fix(core): define Vue feature flags for non-Vue hosts

packages/core/src/node/plugins/__tests__/injection.test.ts

@@ -0,0 +1,36 @@
+import { resolveConfig } from 'vite'
+import { describe, expect, it } from 'vitest'
+import { DevToolsInjection } from '../injection'
+
+describe('devToolsInjection', () => {
+  it('defines Vue feature flags for non-Vue hosts', async () => {
+    const config = await resolveConfig({
+      configFile: false,
+      plugins: [DevToolsInjection()],
+    }, 'serve')
+
+    expect(config.define).toMatchObject({
+      __VUE_OPTIONS_API__: true,
+      __VUE_PROD_DEVTOOLS__: false,
+      __VUE_PROD_HYDRATION_MISMATCH_DETAILS__: false,
+    })
+  })
+
+  it('preserves Vue feature flags defined by the host', async () => {
+    const config = await resolveConfig({
+      configFile: false,
+      define: {
+        __VUE_OPTIONS_API__: 'false',
+        __VUE_PROD_DEVTOOLS__: 'true',
+        __VUE_PROD_HYDRATION_MISMATCH_DETAILS__: 'true',
+      },
+      plugins: [DevToolsInjection()],
+    }, 'serve')
+
+    expect(config.define).toMatchObject({
+      __VUE_OPTIONS_API__: 'false',
+      __VUE_PROD_DEVTOOLS__: 'true',
+      __VUE_PROD_HYDRATION_MISMATCH_DETAILS__: 'true',
+    })
+  })
+})

packages/core/src/node/plugins/injection.ts

@@ -63,6 +63,15 @@ export function DevToolsInjection(options: DevToolsInjectionOptions = {}): Plugi
     apply(_config, env) {
       return env.command === 'serve' && !env.isSsrBuild
     },
+    config(config) {
+      return {
+        define: {
+          __VUE_OPTIONS_API__: config.define?.__VUE_OPTIONS_API__ ?? true,
+          __VUE_PROD_DEVTOOLS__: config.define?.__VUE_PROD_DEVTOOLS__ ?? false,
+          __VUE_PROD_HYDRATION_MISMATCH_DETAILS__: config.define?.__VUE_PROD_HYDRATION_MISMATCH_DETAILS__ ?? false,
+        },
+      }
+    },
     configResolved(config) {
       root = config.root
     },