Add fetch with headers and body sample

package.json

@@ -29,7 +29,7 @@
   "scripts": {
     "test": "node tests/index.js",
     "build": "rewatch",
-    "format": "rescript format -all && prettier --write ./docs ./tests/index.js ./package.json",
+    "format": "rescript format -all && prettier --write ./tests/index.js ./package.json",
     "docs": "astro dev",
     "build:docs": "astro build"
   },

src/FetchAPI.res

@@ -218,7 +218,9 @@ type urlSearchParams = {
   size: int,
 }
 
-type headersInit = any
+type headersInit
+
+type bodyInit
 
 type requestInfo = any
 
@@ -236,7 +238,7 @@ type requestInit = {
   /**
     A BodyInit object or null to set request's body.
     */
-  mutable body?: Null.t<bodyInit>,
+  mutable body?: bodyInit,
   /**
     A string whose value is a same-origin URL, "about:client", or the empty string, to set request's referrer.
     */

src/FetchAPI/BodyInit.res

@@ -0,0 +1,47 @@
+open FileAPI
+open FetchAPI
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromString: string => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromArrayBuffer: ArrayBuffer.t => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromTypedArray: TypedArray.t<'t> => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromDataView: DataView.t => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromBlob: blob => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromFile: file => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromURLSearchParams: urlSearchParams => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromFormData: formData => bodyInit = "%identity"
+
+/**
+[Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_a_body)
+ */
+external fromReadableStream: readableStream<'t> => bodyInit = "%identity"

src/FetchAPI/HeadersInit.res

@@ -0,0 +1,11 @@
+open FetchAPI
+
+/**
+ [Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_headers)
+ */
+external fromDict: dict<string> => headersInit = "%identity"
+
+/**
+ [Read more on MDN](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#setting_headers)
+ */
+external fromHeaders: headers => headersInit = "%identity"

src/Prelude.res

@@ -5,8 +5,6 @@ external unsafeConversation: 'tinput => 'toutput = "%identity"
 
 type bufferSource = any
 
-type bodyInit = any
-
 type sharedArrayBuffer = any
 
 type float64Array = any

tests/Global__test.res

@@ -1,3 +1,16 @@
 open WebAPI.Global
 
 let response = await fetch("https://rescript-lang.org/")
+
+let response2 = await fetch(
+  "https://rescript-lang.org/",
+  ~init={
+    headers: HeadersInit.fromDict(
+      dict{
+        "Content-Type": "application/json",
+        "Authorization": "Bearer token",
+      },
+    ),
+    body: BodyInit.fromString(`secret=foo&response=bar`),
+  },
+)