Blame · successionUtils.ts

b69ab31	1	/**
b69ab31	2	* Copyright (c) Meta Platforms, Inc. and affiliates.
b69ab31	3	*
b69ab31	4	* This source code is licensed under the MIT license found in the
b69ab31	5	* LICENSE file in the root directory of this source tree.
b69ab31	6	*/
b69ab31	7
b69ab31	8	import type {Dag} from './dag/dag';
b69ab31	9	import type {ExactRevset, OptimisticRevset} from './types';
b69ab31	10
b69ab31	11	import {
b69ab31	12	exactRevset,
b69ab31	13	optimisticRevset,
b69ab31	14	succeedableRevset,
b69ab31	15	type CommitInfo,
b69ab31	16	type SucceedableRevset,
b69ab31	17	} from './types';
b69ab31	18
b69ab31	19	/**
b69ab31	20	* Get the latest successor hash of the given hash,
b69ab31	21	* traversing multiple successions if necessary.
b69ab31	22	* Returns original hash if no successors were found.
b69ab31	23	*
b69ab31	24	* Useful for previews to ensure they're working with the latest version of a commit,
b69ab31	25	* given that they may have been queued up while another operation ran and eventually caused succession.
b69ab31	26	*
b69ab31	27	* Note: if an ExactRevset is passed, don't look up the successor.
b69ab31	28	*/
b69ab31	29	export function latestSuccessor(
b69ab31	30	ctx: Dag,
b69ab31	31	oldRevset: SucceedableRevset \| ExactRevset \| OptimisticRevset,
b69ab31	32	): string {
b69ab31	33	let hash = oldRevset.type === 'optimistic-revset' ? oldRevset.fake : oldRevset.revset;
b69ab31	34	if (oldRevset.type === 'exact-revset') {
b69ab31	35	return hash;
b69ab31	36	}
b69ab31	37	hash = ctx.followSuccessors(hash).toHashes().first() ?? hash;
b69ab31	38	return hash;
b69ab31	39	}
b69ab31	40
b69ab31	41	/**
b69ab31	42	* Typically we want to use succeedable revsets everywhere, to maximize support for queued commands.
b69ab31	43	* But if you see and act on a visibly obsolete commit in the UI, we should use its exact hash,
b69ab31	44	* so that you don't suddenly act on a seemingly unrelated commit.
b69ab31	45	*/
b69ab31	46	export function latestSuccessorUnlessExplicitlyObsolete(
b69ab31	47	commit: Readonly<CommitInfo>,
b69ab31	48	): SucceedableRevset \| ExactRevset \| OptimisticRevset {
b69ab31	49	if (commit.optimisticRevset != null) {
b69ab31	50	return optimisticRevset(commit.optimisticRevset, commit.hash);
b69ab31	51	}
b69ab31	52	if (commit.successorInfo?.type != null) {
b69ab31	53	return exactRevset(commit.hash);
b69ab31	54	}
b69ab31	55	return succeedableRevset(commit.hash);
b69ab31	56	}