diff --git a/lint/plugin.js b/lint/plugin.js
index 38faf6dfe..4db8b45c1 100644
--- a/lint/plugin.js
+++ b/lint/plugin.js
@@ -201,6 +201,45 @@ const noVueStyleBlocks = {
   }
 }
 
+const TEST_ID_FORMAT = /^[a-z][a-z0-9]*(?:-[a-z0-9]+)*$/
+
+const noInvalidTestIdAttributes = {
+  meta: {
+    docs: {
+      description: 'Enforce data-test-id spelling and kebab-case static test ids in Vue components'
+    }
+  },
+  create(context) {
+    const file = normalizedFilename(context)
+    if (!file.endsWith('.vue')) return {}
+
+    return {
+      Program(node) {
+        const source = context.sourceCode.getText()
+        const invalidAttr = source.match(/\bdata-testid\s*=/)
+        if (invalidAttr) {
+          context.report({
+            node,
+            message: 'Use data-test-id instead of data-testid.'
+          })
+          return
+        }
+
+        const attrPattern = /\bdata-test-id\s*=\s*"([^"]+)"/g
+        for (const match of source.matchAll(attrPattern)) {
+          const id = match[1]
+          if (TEST_ID_FORMAT.test(id)) continue
+          context.report({
+            node,
+            message: `Static data-test-id values must be kebab-case. Invalid id: "${id}".`
+          })
+          return
+        }
+      }
+    }
+  }
+}
+
 const noDocumentQuerySelectorInVue = {
   meta: {
     docs: {
@@ -1286,6 +1325,7 @@ const plugin = {
     'no-inline-named-types': noInlineNamedTypes,
     'no-structuredclone-scene-arrays': noStructuredCloneSceneArrays,
     'no-vue-style-blocks': noVueStyleBlocks,
+    'no-invalid-test-id-attributes': noInvalidTestIdAttributes,
     'no-document-query-selector-in-vue': noDocumentQuerySelectorInVue,
     'no-direct-selection-tool-state-mutation': noDirectSelectionToolStateMutation,
     'no-math-random': noMathRandom,
diff --git a/oxlint.json b/oxlint.json
index 57c09f838..ea5c29985 100644
--- a/oxlint.json
+++ b/oxlint.json
@@ -112,6 +112,7 @@
     ],
     "open-pencil/no-structuredclone-scene-arrays": "error",
     "open-pencil/no-vue-style-blocks": "error",
+    "open-pencil/no-invalid-test-id-attributes": "error",
     "open-pencil/no-document-query-selector-in-vue": "error",
     "open-pencil/no-direct-selection-tool-state-mutation": "error",
     "open-pencil/no-math-random": "error",
diff --git a/packages/vue/src/index.ts b/packages/vue/src/index.ts
index 56e71500b..7d727be92 100644
--- a/packages/vue/src/index.ts
+++ b/packages/vue/src/index.ts
@@ -47,6 +47,8 @@ export { useToolbarState } from '#vue/primitives/Toolbar/useToolbarState'
 export { useNodeFontStatus } from '#vue/shared/font-status/use'
 export { usePropScrub } from '#vue/controls/prop-scrub/use'
 export { toolCursor } from '#vue/editor/tool-cursor'
+export { testId, testIdSelector } from '#vue/testing/test-id'
+export type { TestId, TestIdProps } from '#vue/testing/test-id'
 
 /** Property-panel composables. */
 export { usePosition } from '#vue/controls/position/use'
diff --git a/packages/vue/src/testing/test-id.ts b/packages/vue/src/testing/test-id.ts
new file mode 100644
index 000000000..521690fb6
--- /dev/null
+++ b/packages/vue/src/testing/test-id.ts
@@ -0,0 +1,17 @@
+export type TestId = string
+
+export type TestIdProps = {
+  testId?: TestId
+}
+
+export function testId(id?: TestId | null): { 'data-test-id'?: TestId } {
+  return id ? { 'data-test-id': id } : {}
+}
+
+export function testIdSelector(id: TestId): string {
+  return `[data-test-id="${cssEscape(id)}"]`
+}
+
+function cssEscape(value: string): string {
+  return CSS.escape(value)
+}
diff --git a/playwright.config.ts b/playwright.config.ts
index c50532e1d..44a3e4758 100644
--- a/playwright.config.ts
+++ b/playwright.config.ts
@@ -16,6 +16,7 @@ export default defineConfig({
   },
   use: {
     baseURL: 'http://localhost:1420',
+    testIdAttribute: 'data-test-id',
     viewport: { width: 1280, height: 800 },
     deviceScaleFactor: 2,
     colorScheme: 'dark',
diff --git a/src/components/PickerSlider.vue b/src/components/PickerSlider.vue
index 71aa053dd..0a6f1bbac 100644
--- a/src/components/PickerSlider.vue
+++ b/src/components/PickerSlider.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { inputNumberValue } from '@open-pencil/vue'
+import { inputNumberValue, testId as testIdAttr, type TestIdProps } from '@open-pencil/vue'
 import { usePickerSliderUI } from './ui/picker-slider'
 
 type PickerSliderDisplay = {
@@ -11,6 +11,21 @@ type PickerSliderDisplay = {
   parse?: (value: number) => number
 }
 
