refined-github · fregante · Jul 12, 2026 · Jul 11, 2026 · Jul 11, 2026 · Jul 12, 2026
diff --git a/build/__snapshots__/features-meta.json b/build/__snapshots__/features-meta.json
@@ -1031,6 +1031,7 @@
 	{
 		"id": "useful-not-found-page",
 		"description": "Adds possible related pages and alternatives on 404 pages.",
+		"css": true,
 		"screenshot": "https://user-images.githubusercontent.com/1402241/46402857-7bdada80-c733-11e8-91a1-856573078ff5.png"
 	},
 	{

diff --git a/build/features.test.ts b/build/features.test.ts
@@ -97,6 +97,10 @@ class FeatureFile {
 	get css(): FeatureFile {
 		return new FeatureFile(this.id + '.css');
 	}
+
+	get svelte(): FeatureFile {
+		return new FeatureFile(this.id + '.svelte');
+	}
 }
 
 function validateReadme(featureId: FeatureId): void {
@@ -158,8 +162,9 @@ function validateGql(file: FeatureFile): void {
 	);
 
 	assert(
-		file.tsx.contents().includes(`from './${file.name}';`),
-		`Should be imported by \`${file.tsx.name}\``,
+		file.tsx.contents().includes(`from './${file.name}';`)
+			|| file.svelte.exists() && file.svelte.contents().includes(`from './${file.name}';`),
+		`Should be imported by \`${file.tsx.name}\` or \`${file.svelte.name}\``,
 	);
 }
 

diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -39,7 +39,7 @@
 		"filter-altered-clicks": "^2.1.1",
 		"flat-zip": "^1.0.1",
 		"github-reserved-names": "^2.2.0",
-		"github-url-detection": "^11.2.2",
+		"github-url-detection": "^11.2.3",
 		"indent-textarea": "^4.0.0",
 		"js-abbreviation-number": "^1.4.0",
 		"linkify-issues": "^4.2.0",

diff --git a/source/features/easy-toggle-commit-messages.tsx b/source/features/easy-toggle-commit-messages.tsx
@@ -51,7 +51,7 @@ void features.add(import.meta.url, {
 		pageDetect.isSingleFile,
 	],
 	exclude: [
-		pageDetect.isRepoFile404,
+		pageDetect.is404,
 	],
 	init,
 });

diff --git a/source/features/file-age-color.tsx b/source/features/file-age-color.tsx
@@ -36,7 +36,7 @@ void features.add(import.meta.url, {
 		pageDetect.isRepoTree,
 	],
 	exclude: [
-		pageDetect.isRepoFile404,
+		pageDetect.is404,
 	],
 	init,
 });

diff --git a/source/features/quick-file-edit.tsx b/source/features/quick-file-edit.tsx
@@ -32,7 +32,7 @@ void features.add(import.meta.url, {
 		pageDetect.isRepoTree,
 	],
 	exclude: [
-		pageDetect.isRepoFile404,
+		pageDetect.is404,
 		isArchivedRepoAsync,
 		isPermalink,
 	],

