feat(adapter): add fetch adapter; (#6371)

lib/adapters/fetch.js

@@ -0,0 +1,197 @@
+import platform from "../platform/index.js";
+import utils from "../utils.js";
+import AxiosError from "../core/AxiosError.js";
+import composeSignals from "../helpers/composeSignals.js";
+import {trackStream} from "../helpers/trackStream.js";
+import AxiosHeaders from "../core/AxiosHeaders.js";
+import progressEventReducer from "../helpers/progressEventReducer.js";
+import resolveConfig from "../helpers/resolveConfig.js";
+import settle from "../core/settle.js";
+
+const fetchProgressDecorator = (total, fn) => {
+  const lengthComputable = total != null;
+  return (loaded) => setTimeout(() => fn({
+    lengthComputable,
+    total,
+    loaded
+  }));
+}
+
+const isFetchSupported = typeof fetch !== 'undefined';
+
+const supportsRequestStreams = isFetchSupported && (() => {
+  let duplexAccessed = false;
+
+  const hasContentType = new Request(platform.origin, {
+    body: new ReadableStream(),
+    method: 'POST',
+    get duplex() {
+      duplexAccessed = true;
+      return 'half';
+    },
+  }).headers.has('Content-Type');
+
+  return duplexAccessed && !hasContentType;
+})();
+
+const DEFAULT_CHUNK_SIZE = 64 * 1024;
+
+const resolvers = {
+  stream: (res) => res.body
+};
+
+isFetchSupported && ['text', 'arrayBuffer', 'blob', 'formData'].forEach(type => [
+  resolvers[type] = utils.isFunction(Response.prototype[type]) ? (res) => res[type]() : (_, config) => {
+    throw new AxiosError(`Response type ${type} is not supported`, AxiosError.ERR_NOT_SUPPORT, config);
+  }
+])
+
+const getBodyLength = async (body) => {
+  if(utils.isBlob(body)) {
+    return body.size;
+  }
+
+  if(utils.isSpecCompliantForm(body)) {
+    return (await new Request(body).arrayBuffer()).byteLength;
+  }
+
+  if(utils.isArrayBufferView(body)) {
+    return body.byteLength;
+  }
+
+  if(utils.isURLSearchParams(body)) {
+    body = body + '';
+  }
+
+  if(utils.isString(body)) {
+    return (await new TextEncoder().encode(body)).byteLength;
+  }
+}
+
+const resolveBodyLength = async (headers, body) => {
+  const length = utils.toFiniteNumber(headers.getContentLength());
+
+  return length == null ? getBodyLength(body) : length;
+}
+
+export default async (config) => {
+  let {
+    url,
+    method,
+    data,
+    signal,
+    cancelToken,
+    timeout,
+    onDownloadProgress,
+    onUploadProgress,
+    responseType,
+    headers,
+    withCredentials = 'same-origin',
+    fetchOptions
+  } = resolveConfig(config);
+
+  responseType = responseType ? (responseType + '').toLowerCase() : 'text';
+
+  let [composedSignal, stopTimeout] = (signal || cancelToken || timeout) ?
+    composeSignals([signal, cancelToken], timeout) : [];
+
+  let finished, request;
+
+  const onFinish = () => {
+    !finished && setTimeout(() => {
+      composedSignal && composedSignal.unsubscribe();
+    });
+
+    finished = true;
+  }
+
+  try {
+    if (onUploadProgress && supportsRequestStreams && method !== 'get' && method !== 'head') {
+      let requestContentLength = await resolveBodyLength(headers, data);
+
+      let _request = new Request(url, {
+        method,
+        body: data,
+        duplex: "half"
+      });
+
+      let contentTypeHeader;
+
+      if (utils.isFormData(data) && (contentTypeHeader = _request.headers.get('content-type'))) {
+        headers.setContentType(contentTypeHeader)
+      }
+
+      data = trackStream(_request.body, DEFAULT_CHUNK_SIZE, fetchProgressDecorator(
+        requestContentLength,
+        progressEventReducer(onUploadProgress)
+      ));
+    }
+
+    if (!utils.isString(withCredentials)) {
+      withCredentials = withCredentials ? 'cors' : 'omit';
+    }
+
+    request = new Request(url, {
+      ...fetchOptions,
+      signal: composedSignal,
+      method,
+      headers: headers.normalize().toJSON(),
+      body: data,
+      duplex: "half",
+      withCredentials
+    });
+
+    let response = await fetch(request);
+
+    const isStreamResponse = responseType === 'stream' || responseType === 'response';
+
+    if (onDownloadProgress || isStreamResponse) {
+      const options = {};
+
+      Object.getOwnPropertyNames(response).forEach(prop => {
+        options[prop] = response[prop];
+      });
+
+      const responseContentLength = utils.toFiniteNumber(response.headers.get('content-length'));
+
+      response = new Response(
+        trackStream(response.body, DEFAULT_CHUNK_SIZE, onDownloadProgress && fetchProgressDecorator(
+          responseContentLength,
+          progressEventReducer(onDownloadProgress, true)
+        ), isStreamResponse && onFinish),
+        options
+      );
+    }
+
+    responseType = responseType || 'text';
+
+    let responseData = await resolvers[utils.findKey(resolvers, responseType) || 'text'](response, config);
+
+    !isStreamResponse && onFinish();
+
+    stopTimeout && stopTimeout();
+
+    return await new Promise((resolve, reject) => {
+      settle(resolve, reject, {
+        data: responseData,
+        headers: AxiosHeaders.from(response.headers),
+        status: response.status,
+        statusText: response.statusText,
+        config,
+        request
+      })
+    })
+  } catch (err) {
+    onFinish();
+
+    let {code} = err;
+
+    if (err.name === 'NetworkError') {
+      code = AxiosError.ERR_NETWORK;
+    }
+
+    throw AxiosError.from(err, code, config, request);
+  }
+}
+
+