feat: add Workers Previews support

.changeset/workers-previews.md

@@ -0,0 +1,5 @@
+---
+"wrangler-action": minor
+---
+
+Add support for Workers Previews, including Preview artifact parsing, Preview outputs, GitHub Deployments, and job summaries for `wrangler preview`.

README.md

@@ -270,6 +270,80 @@ jobs:
           command: versions upload
 ```
 
+### Deploy a Workers Preview
+
+Workers Previews let you test non-production branches with their own URLs, variables, secrets, and bindings. Use `command: preview` instead of the default `deploy` command.
+
+Before using this workflow, add your Cloudflare credentials as GitHub Actions secrets:
+
+```sh
+gh auth login
+gh secret set CLOUDFLARE_API_TOKEN
+gh secret set CLOUDFLARE_ACCOUNT_ID
+```
+
+GitHub Actions provides `${{ secrets.GITHUB_TOKEN }}` automatically. You do not need to create it yourself.
+
+If you prefer plain YAML without this action, run Wrangler directly:
+
+```yaml
+name: Preview
+
+on: [pull_request]
+
+jobs:
+  preview:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - run: npx wrangler preview --json
+        env:
+          CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}
+          CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
+```
+
+Add install or build steps before `npx wrangler preview --json` if your Worker needs them. To use `wrangler-action` instead, use this workflow:
+
+```yaml
+name: Preview
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, closed]
+
+permissions:
+  contents: read
+  deployments: write
+
+jobs:
+  preview:
+    if: github.event.action != 'closed'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - name: Deploy preview
+        id: preview
+        uses: cloudflare/wrangler-action@v4
+        with:
+          apiToken: ${{ secrets.CLOUDFLARE_API_TOKEN }}
+          accountId: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
+          command: preview
+          gitHubToken: ${{ secrets.GITHUB_TOKEN }}
+```
+
+The action sets the following outputs for preview commands:
+
+| Output                   | Description                                        |
+| ------------------------ | -------------------------------------------------- |
+| `deployment-url`         | The stable preview URL (same as `preview-url`)     |
+| `preview-url`            | The stable Preview URL for the branch              |
+| `preview-deployment-url` | The immutable URL for this specific deployment     |
+| `preview-name`           | The Preview name (defaults to the git branch name) |
+| `preview-id`             | The Preview resource ID                            |
+| `preview-deployment-id`  | The deployment ID within the Preview               |
+
+When `gitHubToken` is provided, the action creates a GitHub Deployment with the Preview URL linked as the environment URL and writes a job summary. For the plain `wrangler preview --json` workflow, PR comments, and cleanup examples, refer to [Automation examples](https://developers.cloudflare.com/workers/previews/automation-examples/).
+
 ## Advanced Usage
 
 ### Setting A Worker Secret for A Specific Environment

action.yml

@@ -60,3 +60,13 @@ outputs:
     description: "If the command was a Pages deployment, this will be the ID of the deployment - needs wrangler >= 3.81.0"
   pages-environment:
     description: "If the command was a Pages deployment, this will be the environment of the deployment - needs wrangler >= 3.81.0"
+  preview-url:
+    description: "If the command was a Workers Preview deployment, this will be the stable Preview URL for the branch"
+  preview-deployment-url:
+    description: "If the command was a Workers Preview deployment, this will be the immutable deployment URL"
+  preview-name:
+    description: "If the command was a Workers Preview deployment, this will be the Preview name (typically the branch name)"
+  preview-id:
+    description: "If the command was a Workers Preview deployment, this will be the Preview resource ID"
+  preview-deployment-id:
+    description: "If the command was a Workers Preview deployment, this will be the deployment ID within the Preview"

src/commandOutputParsing.ts

@@ -4,9 +4,13 @@ import {
 	getOutputEntry,
 	OutputEntryDeployment,
 	OutputEntryPagesDeployment,
+	OutputEntryPreview,
 	OutputEntryVersionUpload,
 } from "./wranglerArtifactManager";
-import { createGitHubDeploymentAndJobSummary } from "./service/github";
+import {
+	createGitHubDeploymentAndJobSummary,
+	createPreviewGitHubDeploymentAndJobSummary,
+} from "./service/github";
 
 // fallback to trying to extract the deployment-url and pages-deployment-alias-url from stdout for wranglerVersion < 3.81.0
 function extractDeploymentUrlsFromStdout(stdOut: string): {
@@ -114,6 +118,27 @@ function handleVersionsUploadOutputEntry(
 	setOutput("deployment-url", versionsOutputEntry.preview_url);
 }
 
+async function handlePreviewOutputEntry(
+	config: WranglerActionConfig,
+	previewOutputEntry: OutputEntryPreview,
+) {
+	const previewUrl = previewOutputEntry.preview_urls?.[0] ?? undefined;
+	const deploymentUrl = previewOutputEntry.deployment_urls?.[0] ?? undefined;
+
+	// Set the primary deployment-url to the preview URL (stable branch URL)
+	setOutput("deployment-url", previewUrl);
+
+	// Set preview-specific outputs
+	setOutput("preview-url", previewUrl);
+	setOutput("preview-deployment-url", deploymentUrl);
