Function parseRuntimeConfig

src/cli/run.ts:99–141

(value: string | undefined, srcBaseDir: string)

type CLIMode = "plan" | "exec";

function parseRuntimeConfig(value: string | undefined, srcBaseDir: string): RuntimeConfig {
  if (!value) {
    // Default to local for `mux run` (no worktree isolation needed for one-off)
    return { type: "local" };
  }

  const parsed = parseRuntimeModeAndHost(value);
  if (!parsed) {
    throw new Error(
      `Invalid runtime: '${value}'. Use 'local', 'worktree', 'ssh <host>', or 'docker <image>'`
    );
  }

  switch (parsed.mode) {
    case RUNTIME_MODE.LOCAL:
      return { type: "local" };
    case RUNTIME_MODE.WORKTREE:
      return { type: "worktree", srcBaseDir };
    case RUNTIME_MODE.SSH:
      // STARTUP-PERF: Use a STABLE remote `srcBaseDir` (default: `~/mux`,
      // matching the desktop app) instead of the CLI's ephemeral temp dir.
      //
      // The remote `baseRepoPath` is derived as
      //     <srcBaseDir>/<projectId>/.mux-base.git
      // where `projectId` is keyed by the *local* project path. If
      // `srcBaseDir` is ephemeral (a fresh `mux-run-*` temp dir per
      // invocation), every CLI run gets a brand-new remote base repo even
      // when running back-to-back against the same SSH host + project, so
      // every run pays the full cold-init cost (git init, push, fetch,
      // worktree-add ~2.2s).
      //
      // Anchoring `srcBaseDir` to the stable `~/mux` location lets the second
      // and subsequent `mux run` invocations reuse the existing shared base
      // repo on the remote, hitting the warm path
      // (`Reusing existing remote project snapshot`) — a single bounded SSH
      // round-trip instead of a full create + sync + push.
      return { type: "ssh", host: parsed.host, srcBaseDir: "~/mux" };
    case RUNTIME_MODE.DOCKER:
      return { type: "docker", image: parsed.image };
    default:
      return { type: "local" };
  }
}

function parseThinkingLevel(value: string | undefined): ParsedThinkingInput {
  if (!value) return DEFAULT_THINKING_LEVEL; // Default for mux run