Add fensak configuration to ensure merges to release branch can only …

…happen from main branch

Signed-off-by: Yoriyasu Yano <[email protected]>

fensak.yml

@@ -1,28 +1,8 @@
-# This file contains the Fensak configuration file for this GitHub Organization.
-# The config file specifies which rules should be applied to the different repositories in your organization.
-#
-# This contains a starting point for a fictional repo `my-repo` in your org. Update to point to your real repos and
-# rules to get started using Fensak.
-#
-# Refer to https://github.com/fensak-io/fensak/blob/main/fskconfig/schema.json
-# for the expected config schema.
-
 repos:
-  # Each entry in this configuration represents a single repository, and the corresponding rule that should be run
-  # to determine auto-approval for PRs in the repo.
-  my-repo:
-    # The path to the rule relative to the repo root.
-    ruleFile: rules/sample.ts
-
-    # The following attribute is optional. When omitted, the rule language is automatically determined based on the rule
-    # file extension. Refer to the schema for the list of allowed values here.
-    # ruleLang: ts
-
-    # The following attribute is optional. This setting controls how many approvals should be required for PRs where the
-    # rule does not pass. The default is 1.
-    # requiredApprovals: 1
+  fensak:
+    requiredRuleFile: rules/fensak_required_rule.ts
+    requiredApprovals: 0
 
-  # You can add more repositories by extending the repos map with more entries like so:
-  #
-  # my-other-repo:
-  #   ruleFile: rules/sample.ts
+  dashboard:
+    requiredRuleFile: rules/fensak_required_rule.ts
+    requiredApprovals: 0

rules/fensak_required_rule.ts

@@ -0,0 +1,21 @@
+/**
+ * A Fensak rule for the repositories that use release branch strategy. This rule requires that the source branch of the
+ * release branch is set to main. This ensures that only the main branch can merge into the release branch.
+ */
+
+// fensak remove-start
+import type { IChangeSetMetadata, IPatch } from "npm:@fensak-io/reng@^1.2.1";
+// fensak remove-end
+
+// deno-lint-ignore no-unused-vars
+function main(_inp: IPatch[], metadata: IChangeSetMetadata): boolean {
+  if (metadata.targetBranch === "release" && metadata.sourceBranch !== "main") {
+    console.log(
+      "Rejecting since merging non-main branch into the release branch.",
+    );
+    return false;
+  }
+
+  // Allow all other PRs.
+  return true;
+}

rules/fensak_required_rule_test.ts

@@ -0,0 +1,66 @@
+import {
+  assert,
+  assertFalse,
+} from "https://deno.land/[email protected]/testing/asserts.ts";
+import {
+  compileRuleFn,
+  IGitHubRepository,
+  patchFromGitHubPullRequest,
+  RuleFnSourceLang,
+  RuleLogMode,
+  runRule,
+} from "npm:@fensak-io/reng@^1.2.1";
+import { Octokit } from "npm:@octokit/rest@^20.0.0";
+
+const __dirname = new URL(".", import.meta.url).pathname;
+const ruleFn = compileRuleFn(
+  await Deno.readTextFile(`${__dirname}/fensak_required_rule.ts`),
+  RuleFnSourceLang.Typescript,
+);
+const octokit = new Octokit({
+  auth: Deno.env.get("GITHUB_API_TOKEN"),
+});
+const fensakRepo: IGitHubRepository = {
+  owner: "fensak-io",
+  name: "fensak",
+};
+const opts = { logMode: RuleLogMode.Console };
+
+Deno.test("Normal release PR should be approved", async () => {
+  // View PR at
+  // https://github.com/fensak-io/fensak/pull/125
+  const patches = await patchFromGitHubPullRequest(octokit, fensakRepo, 125);
+  const result = await runRule(
+    ruleFn,
+    patches.patchList,
+    patches.metadata,
+    opts,
+  );
+  assert(result.approve);
+});
+
+Deno.test("Normal PRs to main should be approved", async () => {
+  // View PR at
+  // https://github.com/fensak-io/fensak/pull/124
+  const patches = await patchFromGitHubPullRequest(octokit, fensakRepo, 124);
+  const result = await runRule(
+    ruleFn,
+    patches.patchList,
+    patches.metadata,
+    opts,
+  );
+  assert(result.approve);
+});
+
+Deno.test("PRs to release from a random branch should be rejected", async () => {
+  // View PR at
+  // https://github.com/fensak-io/fensak/pull/126
+  const patches = await patchFromGitHubPullRequest(octokit, fensakRepo, 126);
+  const result = await runRule(
+    ruleFn,
+    patches.patchList,
+    patches.metadata,
+    opts,
+  );
+  assertFalse(result.approve);
+});