Part 2️⃣ of removing `CfWorkerInit["bindings"]` by penalosa · Pull Request #12455 · cloudflare/workers-sdk

penalosa · 2026-02-06T20:31:49Z

Part 2 of landing #12151 in stages. This part:

Modifies LocalRuntimeController so that it no longer converts StartDevWorkerOptions["bindings"] -> CfWorkerInit["bindings"] -> Miniflare, it just goes straight from StartDevWorkerOptions["bindings"] to Miniflare's config.

Tests
- Tests included/updated
- Automated tests not possible - manual testing has been completed as follows:
- Additional testing not necessary because: covered by existing tests, which have not been changed.
Public documentation
- Cloudflare docs PR(s):
- Documentation not necessary because: internal refactor

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changeset-bot · 2026-02-06T20:31:55Z

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penalosa · 2026-02-06T20:34:15Z

+		"version_metadata",
+		bindings
+	);
+	const fetchers = extractBindingsOfType("fetcher", bindings);


This is messy for now, but a followup will eventually allow Miniflare's config to take a similar structure, removing a lot of this conversion logic

devin-ai-integration

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 6 additional findings.

penalosa · 2026-02-06T20:36:19Z

-			// In remote `dev`, we make folks use a separate kv namespace called
-			// `preview_id` instead of `id` so that they don't
-			// break production data. So here we check that a `preview_id`
-			// has actually been configured.
-			// This whole block of code will be obsoleted in the future
-			// when we have copy-on-write for previews on edge workers.
-			if (!preview_id && !local) {
-				// TODO: This error has to be a _lot_ better, ideally just asking
-				// to create a preview namespace for the user automatically
-				throw new UserError(
-					`In development, you should use a separate kv namespace than the one you'd use in production. Please create a new kv namespace with "wrangler kv namespace create <name> --preview" and add its id as preview_id to the kv_namespace "${binding}" in your ${configFileName(configParam.configPath)} file`,
-					{
-						telemetryMessage:
-							"no preview kv namespace configured in remote dev",
-					}
-				); // Ugh, I really don't like this message very much
-			}


This error (and the below duplicates of it) has been removed. We no longer recommend remote mode dev, and will be removing preview IDs entirely eventually.

Is this removal an essential part of this restructure?
It feels like this is a significant change to behaviour in what should be a no-op refactor?

It's not essential, but given I was touching this area of the codebase anyway (and it's a simple enough change) it seemed worth doing. This logic throws an error if the user hasn't specified a preview ID when using KV or R2 bindings and wrangler dev --remote. Crucially, it doesn't display when using remote bindings, which is what we expect most people to use going forward. This error made sense in a world where wrangler dev connected to production resources by default, but since you now have to opt-in with remote = true or --remote it's much clearer to the user that that is happening, and if they want to they can use alternatives like environments.

pkg-pr-new · 2026-02-06T20:36:41Z

create-cloudflare

npm i https://pkg.pr.new/create-cloudflare@12455

@cloudflare/kv-asset-handler

npm i https://pkg.pr.new/@cloudflare/kv-asset-handler@12455

miniflare

npm i https://pkg.pr.new/miniflare@12455

@cloudflare/pages-shared

npm i https://pkg.pr.new/@cloudflare/pages-shared@12455

@cloudflare/unenv-preset

npm i https://pkg.pr.new/@cloudflare/unenv-preset@12455

@cloudflare/vite-plugin

npm i https://pkg.pr.new/@cloudflare/vite-plugin@12455

@cloudflare/vitest-pool-workers

npm i https://pkg.pr.new/@cloudflare/vitest-pool-workers@12455

@cloudflare/workers-editor-shared

npm i https://pkg.pr.new/@cloudflare/workers-editor-shared@12455

@cloudflare/workers-utils

npm i https://pkg.pr.new/@cloudflare/workers-utils@12455

wrangler

npm i https://pkg.pr.new/wrangler@12455

commit: a3eab05

penalosa · 2026-02-06T20:36:45Z

+export function getFlatBindings(
+	configParam: Config,
+	env: string | undefined,
+	envFiles: string[] | undefined,
+	local: boolean,
+	args: AdditionalDevProps
+): StartDevWorkerInput["bindings"] {
+	const bindings = getBindings(configParam, env, envFiles, local, args);
+	return convertCfWorkerInitBindingsToBindings(bindings);
+}
+


This is messy and will be removed in part 3️⃣ or 4️⃣

devin-ai-integration

Devin Review found 1 new potential issue.

View 9 additional findings in Devin Review.

devin-ai-integration

Devin Review found 1 new potential issue.

