fix #461: add minlength breaking change detection

core/src/main/java/org/openapitools/openapidiff/core/compare/schemadiffresult/SchemaDiffResult.java

@@ -66,6 +66,7 @@ public <V extends Schema<X>, X> DeferredChanged<ChangedSchema> diff(
         .setReadOnly(new ChangedReadOnly(left.getReadOnly(), right.getReadOnly(), context))
         .setWriteOnly(new ChangedWriteOnly(left.getWriteOnly(), right.getWriteOnly(), context))
         .setMaxLength(new ChangedMaxLength(left.getMaxLength(), right.getMaxLength(), context))
+        .setMinLength(new ChangedMinLength(left.getMinLength(), right.getMinLength(), context))
         .setNumericRange(
             new ChangedNumericRange(
                 left.getMinimum(),

core/src/main/java/org/openapitools/openapidiff/core/model/BackwardIncompatibleProp.java

@@ -14,6 +14,7 @@ public enum BackwardIncompatibleProp {
   REQUEST_CONTENT_DECREASED("incompatible.request.content.decreased", true),
   REQUEST_ENUM_DECREASED("incompatible.request.enum.decreased", true),
   REQUEST_MAX_LENGTH_DECREASED("incompatible.request.max.length.decreased", true),
+  REQUEST_MIN_LENGTH_INCREASED("incompatible.request.min.length.increased", true),
   REQUEST_NUMERIC_RANGE_DECREASED("incompatible.request.numeric.range.decreased", true),
   REQUEST_ONEOF_DECREASED("incompatible.request.oneof.decreased", true),
   REQUEST_PARAM_ALLOWEMPTY_DECREASED("incompatible.request.param.allowempty.decreased", true),
@@ -31,6 +32,7 @@ public enum BackwardIncompatibleProp {
   RESPONSE_HEADER_REQUIRED_INCREASED("incompatible.response.header.required.increased", true),
   RESPONSE_HEADERS_DECREASED("incompatible.response.headers.decreased", true),
   RESPONSE_MAX_LENGTH_INCREASED("incompatible.response.max.length.increased", true),
+  RESPONSE_MIN_LENGTH_INCREASED("incompatible.response.min.length.increased", true),
   RESPONSE_NUMERIC_RANGE_INCREASED("incompatible.response.numeric.range.increased", false),
   RESPONSE_ONEOF_INCREASED("incompatible.response.oneof.increased", true),
   RESPONSE_REQUIRED_DECREASED("incompatible.response.required.decreased", true),

core/src/main/java/org/openapitools/openapidiff/core/model/ChangedSchema.java

@@ -17,6 +17,7 @@
 import org.openapitools.openapidiff.core.model.schema.ChangedMaxLength;
 import org.openapitools.openapidiff.core.model.schema.ChangedMaxProperties;
 import org.openapitools.openapidiff.core.model.schema.ChangedMinItems;
+import org.openapitools.openapidiff.core.model.schema.ChangedMinLength;
 import org.openapitools.openapidiff.core.model.schema.ChangedMinProperties;
 import org.openapitools.openapidiff.core.model.schema.ChangedMultipleOf;
 import org.openapitools.openapidiff.core.model.schema.ChangedNullable;
@@ -49,6 +50,7 @@ public class ChangedSchema implements ComposedChanged {
   protected ChangedWriteOnly writeOnly;
   protected boolean changedType;
   protected ChangedMaxLength maxLength;
+  protected ChangedMinLength minLength;
   protected ChangedNumericRange numericRange;
   protected ChangedMultipleOf multipleOf;
   protected ChangedMaxItems maxItems;
@@ -139,6 +141,7 @@ public List<Changed> getChangedElements() {
                       enumeration,
                       required,
                       maxLength,
+                      minLength,
                       numericRange,
                       multipleOf,
                       maxItems,
@@ -303,6 +306,10 @@ public ChangedMaxLength getMaxLength() {
     return this.maxLength;
   }
 
+  public ChangedMinLength getMinLength() {
+    return this.minLength;
+  }
+
   public ChangedNumericRange getNumericRange() {
     return this.numericRange;
   }
@@ -475,6 +482,12 @@ public ChangedSchema setMaxLength(final ChangedMaxLength maxLength) {
     return this;
   }
 
+  public ChangedSchema setMinLength(final ChangedMinLength minLength) {
+    clearChangedCache();
+    this.minLength = minLength;
+    return this;
+  }
+
   public ChangedSchema setNumericRange(final ChangedNumericRange numericRange) {
     clearChangedCache();
     this.numericRange = numericRange;
@@ -585,6 +598,7 @@ public boolean equals(Object o) {
         && Objects.equals(readOnly, that.readOnly)
         && Objects.equals(writeOnly, that.writeOnly)
         && Objects.equals(maxLength, that.maxLength)
+        && Objects.equals(minLength, that.minLength)
         && Objects.equals(numericRange, that.numericRange)
         && Objects.equals(multipleOf, that.multipleOf)
         && Objects.equals(maxItems, that.maxItems)
@@ -623,6 +637,7 @@ public int hashCode() {
         writeOnly,
         changedType,
         maxLength,
+        minLength,
         numericRange,
         multipleOf,
         maxItems,
@@ -681,6 +696,8 @@ public java.lang.String toString() {
         + this.isChangedType()
         + ", maxLength="
         + this.getMaxLength()
+        + ", minLength="
+        + this.getMinLength()
         + ", numericRange="
         + this.getNumericRange()
         + ", multipleOf="

core/src/main/java/org/openapitools/openapidiff/core/model/schema/ChangedMinLength.java

