perf: improve isBlobLike (#3070)

benchmarks/core/is-blob-like.mjs

@@ -0,0 +1,64 @@
+import { bench, group, run } from 'mitata'
+import { isBlobLike } from '../../lib/core/util.js'
+
+const buffer = Buffer.alloc(1)
+
+const blob = new Blob(['asd'], {
+  type: 'application/json'
+})
+
+const file = new File(['asd'], 'file.txt', {
+  type: 'text/plain'
+})
+
+const blobLikeStream = {
+  [Symbol.toStringTag]: 'Blob',
+  stream: () => {}
+}
+
+const fileLikeStream = {
+  stream: () => {},
+  [Symbol.toStringTag]: 'File'
+}
+
+const blobLikeArrayBuffer = {
+  [Symbol.toStringTag]: 'Blob',
+  arrayBuffer: () => {}
+}
+
+const fileLikeArrayBuffer = {
+  [Symbol.toStringTag]: 'File',
+  arrayBuffer: () => {}
+}
+
+group('isBlobLike', () => {
+  bench('blob', () => {
+    return isBlobLike(blob)
+  })
+  bench('file', () => {
+    return isBlobLike(file)
+  })
+  bench('blobLikeStream', () => {
+    return isBlobLike(blobLikeStream)
+  })
+  bench('fileLikeStream', () => {
+    return isBlobLike(fileLikeStream)
+  })
+  bench('fileLikeArrayBuffer', () => {
+    return isBlobLike(fileLikeArrayBuffer)
+  })
+  bench('blobLikeArrayBuffer', () => {
+    return isBlobLike(blobLikeArrayBuffer)
+  })
+  bench('buffer', () => {
+    return isBlobLike(buffer)
+  })
+  bench('null', () => {
+    return isBlobLike(null)
+  })
+  bench('string', () => {
+    return isBlobLike('invalid')
+  })
+})
+
+await run()

lib/core/util.js

@@ -22,13 +22,20 @@ function isStream (obj) {
 
 // based on https://github.com/node-fetch/fetch-blob/blob/8ab587d34080de94140b54f07168451e7d0b655e/index.js#L229-L241 (MIT License)
 function isBlobLike (object) {
-  return (Blob && object instanceof Blob) || (
-    object &&
-    typeof object === 'object' &&
-    (typeof object.stream === 'function' ||
-      typeof object.arrayBuffer === 'function') &&
-    /^(Blob|File)$/.test(object[Symbol.toStringTag])
-  )
+  if (object === null) {
+    return false
+  } else if (object instanceof Blob) {
+    return true
+  } else if (typeof object !== 'object') {
+    return false
+  } else {
+    const sTag = object[Symbol.toStringTag]
+
+    return (sTag === 'Blob' || sTag === 'File') && (
+      ('stream' in object && typeof object.stream === 'function') ||
+      ('arrayBuffer' in object && typeof object.arrayBuffer === 'function')
+    )
+  }
 }
 
 function buildURL (url, queryParams) {

test/util.js

@@ -0,0 +1,67 @@
+'use strict'
+
+const { strictEqual } = require('node:assert')
+const { test, describe } = require('node:test')
+const { isBlobLike } = require('../lib/core/util')
+const { Blob, File } = require('node:buffer')
+
+describe('isBlobLike', () => {
+  test('buffer', () => {
+    const buffer = Buffer.alloc(1)
+    strictEqual(isBlobLike(buffer), false)
+  })
+
+  test('blob', { skip: !Blob }, () => {
+    const blob = new Blob(['asd'], {
+      type: 'application/json'
+    })
+    strictEqual(isBlobLike(blob), true)
+  })
+
+  test('file', { skip: !File }, () => {
+    const file = new File(['asd'], 'file.txt', {
+      type: 'text/plain'
+    })
+    strictEqual(isBlobLike(file), true)
+  })
+
+  test('blobLikeStream', () => {
+    const blobLikeStream = {
+      [Symbol.toStringTag]: 'Blob',
+      stream: () => { }
+    }
+    strictEqual(isBlobLike(blobLikeStream), true)
+  })
+
+  test('fileLikeStream', () => {
+    const fileLikeStream = {
+      stream: () => { },
+      [Symbol.toStringTag]: 'File'
+    }
+    strictEqual(isBlobLike(fileLikeStream), true)
+  })
+
+  test('fileLikeArrayBuffer', () => {
+    const blobLikeArrayBuffer = {
+      [Symbol.toStringTag]: 'Blob',
+      arrayBuffer: () => { }
+    }
+    strictEqual(isBlobLike(blobLikeArrayBuffer), true)
+  })
+
+  test('blobLikeArrayBuffer', () => {
+    const fileLikeArrayBuffer = {
+      [Symbol.toStringTag]: 'File',
+      arrayBuffer: () => { }
+    }
+    strictEqual(isBlobLike(fileLikeArrayBuffer), true)
+  })
+
+  test('string', () => {
+    strictEqual(isBlobLike('Blob'), false)
+  })
+
+  test('null', () => {
+    strictEqual(isBlobLike(null), false)
+  })
+})