+type PickerSliderProps = TestIdProps & {
+  label: string
+  modelValue: number
+  min: number
+  max: number
+  step?: number
+  display?: PickerSliderDisplay
+  gradientStyle?: string
+  checkerboard?: boolean
+  thumbFill?: string
+  ui?: Partial<
+    Record<'root' | 'label' | 'track' | 'gradient' | 'range' | 'thumb' | 'input', string>
+  >
+}
+
 const {
   label,
   modelValue,
@@ -23,21 +38,7 @@ const {
   thumbFill = '#fff',
   testId,
   ui
-} = defineProps<{
-  label: string
-  modelValue: number
-  min: number
-  max: number
-  step?: number
-  display?: PickerSliderDisplay
-  gradientStyle?: string
-  checkerboard?: boolean
-  thumbFill?: string
-  testId?: string
-  ui?: Partial<
-    Record<'root' | 'label' | 'track' | 'gradient' | 'range' | 'thumb' | 'input', string>
-  >
-}>()
+} = defineProps<PickerSliderProps>()
 
 const emit = defineEmits<{
   'update:modelValue': [value: number]
@@ -63,7 +64,7 @@ function thumbLeft(): string {
 </script>
 
 <template>
-  <div :class="cls.root" :data-test-id="testId">
+  <div :class="cls.root" v-bind="testIdAttr(testId)">
     <span :class="cls.label">{{ label }}</span>
     <div :class="cls.track">
       <div :class="cls.gradient" :style="gradientStyle" />
diff --git a/src/components/ui/AppGroupedSelect.vue b/src/components/ui/AppGroupedSelect.vue
index 0f341d5c2..0f461c69f 100644
--- a/src/components/ui/AppGroupedSelect.vue
+++ b/src/components/ui/AppGroupedSelect.vue
@@ -11,6 +11,7 @@ import {
   SelectTrigger,
   SelectViewport
 } from 'reka-ui'
+import { testId as testIdAttr, type TestIdProps } from '@open-pencil/vue'
 
 import { useSelectUI } from '@/components/ui/select'
 
@@ -32,12 +33,13 @@ interface GroupedSelectUi {
   separator?: string
 }
 
-const { groups, displayValue, ui, testId } = defineProps<{
-  groups: SelectGroupDef<T>[]
-  displayValue: string
-  ui?: GroupedSelectUi
-  testId?: string
-}>()
+const { groups, displayValue, ui, testId } = defineProps<
+  TestIdProps & {
+    groups: SelectGroupDef<T>[]
+    displayValue: string
+    ui?: GroupedSelectUi
+  }
+>()
 
 const modelValue = defineModel<T>({ required: true })
 
@@ -55,7 +57,7 @@ const separator = ui?.separator ?? 'mx-1 my-1 h-px bg-border'
 
 <template>
   <SelectRoot v-model="modelValue">
-    <SelectTrigger :data-test-id="testId" :class="select.trigger">
+    <SelectTrigger v-bind="testIdAttr(testId)" :class="select.trigger">
       <slot name="value">{{ displayValue }}</slot>
       <icon-lucide-chevron-down class="size-2.5 shrink-0 text-muted" />
     </SelectTrigger>
diff --git a/src/components/ui/AppSelect.vue b/src/components/ui/AppSelect.vue
index ae0db58c0..1596ba0d8 100644
--- a/src/components/ui/AppSelect.vue
+++ b/src/components/ui/AppSelect.vue
@@ -11,6 +11,8 @@ import {
   SelectViewport
 } from 'reka-ui'
 
+import { testId as testIdAttr, type TestIdProps } from '@open-pencil/vue'
+
 import { useSelectUI } from '@/components/ui/select'
 import type { SelectUi } from '@/components/ui/select'
 
@@ -24,12 +26,13 @@ const {
   placeholder,
   ui,
   testId = 'app-select-trigger'
-} = defineProps<{
-  options: { value: T; label: string }[]
-  placeholder?: string
-  ui?: AppSelectUi
-  testId?: string
-}>()
+} = defineProps<
+  TestIdProps & {
+    options: { value: T; label: string }[]
+    placeholder?: string
+    ui?: AppSelectUi
+  }
+>()
 
 const modelValue = defineModel<T>({ required: true })
 
@@ -44,7 +47,7 @@ const indicator = ui?.indicator ?? 'absolute left-1.5 inline-flex items-center j
 
 <template>
   <SelectRoot v-model="modelValue">
-    <SelectTrigger :data-test-id="testId" :class="select.trigger">
+    <SelectTrigger v-bind="testIdAttr(testId)" :class="select.trigger">
       <SelectValue :placeholder="placeholder" />
       <icon-lucide-chevron-down class="ml-1 size-3 shrink-0 text-muted" />
     </SelectTrigger>