WindowOrderResolver — Specs

Line coverage: WindowOrderResolver.swift 96% · refreshed 2026-05-27 by /coverage-explore

Summary

WindowOrderResolver.isOrderedBefore decides the order windows appear in the switcher. It's the comparator behind Windows.sort, extracted as a pure kernel: the caller precomputes each window's ordering facts once (OrderWindow — a window's WindowState + its ApplicationState + the query-derived search rank) and the kernel compares two of them; the sort-mode knobs (searchActive, windowlessAtEnd, hiddenAtEnd, minimizedAtEnd, sortType) are labeled parameters with defaults, hoisted once per sort by the caller and captured by the comparator closure. Besides testability, precomputing OrderWindows let the sort drop from O(n log n) Search calls to O(n) (facts are snapshotted once).

Decision order:

1. Search active → matched windows first; then higher relevance; then lastFocusOrder.
2. Show-at-the-end buckets → windows whose type is set to "show at the end" (windowless / hidden / minimized) sink below the rest.
3. Sort type → recentlyFocused (lowest lastFocusOrder), recentlyCreated (highest creationOrder), alphabetical (app name, then title; localizedStandardCompare), or space (all-spaces windows first, then lowest space index, then alphabetical).
4. Tiebreak → lastFocusOrder (for the alphabetical/space paths).

Behavior & edge cases

• Buckets only separate when the relevant "show at the end" preference is set and the two windows differ on that trait; otherwise ordering falls through to the sort type.
• recentlyFocused/recentlyCreated return directly (no alphabetical tiebreak); the lastFocusOrder tiebreak applies to the alphabetical/space paths.
• space: windows on all spaces sort ahead of space-bound ones; ties within a space fall back to alphabetical, then lastFocusOrder.
• Equal facts → not ordered before each other (strict weak ordering, required by Array.sort).

Test scenarios

Mirrors WindowOrderResolverTests.swift 1:1.

A. Search ranking

• testSearchMatchedSortsBeforeUnmatched — matched windows precede unmatched.
• testSearchHigherRelevanceSortsFirst — higher relevance first.
• testSearchEqualRelevanceTiebreaksByLastFocusOrder — equal relevance → lastFocusOrder.

B. Show-at-the-end buckets

• testWindowlessPushedToEndWhenConfigured — a windowless row sinks below a real window.
• testRealWindowBeforeWindowlessWhenConfigured — the real window comes first.
• testWindowlessNotSeparatedWhenFlagOff — with the bucket off, the sort type decides instead.
• testHiddenPushedToEndWhenConfigured — hidden-app windows sink when configured.
• testMinimizedPushedToEndWhenConfigured — minimized windows sink when configured.

C. Recently focused

• testRecentlyFocusedLowerOrderFirst — lowest lastFocusOrder first.

D. Recently created

• testRecentlyCreatedHigherCreationOrderFirst — highest creationOrder first.

E. Alphabetical

• testAlphabeticalByAppName — by app name.
• testAlphabeticalTitleBreaksTieWithinSameApp — same app → by window title.
• testAlphabeticalTiebreaksByLastFocusOrder — identical app+title → lastFocusOrder.

F. Space

• testSpaceAllSpacesWindowsFirst — all-spaces windows precede space-bound ones (a on all spaces).
• testSpaceLowerSpaceIndexFirst — lower space index first.
• testSpaceTiebreaksByAppName — same space → alphabetical.
• testSpaceBothOnAllSpacesTiebreaksByAppName — both on all spaces → no space-index ordering; fall through to alphabetical.
• testSpaceOnlyBOnAllSpacesSortsBFirst — mirror of testSpaceAllSpacesWindowsFirst: only b on all spaces → b sorts first (pins comparator symmetry).

G. Tiebreak / symmetry

• testEqualWindowsAreNotOrderedBeforeEachOther — equal facts are not ordered before each other.