[tuya] Fix unitHint set on non-dimension item types (#20617)

* Fix unit hint on non-dimension item types in Tuya

Signed-off-by: Çağlar Eker <ekercaglar@gmail.com>

Author: caglareker

bundles/org.openhab.binding.tuya/src/main/java/org/openhab/binding/tuya/internal/TuyaChannelTypeProvider.java

@@ -370,7 +370,7 @@ private ChannelType clone(ChannelTypeUID channelTypeUID, ChannelType orig) {
         } catch (URISyntaxException e) {
         }
 
-        if (!schemaDp.unit.isEmpty()) {
+        if (!schemaDp.unit.isEmpty() && acceptedItemType.startsWith(NUMBER + ":")) {
             channelTypeBuilder.withUnitHint(schemaDp.unit);
         }
 

bundles/org.openhab.binding.tuya/src/test/java/org/openhab/binding/tuya/internal/TuyaChannelTypeProviderTest.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2010-2026 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.binding.tuya.internal;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.lenient;
+import static org.openhab.binding.tuya.internal.TuyaBindingConstants.BINDING_ID;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.openhab.binding.tuya.internal.util.SchemaDp;
+import org.openhab.core.thing.i18n.ChannelTypeI18nLocalizationService;
+import org.openhab.core.thing.type.ChannelType;
+import org.openhab.core.thing.type.ChannelTypeUID;
+
+/**
+ * The {@link TuyaChannelTypeProviderTest} verifies that the channel type provider
+ * only sets a unit hint when the accepted item type is a {@code Number:<Dimension>}.
+ * <p>
+ * Previously, an unparseable or dimensionless unit on a {@code value}-type schema
+ * produced an item type of {@code Number} while still calling
+ * {@code withUnitHint(...)}, which made {@code ChannelType} throw
+ * {@code IllegalArgumentException: A unit hint must not be set if the item type is
+ * not a number with dimension!} and left the thing in
+ * {@code HANDLER_INITIALIZING_ERROR}. See issue #20616.
+ *
+ * @author Caglar Eker - Initial contribution
+ */
+@ExtendWith(MockitoExtension.class)
+@NonNullByDefault
+public class TuyaChannelTypeProviderTest {
+
+    private @Mock @NonNullByDefault({}) ChannelTypeI18nLocalizationService localizationServiceMock;
+
+    private static final String PRODUCT_ID = "testprod";
+
+    @BeforeEach
+    public void setUp() {
+        // Return the input channel type unchanged so the test focuses on
+        // TuyaChannelTypeProvider behavior, not on localization.
+        lenient().when(localizationServiceMock.createLocalizedChannelType(any(), any(ChannelType.class), any()))
+                .thenAnswer(inv -> inv.getArgument(1));
+        TuyaSchemaDB.cache.put(PRODUCT_ID, new ConcurrentHashMap<>());
+    }
+
+    @AfterEach
+    public void tearDown() {
+        TuyaSchemaDB.cache.remove(PRODUCT_ID);
+    }
+
+    @Test
+    public void parseableDimensionalUnitSetsNumberDimensionAndUnitHint() {
+        SchemaDp dp = valueDp("°C");
+        putDp("temp", dp);
+
+        ChannelType ct = getChannelType("temp");
+
+        assertNotNull(ct);
+        assertEquals("Number:Temperature", ct.getItemType());
+        assertEquals("°C", ct.getUnitHint());
+    }
+
+    @Test
+    public void unparseableUnitKeepsPlainNumberAndOmitsUnitHint() {
+        // A unit string openHAB can't parse used to trigger
+        // "A unit hint must not be set if the item type is not a number with dimension!"
+        SchemaDp dp = valueDp("bogusunit");
+        putDp("garbage", dp);
+
+        ChannelType ct = getChannelType("garbage");
+
+        assertNotNull(ct);
+        assertEquals("Number", ct.getItemType());
+        assertNull(ct.getUnitHint(), "unit hint must not be set on plain Number item type");
+    }
+
+    @Test
+    public void boolSchemaProducesSwitchWithoutUnitHint() {
+        // Defensive check: even if unit is somehow populated, non-numeric item
+        // types must never receive a unit hint.
+        SchemaDp dp = new SchemaDp();
+        dp.type = "bool";
+        dp.label = "Power";
+        dp.unit = "";
+        putDp("power", dp);
+
+        ChannelType ct = getChannelType("power");
+
+        assertNotNull(ct);
+        assertEquals("Switch", ct.getItemType());
+        assertNull(ct.getUnitHint());
+    }
+
+    private SchemaDp valueDp(String unit) {
+        SchemaDp dp = new SchemaDp();
+        dp.type = "value";
+        dp.label = "Test";
+        dp.unit = unit;
+        return dp;
+    }
+
+    private void putDp(String channelTypeId, SchemaDp dp) {
+        Map<String, SchemaDp> schema = TuyaSchemaDB.cache.get(PRODUCT_ID);
+        assertNotNull(schema);
+        schema.put(channelTypeId, dp);
+    }
+
+    private ChannelType getChannelType(String channelTypeId) {
+        TuyaChannelTypeProvider provider = new TuyaChannelTypeProvider(localizationServiceMock);
+        ChannelTypeUID uid = new ChannelTypeUID(BINDING_ID, PRODUCT_ID + "_" + channelTypeId);
+        ChannelType ct = provider.getChannelType(uid, null);
+        assertNotNull(ct);
+        return ct;
+    }
+}