---
title: Fusion source planning
description: Inspect exact Bun source ancestry, original migration provenance and upstream conflicts before integration.
---

# Fusion source planning

Run the source plan without synchronizing or changing the checkout:

```sh
bun scripts/aphrody/fusion-sources.ts --root /path/to/bun-os
```

The JSON receipt uses schema `bun.fusion-source-plan/1`. It records the existing
`HEAD`, `bun-os/main`, `origin/main` and `upstream/main` commit SHAs. Each available
comparison includes the exact merge base and counts: `ahead` counts commits only
in HEAD; `behind` counts commits only in the selected reference. A missing ref,
unrelated history or shallow checkout is reported unavailable. The planner
never fetches to hide that missing evidence.

The upstream preview uses those exact commits with
`git merge-tree --write-tree --name-only --no-messages -z`. A successful preview
records its tree; exit code 1 records all conflict paths. Other failures are
unavailable, never clean. This command may create unreferenced tree objects in
the Git object database. It does not run checkout, merge, staging or push and
does not modify the index or working files. Partial-clone lazy fetching and
interactive authentication are disabled during inspection.

## Integration with the verifier

```ts
import { collectFusionSources, summarizeOfficialHtml } from "./fusion-sources.ts";

const sources = await collectFusionSources(root);
// Attach sources to the verification journal. Conflicts require the owner's
// explicit integration batch; an unavailable source does not prove ancestry.
const navigation = await summarizeOfficialHtml(officialUrl, alreadyBoundedHtml);
```

`collectFusionSources` reads `src/browser/MIGRATION.json` and
`src/browser/BROWSER-MIGRATION.json` with native Bun file APIs. Their original
source repository, exact original commit, original byte count and original
SHA256 coverage remain distinct from integrated-source hashes. The receipt also
records whether the original commit exists in this object store; a recorded
commit does not imply that its repository is locally available. Remote URLs
are redacted to omit credentials, login names and query parameters.

## Bounded primary-source research

`summarizeOfficialHtml(url, html)` extracts metadata with native HTMLRewriter
and decodes character references with the shared `Bun.HTML` DOM parser. Its
behavior gate therefore requires the newly built candidate, not an older Bun.
It accepts HTTPS pages on the declared official Bun, Deno, V8 and WebKit hosts.
It returns only the title, at most 24 headings and 32 deduplicated links to
those official hosts. Each text field is limited to 200 characters and parsed
input to 512 KiB; a truncated page is labeled explicitly. Relative links are
resolved against the supplied page URL. The helper performs no network calls,
follows no links and executes no script or code example. Extracted text is
untrusted source data, not agent instructions or proof of implemented parity.

HTTP fetching, status/redirect validation and full-response acquisition budgets
remain with the verifier's research owner. Reject redirects to unapproved
origins before passing HTML to the summary helper. Do not copy complete articles
or turn documentation examples into shell commands.

## Qualification

The companion tests exercise refs/counts, missing and shallow history, merge
conflicts, original ledger provenance, credential redaction and bounded HTML
metadata. Execute them in the declared SSH VPS factory as part of the
verification batch. This plan is source evidence; it does not establish build,
runtime behavior, performance, installation or complete engine parity.