feat(dropdown): support minLength/maxLength/pattern on single-select drop-down

bundles/af-core/src/main/java/com/adobe/cq/forms/core/components/internal/models/v1/form/DropDownImpl.java

@@ -22,6 +22,7 @@
 import org.apache.sling.models.annotations.Model;
 import org.apache.sling.models.annotations.injectorspecific.InjectionStrategy;
 import org.apache.sling.models.annotations.injectorspecific.ValueMapValue;
+import org.jetbrains.annotations.Nullable;
 
 import com.adobe.cq.export.json.ComponentExporter;
 import com.adobe.cq.export.json.ExporterConstants;
@@ -44,6 +45,10 @@ public class DropDownImpl extends AbstractOptionsFieldImpl implements DropDown {
     @Default(booleanValues = false)
     protected boolean multiSelect;
 
+    @ValueMapValue(injectionStrategy = InjectionStrategy.OPTIONAL, name = ReservedProperties.PN_PATTERN)
+    @Nullable
+    protected String pattern;
+
     @Override
     public Integer getMinItems() {
         return minItems;
@@ -87,4 +92,34 @@ public Type getType() {
     public String getFieldType() {
         return super.getFieldType(FieldType.DROP_DOWN);
     }
+
+    /**
+     * String length/pattern constraints are only meaningful for a single-select (string-typed) drop-down,
+     * e.g. a searchable drop-down where {@code enforceEnum} is disabled and free text is allowed. For a
+     * multi-select drop-down the value type is an array, so these constraints are not applicable and are
+     * omitted from the model (mirroring the runtime, which strips them for non-string types).
+     */
+    @Override
+    public Integer getMinLength() {
+        return isMultiSelect() ? null : minLength;
+    }
+
+    @Override
+    public Integer getMaxLength() {
+        return isMultiSelect() ? null : maxLength;
+    }
+
+    @Override
+    public String getPattern() {
+        return isMultiSelect() ? null : pattern;
+    }
+
+    /**
+     * Drop-down does not support the {@code format} string constraint (there is no authorable format for an
+     * enumerated field), so this always returns {@code null} and is omitted from the exported model.
+     */
+    @Override
+    public String getFormat() {
+        return null;
+    }
 }

bundles/af-core/src/main/java/com/adobe/cq/forms/core/components/models/form/DropDown.java

@@ -25,7 +25,7 @@
  * @since com.adobe.cq.forms.core.components.models.form 2.0.0
  */
 @ConsumerType
-public interface DropDown extends Field, OptionsConstraint, ContainerConstraint {
+public interface DropDown extends Field, OptionsConstraint, ContainerConstraint, StringConstraint {
 
     /**
      * Returns {@code true} if multiple items can be selected in dropdown, {@code false} otherwise

bundles/af-core/src/test/java/com/adobe/cq/forms/core/components/internal/models/v1/form/DropDownImplTest.java

@@ -56,6 +56,7 @@ public class DropDownImplTest {
     private static final String PATH_MULTISELECT_DROPDOWN = CONTENT_ROOT + "/multiselect-dropdown";
     private static final String PATH_MULTISELECT_DROPDOWN_WITH_VARIANT_PROPERTY = CONTENT_ROOT + "/multiselect-dropdown-2";
     private static final String PATH_DROPDOWN2 = CONTENT_ROOT + "/dropdown2";
+    private static final String PATH_SEARCHABLE_DROPDOWN = CONTENT_ROOT + "/searchable-dropdown";
 
     private static final String PATH_DROPDOWN = CONTENT_ROOT + "/dropdown";
     private static final String PATH_DROPDOWN_DATALAYER = CONTENT_ROOT + "/dropdown-datalayer";
@@ -287,6 +288,38 @@ void testMultiSelectJSONExport() throws Exception {
         Utils.testJSONExport(dropdown, Utils.getTestExporterJSONPath(BASE, PATH_MULTISELECT_DROPDOWN));
     }
 
+    @Test
+    void testStringConstraintsForSingleSelect() {
+        DropDown dropdown = Utils.getComponentUnderTest(PATH_SEARCHABLE_DROPDOWN, DropDown.class, context);
+        assertFalse(dropdown.isMultiSelect());
+        assertEquals(Integer.valueOf(2), dropdown.getMinLength());
+        assertEquals(Integer.valueOf(10), dropdown.getMaxLength());
+        assertEquals("[a-z]+", dropdown.getPattern());
+    }
+
+    @Test
+    void testStringConstraintsNullForMultiSelect() {
+        // authored minLength/maxLength/pattern must be dropped for a multi-select (array-typed) drop-down
+        DropDown dropdown = Utils.getComponentUnderTest(PATH_MULTISELECT_DROPDOWN, DropDown.class, context);
+        assertTrue(dropdown.isMultiSelect());
+        assertNull(dropdown.getMinLength());
+        assertNull(dropdown.getMaxLength());
+        assertNull(dropdown.getPattern());
+    }
+
+    @Test
+    void testGetPatternDefault() {
+        DropDown dropdownMock = Mockito.mock(DropDown.class);
+        Mockito.when(dropdownMock.getPattern()).thenCallRealMethod();
+        assertNull(dropdownMock.getPattern());
+    }
+
+    @Test
+    void testSearchableDropdownJSONExport() throws Exception {
+        DropDown dropdown = Utils.getComponentUnderTest(PATH_SEARCHABLE_DROPDOWN, DropDown.class, context);
+        Utils.testJSONExport(dropdown, Utils.getTestExporterJSONPath(BASE, PATH_SEARCHABLE_DROPDOWN));
+    }
+
     @Test
     void testGetProperties() throws Exception {
         DropDown dropdown = Utils.getComponentUnderTest(PATH_DROPDOWN_1, DropDown.class, context);

bundles/af-core/src/test/resources/form/dropdown/exporter-searchable-dropdown.json

