fix(nuxt): update warning message to warn against null values

danielroe · danielroe · commit c1b83eab5f2b · 2025-07-11T21:47:04.000+01:00
resolves #28920
diff --git a/packages/nuxt/src/app/composables/asyncData.ts b/packages/nuxt/src/app/composables/asyncData.ts
@@ -676,12 +676,12 @@ function createAsyncData<
             result = pick(result as any, options.pick) as DataT
           }
 
-          if (import.meta.dev && import.meta.server && typeof result === 'undefined') {
+          if (import.meta.dev && import.meta.server && result == null) {
             const stack = captureStackTrace()
             const { source, line, column } = stack[stack.length - 1] ?? {}
             const explanation = source ? ` (used at ${source.replace(/^file:\/\//, '')}:${line}:${column})` : ''
             // @ts-expect-error private property
-            console.warn(`[nuxt] \`${options._functionName || 'useAsyncData'}${explanation}\` must return a value (it should not be \`undefined\`) or the request may be duplicated on the client side.`)
+            console.warn(`[nuxt] \`${options._functionName || 'useAsyncData'}${explanation}\` must return a value (it should not be \`undefined\` or \`null\`) or the request may be duplicated on the client side.`)
           }
 
           nuxtApp.payload.data[key] = result

Original file line number	Diff line number	Diff line change
`@@ -676,12 +676,12 @@ function createAsyncData<`
`676`	`676`	`result = pick(result as any, options.pick) as DataT`
`677`	`677`	`}`
`678`	`678`
`679`		`- if (import.meta.dev && import.meta.server && typeof result === 'undefined') {`
	`679`	`+ if (import.meta.dev && import.meta.server && result == null) {`
`680`	`680`	`const stack = captureStackTrace()`
`681`	`681`	`const { source, line, column } = stack[stack.length - 1] ?? {}`
`682`	`682`	const explanation = source ? ` (used at ${source.replace(/^file:\/\//, '')}:${line}:${column})` : ''
`683`	`683`	`// @ts-expect-error private property`
`684`		- console.warn(`[nuxt] \`${options._functionName \|\| 'useAsyncData'}${explanation}\` must return a value (it should not be \`undefined\`) or the request may be duplicated on the client side.`)
	`684`	+ console.warn(`[nuxt] \`${options._functionName \|\| 'useAsyncData'}${explanation}\` must return a value (it should not be \`undefined\` or \`null\`) or the request may be duplicated on the client side.`)
`685`	`685`	`}`
`686`	`686`
`687`	`687`	`nuxtApp.payload.data[key] = result`