chore: revert support of duplicate form data fields in multipart post…

… data (#30127)

We want to adopt FormData API for the requests.

This is a revert of 4b3c596 and
a849ea9

Reference #28070

docs/src/api/class-apirequestcontext.md

@@ -566,7 +566,7 @@ api_request_context.post("https://example.com/api/createBook", data=data)
 
 ```csharp
 var data = new Dictionary<string, object>() {
-  { "firstName", "John" },
+  { "firstNam", "John" },
   { "lastName", "Doe" }
 };
 await request.PostAsync("https://example.com/api/createBook", new() { DataObject = data });

docs/src/api/class-formdata.md

@@ -14,72 +14,6 @@ FormData form = FormData.create()
 page.request().post("http://localhost/submit", RequestOptions.create().setForm(form));
 ```
 
-## method: FormData.add
-* since: v1.43
-- returns: <[FormData]>
-
-Adds a field to the form. File values can be passed either as `Path` or as `FilePayload`.
-Multiple fields with the same name can be added.
-
-```java
-import com.microsoft.playwright.options.FormData;
-...
-FormData form = FormData.create()
-    // Only name and value are set.
-    .add("firstName", "John")
-    // Name and value are set, filename and Content-Type are inferred from the file path.
-    .add("attachment", Paths.get("pic.jpg"))
-    // Name, value, filename and Content-Type are set.
-    .add("attachment", new FilePayload("table.csv", "text/csv", Files.readAllBytes(Paths.get("my-tble.csv"))));
-page.request().post("http://localhost/submit", RequestOptions.create().setForm(form));
-```
-
-```csharp
-var multipart = Context.APIRequest.CreateFormData();
-// Only name and value are set.
-multipart.Add("firstName", "John");
-// Name, value, filename and Content-Type are set.
-multipart.Add("attachment", new FilePayload()
-{
-    Name = "pic.jpg",
-    MimeType = "image/jpeg",
-    Buffer = File.ReadAllBytes("john.jpg")
-});
-// Name, value, filename and Content-Type are set.
-multipart.Add("attachment", new FilePayload()
-{
-    Name = "table.csv",
-    MimeType = "text/csv",
-    Buffer = File.ReadAllBytes("my-tble.csv")
-});
-await Page.APIRequest.PostAsync("https://localhost/submit", new() { Multipart = multipart });
-```
-
-### param: FormData.add.name
-* since: v1.43
-- `name` <[string]>
-
-Field name.
-
-### param: FormData.add.value
-* since: v1.43
-- `value` <[string]|[boolean]|[int]|[Path]|[Object]>
-  - `name` <[string]> File name
-  - `mimeType` <[string]> File type
-  - `buffer` <[Buffer]> File content
-
-Field value.
-
-### param: FormData.add.value
-* since: v1.43
-* langs: csharp
-- `value` <[string]|[boolean]|[int]|[Object]>
-  - `name` <[string]> File name
-  - `mimeType` <[string]> File type
-  - `buffer` <[Buffer]> File content
-
-Field value.
-
 ## method: FormData.create
 * since: v1.18
 * langs: java
@@ -102,7 +36,7 @@ FormData form = FormData.create()
     // Name and value are set, filename and Content-Type are inferred from the file path.
     .set("profilePicture1", Paths.get("john.jpg"))
     // Name, value, filename and Content-Type are set.
-    .set("profilePicture2", new FilePayload("john.jpg", "image/jpeg", Files.readAllBytes(Paths.get("john.jpg"))))
+    .set("profilePicture2", new FilePayload("john.jpg", "image/jpeg", Files.readAllBytes(Paths.get("john.jpg"))));
     .set("age", 30);
 page.request().post("http://localhost/submit", RequestOptions.create().setForm(form));
 ```
@@ -118,7 +52,6 @@ multipart.Set("profilePicture", new FilePayload()
     MimeType = "image/jpeg",
     Buffer = File.ReadAllBytes("john.jpg")
 });
-multipart.Set("age", 30);
 await Page.APIRequest.PostAsync("https://localhost/submit", new() { Multipart = multipart });
 ```
 

docs/src/api/params.md

@@ -405,16 +405,15 @@ An instance of [FormData] can be created via [`method: APIRequestContext.createF
 
 ## js-python-fetch-option-multipart
 * langs: js, python
-- `multipart` <[Object]<[string], [string]|[float]|[boolean]|[ReadStream]|[Object]|Array<[string]|[float]|[boolean]|[ReadStream]|[Object]>>>
+- `multipart` <[Object]<[string], [string]|[float]|[boolean]|[ReadStream]|[Object]>>
   - `name` <[string]> File name
   - `mimeType` <[string]> File type
   - `buffer` <[Buffer]> File content
 
 Provides an object that will be serialized as html form using `multipart/form-data` encoding and sent as
 this request body. If this parameter is specified `content-type` header will be set to `multipart/form-data`
 unless explicitly provided. File values can be passed either as [`fs.ReadStream`](https://nodejs.org/api/fs.html#fs_class_fs_readstream)
-or as file-like object containing file name, mime-type and its content. If the value is an array, each element
-will be sent as a separate field with the same name.
+or as file-like object containing file name, mime-type and its content.
 
 ## csharp-fetch-option-multipart
 * langs: csharp

packages/playwright-core/src/client/fetch.ts

@@ -36,7 +36,7 @@ export type FetchOptions = {
   headers?: Headers,
   data?: string | Buffer | Serializable,
   form?: { [key: string]: string|number|boolean; };
-  multipart?: { [key: string]: string|number|boolean|fs.ReadStream|FilePayload|Array<string|number|boolean|fs.ReadStream|FilePayload>; };
+  multipart?: { [key: string]: string|number|boolean|fs.ReadStream|FilePayload; };
   timeout?: number,
   failOnStatusCode?: boolean,
   ignoreHTTPSErrors?: boolean,
@@ -188,11 +188,15 @@ export class APIRequestContext extends ChannelOwner<channels.APIRequestContextCh
         multipartData = [];
         // Convert file-like values to ServerFilePayload structs.
         for (const [name, value] of Object.entries(options.multipart)) {
-          if (Array.isArray(value)) {
-            for (const item of value)
-              multipartData.push(await toFormField(name, item));
+          if (isFilePayload(value)) {
+            const payload = value as FilePayload;
+            if (!Buffer.isBuffer(payload.buffer))
+              throw new Error(`Unexpected buffer type of 'data.${name}'`);
+            multipartData.push({ name, file: filePayloadToJson(payload) });
+          } else if (value instanceof fs.ReadStream) {
+            multipartData.push({ name, file: await readStreamToJson(value as fs.ReadStream) });
           } else {
-            multipartData.push(await toFormField(name, value));
+            multipartData.push({ name, value: String(value) });
           }
         }
       }
@@ -230,19 +234,6 @@ export class APIRequestContext extends ChannelOwner<channels.APIRequestContextCh
   }
 }
 
-async function toFormField(name: string, value: string|number|boolean|fs.ReadStream|FilePayload): Promise<channels.FormField> {
-  if (isFilePayload(value)) {
-    const payload = value as FilePayload;
-    if (!Buffer.isBuffer(payload.buffer))
-      throw new Error(`Unexpected buffer type of 'data.${name}'`);
-    return { name, file: filePayloadToJson(payload) };
-  } else if (value instanceof fs.ReadStream) {
-    return { name, file: await readStreamToJson(value as fs.ReadStream) };
-  } else {
-    return { name, value: String(value) };
-  }
-}
-
 function isJsonParsable(value: any) {
   if (typeof value !== 'string')
     return false;