@@ -0,0 +1,78 @@
+package org.openapitools.openapidiff.core.model.schema;
+
+import static org.openapitools.openapidiff.core.model.BackwardIncompatibleProp.REQUEST_MIN_LENGTH_INCREASED;
+import static org.openapitools.openapidiff.core.model.BackwardIncompatibleProp.RESPONSE_MIN_LENGTH_INCREASED;
+
+import java.util.Objects;
+import org.openapitools.openapidiff.core.model.Changed;
+import org.openapitools.openapidiff.core.model.DiffContext;
+import org.openapitools.openapidiff.core.model.DiffResult;
+
+public final class ChangedMinLength implements Changed {
+  private final Integer oldValue;
+  private final Integer newValue;
+  private final DiffContext context;
+
+  @Override
+  public DiffResult isChanged() {
+    if (Objects.equals(oldValue, newValue)) {
+      return DiffResult.NO_CHANGES;
+    }
+    if (context.isRequest() && (newValue != null && (oldValue == null || newValue > oldValue))) {
+      if (REQUEST_MIN_LENGTH_INCREASED.enabled(context)) {
+        return DiffResult.INCOMPATIBLE;
+      }
+    }
+    if (context.isResponse() && (newValue != null && (oldValue == null || newValue > oldValue))) {
+      if (RESPONSE_MIN_LENGTH_INCREASED.enabled(context)) {
+        return DiffResult.INCOMPATIBLE;
+      }
+    }
+    return DiffResult.COMPATIBLE;
+  }
+
+  public ChangedMinLength(
+      final Integer oldValue, final Integer newValue, final DiffContext context) {
+    this.oldValue = oldValue;
+    this.newValue = newValue;
+    this.context = context;
+  }
+
+  public Integer getOldValue() {
+    return this.oldValue;
+  }
+
+  public Integer getNewValue() {
+    return this.newValue;
+  }
+
+  public DiffContext getContext() {
+    return this.context;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    ChangedMinLength that = (ChangedMinLength) o;
+    return Objects.equals(oldValue, that.oldValue)
+        && Objects.equals(newValue, that.newValue)
+        && Objects.equals(context, that.context);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(oldValue, newValue, context);
+  }
+
+  @Override
+  public String toString() {
+    return "ChangedMinLength(oldValue="
+        + this.getOldValue()
+        + ", newValue="
+        + this.getNewValue()
+        + ", context="
+        + this.getContext()
+        + ")";
+  }
+}

core/src/test/java/org/openapitools/openapidiff/core/backcompat/MinLengthBCTest.java

@@ -0,0 +1,30 @@
+package org.openapitools.openapidiff.core.backcompat;
+
+import static org.openapitools.openapidiff.core.TestUtils.assertSpecIncompatible;
+import static org.openapitools.openapidiff.core.TestUtils.assertSpecUnchanged;
+import static org.openapitools.openapidiff.core.model.BackwardIncompatibleProp.REQUEST_MIN_LENGTH_INCREASED;
+import static org.openapitools.openapidiff.core.model.BackwardIncompatibleProp.RESPONSE_MIN_LENGTH_INCREASED;
+
+import org.junit.jupiter.api.Test;
+import org.openapitools.openapidiff.core.model.BackwardIncompatibleProp;
+
+public class MinLengthBCTest {
+  private final String BASE = "bc_minlength_base.yaml";
+
+  @Test
+  public void minLengthUnchanged() {
+    assertSpecUnchanged(BASE, BASE);
+  }
+
+  @Test
+  public void requestMinLengthIncreased() {
+    BackwardIncompatibleProp prop = REQUEST_MIN_LENGTH_INCREASED;
+    assertSpecIncompatible(BASE, "bc_request_minlength_increased.yaml", prop);
+  }
+
+  @Test
+  public void responseMinLengthIncreased() {
+    BackwardIncompatibleProp prop = RESPONSE_MIN_LENGTH_INCREASED;
+    assertSpecIncompatible(BASE, "bc_response_minlength_increased.yaml", prop);
+  }
+}

core/src/test/resources/bc_minlength_base.yaml

@@ -0,0 +1,30 @@
+openapi: 3.0.0
+info:
+  description: myDesc
+  title: myTitle
+  version: 1.0.0
+paths:
+  /widgets:
+    post:
+      operationId: widgetCreate
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: string
+              minLength: 5
+          application/xml:
+            schema:
+              type: string
+      responses:
+        '200':
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                type: string
+                minLength: 5
+            application/xml:
+              schema:
+                type: string
+

core/src/test/resources/bc_request_minlength_increased.yaml

@@ -0,0 +1,31 @@
+openapi: 3.0.0
+info:
+  description: myDesc
+  title: myTitle
+  version: 1.0.0
+paths:
+  /widgets:
+    post:
+      operationId: widgetCreate
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: string
+              minLength: 10
+          application/xml:
+            schema:
+              type: string
+              minLength: 10
+      responses:
+        '200':
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                type: string
+                minLength: 5
+            application/xml:
+              schema:
+                type: string
+

core/src/test/resources/bc_response_minlength_increased.yaml

@@ -0,0 +1,31 @@
+openapi: 3.0.0
+info:
+  description: myDesc
+  title: myTitle
+  version: 1.0.0
+paths:
+  /widgets:
+    post:
+      operationId: widgetCreate
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: string
+              minLength: 5
+          application/xml:
+            schema:
+              type: string
+      responses:
+        '200':
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                type: string
+                minLength: 10
+            application/xml:
+              schema:
+                type: string
+                minLength: 10
+