feat: encode form data when content type is set to form-urlencoded

packages/better-fetch/src/test/fetch.test.ts

@@ -601,3 +601,26 @@ describe("url", () => {
 		expect(url.toString()).toBe("http://localhost:4000/test?foo=bar");
 	});
 });
+
+describe("form data", async () => {
+	it("should parse json to form data", async () => {
+		const { data } = await betterFetch("/echo", {
+			body: {
+				name: "John Doe",
+				age: 30,
+			},
+			headers: {
+				"Content-Type": "application/x-www-form-urlencoded",
+			},
+			onRequest(context) {
+				console.log(context.body);
+			},
+			customFetchImpl: async (req, init) => {
+				return new Response(JSON.stringify(init?.body), {
+					status: 200,
+				});
+			},
+		});
+		expect(data).toBe("name=John+Doe&age=30");
+	});
+});

packages/better-fetch/src/utils.ts

@@ -206,6 +206,16 @@ export function getBody(options?: BetterFetchOption) {
 		return JSON.stringify(options.body);
 	}
 
+	if (
+		headers.has("content-type") &&
+		headers.get("content-type") === "application/x-www-form-urlencoded"
+	) {
+		if (isJSONSerializable(options.body)) {
+			return new URLSearchParams(options.body).toString();
+		}
+		return options.body;
+	}
+
 	return options.body;
 }
 
@@ -265,7 +275,7 @@ export async function parseStandardSchema<TSchema extends StandardSchemaV1>(
 	schema: TSchema,
 	input: StandardSchemaV1.InferInput<TSchema>,
 ): Promise<StandardSchemaV1.InferOutput<TSchema>> {
-	let result = await schema["~standard"].validate(input);
+	const result = await schema["~standard"].validate(input);
 
 	if (result.issues) {
 		throw new ValidationError(result.issues);