1 files changed, 344 insertions, 0 deletions
diff --git a/lib/fileapi/filereader.js b/lib/fileapi/filereader.js
new file mode 100644
index 0000000..cd36a22
--- /dev/null
+++ b/lib/fileapi/filereader.js
@@ -0,0 +1,344 @@
+'use strict'
+
+const {
+  staticPropertyDescriptors,
+  readOperation,
+  fireAProgressEvent
+} = require('./util')
+const {
+  kState,
+  kError,
+  kResult,
+  kEvents,
+  kAborted
+} = require('./symbols')
+const { webidl } = require('../fetch/webidl')
+const { kEnumerableProperty } = require('../core/util')
+
+class FileReader extends EventTarget {
+  constructor () {
+    super()
+
+    this[kState] = 'empty'
+    this[kResult] = null
+    this[kError] = null
+    this[kEvents] = {
+      loadend: null,
+      error: null,
+      abort: null,
+      load: null,
+      progress: null,
+      loadstart: null
+    }
+  }
+
+  /**
+   * @see https://w3c.github.io/FileAPI/#dfn-readAsArrayBuffer
+   * @param {import('buffer').Blob} blob
+   */
+  readAsArrayBuffer (blob) {
+    webidl.brandCheck(this, FileReader)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FileReader.readAsArrayBuffer' })
+
+    blob = webidl.converters.Blob(blob, { strict: false })
+
+    // The readAsArrayBuffer(blob) method, when invoked,
+    // must initiate a read operation for blob with ArrayBuffer.
+    readOperation(this, blob, 'ArrayBuffer')
+  }
+
+  /**
+   * @see https://w3c.github.io/FileAPI/#readAsBinaryString
+   * @param {import('buffer').Blob} blob
+   */
+  readAsBinaryString (blob) {
+    webidl.brandCheck(this, FileReader)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FileReader.readAsBinaryString' })
+
+    blob = webidl.converters.Blob(blob, { strict: false })
+
+    // The readAsBinaryString(blob) method, when invoked,
+    // must initiate a read operation for blob with BinaryString.
+    readOperation(this, blob, 'BinaryString')
+  }
+
+  /**
+   * @see https://w3c.github.io/FileAPI/#readAsDataText
+   * @param {import('buffer').Blob} blob
+   * @param {string?} encoding
+   */
+  readAsText (blob, encoding = undefined) {
+    webidl.brandCheck(this, FileReader)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FileReader.readAsText' })
+
+    blob = webidl.converters.Blob(blob, { strict: false })
+
+    if (encoding !== undefined) {
+      encoding = webidl.converters.DOMString(encoding)
+    }
+
+    // The readAsText(blob, encoding) method, when invoked,
+    // must initiate a read operation for blob with Text and encoding.
+    readOperation(this, blob, 'Text', encoding)
+  }
+
+  /**
+   * @see https://w3c.github.io/FileAPI/#dfn-readAsDataURL
+   * @param {import('buffer').Blob} blob
+   */
+  readAsDataURL (blob) {
+    webidl.brandCheck(this, FileReader)
+
+    webidl.argumentLengthCheck(arguments, 1, { header: 'FileReader.readAsDataURL' })
+
+    blob = webidl.converters.Blob(blob, { strict: false })
+
+    // The readAsDataURL(blob) method, when invoked, must
+    // initiate a read operation for blob with DataURL.
+    readOperation(this, blob, 'DataURL')
+  }
+
+  /**
+   * @see https://w3c.github.io/FileAPI/#dfn-abort
+   */
+  abort () {
+    // 1. If this's state is "empty" or if this's state is
+    //    "done" set this's result to null and terminate
+    //    this algorithm.
+    if (this[kState] === 'empty' || this[kState] === 'done') {
+      this[kResult] = null
+      return
+    }
+
+    // 2. If this's state is "loading" set this's state to
+    //    "done" and set this's result to null.
+    if (this[kState] === 'loading') {
+      this[kState] = 'done'
+      this[kResult] = null
+    }
+
+    // 3. If there are any tasks from this on the file reading
+    //    task source in an affiliated task queue, then remove
+    //    those tasks from that task queue.
+    this[kAborted] = true
+
+    // 4. Terminate the algorithm for the read method being processed.
+    // TODO
+
+    // 5. Fire a progress event called abort at this.
+    fireAProgressEvent('abort', this)
+
+    // 6. If this's state is not "loading", fire a progress
+    //    event called loadend at this.
+    if (this[kState] !== 'loading') {
+      fireAProgressEvent('loadend', this)
+    }
+  }
+
+  /**
+   * @see https://w3c.github.io/FileAPI/#dom-filereader-readystate
+   */
+  get readyState () {
+    webidl.brandCheck(this, FileReader)
+
+    switch (this[kState]) {
+      case 'empty': return this.EMPTY
+      case 'loading': return this.LOADING
+      case 'done': return this.DONE
+    }
+  }
+
+  /**
+   * @see https://w3c.github.io/FileAPI/#dom-filereader-result
+   */
+  get result () {
+    webidl.brandCheck(this, FileReader)
+
+    // The result attribute’s getter, when invoked, must return
+    // this's result.
