CLI: format GitHub query errors

bin/good-first-issue.js

@@ -6,6 +6,7 @@ const opn = require('open')
 const gfi = require('libgfi')
 
 const packageJSON = require('../package.json')
+const formatError = require('../lib/format-error')
 const log = require('../lib/log')
 const prompt = require('../lib/prompt')
 const projects = require('../data/projects.json')
@@ -54,7 +55,7 @@ cli
         process.exitCode = 0
       }
     } catch (err) {
-      console.error(err)
+      console.error(`\n${formatError(err, input)}\n`)
       process.exitCode = 1
     }
   })

lib/format-error.js

@@ -0,0 +1,63 @@
+function formatError (err, input) {
+  const target = input ? `"${input}"` : 'the requested project'
+  const prefix = `Error: Unable to fetch issues for ${target}.`
+
+  if (isRateLimitError(err)) {
+    return `${prefix}\nGitHub API rate limit reached. Retry later or pass --auth <token> for higher limits.`
+  }
+
+  if (isInvalidProjectError(err)) {
+    return `${prefix}\nPlease check the project name or repository path and try again.`
+  }
+
+  if (isNetworkError(err)) {
+    return `${prefix}\nPlease check your network connection and try again.`
+  }
+
+  return `${prefix}\n${getErrorDetail(err)}`
+}
+
+function getErrorDetail (err) {
+  if (err && typeof err.message === 'string' && err.message.trim()) {
+    return err.message.trim()
+  }
+
+  return 'An unexpected error occurred while querying the GitHub API.'
+}
+
+function isInvalidProjectError (err) {
+  if (!err || err.status !== 422) {
+    return false
+  }
+
+  const errors = err.response && err.response.data && err.response.data.errors
+  return Array.isArray(errors) && errors.some(error => error && error.code === 'invalid')
+}
+
+function isRateLimitError (err) {
+  if (!err) {
+    return false
+  }
+
+  const headers = getResponseHeaders(err)
+  const remaining = headers && headers['x-ratelimit-remaining']
+  return err.status === 403 && remaining === '0'
+}
+
+function isNetworkError (err) {
+  if (!err || err.status) {
+    return false
+  }
+
+  return Boolean(err.code) || /network|timed? out|fetch failed|socket/i.test(getErrorDetail(err))
+}
+
+function getResponseHeaders (err) {
+  if (err.response && err.response.headers) {
+    return err.response.headers
+  }
+
+  return err.headers || null
+}
+
+module.exports = formatError

tests/format-error.spec.js

@@ -0,0 +1,50 @@
+const formatError = require('../lib/format-error')
+
+test('formats invalid project errors clearly', () => {
+  const actual = formatError({
+    status: 422,
+    response: {
+      data: {
+        errors: [{ code: 'invalid' }]
+      }
+    }
+  }, 'thisisntarealprojectorgithuborg')
+
+  expect(actual).toBe(
+    'Error: Unable to fetch issues for "thisisntarealprojectorgithuborg".\nPlease check the project name or repository path and try again.'
+  )
+})
+
+test('formats rate limit errors clearly', () => {
+  const actual = formatError({
+    status: 403,
+    response: {
+      headers: {
+        'x-ratelimit-remaining': '0'
+      }
+    }
+  }, 'facebook/react')
+
+  expect(actual).toBe(
+    'Error: Unable to fetch issues for "facebook/react".\nGitHub API rate limit reached. Retry later or pass --auth <token> for higher limits.'
+  )
+})
+
+test('formats network errors clearly', () => {
+  const actual = formatError({
+    code: 'ENOTFOUND',
+    message: 'getaddrinfo ENOTFOUND api.github.com'
+  }, 'nodejs/node')
+
+  expect(actual).toBe(
+    'Error: Unable to fetch issues for "nodejs/node".\nPlease check your network connection and try again.'
+  )
+})
+
+test('falls back to the original error message for unknown failures', () => {
+  const actual = formatError(new Error('Something odd happened'), 'vercel/next.js')
+
+  expect(actual).toBe(
+    'Error: Unable to fetch issues for "vercel/next.js".\nSomething odd happened'
+  )
+})