fix(rules): consult a rule's autoMerge when deciding to merge

test/auto-merge.test.tsmodified+106-0

Changes to test/auto-merge.test.ts

		⋯263 linesShow the 263 lines above this hunk@@ -264,3 +264,109 @@ describe('security-only, end to end', () => {
264	264	expect(evaluateAutoMerge(makePR([makeUpdate()], { labels: ['security'] }), config, true).eligible).toBe(false)
265	265	})
266	266	})
	267	+
	268	+/**
	269	+ * `autoMerge` on a package rule was resolved into `ResolvedEffects` and merged
	270	+ * by `mergeGroupEffects`, and nothing ever read either — so a rule saying
	271	+ * "these are safe to merge without review" did nothing, and one saying the
	272	+ * opposite did nothing either.
	273	+ */
	274	+describe('rule-level auto-merge', () => {
	275	+ /** A config whose global conditions would refuse everything. */
	276	+ function withRules(rules: unknown[]): BuddyConfig {
	277	+ return {
	278	+ pullRequest: { autoMerge: { enabled: true, strategy: 'squash', conditions: ['patch-only'] } },
	279	+ packages: { strategy: 'all', rules },
	280	+ } as unknown as BuddyConfig
	281	+ }
	282	+
	283	+ it('success case - a rule admits a major the conditions would refuse', () => {
	284	+ // `patch-only` alone would send this back. The rule is the point.
	285	+ const pr = makePR([makeUpdate({ name: 'react', updateType: 'major', newVersion: '19.0.0' })])
	286	+ const config = withRules([{ matchPackages: ['react'], autoMerge: true }])
	287	+
	288	+ const decision = evaluateAutoMerge(pr, config, true)
	289	+
	290	+ expect(decision.eligible).toBe(true)
	291	+ expect(decision.reason).toContain('package rule')
	292	+ })
	293	+
	294	+ it('failure case - a rule holds back what the conditions would admit', () => {
	295	+ // A patch that `patch-only` accepts, refused because a rule says so.
	296	+ const pr = makePR([makeUpdate({ name: 'left-pad' })])
	297	+ const config = withRules([{ matchPackages: ['left-pad'], autoMerge: false }])
	298	+
	299	+ const decision = evaluateAutoMerge(pr, config, true)
	300	+
	301	+ expect(decision.eligible).toBe(false)
	302	+ expect(decision.reason).toContain('holds one of these updates back')
	303	+ })
	304	+
	305	+ it('failure case - one uncovered package sends the whole PR back to the conditions', () => {
	306	+ // `mergeGroupEffects` reads this all-or-nothing, and so does this: a
	307	+ // package no rule has vouched for is enough.
	308	+ const pr = makePR([
	309	+ makeUpdate({ name: 'react', updateType: 'major' }),
	310	+ makeUpdate({ name: 'lodash', updateType: 'major' }),
	311	+ ])
	312	+ const config = withRules([{ matchPackages: ['react'], autoMerge: true }])
	313	+
	314	+ expect(evaluateAutoMerge(pr, config, true).eligible).toBe(false)
	315	+ })
	316	+
	317	+ it('success case - a blocking rule wins over an admitting one', () => {
	318	+ const pr = makePR([
	319	+ makeUpdate({ name: 'react', updateType: 'patch' }),
	320	+ makeUpdate({ name: 'danger', updateType: 'patch' }),
	321	+ ])
	322	+ const config = withRules([
	323	+ { matchPackages: ['**'], autoMerge: true },
	324	+ { matchPackages: ['danger'], autoMerge: false },
	325	+ ])
	326	+
	327	+ const decision = evaluateAutoMerge(pr, config, true)
	328	+
	329	+ expect(decision.eligible).toBe(false)
	330	+ })
	331	+
	332	+ it('success case - rules that say nothing about auto-merge change nothing', () => {
	333	+ // A rule setting only a group name must not accidentally decide this.
	334	+ const pr = makePR([makeUpdate({ updateType: 'major' })])
	335	+ const config = withRules([{ matchPackages: ['**'], groupName: 'Everything' }])
	336	+
	337	+ const decision = evaluateAutoMerge(pr, config, true)
	338	+
	339	+ expect(decision.eligible).toBe(false)
	340	+ expect(decision.reason).not.toContain('package rule')
	341	+ })
	342	+
	343	+ it('failure case - a rule cannot grant auto-merge on a shed manifest', () => {
	344	+ // A large manifest drops `type` and `dependencyType` without marking
	345	+ // itself truncated. Rules match on both, so a rule evaluated against one
	346	+ // would be deciding on data that is not there.
	347	+ const pr = makePR([makeUpdate({ name: 'react', updateType: 'major' })])
	348	+ pr.body = pr.body.replace(/"type":"[a-z]+",/g, '').replace(/"dependencyType":"[^"]+",?/g, '')
	349	+ const config = withRules([{ matchPackages: ['react'], autoMerge: true }])
	350	+
	351	+ expect(evaluateAutoMerge(pr, config, true).eligible).toBe(false)
	352	+ })
	353	+
	354	+ it('success case - the same rule applies through evaluateAutoMergeForUpdates', () => {
	355	+ // The pre-PR path must agree with the post-PR one, or a group would be
	356	+ // opened as auto-mergeable and then refused at merge time.
	357	+ const decision = evaluateAutoMergeForUpdates(
	358	+ [makeUpdate({ name: 'react', updateType: 'major' })],
	359	+ [],
	360	+ withRules([{ matchPackages: ['react'], autoMerge: true }]),
	361	+ )
	362	+
	363	+ expect(decision.eligible).toBe(true)
	364	+ })
	365	+
	366	+ it('edge case - no rules at all leaves the conditions in charge', () => {
	367	+ const pr = makePR([makeUpdate()])
	368	+ const config = makeConfig(['patch-only'])
	369	+
	370	+ expect(evaluateAutoMerge(pr, config, true).eligible).toBe(true)
	371	+ })
	372	+})