From a61a96c6d72d4297b2539f4033fbfbd0a3d178ab Mon Sep 17 00:00:00 2001
From: Joe Mou <dev@mou.fo>
Date: Thu, 3 Sep 2026 01:37:35 -0400
Subject: Link blobs to their history and back

Nothing in a commits payload says whether the path it lists is a file or
a directory: currentBlobPath, despite the name, is only the path filter,
and is set for a directory just the same. GitHub's own UI cannot tell
either, and points its browse button at /blob/<oid>/<path> so that the
redirect resolves a file to its blob. We do the same, and the blob route
already turns that redirect into one of our own tree URLs.

Breadcrumbs now stay in the view they were clicked from, so walking up
from a history lands in the history of each parent directory rather than
in its listing. The last crumb remains the page you are already on.

A path with no commits now says so rather than rendering an empty page.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R7pRKdmTvNDgT4ZXrwkbH8
---
 cgithub/src/app.test.ts | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

(limited to 'cgithub/src/app.test.ts')

diff --git a/cgithub/src/app.test.ts b/cgithub/src/app.test.ts
index 265465e..8519d91 100644
--- a/cgithub/src/app.test.ts
+++ b/cgithub/src/app.test.ts
@@ -155,6 +155,62 @@ describe("blob view", () => {
   });
 });
 
+describe("commit history", () => {
+  const repo = { owner: "actions", name: "deploy-pages" };
+  const oid = "b39c421b98f49d83ae50ec502c3ddfc3bf28f2c6";
+  const commitGroups = [
+    {
+      title: "Apr 18, 2023",
+      commits: [
+        { oid, shortMessage: "Remove deprecated input parameters", authors: [{ login: "jmg" }] },
+      ],
+    },
+  ];
+  const history = { repo, branch: "main", path: "src/index.js", commitGroups };
+
+  // A commits payload never says whether its path is a file or a directory, so
+  // every link goes to the tree and GitHub redirects a file's to its blob.
+  it("should browse a file's history at each of its commits", () => {
+    const html = eta.render("commits.eta", history);
+
+    assert.match(html, new RegExp(`href="/actions/deploy-pages/blob/${oid}/src/index.js">Browse`));
+  });
+
+  it("should browse a directory's history the same way", () => {
+    const html = eta.render("commits.eta", { ...history, path: "src" });
+
+    assert.match(html, new RegExp(`href="/actions/deploy-pages/blob/${oid}/src">Browse`));
+  });
+
+  it("should browse the whole repository when the history has no path", () => {
+    const html = eta.render("commits.eta", { ...history, path: "" });
+
+    assert.match(html, new RegExp(`href="/actions/deploy-pages/blob/${oid}">Browse`));
+  });
+
+  // Walking up from a history stays in the history, and its last crumb is the
+  // page you are already on, just as a blob or a tree ends on itself.
+  it("should walk up through the history of each parent directory", () => {
+    const html = eta.render("commits.eta", { ...history, path: "src/lib/index.js" });
+
+    assert.match(html, /href="\/actions\/deploy-pages\/commits\/main">\(top\)</);
+    assert.match(html, /href="\/actions\/deploy-pages\/commits\/main\/src">src</);
+    assert.match(html, /href="\/actions\/deploy-pages\/commits\/main\/src\/lib">lib<\/a>\/index\.js/);
+  });
+
+  it("should say so when a path has no history", () => {
+    const html = eta.render("commits.eta", { ...history, commitGroups: [] });
+
+    assert.match(html, /No commits found\./);
+  });
+
+  it("should link a blob to its own history", () => {
+    const html = eta.render("blob.eta", { ...history, textLines: ["x"] });
+
+    assert.match(html, /href="\/actions\/deploy-pages\/commits\/main\/src\/index.js">History/);
+  });
+});
+
 describe("embedded files", () => {
   function stubGitHub(t: TestContext, body: string, contentType: string, status = 200) {
     t.mock.method(
-- 
cgit v1.3.1