@@ -0,0 +1,32 @@
+{
+  "id": "dropdown-6bc8619e69",
+  "fieldType": "drop-down",
+  "name": "abc",
+  "type": "string",
+  "minLength": 2,
+  "maxLength": 10,
+  "enforceEnum": false,
+  "enumNames": [
+    "m",
+    "f",
+    "o"
+  ],
+  "pattern": "[a-z]+",
+  "label": {
+    "value": "def"
+  },
+  "properties": {
+    "fd:path": "/content/searchable-dropdown"
+  },
+  "events": {
+    "custom:setProperty": [
+      "$event.payload"
+    ]
+  },
+  "enum": [
+    "a",
+    "b",
+    "c"
+  ],
+  ":type": "core/fd/components/form/dropdown/v1/dropdown"
+}

bundles/af-core/src/test/resources/form/dropdown/test-content.json

@@ -51,7 +51,24 @@
     "enumNames" : ["m", "f", "o"],
     "minItems" : 1,
     "maxItems" : 2,
-    "required": true
+    "required": true,
+    "minLength" : 2,
+    "maxLength" : 10,
+    "pattern" : "[a-z]+"
+  },
+  "searchable-dropdown" : {
+    "jcr:primaryType": "nt:unstructured",
+    "sling:resourceType"    : "core/fd/components/form/dropdown/v1/dropdown",
+    "name" : "abc",
+    "jcr:title" : "def",
+    "fieldType": "drop-down",
+    "type" : "string",
+    "enforceEnum" : false,
+    "enum" : ["a", "b", "c"],
+    "enumNames" : ["m", "f", "o"],
+    "minLength" : 2,
+    "maxLength" : 10,
+    "pattern" : "[a-z]+"
   },
   "dropdown2" : {
     "jcr:primaryType": "nt:unstructured",

bundles/af-core/src/test/resources/schema/0.15.2/adaptive-form.schema.json

@@ -578,7 +578,6 @@
         "properties": {
           "fieldType": {
             "enum": [
-              "drop-down",
               "checkbox-group"
             ]
           }
@@ -592,7 +591,6 @@
         "properties": {
           "fieldType": {
             "enum": [
-              "drop-down",
               "checkbox-group"
             ]
           },
@@ -668,7 +666,109 @@
             "enum": "Options are missing from selection. Add an empty enum array"
           },
           "properties": {
-            "fieldType": "${0/fieldType} is not a valid SelectionField field type. It should be either drop-down or checkbox-group"
+            "fieldType": "${0/fieldType} is not a valid SelectionField field type. It should be checkbox-group"
+          }
+        }
+      }
+    },
+    "DropDownField": {
+      "if": {
+        "type": "object",
+        "properties": {
+          "fieldType": {
+            "enum": [
+              "drop-down"
+            ]
+          }
+        },
+        "required": [
+          "fieldType"
+        ]
+      },
+      "then": {
+        "type": "object",
+        "properties": {
+          "fieldType": {
+            "enum": [
+              "drop-down"
+            ]
+          },
+          "type": {
+            "enum": [
+              "string",
+              "number",
+              "boolean",
+              "string[]",
+              "number[]",
+              "boolean[]"
+            ]
+          },
+          "rules": {
+            "type": "object",
+            "propertyNames": {
+              "enum": [
+                "description",
+                "enabled",
+                "enum",
+                "enumNames",
+                "label",
+                "properties",
+                "readOnly",
+                "required",
+                "value",
+                "visible"
+              ]
+            }
+          }
+        },
+        "propertyNames": {
+          "enum": [
+            ":type",
+            "appliedCssClassNames",
+            "constraintMessages",
+            "dataLayer",
+            "dataRef",
+            "default",
+            "description",
+            "enabled",
+            "enforceEnum",
+            "enum",
+            "enumNames",
+            "events",
+            "fieldType",
+            "id",
+            "label",
+            "maxItems",
+            "maxLength",
+            "minItems",
+            "minLength",
+            "name",
+            "pattern",
+            "placeholder",
+            "properties",
+            "readOnly",
+            "required",
+            "rules",
+            "screenReaderText",
+            "tooltip",
+            "type",
+            "uniqueItems",
+            "validationExpression",
+            "visible"
+          ],
+          "errorMessage": {
+            "enum": "${0} property is not allowed in DropDownField"
+          }
+        },
+        "required": [
+          "enum"
+        ],
+        "errorMessage": {
+          "required": {
+            "enum": "Options are missing from selection. Add an empty enum array"
+          },
+          "properties": {
+            "fieldType": "${0/fieldType} is not a valid DropDownField field type. It should be drop-down"
           }
         }
       }
@@ -1696,6 +1796,9 @@
             {
               "$ref": "#/$defs/SelectionField"
             },
+            {
+              "$ref": "#/$defs/DropDownField"
+            },
             {
               "$ref": "#/$defs/RadioGroupField"
             },