feat: add customErrorInfo property to user errors (#25)

src/bundle_error.ts

@@ -0,0 +1,36 @@
+interface BundleErrorOptions {
+  format: string
+}
+
+const getCustomErrorInfo = (options: BundleErrorOptions) => ({
+  location: {
+    format: options.format,
+    runtime: 'deno',
+  },
+  type: 'functionsBundling',
+})
+
+class BundleError extends Error {
+  customErrorInfo: ReturnType<typeof getCustomErrorInfo>
+
+  constructor(originalError: Error, options: BundleErrorOptions) {
+    super(originalError.message)
+
+    this.customErrorInfo = getCustomErrorInfo(options)
+    this.name = 'BundleError'
+    this.stack = originalError.stack
+
+    // https://github.com/microsoft/TypeScript-wiki/blob/8a66ecaf77118de456f7cd9c56848a40fe29b9b4/Breaking-Changes.md#implicit-any-error-raised-for-un-annotated-callback-arguments-with-no-matching-overload-arguments
+    Object.setPrototypeOf(this, BundleError.prototype)
+  }
+}
+
+const wrapBundleError = (input: unknown, options: BundleErrorOptions) => {
+  if (input instanceof Error) {
+    return new BundleError(input, options)
+  }
+
+  return input
+}
+
+export { BundleError, wrapBundleError }

src/bundler.ts

@@ -9,8 +9,8 @@ import type { Bundle } from './bundle.js'
 import type { Declaration } from './declaration.js'
 import { FeatureFlags, getFlags } from './feature_flags.js'
 import { findFunctions } from './finder.js'
-import { bundleESZIP } from './formats/eszip.js'
-import { bundleJS } from './formats/javascript.js'
+import { bundle as bundleESZIP } from './formats/eszip.js'
+import { bundle as bundleJS } from './formats/javascript.js'
 import { ImportMap, ImportMapFile } from './import_map.js'
 import { writeManifest } from './manifest.js'
 

src/formats/eszip.ts

@@ -3,6 +3,7 @@ import { fileURLToPath } from 'url'
 
 import { DenoBridge } from '../bridge.js'
 import type { Bundle } from '../bundle.js'
+import { wrapBundleError } from '../bundle_error.js'
 import { EdgeFunction } from '../edge_function.js'
 import { getFileHash } from '../utils/sha256.js'
 
@@ -15,6 +16,14 @@ interface BundleESZIPOptions {
   functions: EdgeFunction[]
 }
 
+const bundle = async (options: BundleESZIPOptions) => {
+  try {
+    return await bundleESZIP(options)
+  } catch (error: unknown) {
+    throw wrapBundleError(error, { format: 'eszip' })
+  }
+}
+
 const bundleESZIP = async ({
   basePath,
   buildID,
@@ -52,4 +61,4 @@ const getESZIPBundler = () => {
   return bundlerPath
 }
 
-export { bundleESZIP }
+export { bundle }

src/formats/javascript.ts

@@ -7,6 +7,7 @@ import del from 'del'
 
 import { DenoBridge } from '../bridge.js'
 import type { Bundle } from '../bundle.js'
+import { wrapBundleError } from '../bundle_error.js'
 import { EdgeFunction } from '../edge_function.js'
 import { ImportMap } from '../import_map.js'
 import type { FormatFunction } from '../server/server.js'
@@ -24,6 +25,14 @@ interface BundleJSOptions {
   importMap: ImportMap
 }
 
+const bundle = async (options: BundleJSOptions) => {
+  try {
+    return await bundleJS(options)
+  } catch (error: unknown) {
+    throw wrapBundleError(error, { format: 'javascript' })
+  }
+}
+
 const bundleJS = async ({
   buildID,
   debug,
@@ -145,4 +154,4 @@ const getProductionEntryPoint = (functions: EdgeFunction[]) => {
   return [bootImport, importLines, exportDeclaration, defaultExport].join('\n\n')
 }
 
-export { bundleJS, generateStage2, getBootstrapURL }
+export { bundle, generateStage2, getBootstrapURL }

test/bundler.ts

@@ -5,6 +5,7 @@ import { fileURLToPath } from 'url'
 import test from 'ava'
 import tmp from 'tmp-promise'
 
+import { BundleError } from '../src/bundle_error.js'
 import { bundle } from '../src/bundler.js'
 
 const url = new URL(import.meta.url)
@@ -69,3 +70,34 @@ test('Produces an additional ESZIP bundle when the `edge_functions_produce_eszip
 
   await fs.rmdir(tmpDir.path, { recursive: true })
 })
+
+test('Adds a custom error property to bundling errors', async (t) => {
+  const sourceDirectory = resolve(dirname, '..', 'fixtures', 'invalid_functions', 'functions')
+  const tmpDir = await tmp.dir()
+  const declarations = [
+    {
+      function: 'func1',
+      path: '/func1',
+    },
+  ]
+
+  try {
+    await bundle([sourceDirectory], tmpDir.path, declarations)
+
+    t.fail('Expected bundling to throw')
+  } catch (error: unknown) {
+    if (error instanceof BundleError) {
+      t.deepEqual(error.customErrorInfo, {
+        location: {
+          format: 'javascript',
+          runtime: 'deno',
+        },
+        type: 'functionsBundling',
+      })
+    } else {
+      t.fail('Expected custom error')
+    }
+  } finally {
+    await fs.rmdir(tmpDir.path, { recursive: true })
+  }
+})

test/fixtures/invalid_functions/functions/func1.ts

@@ -0,0 +1 @@
+export default async () => new NotAResponse('Hello')