conductor

only.js (2239B)

---

 // src/lib/pipeline/only.js - restricting tasks to particular refs
 //
 // A task carrying an `only` rule runs when the ref that triggered the run
 // matches one of its patterns, and is left out of the run entirely when it
 // does not. Left out rather than recorded as skipped, because the
 // scheduler treats a skipped task as a reason to fail the run: that is the
 // right reading when a dependency collapsed, and the wrong one for a
 // publish step that was never meant to run on this branch.
 //
 // Anything depending on an excluded task is excluded with it. The
 // alternative, quietly dropping the dependency, would let a task run
 // without something it declared it needed, which is a worse surprise than
 // the task not running.
 
 import { transitiveDependents } from './dag.js';
 
 // Glob matching over a whole ref. Only * is special, standing for any run
 // of characters including none; everything else is literal. Deliberately
 // not a regular expression, since these come out of a repository and are
 // read by people who are not thinking about regular expression syntax.
 export function refMatches(pattern, ref) {
   if (typeof pattern !== 'string' || typeof ref !== 'string') return false;
   if (!pattern.includes('*')) return pattern === ref;
 
   const source = pattern
     .split('*')
     .map((part) => part.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'))
     .join('.*');
   return new RegExp(`^${source}$`).test(ref);
 }
 
 export function taskRunsOnRef(task, ref) {
   if (!task.only) return true;
 
   // A run with no ref at all, which a manual or api trigger may produce,
   // cannot match a ref pattern. Restricted tasks stay out rather than
   // being handed a ref they were never written for.
   if (typeof ref !== 'string' || ref === '') return false;
 
   return task.only.refs.some((pattern) => refMatches(pattern, ref));
 }
 
 // The tasks that belong in a run for this ref, in their original order.
 export function selectForRef(tasks, ref) {
   const excluded = new Set(tasks.filter((task) => !taskRunsOnRef(task, ref)).map((task) => task.name));
   if (excluded.size === 0) return tasks;
 
   for (const name of transitiveDependents(tasks, [...excluded])) excluded.add(name);
 
   return tasks.filter((task) => !excluded.has(task.name));
 }