Merge pull request #17 from anzharip/feat/accept-additional-options

feat: accept additional options

Author: anzharip

README.md

@@ -84,3 +84,34 @@ This is the example reponse received on the client:
   ]
 }
 ```
+
+You can also pass [busboy constructor config](https://github.com/mscdex/busboy#busboy-methods) as an optional parameter:
+
+```typescript
+import { AzureFunction, Context, HttpRequest } from "@azure/functions";
+import parseMultipartFormData from "@anzp/azure-function-multipart";
+
+const httpTrigger: AzureFunction = async function (
+  context: Context,
+  req: HttpRequest
+): Promise<void> {
+  // Set the max number of non-file fields to 1 (Default: Infinity).
+  const config = {
+    limits: { fields: 1 },
+  };
+  const { fields, files } = await parseMultipartFormData(req, config);
+  context.log("HTTP trigger function processed a request.");
+  const name = req.query.name || (req.body && req.body.name);
+  const responseMessage = {
+    fields,
+    files,
+  };
+
+  context.res = {
+    // status: 200, /* Defaults to 200 */
+    body: responseMessage,
+  };
+};
+
+export default httpTrigger;
+```

src/index.ts

@@ -3,15 +3,23 @@ import { HttpRequest } from "@azure/functions";
 import { ParsedField } from "./types/parsed-field.type";
 import { ParsedFile } from "./types/parsed-file.type";
 import { ParsedMultipartFormData } from "./types/parsed-multipart-form-data.type";
+import { Config } from "./types/config.type";
 
 export default async function parseMultipartFormData(
-  request: HttpRequest
+  request: HttpRequest,
+  options?: Config
 ): Promise<ParsedMultipartFormData> {
   return new Promise((resolve, reject) => {
     try {
       const fields: Promise<ParsedField>[] = [];
       const files: Promise<ParsedFile>[] = [];
-      const busboy = new Busboy({ headers: request.headers });
+
+      let busboy;
+      if (options) {
+        busboy = new Busboy({ headers: request.headers, ...options });
+      } else {
+        busboy = new Busboy({ headers: request.headers });
+      }
 
       busboy.on(
         "file",

src/types/config.type.ts

@@ -0,0 +1,15 @@
+export type Config = {
+  highWaterMark?: number;
+  fileHwm?: number;
+  defCharset?: string;
+  preservePath?: boolean;
+  limits?: {
+    fieldNameSize?: number;
+    fieldSize?: number;
+    fields?: number;
+    fileSize?: number;
+    files?: number;
+    parts?: number;
+    headerPairs?: number;
+  };
+};

test/index.spec.ts

@@ -10,6 +10,8 @@ describe("index.js", () => {
     const file1 = fs.readFileSync("test/fixture/dummy-data.json");
     const body = new FormData();
     body.append("field1", "value1");
+    body.append("field2", "value2");
+    body.append("field3", "value3");
     body.append("file1", file1);
 
     request = {
@@ -26,7 +28,7 @@ describe("index.js", () => {
 
   it("should populate fields property", async () => {
     const { fields } = await parseMultipartFormData(request);
-    expect(fields.length).toBe(1);
+    expect(fields.length).toBe(3);
   });
 
   it("should populate files property", async () => {
@@ -47,4 +49,11 @@ describe("index.js", () => {
       await parseMultipartFormData(request);
     }).rejects.toThrow();
   });
+
+  it("should accept options parameter, parse only one field", async () => {
+    const { fields } = await parseMultipartFormData(request, {
+      limits: { fields: 1 },
+    });
+    expect(fields.length).toBe(1);
+  });
 });