Add ESLint guard for invalid use server exports and fix plaza staff messages.

Catch Next.js invalid-use-server-value at lint time and move shared form-error copy out of plazaStaffFormActions so the use server module only exports async actions.

eslint-local-rules.mjs

@@ -115,10 +115,177 @@ const componentArrowConventions = {
   },
 }
 
+const isFunctionNode = (node) =>
+  node?.type === 'FunctionDeclaration' ||
+  node?.type === 'FunctionExpression' ||
+  node?.type === 'ArrowFunctionExpression'
+
+const isAsyncFunctionNode = (node) => isFunctionNode(node) && node.async === true
+
+const isUseServerDirectiveStatement = (statement) =>
+  statement?.type === 'ExpressionStatement' &&
+  statement.expression?.type === 'Literal' &&
+  statement.expression.value === 'use server'
+
+const hasTopLevelUseServer = (program) =>
+  Array.isArray(program.body) && program.body.some(isUseServerDirectiveStatement)
+
+const isTypeOnlyNamedExport = (node) => {
+  if (node.exportKind === 'type') return true
+
+  const declaration = node.declaration
+  if (!declaration) return false
+
+  return (
+    declaration.type === 'TSTypeAliasDeclaration' ||
+    declaration.type === 'TSInterfaceDeclaration' ||
+    declaration.type === 'TSModuleDeclaration'
+  )
+}
+
+const resolveLocalAsyncBinding = (program, name) => {
+  for (const statement of program.body) {
+    if (statement.type === 'FunctionDeclaration' && statement.id?.name === name) {
+      return isAsyncFunctionNode(statement)
+    }
+
+    if (statement.type === 'VariableDeclaration') {
+      for (const declarator of statement.declarations) {
+        if (declarator.id?.type === 'Identifier' && declarator.id.name === name) {
+          return isAsyncFunctionNode(declarator.init)
+        }
+      }
+    }
+  }
+
+  return false
+}
+
+/**
+ * Next.js rejects any non-async-function export from a top-level `'use server'`
+ * module (https://nextjs.org/docs/messages/invalid-use-server-value). Inspired by
+ * eslint-plugin-next-recommended's export-server-actions-only, kept local because
+ * that package is unmaintained and ESLint-8-era.
+ */
+const useServerAsyncExports = {
+  meta: {
+    type: 'problem',
+    docs: {
+      description:
+        'Require top-level `use server` modules to export only async functions (plus type-only exports)',
+    },
+    schema: [],
+    messages: {
+      nonAsyncExport:
+        'A `"use server"` file can only export async functions (found non-async export). Move constants, types-as-values, and helpers to a separate module. See https://nextjs.org/docs/messages/invalid-use-server-value',
+      reexport:
+        'A `"use server"` file cannot re-export values (`export … from` / `export *`). Export async functions defined in this file only.',
+    },
+  },
+  create(context) {
+    let programNode = null
+    let useServer = false
+
+    const report = (node, messageId) => {
+      context.report({ node, messageId })
+    }
+
+    return {
+      Program(node) {
+        programNode = node
+        useServer = hasTopLevelUseServer(node)
+      },
+
+      ExportAllDeclaration(node) {
+        if (!useServer) return
+        if (node.exportKind === 'type') return
+        report(node, 'reexport')
+      },
+
+      ExportDefaultDeclaration(node) {
+        if (!useServer) return
+
+        const declaration = node.declaration
+        if (isAsyncFunctionNode(declaration)) return
+
+        if (declaration?.type === 'Identifier' && programNode) {
+          if (resolveLocalAsyncBinding(programNode, declaration.name)) return
+        }
+
+        report(node, 'nonAsyncExport')
+      },
+
+      ExportNamedDeclaration(node) {
+        if (!useServer) return
+        if (isTypeOnlyNamedExport(node)) return
+
+        if (node.source) {
+          const hasValueSpecifier =
+            !node.specifiers?.length ||
+            node.specifiers.some((specifier) => specifier.exportKind !== 'type')
+          if (hasValueSpecifier) {
+            report(node, 'reexport')
+          }
+          return
+        }
+
+        const declaration = node.declaration
+
+        if (declaration?.type === 'FunctionDeclaration') {
+          if (!isAsyncFunctionNode(declaration)) {
+            report(node, 'nonAsyncExport')
+          }
+          return
+        }
+
+        if (declaration?.type === 'VariableDeclaration') {
+          for (const declarator of declaration.declarations) {
+            if (!isAsyncFunctionNode(declarator.init)) {
+              report(node, 'nonAsyncExport')
+              return
+            }
+          }
+          return
+        }
+
+        if (declaration?.type === 'TSEnumDeclaration' || declaration?.type === 'ClassDeclaration') {
+          report(node, 'nonAsyncExport')
+          return
+        }
+
+        if (declaration) {
+          // Unrecognized value declaration (e.g. const enum already covered).
+          if (
+            declaration.type !== 'TSTypeAliasDeclaration' &&
+            declaration.type !== 'TSInterfaceDeclaration'
+          ) {
+            report(node, 'nonAsyncExport')
+          }
+          return
+        }
+
+        for (const specifier of node.specifiers ?? []) {
+          if (specifier.exportKind === 'type') continue
+          if (specifier.type !== 'ExportSpecifier') {
+            report(node, 'nonAsyncExport')
+            continue
+          }
+
+          const localName = specifier.local?.name
+          if (!localName || !programNode || !resolveLocalAsyncBinding(programNode, localName)) {
+            report(specifier, 'nonAsyncExport')
+          }
+        }
+      },
+    }
+  },
+}
+
 export const localRules = {
   rules: {
     'component-arrow-conventions': componentArrowConventions,
     'framework-default-export': frameworkDefaultExport,
     'no-component-default-export': noComponentDefaultExport,
+    'use-server-async-exports': useServerAsyncExports,
   },
 }