+	setOutput("preview-name", previewOutputEntry.preview_name);
+	setOutput("preview-id", previewOutputEntry.preview_id);
+	setOutput("preview-deployment-id", previewOutputEntry.deployment_id);
+
+	// Create GitHub Deployment and Job Summary for the preview
+	await createPreviewGitHubDeploymentAndJobSummary(config, previewOutputEntry);
+}
+
 /**
  * If no wrangler output file found, log a message stating deployment-url will be unavailable for output.
  * @deprecated Use {@link handleVersionsOutputEntry} instead.
@@ -150,6 +175,17 @@ function handleDeprectatedStdoutParsing(
 		handleVersionsOutputCommand(config);
 		return;
 	}
+
+	// Check if this command is a preview deployment
+	if (command.startsWith("preview")) {
+		info(
+			config,
+			"Unable to find a WRANGLER_OUTPUT_DIR, preview outputs will be unavailable. Have you updated wrangler to the latest version?",
+		);
+		const { deploymentUrl } = extractDeploymentUrlsFromStdout(stdOut);
+		setOutput("deployment-url", deploymentUrl);
+		return;
+	}
 }
 
 export async function handleCommandOutputParsing(
@@ -176,5 +212,8 @@ export async function handleCommandOutputParsing(
 		case "version-upload":
 			handleVersionsUploadOutputEntry(outputEntry);
 			break;
+		case "preview":
+			await handlePreviewOutputEntry(config, outputEntry);
+			break;
 	}
 }

src/service/github.ts

@@ -2,7 +2,10 @@ import { summary } from "@actions/core";
 import { context, getOctokit } from "@actions/github";
 import { env } from "process";
 import { info, warn } from "../utils";
-import { OutputEntryPagesDeployment } from "../wranglerArtifactManager";
+import {
+	OutputEntryPagesDeployment,
+	OutputEntryPreview,
+} from "../wranglerArtifactManager";
 import { WranglerActionConfig } from "../wranglerAction";
 
 type Octokit = ReturnType<typeof getOctokit>;
@@ -126,3 +129,106 @@ export async function createGitHubDeploymentAndJobSummary(
 		}
 	}
 }
+
+export async function createPreviewJobSummary({
+	previewName,
+	previewUrl,
+	deploymentUrl,
+	workerName,
+}: {
+	previewName: string;
+	previewUrl?: string;
+	deploymentUrl?: string;
+	workerName: string | null;
+}) {
+	await summary
+		.addRaw(
+			`
+# Workers Preview Deployment
+
+| Name                    | Result |
+| ----------------------- | - |
+| **Worker:**             | ${workerName ?? "unknown"} |
+| **Preview:**            | ${previewName} |
+| **Preview URL**:        | ${previewUrl ?? "N/A"} |
+| **Deployment URL**:     | ${deploymentUrl ?? "N/A"} |
+  `,
+		)
+		.write();
+}
+
+/**
+ * Create GitHub deployment and job summary for a Workers Preview, if GITHUB_TOKEN is present
+ */
+export async function createPreviewGitHubDeploymentAndJobSummary(
+	config: WranglerActionConfig,
+	previewFields: OutputEntryPreview,
+) {
+	const previewUrl = previewFields.preview_urls?.[0];
+	const deploymentUrl = previewFields.deployment_urls?.[0];
+
+	if (config.GITHUB_TOKEN) {
+		const octokit = getOctokit(config.GITHUB_TOKEN);
+		const githubBranch = env.GITHUB_HEAD_REF || env.GITHUB_REF_NAME;
+		const environmentName = `preview: ${previewFields.preview_name}`;
+
+		const [createDeploymentRes, createSummaryRes] = await Promise.allSettled([
+			(async () => {
+				const deployment = await octokit.rest.repos.createDeployment({
+					owner: context.repo.owner,
+					repo: context.repo.repo,
+					ref: githubBranch || context.ref,
+					auto_merge: false,
+					description: "Cloudflare Workers Preview",
+					required_contexts: [],
+					environment: environmentName,
+					production_environment: false,
+				});
+
+				if (deployment.status !== 201) {
+					info(config, "Error creating GitHub deployment for preview");
+					return;
+				}
+
+				await octokit.rest.repos.createDeploymentStatus({
+					owner: context.repo.owner,
+					repo: context.repo.repo,
+					deployment_id: deployment.data.id,
+					environment: environmentName,
+					environment_url: previewUrl,
+					production_environment: false,
+					log_url: `https://dash.cloudflare.com/${config.CLOUDFLARE_ACCOUNT_ID}/workers/services/view/${previewFields.worker_name}`,
+					description: "Cloudflare Workers Preview",
+					state: "success",
+					auto_inactive: false,
+				});
+			})(),
+			createPreviewJobSummary({
+				previewName: previewFields.preview_name,
+				previewUrl,
+				deploymentUrl,
+				workerName: previewFields.worker_name,
+			}),
+		]);
+
+		if (createDeploymentRes.status === "rejected") {
+			warn(config, "Creating Github Deployment for preview failed");
+		}
+
+		if (createSummaryRes.status === "rejected") {
+			warn(config, "Creating Github Job summary for preview failed");
+		}
+	} else {
+		// Still create job summary even without GitHub token
+		try {
+			await createPreviewJobSummary({
+				previewName: previewFields.preview_name,
+				previewUrl,
+				deploymentUrl,
+				workerName: previewFields.worker_name,
+			});
+		} catch {
+			warn(config, "Creating Github Job summary for preview failed");
+		}
+	}
+}

src/wranglerAction.ts

@@ -363,7 +363,9 @@ async function wranglerCommands(
 
 			if (
 				config["VARS"].length &&
-				(command.startsWith("deploy") || command.startsWith("publish")) &&
+				(command.startsWith("deploy") ||
+					command.startsWith("publish") ||
+					command.startsWith("preview")) &&
 				!command.includes("--var")
 			) {
 				args.push("--var");