C3 dependabot improvements (#3829)

* slightly improving the dependabot configs

* add a workflow that generates a proper changeset for such PRs

---------

Co-authored-by: Rahul Sethi <[email protected]>

.github/dependabot.yml

@@ -9,7 +9,16 @@ updates:
       #       being to test the efficacy of the solution, we shall set it
       #       to "weekly" after a testing period of 1/2 weeks
       interval: "daily"
+    versioning-strategy: increase
+    # the following is used to add the [C3] prefix to the PR title,
+    # we override the commit message but setting a prefix like this
+    # makes it so that also the PR title gets such prefix
+    commit-message:
+      prefix: "[C3] "
     assignees:
       - "@cloudflare/c3"
     reviewers:
       - "@cloudflare/c3"
+    labels:
+      - "C3"
+      - "dependencies"

.github/generate-c3-dependabot-pr-changeset.mjs

@@ -0,0 +1,64 @@
+import { execSync } from "child_process";
+import { writeFileSync } from "fs";
+
+const diff = execSync(
+	"git diff HEAD~1 packages/create-cloudflare/src/frameworks/package.json"
+).toString();
+
+const changedPackages =
+	diff
+		.match(/-\s*".*?":\s".*?",?/g)
+		?.map((match) => match.match(/-\s*"(.*)":/)?.[1])
+		.filter(Boolean) ?? [];
+
+const changes = changedPackages.map((pkg) => {
+	const getPackageChangeRegex = (addition) =>
+		new RegExp(`${addition ? "\\+" : "-"}\\s*"${pkg}":\\s"(.*)",?`);
+
+	const from = diff.match(getPackageChangeRegex(false))?.[1];
+	const to = diff.match(getPackageChangeRegex(true))?.[1];
+
+	if (!from || !to) {
+		throw new Error(
+			`Unexpected changes for package ${pkg} (could not determine upgrade)`
+		);
+	}
+
+	return {
+		package: pkg,
+		from,
+		to,
+	};
+});
+
+if (!changes.length) {
+	console.warn("No changes detected!");
+} else {
+	const prNumber = process.argv[2];
+
+	writeFileSync(
+		`.changeset/c3-frameworks-update-${prNumber}.md`,
+		`---
+"dependabot-testing": patch
+---
+
+Framework CLI versions updated in C3
+
+The following framework CLI versions have been updated in C3:
+${[
+	"| package | from | to |",
+	"|---------|------|----|",
+	...changes.map(
+		({ package: pkg, from, to }) => `| \`${pkg}\` | \`${from}\` | \`${to}\` |`
+	),
+]
+	.map((str) => ` ${str}`)
+	.join("\n")}
+
+`
+	);
+
+	execSync("git add .changeset");
+	execSync("git commit --amend -m '[C3] Update frameworks cli dependencies'");
+	execSync("git push -f");
+}

.github/workflows/c3-dependabot-versioning-prs.yml

@@ -0,0 +1,26 @@
+# workflow to update the framework cli versioning PRs we get
+# from dependabot for C3
+
+name: "C3: Generate changeset for dependabot PRs"
+on:
+  pull_request_target:
+    paths:
+      - "packages/create-cloudflare/src/frameworks/package.json"
+
+jobs:
+  generate-changeset:
+    runs-on: ubuntu-latest
+    if: |
+      github.event.pull_request.user.login == 'dependabot[bot]'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 2
+          ref: ${{ github.head_ref }}
+      - name: Configure Git
+        run: |
+          git config --global user.email [email protected]
+          git config --global user.name 'Wrangler automated PR updater'
+      - name: Generate changeset
+        run: node .github/generate-c3-dependabot-pr-changeset.mjs ${{ github.event.number }}