Function resolveKeyWithChordState

src/keybindings/resolver.ts:166–244

(
  input: string,
  key: Key,
  activeContexts: KeybindingContextName[],
  bindings: ParsedBinding[],
  pending: ParsedKeystroke[] | null,
)

 * @returns Resolution result with chord state
 */
export function resolveKeyWithChordState(
  input: string,
  key: Key,
  activeContexts: KeybindingContextName[],
  bindings: ParsedBinding[],
  pending: ParsedKeystroke[] | null,
): ChordResolveResult {
  // Cancel chord on escape
  if (key.escape && pending !== null) {
    return { type: 'chord_cancelled' }
  }

  // Build current keystroke
  const currentKeystroke = buildKeystroke(input, key)
  if (!currentKeystroke) {
    if (pending !== null) {
      return { type: 'chord_cancelled' }
    }
    return { type: 'none' }
  }

  // Build the full chord sequence to test
  const testChord = pending
    ? [...pending, currentKeystroke]
    : [currentKeystroke]

  // Filter bindings by active contexts (Set lookup: O(n) instead of O(n·m))
  const ctxSet = new Set(activeContexts)
  const contextBindings = bindings.filter(b => ctxSet.has(b.context))

  // Check if this could be a prefix for longer chords. Group by chord
  // string so a later null-override shadows the default it unbinds —
  // otherwise null-unbinding `ctrl+x ctrl+k` still makes `ctrl+x` enter
  // chord-wait and the single-key binding on the prefix never fires.
  const chordWinners = new Map<string, string | null>()
  for (const binding of contextBindings) {
    if (
      binding.chord.length > testChord.length &&
      chordPrefixMatches(testChord, binding)
    ) {
      chordWinners.set(chordToString(binding.chord), binding.action)
    }
  }
  let hasLongerChords = false
  for (const action of chordWinners.values()) {
    if (action !== null) {
      hasLongerChords = true
      break
    }
  }

  // If this keystroke could start a longer chord, prefer that
  // (even if there's an exact single-key match)
  if (hasLongerChords) {
    return { type: 'chord_started', pending: testChord }
  }

  // Check for exact matches (last one wins)