View 12 additional findings in Devin Review.

devin-ai-integration

Devin Review found 1 new potential issue.

View 13 additional findings in Devin Review.

devin-ai-integration

Devin Review found 1 new potential issue.

View 17 additional findings in Devin Review.

Co-authored-by: devin-ai-integration[bot] <158243242+devin-ai-integration[bot]@users.noreply.github.com>

petebacondarwin

Just a few comments to resolve before I approve.

petebacondarwin · 2026-02-09T14:37:59Z

+		const workflowBindings = extractBindingsOfType("workflow", bindings);
+		for (const workflow of workflowBindings) {
+			delete bindings?.[workflow.binding];
+		}


Alternatively, we could avoid more work by passing an ignoreBindingTypes param to the getFlatBindings() and so down to convertCfWorkerInitBindingsToBindings() which would mean it would not even compute these in the first place?

Potentially in a followup, yes? convertCfWorkerInitBindingsToBindings() will be entirely removed from the codebase in part 6, which means we won't really be doing any duplicate work over the current state of the codebase.

petebacondarwin · 2026-02-09T14:43:40Z

 		options?.remoteProxyConnectionString
 	);

 	// This function is currently only exported for the Workers Vitest pool.


Outside of this PR but this comment is no longer valid. The vite-plugin calls this function too. Does that also want to avoid using the dev-registry?

I don't think this code actually does anything anymore, since the dev registry is entirely defined in Miniflare. I'll remove it in a followup PR

petebacondarwin · 2026-02-09T14:47:12Z

-			// In remote `dev`, we make folks use a separate kv namespace called
-			// `preview_id` instead of `id` so that they don't
-			// break production data. So here we check that a `preview_id`
-			// has actually been configured.
-			// This whole block of code will be obsoleted in the future
-			// when we have copy-on-write for previews on edge workers.
-			if (!preview_id && !local) {
-				// TODO: This error has to be a _lot_ better, ideally just asking
-				// to create a preview namespace for the user automatically
-				throw new UserError(
-					`In development, you should use a separate kv namespace than the one you'd use in production. Please create a new kv namespace with "wrangler kv namespace create <name> --preview" and add its id as preview_id to the kv_namespace "${binding}" in your ${configFileName(configParam.configPath)} file`,
-					{
-						telemetryMessage:
-							"no preview kv namespace configured in remote dev",
-					}
-				); // Ugh, I really don't like this message very much
-			}


Is this removal an essential part of this restructure?
It feels like this is a significant change to behaviour in what should be a no-op refactor?

penalosa requested a review from a team as a code owner February 6, 2026 20:31

workers-devprod added this to workers-sdk Feb 6, 2026

github-project-automation Bot moved this to Untriaged in workers-sdk Feb 6, 2026

penalosa changed the base branch from main to penalosa/granular-refactor February 6, 2026 20:32

penalosa added the no-changeset-required label Feb 6, 2026

penalosa commented Feb 6, 2026

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penalosa force-pushed the penalosa/granular-refactor-2 branch from 95db292 to a72b4a0 Compare February 6, 2026 21:10

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Comment thread packages/wrangler/src/dev/miniflare/index.ts

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Comment thread packages/wrangler/src/dev/miniflare/index.ts

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Comment thread packages/wrangler/src/dev/miniflare/index.ts

Base automatically changed from penalosa/granular-refactor to main February 9, 2026 13:32

penalosa added 5 commits February 9, 2026 13:41

LocalRuntimeController

352db9f

fix tests and lint

8184089

more fixes

479c6b8

Support text blobs

d4d9f6a

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9c06fb4

penalosa force-pushed the penalosa/granular-refactor-2 branch from 909f63e to 9c06fb4 Compare February 9, 2026 13:41

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Comment thread packages/wrangler/src/dev/miniflare/index.ts

vicb self-requested a review February 9, 2026 14:05

penalosa and others added 2 commits February 9, 2026 14:19

Update packages/wrangler/src/dev/miniflare/index.ts

03db7f8

Co-authored-by: devin-ai-integration[bot] <158243242+devin-ai-integration[bot]@users.noreply.github.com>

fix format

a3eab05

petebacondarwin reviewed Feb 9, 2026

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penalosa requested a review from petebacondarwin February 9, 2026 15:28

petebacondarwin approved these changes Feb 9, 2026

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github-project-automation Bot moved this from Untriaged to Approved in workers-sdk Feb 9, 2026

penalosa merged commit 000cefa into main Feb 9, 2026
47 of 48 checks passed

github-project-automation Bot moved this from Approved to Done in workers-sdk Feb 9, 2026

penalosa deleted the penalosa/granular-refactor-2 branch February 9, 2026 17:29

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