrame.openapi.diff.model.DiffContext;
 import com.qdesrame.openapi.diff.model.ListDiff;
+import com.qdesrame.openapi.diff.model.schema.ChangedExtensions;
 import com.qdesrame.openapi.diff.model.schema.ChangedReadOnly;
 import com.qdesrame.openapi.diff.model.schema.ChangedWriteOnly;
 import io.swagger.v3.oas.models.Components;
@@ -47,6 +48,8 @@ public Optional<ChangedSchema> diff(HashSet<String> refSet, Components leftCompo
         changedSchema.setChangedReadOnly(new ChangedReadOnly(context, left.getReadOnly(), right.getReadOnly()));
         changedSchema.setChangedWriteOnly(new ChangedWriteOnly(context, left.getWriteOnly(), right.getWriteOnly()));
         changedSchema.setChangedMaxLength(!Objects.equals(left.getMaxLength(), right.getMaxLength()));
+        Optional<ChangedExtensions> changedExtensions = openApiDiff.getExtensionsDiff().diff(left.getExtensions(), right.getExtensions(), context);
+        changedExtensions.ifPresent(changedSchema::setChangedExtensions);
 
         Map<String, Schema> leftProperties = null == left ? null : left.getProperties();
         Map<String, Schema> rightProperties = null == right ? null : right.getProperties();

src/main/java/com/qdesrame/openapi/diff/model/ChangedSchema.java

@@ -1,5 +1,6 @@
 package com.qdesrame.openapi.diff.model;
 
+import com.qdesrame.openapi.diff.model.schema.ChangedExtensions;
 import com.qdesrame.openapi.diff.model.schema.ChangedReadOnly;
 import com.qdesrame.openapi.diff.model.schema.ChangedWriteOnly;
 import com.qdesrame.openapi.diff.utils.ChangedUtils;
@@ -38,6 +39,7 @@ public class ChangedSchema implements Changed {
     protected boolean discriminatorPropertyChanged;
     protected ChangedOneOfSchema changedOneOfSchema;
     protected ChangedSchema addPropChangedSchema;
+    protected ChangedExtensions changedExtensions;
 
     public ChangedSchema() {
         increasedProperties = new HashMap<>();
@@ -53,7 +55,8 @@ public DiffResult isChanged() {
                 && !changeFormat && increasedProperties.size() == 0 && missingProperties.size() == 0
                 && changedProperties.values().size() == 0 && !changeDeprecated
                 && (changeRequired == null || changeRequired.isUnchanged()) && !discriminatorPropertyChanged
-                && ChangedUtils.isUnchanged(addPropChangedSchema) && ChangedUtils.isUnchanged(changedOneOfSchema)) {
+                && ChangedUtils.isUnchanged(addPropChangedSchema) && ChangedUtils.isUnchanged(changedOneOfSchema)
+                && ChangedUtils.isUnchanged(changedExtensions)) {
             return DiffResult.NO_CHANGES;
         }
         boolean backwardCompatibleForRequest = (changeEnum == null || changeEnum.getMissing().isEmpty()) &&
@@ -71,7 +74,8 @@ public DiffResult isChanged() {
         if ((context.isRequest() && backwardCompatibleForRequest || context.isResponse() && backwardCompatibleForResponse)
                 && !changedType && !discriminatorPropertyChanged && ChangedUtils.isCompatible(changedOneOfSchema)
                 && ChangedUtils.isCompatible(addPropChangedSchema)
-                && changedProperties.values().stream().allMatch(Changed::isCompatible)) {
+                && changedProperties.values().stream().allMatch(Changed::isCompatible)
+                && ChangedUtils.isCompatible(changedExtensions)) {
             return DiffResult.COMPATIBLE;
         }
 

src/main/java/com/qdesrame/openapi/diff/model/schema/ChangedExtensions.java

@@ -0,0 +1,42 @@
+package com.qdesrame.openapi.diff.model.schema;
+
+import com.qdesrame.openapi.diff.model.Changed;
+import com.qdesrame.openapi.diff.model.DiffContext;
+import com.qdesrame.openapi.diff.model.DiffResult;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+@Getter
+@Setter
+public class ChangedExtensions implements Changed {
+    private final Map<String, Object> oldExtensions;
+    private final Map<String, Object> newExtensions;
+    private final DiffContext context;
+
+    private Map<String, Object> increased;
+    private Map<String, Object> missing;
+    private Map<String, Changed> changed;
+
+    public ChangedExtensions(Map<String, Object> oldExtensions, Map<String, Object> newExtensions, DiffContext context) {
+        this.oldExtensions = oldExtensions;
+        this.newExtensions = newExtensions;
+        this.context = context;
+        this.increased = new LinkedHashMap<>();
+        this.missing = new LinkedHashMap<>();
+        this.changed = new LinkedHashMap<>();
+    }
+
+    @Override
+    public DiffResult isChanged() {
+        if (increased.isEmpty() && missing.isEmpty() && changed.isEmpty()) {
+            return DiffResult.NO_CHANGES;
+        }
+        if (changed.values().stream().allMatch(Changed::isCompatible)) {
+            return DiffResult.COMPATIBLE;
+        }
+        return DiffResult.INCOMPATIBLE;
+    }
+}