From dd7959e5246a362a333c009c2f6708fc3a03882d Mon Sep 17 00:00:00 2001
From: Pascal <pascal.gruen@gmail.com>
Date: Thu, 8 Oct 2020 18:17:04 +0200
Subject: [PATCH] Improve PR property resolving

---
 lib/merge.js       | 37 +++++++------------------------------
 test/merge.test.js |  9 ++++-----
 yarn.lock          |  5 +++++
 3 files changed, 16 insertions(+), 35 deletions(-)

diff --git a/lib/merge.js b/lib/merge.js
index 0bd9762d..a50a25f0 100644
--- a/lib/merge.js
+++ b/lib/merge.js
@@ -1,9 +1,12 @@
+const resolvePath = require("object-resolve-path");
+
 const { logger, retry } = require("./common");
-const resolvePath = require('object-resolve-path');
 
 const MAYBE_READY = ["clean", "has_hooks", "unknown", "unstable"];
 const NOT_READY = ["dirty", "draft"];
 
+const PR_PROPERTY = new RegExp("{pullRequest.([^}]+)}", "g");
+
 async function merge(context, pullRequest) {
   if (skipPullRequest(context, pullRequest)) {
     return false;
@@ -299,28 +302,6 @@ function getMergeMethod(defaultMergeMethod, mergeMethodLabels, pullRequest) {
   return defaultMergeMethod;
 }
 
-// https://stackoverflow.com/a/53620876
-function propertiesToArray(obj) {
-  const isObject = val =>
-      typeof val === 'object' && !Array.isArray(val);
-
-  const addDelimiter = (a, b) =>
-      a ? `${a}.${b}` : b;
-
-  const paths = (obj = {}, head = '') => {
-      return Object.entries(obj)
-          .reduce((product, [key, value]) => 
-              {
-                  let fullPath = addDelimiter(head, key)
-                  return isObject(value) ?
-                      product.concat(paths(value, fullPath))
-                  : product.concat(fullPath)
-              }, []);
-  }
-
-  return paths(obj);
-}
-
 function getCommitMessage(mergeCommitMessage, pullRequest) {
   if (mergeCommitMessage === "automatic") {
     return undefined;
@@ -331,13 +312,9 @@ function getCommitMessage(mergeCommitMessage, pullRequest) {
   } else if (mergeCommitMessage === "pull-request-title-and-description") {
     return pullRequest.title + "\n\n" + pullRequest.body;
   } else {
-    propertiesToArray(pullRequest).forEach(prProp => {
-      mergeCommitMessage = mergeCommitMessage.replace(
-        new RegExp(`{pullRequest.${prProp}}`, "g"),
-          resolvePath(pullRequest, prProp)
-      );
-    });
-    return mergeCommitMessage;
+    return mergeCommitMessage.replace(PR_PROPERTY, (_, prProp) =>
+      resolvePath(pullRequest, prProp)
+    );
   }
 }
 
diff --git a/test/merge.test.js b/test/merge.test.js
index 719d984b..6a4593ef 100644
--- a/test/merge.test.js
+++ b/test/merge.test.js
@@ -16,11 +16,11 @@ beforeEach(() => {
 test("MERGE_COMMIT_MESSAGE with nested custom fields", async () => {
   // GIVEN
   const pr = pullRequest();
-  pr.title = "This is the PR's title"
-  pr.user = {login: "author"};
+  pr.title = "This is the PR's title";
+  pr.user = { login: "author" };
 
   const config = createConfig({
-    MERGE_COMMIT_MESSAGE: "{pullRequest.title} @{pullRequest.user.login}",
+    MERGE_COMMIT_MESSAGE: "{pullRequest.title} @{pullRequest.user.login}"
   });
 
   // WHEN
@@ -29,8 +29,7 @@ test("MERGE_COMMIT_MESSAGE with nested custom fields", async () => {
   // THEN
   expect(octokit.pulls.merge).toHaveBeenCalledWith(
     expect.objectContaining({
-      commit_title:
-        "This is the PR's title @author",
+      commit_title: "This is the PR's title @author",
       commit_message: "",
       pull_number: 1,
       repo: "repository",
diff --git a/yarn.lock b/yarn.lock
index d226a309..084cd0ac 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3055,6 +3055,11 @@ object-copy@^0.1.0:
     define-property "^0.2.5"
     kind-of "^3.0.3"
 
+object-resolve-path@^1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/object-resolve-path/-/object-resolve-path-1.1.1.tgz#a7f8f93e8a20af80e44217ba7db54316d9d12232"
+  integrity sha1-p/j5Poogr4DkQhe6fbVDFtnRIjI=
+
 object-visit@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/object-visit/-/object-visit-1.0.1.tgz#f79c4493af0c5377b59fe39d395e41042dd045bb"