+    return this[kResult]
+  }
+
+  /**
+   * @see https://w3c.github.io/FileAPI/#dom-filereader-error
+   */
+  get error () {
+    webidl.brandCheck(this, FileReader)
+
+    // The error attribute’s getter, when invoked, must return
+    // this's error.
+    return this[kError]
+  }
+
+  get onloadend () {
+    webidl.brandCheck(this, FileReader)
+
+    return this[kEvents].loadend
+  }
+
+  set onloadend (fn) {
+    webidl.brandCheck(this, FileReader)
+
+    if (this[kEvents].loadend) {
+      this.removeEventListener('loadend', this[kEvents].loadend)
+    }
+
+    if (typeof fn === 'function') {
+      this[kEvents].loadend = fn
+      this.addEventListener('loadend', fn)
+    } else {
+      this[kEvents].loadend = null
+    }
+  }
+
+  get onerror () {
+    webidl.brandCheck(this, FileReader)
+
+    return this[kEvents].error
+  }
+
+  set onerror (fn) {
+    webidl.brandCheck(this, FileReader)
+
+    if (this[kEvents].error) {
+      this.removeEventListener('error', this[kEvents].error)
+    }
+
+    if (typeof fn === 'function') {
+      this[kEvents].error = fn
+      this.addEventListener('error', fn)
+    } else {
+      this[kEvents].error = null
+    }
+  }
+
+  get onloadstart () {
+    webidl.brandCheck(this, FileReader)
+
+    return this[kEvents].loadstart
+  }
+
+  set onloadstart (fn) {
+    webidl.brandCheck(this, FileReader)
+
+    if (this[kEvents].loadstart) {
+      this.removeEventListener('loadstart', this[kEvents].loadstart)
+    }
+
+    if (typeof fn === 'function') {
+      this[kEvents].loadstart = fn
+      this.addEventListener('loadstart', fn)
+    } else {
+      this[kEvents].loadstart = null
+    }
+  }
+
+  get onprogress () {
+    webidl.brandCheck(this, FileReader)
+
+    return this[kEvents].progress
+  }
+
+  set onprogress (fn) {
+    webidl.brandCheck(this, FileReader)
+
+    if (this[kEvents].progress) {
+      this.removeEventListener('progress', this[kEvents].progress)
+    }
+
+    if (typeof fn === 'function') {
+      this[kEvents].progress = fn
+      this.addEventListener('progress', fn)
+    } else {
+      this[kEvents].progress = null
+    }
+  }
+
+  get onload () {
+    webidl.brandCheck(this, FileReader)
+
+    return this[kEvents].load
+  }
+
+  set onload (fn) {
+    webidl.brandCheck(this, FileReader)
+
+    if (this[kEvents].load) {
+      this.removeEventListener('load', this[kEvents].load)
+    }
+
+    if (typeof fn === 'function') {
+      this[kEvents].load = fn
+      this.addEventListener('load', fn)
+    } else {
+      this[kEvents].load = null
+    }
+  }
+
+  get onabort () {
+    webidl.brandCheck(this, FileReader)
+
+    return this[kEvents].abort
+  }
+
+  set onabort (fn) {
+    webidl.brandCheck(this, FileReader)
+
+    if (this[kEvents].abort) {
+      this.removeEventListener('abort', this[kEvents].abort)
+    }
+
+    if (typeof fn === 'function') {
+      this[kEvents].abort = fn
+      this.addEventListener('abort', fn)
+    } else {
+      this[kEvents].abort = null
+    }
+  }
+}
+
+// https://w3c.github.io/FileAPI/#dom-filereader-empty
+FileReader.EMPTY = FileReader.prototype.EMPTY = 0
+// https://w3c.github.io/FileAPI/#dom-filereader-loading
+FileReader.LOADING = FileReader.prototype.LOADING = 1
+// https://w3c.github.io/FileAPI/#dom-filereader-done
+FileReader.DONE = FileReader.prototype.DONE = 2
+
+Object.defineProperties(FileReader.prototype, {
+  EMPTY: staticPropertyDescriptors,
+  LOADING: staticPropertyDescriptors,
+  DONE: staticPropertyDescriptors,
+  readAsArrayBuffer: kEnumerableProperty,
+  readAsBinaryString: kEnumerableProperty,
+  readAsText: kEnumerableProperty,
+  readAsDataURL: kEnumerableProperty,
+  abort: kEnumerableProperty,
+  readyState: kEnumerableProperty,
+  result: kEnumerableProperty,
+  error: kEnumerableProperty,
+  onloadstart: kEnumerableProperty,
+  onprogress: kEnumerableProperty,
+  onload: kEnumerableProperty,
+  onabort: kEnumerableProperty,
+  onerror: kEnumerableProperty,
+  onloadend: kEnumerableProperty,
+  [Symbol.toStringTag]: {
+    value: 'FileReader',
+    writable: false,
+    enumerable: false,
+    configurable: true
+  }
+})
+
+Object.defineProperties(FileReader, {
+  EMPTY: staticPropertyDescriptors,
+  LOADING: staticPropertyDescriptors,
+  DONE: staticPropertyDescriptors
+})
+
+module.exports = {
+  FileReader
+}