src/github/pr-files.ts

Functions

Imports

It imports src/env.ts, src/github/client.ts, src/merge-class.ts. Imported by src/auto-merge-tick.ts, src/complete-ci.ts, src/job-overlaps.ts, src/maintenance-prs.ts, src/model-routing-pr.ts, src/review.ts, src/stale-canon.ts, src/test-protection.ts, src/whats-next.ts.

Source

1import type { Env } from "../env";
2import { TEST_FILE } from "../merge-class";
3import { ghFetch } from "./client";
4
5// The one reader of a pull request's changed files. The auto-merge tick judges them
6// (src/auto-merge-tick.ts) and block and complete compare them across open pull requests
7// (src/job-overlaps.ts); a second reader would disagree about a cap or a rename.
8
9// Paged GitHub lists are read to the end, and a list not read whole is reported rather
10// than judged. Bounded: GitHub serves at most FILES_LIMIT files for a pull request, and
11// callers pass their own page cap for other lists. The next page is requested by number;
12// the Link header only says one exists, so its URL never reaches ghFetch.
13export const PER_PAGE = 100;
14export const FILES_LIMIT = 3000;
15const FILES_MAX_PAGES = FILES_LIMIT / PER_PAGE;
16
17export async function readAllPages<T>(
18  env: Env,
19  owner: string,
20  repo: string,
21  path: string,
22  rowsOf: (body: unknown) => T[],
23  maxPages: number
24): Promise<{ items: T[]; problem: string | null }> {
25  const items: T[] = [];
26  for (let page = 1; page <= maxPages; page++) {
27    const resp = await ghFetch(env, owner, repo, `${path}${path.includes("?") ? "&" : "?"}per_page=${PER_PAGE}&page=${page}`);
28    if (!resp.ok) return { items, problem: `page ${page} returned ${resp.status}` };
29    items.push(...(rowsOf(await resp.json()) ?? []));
30    if (!/rel="next"/.test(resp.headers.get("Link") ?? "")) return { items, problem: null };
31  }
32  return { items, problem: `more than ${maxPages} pages` };
33}
34
35// A commit's check runs, read whole (readAllPages), shared by the auto-merge tick, what's
36// next, the maintenance sweep and complete's CI gate (src/complete-ci.ts).
37export interface CheckRunRow {
38  name: string;
39  status: string;
40  conclusion: string | null;
41}
42
43export async function readCheckRuns<T extends CheckRunRow = CheckRunRow>(
44  env: Env,
45  owner: string,
46  repo: string,
47  sha: string,
48  maxPages: number
49): Promise<{ items: T[]; problem: string | null }> {
50  return readAllPages<T>(env, owner, repo, `/repos/${owner}/${repo}/commits/${sha}/check-runs`, (page) => (page as { check_runs: T[] }).check_runs, maxPages);
51}
52
53export interface PrFiles {
54  // A rename is listed under both names, so moving a file counts as touching the old path.
55  paths: string[];
56  // Why the list is not the whole of the pull request's files, or null when it is.
57  problem: string | null;
58  // Additions plus deletions across the files read, as GitHub counts them, or null when a
59  // file came back without its counts. Auto-merge's size cap reads it
60  // (src/auto-merge-policy.ts), and refuses a null rather than reading it as zero.
61  changedLines: number | null;
62  // The existing tests the pull request changes (existingTestEdits below). Auto-merge
63  // never merges one unattended (src/merge-class.ts).
64  testEdits: string[];
65  // The rows as GitHub listed them, with each file's status and a rename's old name. The
66  // stale canon check reads what was removed or renamed (src/stale-canon.ts).
67  rows: PrFileRow[];
68}
69
70export interface PrFileRow {
71  filename: string;
72  previous_filename?: string;
73  status?: string;
74  additions?: number;
75  deletions?: number;
76  // The unified diff of the file, which GitHub leaves out for a binary or very large one.
77  patch?: string;
78}
79
80// Where the tests live: capsid's three directories, and anything merge-class names a test
81// (tests/, __tests__/, e2e/, *.test.* and *.spec.*), which is what the other covered repos use.
82const TEST_DIRS = ["test/", "test-integration/", "dashboard/e2e/"];
83export const inTestDir = (path: string | undefined) => path !== undefined && (TEST_DIRS.some((d) => path.startsWith(d)) || TEST_FILE.test(path));
84
85/** The tests a pull request changes that already exist: a test removed or renamed away
86 *  (the old path is deleted), or any file there with a deleted line. A file added whole,
87 *  or modified with only added lines, is new test code and not an edit. Fails closed: a
88 *  file under a test directory with no status, or with no integer deletions, counts as
89 *  an edit, since a test cannot be shown untouched. Pure. */
90export function existingTestEdits(files: readonly PrFileRow[]): string[] {
91  const edited: string[] = [];
92  for (const f of files) {
93    // A rename is a deletion of the old path whichever directory the new one is in.
94    const path = inTestDir(f.previous_filename) ? f.previous_filename! : inTestDir(f.filename) ? f.filename : null;
95    if (path === null) continue;
96    if (f.status === "added") continue;
97    const pureAdditions = f.status === "modified" && Number.isInteger(f.deletions) && f.deletions === 0;
98    if (!pureAdditions) edited.push(path);
99  }
100  return edited;
101}
102
103export async function readPrFiles(env: Env, owner: string, repo: string, number: number): Promise<PrFiles> {
104  const files = await readAllPages<PrFileRow>(
105    env, owner, repo, `/repos/${owner}/${repo}/pulls/${number}/files`,
106    (page) => page as PrFileRow[], FILES_MAX_PAGES
107  );
108  // A list that reached FILES_LIMIT may have been cut by GitHub with no next page.
109  const problem = files.problem ?? (files.items.length >= FILES_LIMIT ? `GitHub lists at most ${FILES_LIMIT} files for a pull request and this one reached that` : null);
110  const paths = files.items.flatMap((f) => (f.previous_filename ? [f.previous_filename, f.filename] : [f.filename]));
111  const counted = files.items.every((f) => Number.isInteger(f.additions) && Number.isInteger(f.deletions));
112  const changedLines = counted ? files.items.reduce((n, f) => n + (f.additions ?? 0) + (f.deletions ?? 0), 0) : null;
113  return { paths, problem, changedLines, testEdits: existingTestEdits(files.items), rows: files.items };
114}