Show parent commits from the pull request view of a commit #2331

I personally think this is more work than it's worth to implement, but you should definitely send a feature request to GitHub: support@github.com

This doesn't seem terribly hard, but I basically never use this information. If needed it's behind the commit hash that we already linkify.

Here's a demo GQL (try it on https://developer.github.com/v4/explorer/)

{
  repository(owner: "chinese-poetry", name: "chinese-poetry") {
    object(oid: "5aeb8445648373432ff049f0aab5761f360c7555") {
      ... on Commit {
        parents(first: 100) {
          nodes {
            id
          }
        }
      }
    }
  }
}

Or v3

https://api.github.com/repos/chinese-poetry/chinese-poetry/git/commits/5aeb8445648373432ff049f0aab5761f360c7555

This doesn't seem terribly hard, but I basically never use this information.

I use it to check merge commits during code reviews.

For example:

feature/a .  . master
          .  .
          .  .
          .  .
          .  .
           \ .
            \. master~6

If a pull request merges master in feature/a (to update feature/a before merging it in master), I want to ensure the merge commit parents really are master's HEAD and feature/a's HEAD:

          . "Merge master in feature/a"
          |\
          | \
feature/a .  . master
          .  .
          .  .
          .  .
          .  .
           \ .
            \. master~6

master commits could have (inadvertently) been rewritten locally before merging.

It is already easier to check with Refined Github as the "real" commit page can be accessed from the commit hash:

I had fun

import React from 'dom-chef';
import cache from 'webext-storage-cache';
import elementReady from 'element-ready';
import * as pageDetect from 'github-url-detection';

import features from '.';
import * as api from '../github-helpers/api';
import {getRepoGQL, getRepoURL} from '../github-helpers';

const getCommitParents = cache.function(async (commit: string): Promise<string[]> => {
    const {repository} = await api.v4(`
        repository(${getRepoGQL()}) {
            object(expression: "${commit}") {
                ... on Commit {
                    parents(first: 2) {
                        nodes {
                            abbreviatedOid
                        }
                    }
                }
            }
        }
    `);

    return repository.object.parents.nodes.map((parent: AnyObject) => parent.abbreviatedOid);
}, {
    cacheKey: ([commit]) => 'pr-commit-parents:' + commit
});

async function init(): Promise<void> {
    const commitSha = location.pathname.split('/').pop()!;
    const parents = await getCommitParents(commitSha);
    const shaBlock = await elementReady('.sha-block');
    shaBlock!.before(
        <span className="sha-block ml-0">
            {parents.length === 1 ? '1 Parent ' : '2 Parents '}
            {parents.map((parent, index) => (
                <>
                    <a
                        className="sha"
                        data-hotkey={index === 0 ? 'p' : 'o'}
                        href={`/${getRepoURL()}/commit/${parent}`}
                    >
                        {parent}
                    </a>
                    {parents.length === 2 && index === 0 ? ' +   ' : ' '}
                </>
            ))}
        </span>
    );
}

void features.add({
    id: __filebasename,
    description: 'Adds commit parents on PR commits.',
    /*real screenshot*/
    screenshot: 'https://user-images.githubusercontent.com/16872793/83922964-4cbe0d00-a74f-11ea-9978-c863725b8663.png'
}, {
    include: [
        pageDetect.isPRCommit
    ],
    waitForDomReady: false,
    init
});

If this is accepted then I made POC https://github.com/yakov116/refined-github/tree/pr-parent-commit If not lets close the issue

We are going to pass on this, the information is just one page away.