eslint.config.mjs

@@ -1,9 +1,9 @@
-import { dirname } from 'path'
-import { fileURLToPath } from 'url'
 import { FlatCompat } from '@eslint/eslintrc'
-import { globalIgnores } from 'eslint/config'
 import prettier from 'eslint-config-prettier/flat'
 import checkFile from 'eslint-plugin-check-file'
+import { globalIgnores } from 'eslint/config'
+import { dirname } from 'path'
+import { fileURLToPath } from 'url'
 import { localRules } from './eslint-local-rules.mjs'
 
 const __filename = fileURLToPath(import.meta.url)
@@ -131,6 +131,16 @@ const eslintConfig = [
       ],
     },
   },
+  {
+    // Catch Next.js invalid-use-server-value before `next build` (Vercel).
+    files: ['src/**/*.{ts,tsx}'],
+    plugins: {
+      local: localRules,
+    },
+    rules: {
+      'local/use-server-async-exports': 'error',
+    },
+  },
   prettier,
   // Override default ignores of eslint-config-next.
   globalIgnores([

src/app/(campaign)/campanha/(app)/pracas/[slug]/editar/formActions.ts

@@ -14,7 +14,7 @@ import {
   type CampaignFormActionState,
 } from '@/utilities/campaignFormActionError'
 import { revalidatePlazaListPaths } from '@/utilities/plazaRevalidation'
-import { plazaStaffEditSafeMessages } from '../../plazaStaffFormActions'
+import { plazaStaffEditSafeMessages } from '../../plazaStaffEditMessages'
 
 export const updatePlazaStrategyFormAction = async (
   _state: CampaignFormActionState,

src/app/(campaign)/campanha/(app)/pracas/plazaStaffEditMessages.ts

@@ -0,0 +1,4 @@
+/** Shared form-error copy for plaza staff edits — kept out of `'use server'` files. */
+export const plazaStaffEditSafeMessages = [
+  'Somente a coordenação e a assessoria podem editar a Praça.',
+] as const

src/app/(campaign)/campanha/(app)/pracas/plazaStaffFormActions.ts

@@ -20,9 +20,7 @@ import {
 } from '@/utilities/campaignFormActionError'
 import { revalidatePlazaListPaths } from '@/utilities/plazaRevalidation'
 
