refactor: replace sort package with slices package by dongjiang1989 · Pull Request #14356 · kgateway-dev/kgateway

dongjiang1989 · 2026-07-05T16:55:46Z

Description

Replace all usage of Go's sort package with the modern slices and cmp packages (Go 1.21+) for more concise and readable sorting code.

Changes

sort.Strings → slices.Sort
sort.Ints → slices.Sort
sort.Slice → slices.SortFunc with cmp.Compare
sort.SliceStable → slices.SortStableFunc
sort.Sort/sort.Stable on sort.Interface types → new Sort()/CompareTo() methods using slices.SortStableFunc internally
Added CompareStagedFilters generic helper for StagedFilterList
Added depguard linter rule to forbid future use of the sort package

For files importing istio.io/istio/pkg/slices, the istio import is aliased to istioslices to avoid conflict with stdlib slices.

Change Type

/kind cleanup

Changelog

Refactor: replace sort package with slices package for cleaner sorting code.

Additional Notes

All unit tests pass
Build and go vet clean

Copilot

Pull request overview

This PR modernizes sorting across kgateway by replacing uses of Go’s sort package with the slices + cmp APIs and adds a depguard rule to prevent reintroducing sort. It also adjusts a few internal sortable abstractions (routes and staged filters) to work naturally with slices.Sort* comparators.

Changes:

Refactor call sites from sort.Strings / sort.Ints / sort.Slice* / sort.Sort to slices.Sort* and cmp.Compare.
Introduce comparator-style helpers (SortableRoute.CompareTo, CompareStagedFilters) to support slices.Sort*Func.
Add depguard configuration to forbid future imports of the sort package.

Reviewed changes

Copilot reviewed 26 out of 26 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
test/translator/test.go	Switch deterministic sorting in translator tests to `slices.SortFunc` + stdlib `cmp` (aliased).
test/translator/status.go	Replace `sort.Strings` with `slices.Sort` for stable status key ordering in tests.
test/e2e/tests/shards_test.go	Replace string sorting with `slices.Sort` for shard coverage checks.
test/e2e/features/loadtesting/startup_suite.go	Replace snapshot/event sorting with `slices.Sort` / `slices.SortFunc`.
test/e2e/features/loadtesting/attachedroutes_suite.go	Replace caller key sorting with `slices.Sort`.
pkg/pluginsdk/filters/stages.go	Add comparator-based staged filter sorting helpers and new `Sort`/`SortStable` methods.
pkg/metrics/cmd/findmetrics/main.go	Replace metrics list sorting with `slices.SortFunc` + `cmp.Compare`.
pkg/kgateway/translator/routeutils/sortable_route.go	Add `CompareTo` comparator for `SortableRoute` to support `slices.SortStableFunc`.
pkg/kgateway/translator/listener/gateway_listener_translator.go	Replace route/vhost sorting with `slices.Sort*Func` using the new comparator APIs.
pkg/kgateway/translator/irtranslator/gateway.go	Replace filter-chain sorting with `slices.SortFunc`; alias Istio slices to avoid stdlib name collision.
pkg/kgateway/translator/irtranslator/fc.go	Replace `sort.Sort` usage on staged filter lists with the new `.Sort()` method.
pkg/kgateway/translator/irtranslator/endpoint_plugins.go	Replace stable slice sorting with `slices.SortStableFunc` + `cmp.Compare`.
pkg/kgateway/setup/setup_test.go	Replace various test sort helpers with `slices.Sort*` + stdlib `cmp` (aliased) for determinism.
pkg/kgateway/proxy_syncer/status.go	Replace `sort.Strings` with `slices.Sort` for deterministic error message aggregation.
pkg/kgateway/proxy_syncer/perclient.go	Replace string slice sorting with `slices.Sort` for deterministic reporting.
pkg/kgateway/proxy_syncer/perclient_clusters_test.go	Replace `sort.Strings` with `slices.Sort` in tests.
pkg/kgateway/proxy_syncer/local_cluster.go	Replace endpoint ordering sort with `slices.SortFunc` + `cmp.Compare`.
pkg/kgateway/proxy_syncer/effective_endpoints.go	Replace `sort.Slice` with `slices.SortFunc` for deterministic policy hashing inputs.
pkg/kgateway/extensions2/pluginutils/headers.go	Replace header pair sorting with `slices.SortFunc` + `cmp.Compare`.
pkg/kgateway/extensions2/plugins/trafficpolicy/transformation_plugin.go	Replace key sorting with `slices.Sort` for deterministic metadata generation.
pkg/kgateway/extensions2/plugins/trafficpolicy/jwt.go	Replace requirement sorting with `slices.SortFunc` + `cmp.Compare` for idempotency.
pkg/kgateway/endpoints/prioritize.go	Replace priority sorting with `slices.Sort`; alias Istio slices helpers to `istioslices`.
pkg/kgateway/admin/server.go	Replace profile list sorting with `slices.SortFunc` + `cmp.Compare`.
pkg/kgateway/admin/logging.go	Replace component sorting with `slices.Sort`.
pkg/deployer/values_helpers.go	Replace string sorting with `slices.Sort`; alias Istio slices helpers to `istioslices`.
.golangci.yaml	Enable/configure `depguard` to forbid importing `sort`.

