KV: improve error messages for 400 errors (#8860)

* KV: improve error messages for 400 errors

* update changelog

---------

Co-authored-by: talves <[email protected]>

Author: teresalves

.changeset/tender-bushes-move.md

@@ -0,0 +1,5 @@
+---
+"miniflare": patch
+---
+
+KV: update error messages for 400 errors

packages/miniflare/src/workers/kv/namespace.worker.ts

@@ -136,13 +136,17 @@ export class KVNamespaceObject extends MiniflareDurableObject {
 			const keys: string[] = parsedBody.keys;
 			const type = parsedBody?.type;
 			if (type && type !== "text" && type !== "json") {
-				return new Response("Bad Request", { status: 400 });
+				const errorStr = `"${type}" is not a valid type. Use "json" or "text"`;
+				return new Response(errorStr, { status: 400, statusText: errorStr });
 			}
 			const obj: { [key: string]: any } = {};
 			if (keys.length > MAX_BULK_GET_KEYS) {
-				return new Response("Bad Request", {
-					status: 400,
-				});
+				const errorStr = `You can request a maximum of ${MAX_BULK_GET_KEYS} keys`;
+				return new Response(errorStr, { status: 400, statusText: errorStr });
+			}
+			if (keys.length < 1) {
+				const errorStr = "You must request a minimum of 1 key";
+				return new Response(errorStr, { status: 400, statusText: errorStr });
 			}
 			let totalBytes = 0;
 			for (const key of keys) {

packages/miniflare/test/plugins/kv/index.spec.ts

@@ -146,7 +146,34 @@ test("bulk get: check max keys", async (t) => {
 	try {
 		await kv.get(keyArray);
 	} catch (error: any) {
-		t.is(error.message, "KV GET_BULK failed: 400 Bad Request");
+		t.is(
+			error.message,
+			"KV GET_BULK failed: 400 You can request a maximum of 100 keys"
+		);
+	}
+});
+
+test("bulk get: check minimum keys", async (t) => {
+	const { kv } = t.context;
+	try {
+		await kv.get([]);
+	} catch (error: any) {
+		t.is(
+			error.message,
+			"KV GET_BULK failed: 400 You must request a minimum of 1 key"
+		);
+	}
+});
+
+test("bulk get: invalid type", async (t) => {
+	const { kv } = t.context;
+	try {
+		await kv.get(["key"], { type: "invalid" as "json" });
+	} catch (error: any) {
+		t.is(
+			error.message,
+			'KV GET_BULK failed: 400 "invalid" is not a valid type. Use "json" or "text"'
+		);
 	}
 });