diff --git a/source/features/useful-not-found-page.css b/source/features/useful-not-found-page.css
@@ -0,0 +1,6 @@
+/* Missing file */
+.flex-items-center a[aria-label='go to Overview'],
+/* Missing branch */
+.flex-items-center a[aria-label='go to default branch'] {
+	display: none;
+}
diff --git a/source/features/useful-not-found-page.svelte b/source/features/useful-not-found-page.svelte
@@ -0,0 +1,154 @@
+<script lang="ts">
+	import api from '../github-helpers/api.js';
+	import getDefaultBranch from '../github-helpers/get-default-branch.js';
+	import GitHubFileUrl from '../github-helpers/github-file-url.js';
+	import {isUrlReachable} from '../github-helpers/index.js';
+	import GetLatestCommitToFile from './useful-not-found-page.gql';
+
+	type File = {
+		previous_filename?: string;
+		filename: string;
+		status: string;
+		blob_url: string;
+	};
+
+	type FileChanges = {
+		file: File;
+		commit: {
+			parentSha: string;
+			date: Date;
+			url: string;
+		};
+	};
+
+	type GitHistory = {
+		oldFilename: string;
+		lastVersionUrl: string;
+		status: string;
+		movedUrl: string;
+		commitUrl: string;
+		commitDate: Date;
+	};
+
+	function getType(): string {
+		return location.pathname.split('/').pop()!.includes('.') ? 'file' : 'object';
+	}
+
+	async function getLatestCommitToFile(
+		branch: string,
+		filePath: string,
+	): Promise<string> {
+		const {repository} = await api.v4(GetLatestCommitToFile, {
+			variables: {branch, filePath},
+		});
+
+		return repository.object
+			// Missing if the ref doesn't exist
+			?.history.nodes[0]
+			// Missing if the ref exists but the file never existed
+			?.oid;
+	}
+
+	async function getChangesToFileInCommit(
+		sha: string,
+		filePath: string,
+	): Promise<FileChanges | undefined> {
+		const commit = await api.v3(`commits/${sha}`);
+		for (const fileInfo of commit.files as File[]) {
+			if ([fileInfo.filename, fileInfo.previous_filename].includes(filePath)) {
+				return {
+					commit: {
+						parentSha: commit.parents[0].sha,
+						date: commit.commit.committer.date,
+						url: commit.html_url,
+					},
+					file: fileInfo,
+				};
+			}
+		}
+
+		return undefined;
+	}
+
+	async function getUrlToFileOnDefaultBranch(): Promise<string | undefined> {
+		const parsedUrl = new GitHubFileUrl(location.href);
+		if (!parsedUrl.branch) {
+			return undefined;
+		}
+
+		parsedUrl.assign({branch: await getDefaultBranch()});
+		const urlOnDefault = parsedUrl.href;
+		if (urlOnDefault !== location.href && await isUrlReachable(urlOnDefault)) {
+			return urlOnDefault;
+		}
+
+		return undefined;
+	}
+
+	async function getGitHistory(): Promise<GitHistory | undefined> {
+		const url = new GitHubFileUrl(location.href);
+		if (!url.branch || !url.filePath) {
+			return undefined;
+		}
+
+		const commitSha = await getLatestCommitToFile(url.branch, url.filePath);
+		if (!commitSha) {
+			// Never existed
+			return undefined;
+		}
+
+		const fileChanges = await getChangesToFileInCommit(commitSha, url.filePath);
+		if (!fileChanges) {
+			return undefined;
+		}
+
+		return {
+			oldFilename: fileChanges.file.previous_filename ?? fileChanges.file.filename,
+			lastVersionUrl: fileChanges.file.status === 'removed'
+				? fileChanges.file.blob_url
+				: url.href,
+			status: fileChanges.file.status,
+			movedUrl: decodeURIComponent(fileChanges.file.blob_url), // Why is the API returning dir%2Ffile.js??!
+			commitUrl: fileChanges.commit.url,
+			commitDate: fileChanges.commit.date,
+		};
+	}
+
+	const type = getType();
+</script>
+
+<div class="color-fg-muted rgh-hide-if-empty">
+	{#await getGitHistory()}
+		Loading history of this {type}...
+	{:then gitHistory}
+		{#if gitHistory}
+			<span class="commit-ref">
+				<a href={gitHistory.commitUrl}>
+					{new GitHubFileUrl(gitHistory.commitUrl).branch.slice(0, 8)}
+				</a>
+			</span>
+			{gitHistory.status}
+			<a href={gitHistory.lastVersionUrl}>{gitHistory.oldFilename}</a>
+			{#if gitHistory.status !== 'removed'}
+				to <a href={gitHistory.movedUrl}>{
+					gitHistory.movedUrl.split('/').slice(7).join('/')
+				}</a>
+			{/if}
+			<relative-time datetime={gitHistory.commitDate}></relative-time>.
+		{:else}
+			<!-- TODO: Handle scenario. Can be because branch OR file is 404 -->
+		{/if}
+	{/await}
+</div>
+
+<div class="color-fg-muted rgh-hide-if-empty">
+	{#await getUrlToFileOnDefaultBranch()}
+		Loading default branch...
+	{:then defaultBranchUrl}
+		{#if defaultBranchUrl}
+			<a href={defaultBranchUrl}>{
+				new GitHubFileUrl(defaultBranchUrl).filePath
+			}</a> exists on the default branch.
+		{/if}
+	{/await}
+</div>