Add support to anchor links to a specific commit

[OlivierBlanvillain]

Phabricator has a hidden feature where urls of the form .../source/repo/browse/master/.../README.md;SHA$88 point to specific line of a specific file at a specific commit, which is almost always better than using the latest version of that file.

I believe the best way to use that would be to use the "fork point" commit or something like this (as opposed to the current commit), given that the "current commit" might only exists locally.

[ryan953]

@OlivierBlanvillain that would be awesome, if I had known about this hidden feature earlier I would've loved to use it.

Unfortunately I'm not using phabricator anymore, so I don't have an environment to test this kind of change :(

But you could put it together and submit a PR if you want! assembleUrl is probably the place:

vscode-open-in-diffusion/extension.js

Lines 48 to 56 in f43a4b1

	async function assembleUrl(activeEditor, workspace) {
	const repoRootPath = await getRepoRootOfFile(workspace, activeEditor.document);
	const arcconfig = JSON.parse(await readFilePath(workspace, `${repoRootPath}/.arcconfig`));
	const domain = removeTrailingSlash(getDiffusionDomain(arcconfig));
	const callsign = removeLeadingSlash(removeTrailingSlash(getProjectCallsign(arcconfig)));
	const projectFile = removeLeadingSlash(documentToProjectFile(activeEditor.document, repoRootPath));
	const lineRange = selectionToUrlRange(activeEditor.selection);
	return `${domain}/diffusion/${callsign}/browse/master/${projectFile}${lineRange}`;
	}

You can see how at the end of the method it returns the link, including the line range to highlight. This could be modified to include the SHA given we have the repoRootPath and can shell out to ask git or arc for the the fork point.