-export const plazaStaffEditSafeMessages = [
-  'Somente a coordenação e a assessoria podem editar a Praça.',
-] as const
+import { plazaStaffEditSafeMessages } from './plazaStaffEditMessages'
 
 export const setPlazaExpectedVotesFormAction = async (
   _state: CampaignFormActionState,

tests/int/eslintConventions.int.spec.ts

@@ -40,9 +40,7 @@ const expectInvalid = async (filePath: string, code: string, ruleId: string) =>
 }
 
 describe('ESLint conventions', () => {
-  it(
-    'enforces PascalCase component and camelCase utility/test filenames',
-    async () => {
+  it('enforces PascalCase component and camelCase utility/test filenames', async () => {
     await expectValid('src/components/FutureCard.tsx', 'export const FutureCard = () => <div />')
     await expectInvalid(
       'src/components/future-card.tsx',
@@ -56,9 +54,7 @@ describe('ESLint conventions', () => {
       'export const futureValue = 1',
       'check-file/filename-naming-convention',
     )
-    },
-    15_000,
-  )
+  }, 15_000)
 
   it('requires uppercase component arrows to use const', async () => {
     await expectInvalid(
@@ -73,9 +69,9 @@ describe('ESLint conventions', () => {
     const result = await lint('src/components/FutureCard.tsx', code)
     const output = await lintWithFix('src/components/FutureCard.tsx', code)
 
-    expect(result.errors.some((error) => error.ruleId === 'local/component-arrow-conventions')).toBe(
-      true,
-    )
+    expect(
+      result.errors.some((error) => error.ruleId === 'local/component-arrow-conventions'),
+    ).toBe(true)
     expect(output).toContain('export const FutureCard = () => (<div />)')
 
     await expectValid(
@@ -89,9 +85,9 @@ describe('ESLint conventions', () => {
     const result = await lint('src/components/FutureCard.tsx', code)
     const output = (await lintWithFix('src/components/FutureCard.tsx', code)) ?? code
 
-    expect(result.errors.some((error) => error.ruleId === 'local/component-arrow-conventions')).toBe(
-      true,
-    )
+    expect(
+      result.errors.some((error) => error.ruleId === 'local/component-arrow-conventions'),
+    ).toBe(true)
     expect(output).toContain('keep this rationale')
   })
 
@@ -137,11 +133,7 @@ describe('ESLint conventions', () => {
     ]
 
     for (const code of invalidExamples) {
-      await expectInvalid(
-        'src/app/future/page.tsx',
-        code,
-        'local/framework-default-export',
-      )
+      await expectInvalid('src/app/future/page.tsx', code, 'local/framework-default-export')
     }
   })
 
@@ -175,4 +167,33 @@ describe('ESLint conventions', () => {
       'const futureConfig = { enabled: true }; export default futureConfig',
     )
   })
+
+  it('rejects non-async exports from top-level use server modules', async () => {
+    await expectInvalid(
+      'src/app/(campaign)/campanha/actions/futureAction.ts',
+      `'use server'\n\nexport const safeMessages = ['x'] as const\n`,
+      'local/use-server-async-exports',
+    )
+    await expectInvalid(
+      'src/app/(campaign)/campanha/actions/futureAction.ts',
+      `'use server'\n\nexport function syncAction() { return 1 }\n`,
+      'local/use-server-async-exports',
+    )
+    await expectInvalid(
+      'src/app/(campaign)/campanha/actions/futureAction.ts',
+      `'use server'\n\nexport { helper } from './futureHelper'\n`,
+      'local/use-server-async-exports',
+    )
+  })
+
+  it('allows async function and type-only exports from use server modules', async () => {
+    await expectValid(
+      'src/app/(campaign)/campanha/actions/futureAction.ts',
+      `'use server'\n\nexport type Result = { ok: true }\nexport const save = async () => ({ ok: true as const })\nexport async function load() { return 1 }\n`,
+    )
+    await expectValid(
+      'src/app/(campaign)/campanha/(app)/pracas/plazaStaffEditMessages.ts',
+      `export const plazaStaffEditSafeMessages = ['x'] as const\n`,
+    )
+  })
 })