fix: improve DX around not found telefunction

telefunc/node/server/runTelefunc.ts

@@ -1,8 +1,8 @@
 export { runTelefunc }
 
-import type { TelefuncFiles, Telefunction } from './types'
+import type { TelefuncFiles } from './types'
 import type { ViteDevServer } from 'vite'
-import { assert, assertUsage, checkType, objectAssign } from '../utils'
+import { assert, objectAssign } from '../utils'
 import { getContextOptional } from './getContext'
 import { loadTelefuncFiles } from './runTelefunc/loadTelefuncFiles'
 import { parseHttpRequest } from './runTelefunc/parseHttpRequest'
@@ -13,6 +13,7 @@ import { serializeTelefunctionResult } from './runTelefunc/serializeTelefunction
 import { handleError } from './runTelefunc/handleError'
 import { executeServerErrorListeners } from './runTelefunc/onTelefuncServerError'
 import { applyShield } from './runTelefunc/applyShield'
+import { findTelefunction } from './runTelefunc/findTelefunction'
 
 type HttpResponse = {
   body: string
@@ -62,40 +63,33 @@ async function runTelefunc_(runContext: {
     if (parsed.isMalformed) {
       return malformedRequest
     }
-    const { telefunctionName, telefunctionKey, telefunctionArgs } = parsed
+    const { telefunctionName, telefunctionKey, telefunctionArgs, telefunctionFilePath, telefunctionFileExport } = parsed
     objectAssign(runContext, {
       telefunctionName,
       telefunctionKey,
       telefunctionArgs,
+      telefunctionFilePath,
+      telefunctionFileExport,
     })
   }
 
   {
     const telefuncFiles = runContext.telefuncFiles || (await loadTelefuncFiles(runContext))
     assert(telefuncFiles, 'No `.telefunc.js` file found')
-    checkType<TelefuncFiles>(telefuncFiles)
     objectAssign(runContext, { telefuncFiles })
     runContext.telefuncFiles
   }
 
   {
     const { telefunctions } = await getTelefunctions(runContext)
-    checkType<Record<string, Telefunction>>(telefunctions)
     objectAssign(runContext, { telefunctions })
   }
 
   {
-    assertUsage(
-      runContext.telefunctionKey in runContext.telefunctions,
-      [
-        `Could not find telefunction ${
-          runContext.telefunctionName
-        }. The client is likely out-of-sync with the server, see https://telefunc.com/out-of-sync. Try reloading the client and/or server. Loaded telefunctions: [${Object.keys(
-          runContext.telefunctions,
-        ).join(', ')}]`,
-      ].join(' '),
-    )
-    const telefunction = runContext.telefunctions[runContext.telefunctionKey]
+    const telefunction = findTelefunction(runContext)
+    if (!telefunction) {
+      return malformedRequest
+    }
     objectAssign(runContext, { telefunction })
   }
 

telefunc/node/server/runTelefunc/findTelefunction.ts

@@ -0,0 +1,54 @@
+export { findTelefunction }
+
+import { assert, assertUsage, getPluginError } from '../../utils'
+import type { Telefunction } from '../types'
+
+function findTelefunction(runContext: {
+  telefunctionKey: string
+  telefunctionName: string
+  telefunctionFilePath: string
+  telefuncFiles: Record<string, Record<string, unknown>>
+  telefunctionFileExport: string
+  telefunctions: Record<string, Telefunction>
+  isProduction: boolean
+}) {
+  const telefunctionsFound = Object.keys(runContext.telefunctions)
+  assertUsage(
+    telefunctionsFound.length > 0,
+    [
+      `Telefunction ${runContext.telefunctionName} not found.`,
+      "Your app doesn't seem to have any `.telefunc.{js|ts|...}` file.",
+    ].join(' '),
+  )
+
+  const telefunction = runContext.telefunctions[runContext.telefunctionKey]
+  if (!telefunction) {
+    if (!runContext.isProduction) {
+      const errMsg = getNotFoundErrMsg()
+      console.error(getPluginError(errMsg))
+    }
+    return null
+  }
+
+  return telefunction
+
+  function getNotFoundErrMsg() {
+    let errMsg = `Telefunction ${runContext.telefunctionName} not found.`
+    const { telefuncFiles, telefunctionFilePath, telefunctionFileExport } = runContext
+    const telefuncFile = telefuncFiles[telefunctionFilePath]
+    if (!telefuncFile) {
+      errMsg += ` The file \`${runContext.telefunctionFilePath}\` doens't seem to exist.`
+    } else {
+      assert(!telefuncFile[telefunctionFileExport])
+      errMsg += ` The file \`${runContext.telefunctionFilePath}\` doens't seem to have an export \`${telefunctionFileExport}\`.`
+    }
+    errMsg += [runContext.telefunctionKey, ...telefunctionsFound]
+      .sort()
+      .map(
+        (telefunctionKey) =>
+          `\n${telefunctionKey} ${telefunctionsFound.includes(telefunctionKey) ? '[✅ Found]' : '[❌ Not Found]'}`,
+      )
+      .join('')
+    return errMsg
+  }
+}