fix(wrangler): replace existing resource bindings during creation

.changeset/tidy-kv-placeholder.md

@@ -0,0 +1,7 @@
+---
+"wrangler": patch
+---
+
+Replace existing bindings when adding newly created resources to Wrangler configuration
+
+When config updates are authorized interactively or through `--update-config` or `--binding`, Wrangler now replaces an existing resource binding with the selected name instead of adding a duplicate entry. This allows template bindings with placeholder resource IDs to be updated in both interactive and non-interactive workflows.

packages/wrangler/src/__tests__/update-config-file.test.ts

@@ -142,6 +142,96 @@ describe("createdResourceConfig()", () => {
 		);
 	});
 
+	it("interactive: replaces an existing binding with the same name", async ({
+		expect,
+	}) => {
+		writeWranglerConfig(
+			{
+				name: "worker",
+				kv_namespaces: [
+					{ binding: "OTHER_KV", id: "other-id" },
+					{
+						binding: "KV",
+						id: "<your-kv-namespace-id>",
+						preview_id: "preview-id",
+						remote: true,
+					},
+				],
+			},
+			"wrangler.json"
+		);
+
+		setIsTTY(true);
+		mockConfirm({
+			text: "Would you like Wrangler to add it on your behalf?",
+			result: true,
+		});
+		mockPrompt({
+			text: "What binding name would you like to use?",
+			result: "KV",
+		});
+		mockConfirm({
+			text: "For local dev, do you want to connect to the remote resource instead of a local resource?",
+			result: false,
+		});
+
+		await createdResourceConfig(
+			"kv_namespaces",
+			(name) => ({ binding: name ?? "KV", id: "random-id" }),
+			"wrangler.json",
+			undefined
+		);
+
+		expect(await readFile("wrangler.json", "utf8")).toMatchInlineSnapshot(`
+			"{
+				"compatibility_date": "2022-01-12",
+				"name": "worker",
+				"kv_namespaces": [
+					{
+						"binding": "OTHER_KV",
+						"id": "other-id"
+					},
+					{
+						"binding": "KV",
+						"id": "random-id",
+						"preview_id": "preview-id"
+					}
+				]
+			}"
+		`);
+	});
+
+	it("non interactive: replaces an existing binding with the same name", async ({
+		expect,
+	}) => {
+		writeWranglerConfig(
+			{
+				name: "worker",
+				kv_namespaces: [
+					{
+						binding: "KV",
+						id: "<your-kv-namespace-id>",
+						remote: true,
+					},
+				],
+			},
+			"wrangler.json"
+		);
+
+		await createdResourceConfig(
+			"kv_namespaces",
+			(name) => ({ binding: name ?? "KV", id: "random-id" }),
+			"wrangler.json",
+			undefined,
+			{ binding: "KV", updateConfig: true }
+		);
+
+		expect(await readFile("wrangler.json", "utf8")).toContain(
+			'"id": "random-id"'
+		);
+		expect(await readFile("wrangler.json", "utf8")).not.toContain('"remote"');
+	});
+
 	it("interactive: file update in env after answering yes", async ({
 		expect,
 	}) => {

packages/wrangler/src/utils/add-created-resource-config.ts

@@ -1,5 +1,6 @@
 import {
 	configFormat,
+	experimental_readRawConfig,
 	experimental_patchConfig,
 	formatConfigSnippet,
 	friendlyBindingNames,
@@ -129,16 +130,39 @@ export async function createdResourceConfig<K extends ValidKeys>(
 							{ defaultValue: false }
 						));
 
-			const configFilePatch = {
-				[resource]: [
-					{ ...snippet(bindingName), ...(useRemote ? { remote: true } : {}) },
-				],
+			const { rawConfig } = experimental_readRawConfig({ config: configPath });
+			const environment = env ? rawConfig.env?.[env] : rawConfig;
+
+			const binding = {
+				...snippet(bindingName),
+				remote: useRemote ? true : undefined,
 			};
 
+			const existingBindings = environment?.[resource];
+			const matchingBindingIndex = existingBindings?.findIndex(
+				(existingBinding) => existingBinding.binding === binding.binding
+			);
+
+			const shouldReplaceExistingBinding =
+				existingBindings !== undefined &&
+				matchingBindingIndex !== undefined &&
+				matchingBindingIndex !== -1;
+
+			let bindings: Partial<NonNullable<RawConfig[K]>[number]>[] = [binding];
+			if (shouldReplaceExistingBinding) {
+				bindings = existingBindings.map((existingBinding, index) => {
+					if (index !== matchingBindingIndex) {
+						return existingBinding;
+					}
+					return { ...existingBinding, ...binding };
+				});
+			}
+
+			const configFilePatch = { [resource]: bindings };
 			experimental_patchConfig(
 				configPath,
 				env ? { env: { [env]: configFilePatch } } : configFilePatch,
-				true
+				!shouldReplaceExistingBinding
 			);
 		}
 	}