feat: disallow unique entry file name (#1328)

* feat: disallow unique entry file name

* Apply suggestions from code review

Co-authored-by: Eduardo Bouças <mail@eduardoboucas.com>

* chore: review fixes

* chore: fixes

* chore: fix name

---------

Co-authored-by: Eduardo Bouças <mail@eduardoboucas.com>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

Author: 3 people

src/feature_flags.ts

@@ -23,6 +23,9 @@ export const defaultFlags: Record<string, boolean> = {
 
   // Output CJS file extension
   zisi_output_cjs_extension: false,
+
+  // Do not allow ___netlify-entry-point as function or file name
+  zisi_disallow_new_entry_name: false,
 }
 
 export type FeatureFlag = keyof typeof defaultFlags

src/runtimes/index.ts

@@ -4,9 +4,11 @@ import { Config, getConfigForFunction, FunctionWithoutConfig } from '../config.j
 import { defaultFlags, FeatureFlags } from '../feature_flags.js'
 import { FunctionSource } from '../function.js'
 import type { RuntimeCache } from '../utils/cache.js'
+import { FunctionBundlingUserError } from '../utils/error.js'
 
 import goRuntime from './go/index.js'
 import jsRuntime from './node/index.js'
+import { ENTRY_FILE_NAME } from './node/utils/entry_file.js'
 import type { Runtime } from './runtime.js'
 import rustRuntime from './rust/index.js'
 
@@ -47,15 +49,27 @@ const findFunctionsInRuntime = async function ({
   const key = dedupe ? 'name' : 'srcPath'
 
   // Augmenting the function objects with additional information.
-  const augmentedFunctions: FunctionTupleWithoutConfig[] = functions.map((func) => [
-    func[key],
-    {
-      ...func,
-      extension: extname(func.mainFile),
-      filename: basename(func.srcPath),
-      runtime,
-    },
-  ])
+  const augmentedFunctions: FunctionTupleWithoutConfig[] = functions.map((func) => {
+    if (featureFlags.zisi_disallow_new_entry_name && func.name === ENTRY_FILE_NAME) {
+      throw new FunctionBundlingUserError(
+        `'${ENTRY_FILE_NAME}' is a reserved word and cannot be used as a function name.`,
+        {
+          functionName: func.name,
+          runtime: runtime.name,
+        },
+      )
+    }
+
+    return [
+      func[key],
+      {
+        ...func,
+        extension: extname(func.mainFile),
+        filename: basename(func.srcPath),
+        runtime,
+      },
+    ]
+  })
   const usedPaths = new Set(augmentedFunctions.map(([path]) => path))
   const remainingPaths = paths.filter((path) => !usedPaths.has(path))
 

src/runtimes/node/utils/entry_file.ts

@@ -1,10 +1,14 @@
 import { basename, extname, resolve } from 'path'
 
 import type { FeatureFlags } from '../../../feature_flags.js'
+import { FunctionBundlingUserError } from '../../../utils/error.js'
+import { RuntimeType } from '../../runtime.js'
 
 import { getFileExtensionForFormat, ModuleFileExtension, ModuleFormat } from './module_format.js'
 import { normalizeFilePath } from './normalize_path.js'
 
+export const ENTRY_FILE_NAME = '___netlify-entry-point'
+
 export interface EntryFile {
   contents: string
   filename: string
@@ -46,14 +50,38 @@ export const conflictsWithEntryFile = (
   srcFiles: string[],
   {
     basePath,
-    mainFile,
+    extension,
+    featureFlags,
     filename,
+    mainFile,
   }: {
     basePath: string
+    extension: string
+    featureFlags: FeatureFlags
     filename: string
     mainFile: string
   },
-) => srcFiles.some((srcFile) => isNamedLikeEntryFile(srcFile, { basePath, filename }) && srcFile !== mainFile)
+) => {
+  let hasConflict = false
+
+  srcFiles.forEach((srcFile) => {
+    if (featureFlags.zisi_disallow_new_entry_name && srcFile.includes(ENTRY_FILE_NAME)) {
+      throw new FunctionBundlingUserError(
+        `'${ENTRY_FILE_NAME}' is a reserved word and cannot be used as a file or directory name.`,
+        {
+          functionName: basename(filename, extension),
+          runtime: RuntimeType.JAVASCRIPT,
+        },
+      )
+    }
+
+    if (!hasConflict && isNamedLikeEntryFile(srcFile, { basePath, filename }) && srcFile !== mainFile) {
+      hasConflict = true
+    }
+  })
+
+  return hasConflict
+}
 
 // Returns the name for the AWS Lambda entry file
 // We do set the handler in AWS Lambda to `<func-name>.handler` and because of

src/runtimes/node/utils/zip.ts

@@ -113,6 +113,8 @@ const createZipArchive = async function ({
   // take.
   const hasEntryFileConflict = conflictsWithEntryFile(srcFiles, {
     basePath,
+    extension,
+    featureFlags,
     filename,
     mainFile,
   })

tests/fixtures/entry-file-file-name/___netlify-entry-point/other.js

@@ -0,0 +1 @@
+module.exports.handler = () => {}

tests/fixtures/entry-file-file-name/func1.js

@@ -0,0 +1,3 @@
+const { handler } = require('./___netlify-entry-point/other.js')
+
+module.exports.handler = handler

tests/fixtures/entry-file-func-name/___netlify-entry-point.js

@@ -0,0 +1 @@
+module.exports.handler = () => {}

tests/main.test.ts

@@ -2658,4 +2658,37 @@ describe('zip-it-and-ship-it', () => {
       expect(`${tmpDir}/func2.mjs`).not.toPathExist()
     },
   )
+
+  testMany('Does throw on a function which is named like the entry file', [...allBundleConfigs], async (options) => {
+    const fixtureName = 'entry-file-func-name'
+    const opts = merge(options, {
+      basePath: join(FIXTURES_DIR, fixtureName),
+      featureFlags: { zisi_disallow_new_entry_name: true },
+    })
+    await expect(
+      zipFixture(fixtureName, {
+        length: 1,
+        opts,
+      }),
+    ).rejects.toThrowError(/is a reserved word and cannot be used as a function name\.$/)
+  })
+
+  // esbuild does bundle everything into one file, so it does not have any other files in the bundle
+  testMany(
+    'Does throw on a function which has files named like the entry file',
+    ['bundler_default', 'bundler_nft'],
+    async (options) => {
+      const fixtureName = 'entry-file-file-name'
+      const opts = merge(options, {
+        basePath: join(FIXTURES_DIR, fixtureName),
+        featureFlags: { zisi_disallow_new_entry_name: true },
+      })
+      await expect(
+        zipFixture(fixtureName, {
+          length: 1,
+          opts,
+        }),
+      ).rejects.toThrowError(/is a reserved word and cannot be used as a file or directory name\.$/)
+    },
+  )
 })