Add option to intercept HTTP requests

README.md

@@ -132,6 +132,39 @@ playground('.selector', options)
   instance.getCode()  // function for getting code from snippet.
   ```
 
+- `onRequest(request)` — Request interceptor that allows you to modify HTTP requests before they are sent.
+   _request_ — request with the following properties:
+  - `url` — the request URL
+  - `method` — HTTP method (GET, POST, etc.)
+  - `headers` — request headers
+  - `body` — request body (if applicable)
+
+  The interceptor should return the modified request
+
+  ```js
+  const options = {
+    onRequest: async (request) => {
+      request.headers = {
+        ...request.headers,
+        'Authorization': 'Basic a290bGluLXBsYXlncm91bmQ6MTIzNA=='
+      };
+
+      if (request.url.includes("/compiler/highlight"))
+      request.url = request.url + '?severity=WARNING';
+
+      if (request.body && request.url.includes("/compiler/complete")) {
+        const body = JSON.parse(request.body);
+        body.type = 'CLASS';
+        request.body = JSON.stringify(body);
+      }
+
+      return request;
+    }
+  };
+
+  playground('.selector', options);
+  ```
+
 ## Customizing editors
 
 

src/config.js

@@ -3,7 +3,12 @@ import { TargetPlatforms } from './utils/platforms';
 
 const currentScript = getCurrentScript();
 
-export const RUNTIME_CONFIG = { ...getConfigFromElement(currentScript) };
+export const RUNTIME_CONFIG = {
+  ...getConfigFromElement(currentScript),
+  interceptor: {
+    onRequest: null,
+  }
+};
 
 /**
  * API Paths

src/index.js

@@ -22,13 +22,19 @@ polyfill();
  * @property {Function} onConsoleOpen
  * @property {Function} onConsoleClose
  * @property {Function} callBack
+ * @property {Function} onRequest
  *
  * @param {string} selector
  * @param {Object} options
  * @return {Promise<Array<ExecutableCode>>}
  */
 export default function create(selector, options = {}) {
   API_URLS.server = options.server || API_URLS.server;
+
+  if (options.onRequest) {
+    RUNTIME_CONFIG.interceptor.onRequest = options.onRequest;
+  }
+
   return ExecutableCode.create(selector, options);
 }
 

src/interceptor/fetch-interceptor.js

@@ -0,0 +1,23 @@
+import { fetch } from 'whatwg-fetch';
+import { RUNTIME_CONFIG } from '../config';
+
+export const fetchWithInterceptor = async function(url, config = {}) {
+  const onRequest = RUNTIME_CONFIG.interceptor?.onRequest;
+
+  const request = {
+    url,
+    method: config.method || 'GET',
+    headers: { ...config.headers },
+    body: config.body,
+  };
+
+  const modified = typeof onRequest === 'function'
+    ? await onRequest(request).catch(() => null) ?? request
+    : request;
+
+  return fetch(modified.url, {
+    method: modified.method,
+    headers: modified.headers,
+    body: modified.body,
+  });
+};

src/js-executor/index.js

@@ -4,7 +4,7 @@ import {showJsException} from '../view/output-view';
 import {processingHtmlBrackets} from '../utils';
 import {isWasmRelated, TargetPlatforms} from '../utils/platforms';
 import {executeJs, executeWasmCode, executeWasmCodeWithSkiko, executeWasmCodeWithStdlib} from './execute-es-module';
-import {fetch} from "whatwg-fetch";
+import {fetchWithInterceptor} from '../interceptor/fetch-interceptor';
 
 const INIT_SCRIPT =
   'if(kotlin.BufferedOutput!==undefined){kotlin.out = new kotlin.BufferedOutput()}' +
@@ -183,13 +183,13 @@ export default class JsExecutor {
     }
     if (targetPlatform === TargetPlatforms.COMPOSE_WASM) {
 
-      const skikoStdlib = fetch(API_URLS.RESOURCE_VERSIONS(),{
+      const skikoStdlib = fetchWithInterceptor(API_URLS.RESOURCE_VERSIONS(),{
         method: 'GET'
       }).then(response => response.json())
         .then(versions => {
           const skikoVersion = versions["skiko"];
 
-          const skikoExports = fetch(API_URLS.SKIKO_MJS(skikoVersion), {
+          const skikoExports = fetchWithInterceptor(API_URLS.SKIKO_MJS(skikoVersion), {
             method: 'GET',
             headers: {
               'Content-Type': 'text/javascript',
@@ -208,7 +208,7 @@ export default class JsExecutor {
 
           const stdlibVersion = versions["stdlib"];
 
-          const stdlibExports = fetch(API_URLS.STDLIB_MJS(stdlibVersion), {
+          const stdlibExports = fetchWithInterceptor(API_URLS.STDLIB_MJS(stdlibVersion), {
             method: 'GET',
             headers: {
               'Content-Type': 'text/javascript',

src/webdemo-api.js

@@ -1,4 +1,3 @@
-import { fetch } from 'whatwg-fetch';
 import { API_URLS } from './config';
 import flatten from 'flatten';
 import { isWasmRelated, TargetPlatforms } from './utils/platforms';
@@ -9,6 +8,7 @@ import {
   processJUnitResults,
   processJVMOutput,
 } from './view/output-view';
+import { fetchWithInterceptor } from './interceptor/fetch-interceptor';
 
 /**
  * @typedef {Object} KotlinVersion
@@ -31,7 +31,7 @@ export default class WebDemoApi {
    */
   static getCompilerVersions() {
     if (!CACHE.compilerVersions) {
-      CACHE.compilerVersions = fetch(API_URLS.VERSIONS)
+      CACHE.compilerVersions = fetchWithInterceptor(API_URLS.VERSIONS)
         .then((response) => response.json())
         .catch(() => (CACHE.compilerVersions = null));
     }
@@ -268,7 +268,7 @@ function executeCode(
     ...(options || {}),
   };
 
-  return fetch(url, {
+  return fetchWithInterceptor(url, {
     method: 'POST',
     body: JSON.stringify(body),
     headers: {