0.0.8 - fix empty Blob URL and invalid byte range

Author: severo

CHANGELOG.md

@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## [0.0.8]
+
+- return with no iteration if the URL is an empty Blob URL
+- return with no iteration if the byte range is invalid
+
 ## [0.0.7]
 
 - export toURL utility function

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "csv-range",
-  "version": "0.0.7",
+  "version": "0.0.8",
   "description": "Parse ranges of a CSV file.",
   "type": "module",
   "license": "MIT",
@@ -46,7 +46,7 @@
     "@vitest/ui": "4.0.10",
     "bumpp": "10.3.1",
     "eslint": "9.39.1",
-    "eslint-plugin-jsdoc": "61.2.1",
+    "eslint-plugin-jsdoc": "61.3.0",
     "eslint-plugin-simple-import-sort": "12.1.1",
     "globals": "16.5.0",
     "tsdown": "0.16.5",

package.json

@@ -78,6 +78,10 @@ export async function fetchRange({
     },
   }
   const response = await fetch(url, mergedRequestInit)
+  // Note that the range fetch might throw if the range is invalid, and the URL is a Blob URL.
+  // With "normal" URLs (http, https), the server should return a 416 status code instead.
+  // See the spec https://fetch.spec.whatwg.org/#scheme-fetch.
+
   if (response.status === 416) {
     // Requested Range Not Satisfiable
     throw new Error(

src/fetch.ts

@@ -4,7 +4,7 @@ import { defaultChunkSize } from './options/constants'
 import { type DelimiterError, type ParseOptions, validateAndGuessParseOptions } from './options/parseOptions'
 import { parse } from './parser'
 import type { ParseResult } from './types'
-import { decode } from './utils'
+import { decode, isEmptyBlobURL } from './utils'
 
 interface FetchOptions {
   chunkSize?: number
@@ -45,7 +45,19 @@ export async function* parseURL(
 ): AsyncGenerator<ParseResult, void, unknown> {
   const chunkSize = checkIntegerGreaterOrEqualThan(options.chunkSize, 1) ?? defaultChunkSize
   let firstByte = checkIntegerGreaterOrEqualThan(options.firstByte, 0) ?? 0
+  // Note: lastByte can be -1 to indicate no data to fetch.
+  // It's related to the bug in Node.js (https://github.com/nodejs/node/issues/60382) and the
+  // workaround we propose with toURL util (add ' ' at the end of the file, and set lastByte
+  // to the original file size - 1). If the file is empty, lastByte will be -1.
   let lastByte = checkIntegerGreaterOrEqualThan(options.lastByte, -1)
+  if (lastByte !== undefined && lastByte < firstByte) {
+    // No data to fetch
+    return
+  }
+  // Return if the URL is an empty Blob URL
+  if (await isEmptyBlobURL(url)) {
+    return
+  }
 
   const { delimitersToGuess, stripBOM } = options
   let parseOptions: ParseOptions | undefined = undefined

src/url.ts

@@ -1,25 +1,50 @@
 /**
  * Creates a blob URL from the given text.
  * @param text The text to create a blob URL from.
- * @returns An object containing the blob URL, the size of the text in bytes, and a function to revoke the URL.
+ * @param options Options.
+ * @param options.withNodeWorkaround Whether to add an extra space at the end of the text
+ * to work around the Node.js bug (https://github.com/nodejs/node/issues/60382). Defaults to false.
+ * @returns An object containing the blob URL, the size of the file in bytes (without the extra space,
+ *  if `withNodeWorkaround` is true), and a function to revoke the URL.
  */
-export function toURL(text: string): {
+export function toURL(text: string, { withNodeWorkaround }: { withNodeWorkaround?: boolean } = {}): {
   url: string
   fileSize: number
   revoke: () => void
 } {
+  withNodeWorkaround = withNodeWorkaround ?? false
   // add an extra space to fix https://github.com/nodejs/node/issues/60382
-  const blob = new Blob([text + ' '])
+  const blob = new Blob([withNodeWorkaround ? text + ' ' : text])
   const url = URL.createObjectURL(blob)
   return {
     url,
-    fileSize: blob.size - 1, // subtract the extra space
+    // remove the extra space from the file size
+    fileSize: withNodeWorkaround ? blob.size - 1 : blob.size,
     revoke: () => {
       URL.revokeObjectURL(url)
     },
   }
 }
 
+/**
+ * Checks if the given URL is an empty Blob URL.
+ * @param url The URL to check.
+ * @returns Whether the URL is an empty Blob URL.
+ */
+export async function isEmptyBlobURL(url: string): Promise<boolean> {
+  if (!url.startsWith('blob:')) {
+    return false
+  }
+  try {
+    const response = await fetch(url)
+    const blob = await response.blob()
+    return blob.size === 0
+  }
+  catch {
+    return false
+  }
+}
+
 /**
  * Decodes the given bytes using the provided decoder.
  * @param bytes The bytes to decode.