fix: improve error handling

brillout · Sep 13, 2022 · 1dc21e2 · 1dc21e2
1 parent 03b8167
commit 1dc21e2
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Showing 2 changed files with 37 additions and 13 deletions.
diff --git a/telefunc/client/callTelefunc/makeHttpRequest.ts b/telefunc/client/callTelefunc/makeHttpRequest.ts
@@ -9,6 +9,7 @@ const method = 'POST'
 const STATUS_CODE_SUCCESS = 200
 const STATUS_CODE_ABORT = 403
 const STATUS_CODE_BUG = 500
+const STATUS_CODE_INVALID = 400
 
 async function makeHttpRequest(callContext: {
   telefuncUrl: string
@@ -50,7 +51,7 @@ async function makeHttpRequest(callContext: {
   } else if (statusCode === STATUS_CODE_BUG) {
     const responseBody = await response.text()
     assertUsage(
-      responseBody === 'Internal Server Error (Telefunc Request)',
+      responseBody === 'Internal Server Error (Telefunc)',
       installErr({
         reason: 'an HTTP response body that Telefunc never generates',
         method,
@@ -59,6 +60,19 @@ async function makeHttpRequest(callContext: {
     )
     const telefunctionCallError = new Error('Server Error')
     return { telefunctionCallError }
+  } else if (statusCode === STATUS_CODE_INVALID) {
+    const responseBody = await response.text()
+    assertUsage(
+      responseBody === 'Invalid Request (Telefunc)',
+      installErr({
+        reason: 'an HTTP response body that Telefunc never generates',
+        method,
+        callContext
+      })
+    )
+    // In theory this error should never happen.
+    const telefunctionCallError = new Error('Invalid Telefunc Request')
+    return { telefunctionCallError }
   } else {
     assertUsage(
       statusCode !== 404,
@@ -72,7 +86,7 @@ async function makeHttpRequest(callContext: {
     assertUsage(
       false,
       installErr({
-        reason: `a status code \`${statusCode}\` which Telefunc does not return`,
+        reason: `a status code \`${statusCode}\` which Telefunc never uses`,
         method,
         callContext
       })
@@ -115,6 +129,6 @@ function installErr({
   if (reason) {
     msg.push(...[`: the HTTP ${method} \`${callContext.telefuncUrl}\` request returned `, reason])
   }
-  msg.push(`. See https://telefunc.com/install`)
+  msg.push(`, see https://telefunc.com/install`)
   return msg.join('')
 }
diff --git a/telefunc/node/server/runTelefunc.ts b/telefunc/node/server/runTelefunc.ts
@@ -16,24 +16,34 @@ import { globalContext } from './globalContext'
 import { telefuncConfig } from './telefuncConfig'
 
 type HttpResponse = {
-  statusCode: 200 | 500 | 400 | 403
+  statusCode: 200 | 403 | 500 | 400
   body: string
   contentType: 'text/plain'
   etag: string | null
 }
-const malformedRequest = {
-  statusCode: 400 as const,
-  body: 'Malformed Request',
+
+// Status code for `throw Abort()`
+const abortedRequestStatusCode = 403
+
+// HTTP Response for:
+// - User's telefunction threw an error (that isn't `Abort()`).
+// - Telefunc throw an error (i.e. Telefunc has a bug).
+const serverError = {
+  statusCode: 500 as const,
+  body: 'Internal Server Error (Telefunc)',
   contentType: 'text/plain' as const,
   etag: null
 }
-const serverError = {
-  statusCode: 500 as const,
-  body: 'Internal Server Error (Telefunc Request)',
+
+// HTTP Response for:
+// - The telefunction couldn't be found.
+// - Some non-telefunc client makes a malformed HTTP request.
+const invalidRequest = {
+  statusCode: 400 as const,
+  body: 'Invalid Request (Telefunc)',
   contentType: 'text/plain' as const,
   etag: null
 }
-const abortedRequestStatusCode = 403
 
 async function runTelefunc(runContext: Parameters<typeof runTelefunc_>[0]) {
   try {
@@ -63,7 +73,7 @@ async function runTelefunc_(httpRequest: { url: string; method: string; body: un
   {
     const parsed = parseHttpRequest(runContext)
     if (parsed.isMalformed) {
-      return malformedRequest
+      return invalidRequest
     }
     const { telefunctionName, telefunctionKey, telefunctionArgs, telefunctionFilePath, telefunctionFileExport } = parsed
     objectAssign(runContext, {
@@ -90,7 +100,7 @@ async function runTelefunc_(httpRequest: { url: string; method: string; body: un
   {
     const telefunction = findTelefunction(runContext)
     if (!telefunction) {
-      return malformedRequest
+      return invalidRequest
     }
     objectAssign(runContext, { telefunction })
   }