1 files changed, 265 insertions, 0 deletions
diff --git a/lib/fetch/formdata.js b/lib/fetch/formdata.js
new file mode 100644
index 0000000..5975e26
--- /dev/null
+++ b/lib/fetch/formdata.js
@@ -0,0 +1,265 @@
+'use strict'
+
+const { isBlobLike, toUSVString, makeIterator } = require('./util')
+const { kState } = require('./symbols')
+const { File: UndiciFile, FileLike, isFileLike } = require('./file')
+const { webidl } = require('./webidl')
+const { Blob, File: NativeFile } = require('buffer')
+
+/** @type {globalThis['File']} */
+const File = NativeFile ?? UndiciFile
+
+// https://xhr.spec.whatwg.org/#formdata
+class FormData {
+  constructor (form) {
+    if (form !== undefined) {
+      throw webidl.errors.conversionFailed({
+        prefix: 'FormData constructor',
+        argument: 'Argument 1',
+        types: ['undefined']
+      })
+    }
+
+    this[kState] = []
+  }
+
+  append (name, value, filename = undefined) {
+    webidl.brandCheck(this, FormData)
+
+    webidl.argumentLengthCheck(arguments, 2, { header: 'FormData.append' })
+
+    if (arguments.length === 3 && !isBlobLike(value)) {
+      throw new TypeError(
+        "Failed to execute 'append' on 'FormData': parameter 2 is not of type 'Blob'"
+      )
+    }
+
+    // 1. Let value be value if given; otherwise blobValue.
+
+    name = webidl.converters.USVString(name)
+    value = isBlobLike(value)
+      ? webidl.converters.Blob(value, { strict: false })
+      : webidl.converters.USVString(value)
+    filename = arguments.length === 3
+      ? webidl.converters.USVString(filename)
+      : undefined
+
+    // 2. Let entry be the result of creating an entry with
+    // name, value, and filename if given.
+    const entry = makeEntry(name, value, filename)
+
+    // 3. Append entry to this’s entry list.
+    this[kState].push(entry)
+  }
+
+  delete (name) {
+    webidl.brandCheck(this, FormData)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FormData.delete' })
+
+    name = webidl.converters.USVString(name)
+
+    // The delete(name) method steps are to remove all entries whose name
+    // is name from this’s entry list.
+    this[kState] = this[kState].filter(entry => entry.name !== name)
+  }
+
+  get (name) {
+    webidl.brandCheck(this, FormData)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FormData.get' })
+
+    name = webidl.converters.USVString(name)
+
+    // 1. If there is no entry whose name is name in this’s entry list,
+    // then return null.
+    const idx = this[kState].findIndex((entry) => entry.name === name)
+    if (idx === -1) {
+      return null
+    }
+
+    // 2. Return the value of the first entry whose name is name from
+    // this’s entry list.
+    return this[kState][idx].value
+  }
+
+  getAll (name) {
+    webidl.brandCheck(this, FormData)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FormData.getAll' })
+
+    name = webidl.converters.USVString(name)
+
+    // 1. If there is no entry whose name is name in this’s entry list,
+    // then return the empty list.
+    // 2. Return the values of all entries whose name is name, in order,
+    // from this’s entry list.
+    return this[kState]
+      .filter((entry) => entry.name === name)
+      .map((entry) => entry.value)
+  }
+
+  has (name) {
+    webidl.brandCheck(this, FormData)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FormData.has' })
+
+    name = webidl.converters.USVString(name)
+
+    // The has(name) method steps are to return true if there is an entry
+    // whose name is name in this’s entry list; otherwise false.
+    return this[kState].findIndex((entry) => entry.name === name) !== -1
+  }
+
+  set (name, value, filename = undefined) {
+    webidl.brandCheck(this, FormData)
+
+    webidl.argumentLengthCheck(arguments, 2, { header: 'FormData.set' })
+
+    if (arguments.length === 3 && !isBlobLike(value)) {
+      throw new TypeError(
+        "Failed to execute 'set' on 'FormData': parameter 2 is not of type 'Blob'"
+      )
+    }
+
+    // The set(name, value) and set(name, blobValue, filename) method steps
+    // are:
+
+    // 1. Let value be value if given; otherwise blobValue.
