Json file with createMiddleware string throws error

[plckr]

Which project does this relate to?

Router

Describe the bug

If I have a json file with the word createMiddleware, and if I try to pass it down from the loader it throws error

• Frontend
  {"status":500,"unhandled":true,"message":"HTTPError"}

• Terminal

SyntaxError: Missing semicolon. (1:8)
    at constructor (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:367:19)
    ... 29 lines matching cause stack trace ...
    at async EventEmitter.listenerForInvokeHandler (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/chunks/dep-B0GuR2De.js:28467:13) {
  cause: Error [SyntaxError]: Missing semicolon. (1:8)
      at constructor (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:367:19)
      at TypeScriptParserMixin.raise (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:6630:19)
      at TypeScriptParserMixin.semicolon (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:6926:10)
      at TypeScriptParserMixin.parseExpressionStatement (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:13294:10)
      at TypeScriptParserMixin.parseExpressionStatement (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:9616:26)
      at TypeScriptParserMixin.parseStatementContent (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:12908:19)
      at TypeScriptParserMixin.parseStatementContent (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:9532:18)
      at TypeScriptParserMixin.parseStatementLike (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:12776:17)
      at TypeScriptParserMixin.parseStatementListItem (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:12756:17)
      at TypeScriptParserMixin.parseBlockOrModuleBlockBody (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:13325:61)
      at TypeScriptParserMixin.parseBlockBody (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:13318:10)
      at TypeScriptParserMixin.parseBlock (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:13306:10)
      at TypeScriptParserMixin.parseStatementContent (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:12867:21)
      at TypeScriptParserMixin.parseStatementContent (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:9532:18)
      at TypeScriptParserMixin.parseStatementLike (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:12776:17)
      at TypeScriptParserMixin.parseModuleItem (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:12753:17)
      at TypeScriptParserMixin.parseBlockOrModuleBlockBody (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:13325:36)
      at TypeScriptParserMixin.parseBlockBody (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:13318:10)
      at TypeScriptParserMixin.parseProgram (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:12634:10)
      at TypeScriptParserMixin.parseTopLevel (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:12624:25)
      at TypeScriptParserMixin.parse (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:14501:10)
      at TypeScriptParserMixin.parse (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:10149:18)
      at parse (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@babel+parser@7.28.4/node_modules/@babel/parser/lib/index.js:14535:38)
      at parseAst (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@tanstack+router-utils@1.133.3/node_modules/@tanstack/router-utils/dist/esm/ast.js:4:10)
      at compileStartOutput (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@tanstack+start-plugin-core@1.133.13_@tanstack+react-router@1.133.13_react-dom@19.2.0_r_9577aab002c439bae6ef2f5d9446a9fd/node_modules/@tanstack/start-plugin-core/dist/esm/start-compiler-plugin/compilers.js:33:17)
      at TransformPluginContext.handler (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@tanstack+start-plugin-core@1.133.13_@tanstack+react-router@1.133.13_react-dom@19.2.0_r_9577aab002c439bae6ef2f5d9446a9fd/node_modules/@tanstack/start-plugin-core/dist/esm/start-compiler-plugin/plugin.js:74:26)
      at EnvironmentPluginContainer.transform (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/chunks/dep-B0GuR2De.js:30904:51)
      at async loadAndTransform (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/chunks/dep-B0GuR2De.js:26042:26)
      at async fetchModule (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/chunks/dep-B0GuR2De.js:34217:15)
      at async handleInvoke (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/chunks/dep-B0GuR2De.js:28408:21)
      at async EventEmitter.listenerForInvokeHandler (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/chunks/dep-B0GuR2De.js:28467:13) {
    code: 'BABEL_PARSER_SYNTAX_ERROR',
    reasonCode: 'MissingSemicolon',
    loc: Position { line: 1, column: 8, index: 8 },
    pos: 8,
    syntaxPlugin: undefined,
    plugin: 'tanstack-start-core:compiler',
    id: '/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/src/routes/example.json',
    pluginCode: '{ "name": "createMiddleware" }\n',
    frame: '1  |  { "name": "createMiddleware" }\n   |          ^\n2  |  ',
    runnerError: Error: RunnerError
        at reviveInvokeError (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:473:64)
        at Object.invoke (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:546:11)
        at async ModuleRunner.getModuleInformation (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:1052:7)
        at async request (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:1069:83)
        at async eval (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/src/routes/index.tsx:2:1)
        at async ESModulesEvaluator.runInlinedModule (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:905:3)
        at async ModuleRunner.directRequest (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:1112:59)
        at async ModuleRunner.cachedRequest (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:1030:73)
        at async eval (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/src/routeTree.gen.ts:12:1)
        at async ESModulesEvaluator.runInlinedModule (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:905:3)
        at async ModuleRunner.directRequest (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:1112:59)
        at async ModuleRunner.cachedRequest (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:1030:73)
        at async eval (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/src/router.tsx:4:1)
        at async ESModulesEvaluator.runInlinedModule (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:905:3)
        at async ModuleRunner.directRequest (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:1112:59)
        at async ModuleRunner.cachedRequest (file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/vite@7.1.10_@types+node@22.18.11_jiti@2.6.1_lightningcss@1.30.1_tsx@4.20.6/node_modules/vite/dist/node/module-runner.js:1030:73)
        at async getEntries (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@tanstack+start-server-core@1.133.13/node_modules/@tanstack/start-server-core/src/createStartHandler.ts:67:21)
        at async startRequestResolver (/Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@tanstack+start-server-core@1.133.13/node_modules/@tanstack/start-server-core/src/createStartHandler.ts:159:15)
        at async file:///Users/ricardo/Documents/Projects/Self/start-json-createMiddleware-bug/node_modules/.pnpm/@tanstack+start-plugin-core@1.133.13_@tanstack+react-router@1.133.13_react-dom@19.2.0_r_9577aab002c439bae6ef2f5d9446a9fd/node_modules/@tanstack/start-plugin-core/dist/esm/dev-server-plugin/plugin.js:64:30
  },
  status: 500,
  statusText: undefined,
  headers: undefined,
  data: undefined,
  body: undefined,
  unhandled: true
}

Your Example Website or App

https://github.com/plckr/start-json-createMiddleware-bug/blob/main/src/routes/index.tsx

Steps to Reproduce the Bug or Issue

1. Create a json file
2. Include the following json: { "test": "createMiddleware" } for example
3. import in your route file
4. pass it down from the route loader

Expected behavior

Should not throw any error, it's a valid JSON

Screenshots or Videos

No response

Platform

• Router / Start Version: ^1.132.0
• OS: MacOS Sequoia 15.6.1
• Browser: Chrome
• Browser Version: 141.0.7390.77
• Bundler: Vite
• Bundler Version: ^7.1.7

Additional context

No response

[schiller-manuel]

generally, don't put non-route files in the routes folder.
aside from that, yes this must be made robust

[plckr]

generally, don't put non-route files in the routes folder. aside from that, yes this must be made robust

I could have done differently, but the issue remains even if the json file is outside the routes folder. I inserted there for simplicity purposes only