Use Go 1.21+ slices and cmp packages instead of the sort package for more concise and readable sorting code. This matches the pattern used upstream in agentgateway (kgateway-dev#2367). Changes: - sort.Strings -> slices.Sort - sort.Ints -> slices.Sort - sort.Slice -> slices.SortFunc with cmp.Compare - sort.SliceStable -> slices.SortStableFunc - sort.Sort/sort.Stable on sort.Interface types -> Sort()/CompareTo methods using slices.SortFunc internally - Add CompareStagedFilters generic helper for StagedFilterList - Add depguard linter rule to forbid future use of the sort package For files importing istio.io/istio/pkg/slices, the istio import is aliased to istioslices to avoid conflict with stdlib slices. Signed-off-by: dongjiang <[email protected]>

Address Copilot review feedback: - Sort() now uses slices.SortStableFunc to preserve relative order of equal elements (avoids non-deterministic filter ordering) - Remove references to index-based tiebreaker in comments since CompareStagedFilters no longer uses index for comparison Signed-off-by: dongjiang <[email protected]>

davidjumani · 2026-07-13T15:36:28Z

+// Sort sorts the StagedFilterList in place using slices.SortStableFunc to preserve
+// the relative order of equal elements.
+func (s StagedFilterList[WellKnown, FilterType]) Sort() {
+	slices.SortStableFunc(s, CompareStagedFilters[WellKnown, FilterType])


nit: This can call s.SortStable()

…omparator Follow-up to kgateway-dev#14356. After migrating off the sort package, the old sort.Interface trio (Len/Less/Swap) on StagedFilterList and SortableRoutes was left behind, along with an unused SortStable() helper identical to Sort(). - Remove dead SortStable() from StagedFilterList (Sort() already uses slices.SortStableFunc). - Remove the now-unused Len/Less/Swap methods from StagedFilterList and SortableRoutes. Production sorts exclusively via CompareStagedFilters and SortableRoute.CompareTo, so these are vestigial. - Point the routeutils test at CompareTo, the comparator production actually uses, instead of the removed Less. This closes the gap where Less and CompareTo could diverge for equal routes (Less returned true, CompareTo 0) while being tested against different contracts. Signed-off-by: omar <[email protected]>

Copilot AI review requested due to automatic review settings July 5, 2026 16:55

Copilot started reviewing on behalf of dongjiang1989 July 5, 2026 16:56 View session

gateway-bot added do-not-merge/description-invalid kind/cleanup Categorizes issue or PR as related to cleaning up code, process, or technical debt. release-note labels Jul 5, 2026

dongjiang1989 force-pushed the change-sort-to-slices branch from d73ecb7 to f17b18a Compare July 5, 2026 16:57

Copilot AI reviewed Jul 5, 2026

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Comment thread pkg/pluginsdk/filters/stages.go Outdated

Comment thread pkg/pluginsdk/filters/stages.go Outdated

gateway-bot removed the do-not-merge/description-invalid label Jul 6, 2026

dongjiang1989 force-pushed the change-sort-to-slices branch from fbc173b to d8455ef Compare July 6, 2026 03:18

dongjiang1989 added 2 commits July 13, 2026 16:21

dongjiang1989 force-pushed the change-sort-to-slices branch from d8455ef to eaa1d1d Compare July 13, 2026 08:42

Merge branch 'main' into change-sort-to-slices

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davidjumani approved these changes Jul 13, 2026

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davidjumani added this pull request to the merge queue Jul 13, 2026

github-merge-queue Bot removed this pull request from the merge queue due to failed status checks Jul 13, 2026

davidjumani added this pull request to the merge queue Jul 13, 2026

Merged via the queue into kgateway-dev:main with commit 239ba8d Jul 13, 2026
32 checks passed

puertomontt mentioned this pull request Jul 13, 2026

cleanup: prune vestigial sort.Interface methods, keep one canonical comparator #14397

Merged

dongjiang1989 deleted the change-sort-to-slices branch July 14, 2026 00:43

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refactor: replace sort package with slices package#14356

refactor: replace sort package with slices package#14356
davidjumani merged 3 commits into
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dongjiang1989:change-sort-to-slices

dongjiang1989 commented Jul 5, 2026 •

edited

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davidjumani Jul 13, 2026

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dongjiang1989 commented Jul 5, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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davidjumani Jul 13, 2026

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dongjiang1989 commented Jul 5, 2026 •

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