+
+    name = webidl.converters.USVString(name)
+    value = isBlobLike(value)
+      ? webidl.converters.Blob(value, { strict: false })
+      : webidl.converters.USVString(value)
+    filename = arguments.length === 3
+      ? toUSVString(filename)
+      : undefined
+
+    // 2. Let entry be the result of creating an entry with name, value, and
+    // filename if given.
+    const entry = makeEntry(name, value, filename)
+
+    // 3. If there are entries in this’s entry list whose name is name, then
+    // replace the first such entry with entry and remove the others.
+    const idx = this[kState].findIndex((entry) => entry.name === name)
+    if (idx !== -1) {
+      this[kState] = [
+        ...this[kState].slice(0, idx),
+        entry,
+        ...this[kState].slice(idx + 1).filter((entry) => entry.name !== name)
+      ]
+    } else {
+      // 4. Otherwise, append entry to this’s entry list.
+      this[kState].push(entry)
+    }
+  }
+
+  entries () {
+    webidl.brandCheck(this, FormData)
+
+    return makeIterator(
+      () => this[kState].map(pair => [pair.name, pair.value]),
+      'FormData',
+      'key+value'
+    )
+  }
+
+  keys () {
+    webidl.brandCheck(this, FormData)
+
+    return makeIterator(
+      () => this[kState].map(pair => [pair.name, pair.value]),
+      'FormData',
+      'key'
+    )
+  }
+
+  values () {
+    webidl.brandCheck(this, FormData)
+
+    return makeIterator(
+      () => this[kState].map(pair => [pair.name, pair.value]),
+      'FormData',
+      'value'
+    )
+  }
+
+  /**
+   * @param {(value: string, key: string, self: FormData) => void} callbackFn
+   * @param {unknown} thisArg
+   */
+  forEach (callbackFn, thisArg = globalThis) {
+    webidl.brandCheck(this, FormData)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FormData.forEach' })
+
+    if (typeof callbackFn !== 'function') {
+      throw new TypeError(
+        "Failed to execute 'forEach' on 'FormData': parameter 1 is not of type 'Function'."
+      )
+    }
+
+    for (const [key, value] of this) {
+      callbackFn.apply(thisArg, [value, key, this])
+    }
+  }
+}
+
+FormData.prototype[Symbol.iterator] = FormData.prototype.entries
+
+Object.defineProperties(FormData.prototype, {
+  [Symbol.toStringTag]: {
+    value: 'FormData',
+    configurable: true
+  }
+})
+
+/**
+ * @see https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#create-an-entry
+ * @param {string} name
+ * @param {string|Blob} value
+ * @param {?string} filename
+ * @returns
+ */
+function makeEntry (name, value, filename) {
+  // 1. Set name to the result of converting name into a scalar value string.
+  // "To convert a string into a scalar value string, replace any surrogates
+  //  with U+FFFD."
+  // see: https://nodejs.org/dist/latest-v18.x/docs/api/buffer.html#buftostringencoding-start-end
+  name = Buffer.from(name).toString('utf8')
+
+  // 2. If value is a string, then set value to the result of converting
+  //    value into a scalar value string.
+  if (typeof value === 'string') {
+    value = Buffer.from(value).toString('utf8')
+  } else {
+    // 3. Otherwise:
+
+    // 1. If value is not a File object, then set value to a new File object,
+    //    representing the same bytes, whose name attribute value is "blob"
+    if (!isFileLike(value)) {
+      value = value instanceof Blob
+        ? new File([value], 'blob', { type: value.type })
+        : new FileLike(value, 'blob', { type: value.type })
+    }
+
+    // 2. If filename is given, then set value to a new File object,
+    //    representing the same bytes, whose name attribute is filename.
+    if (filename !== undefined) {
+      /** @type {FilePropertyBag} */
+      const options = {
+        type: value.type,
+        lastModified: value.lastModified
+      }
+
+      value = (NativeFile && value instanceof NativeFile) || value instanceof UndiciFile
+        ? new File([value], filename, options)
+        : new FileLike(value, filename, options)
+    }
+  }
+
+  // 4. Return an entry whose name is name and whose value is value.
+  return { name, value }
+}
+
+module.exports = { FormData }