Function resolveLocalPtyShell

src/node/utils/main/resolveLocalPtyShell.ts:141–205

(
  params: Partial<ResolveLocalPtyShellParams> = {}
)

 * mutating `process.platform` / `process.env`.
 */
export function resolveLocalPtyShell(
  params: Partial<ResolveLocalPtyShellParams> = {}
): ResolvedPtyShell {
  const platform = params.platform ?? process.platform;
  const env = params.env ?? process.env;
  const isCommandAvailable = params.isCommandAvailable ?? defaultIsCommandAvailable(platform);
  const isPathAccessible = params.isPathAccessible ?? defaultIsPathAccessible;
  const getBashPathFn = params.getBashPath ?? getBashPath;

  const candidates: ResolvedPtyShell[] = [];

  // User-configured shell from config.json stays highest priority, but only when valid.
  const configuredShell = params.configuredShell?.trim();
  if (configuredShell) {
    candidates.push({ command: configuredShell, args: [] });
  }

  // `process.env.SHELL` can be present-but-empty (""), especially in packaged apps.
  // Treat empty/whitespace as "unset".
  const envShell = env.SHELL?.trim();
  if (envShell) {
    // On Windows, `SHELL=bash` often routes to WSL (via System32\\bash.exe).
    // Ignore WSL shells and fall back to Git Bash/pwsh/cmd selection below.
    if (platform !== "win32" || !looksLikeWslShell(envShell)) {
      candidates.push({ command: envShell, args: [] });
    }
  }

  if (platform === "win32") {
    // Prefer Git Bash when available (works well with repo tooling).
    try {
      const bashPath = getBashPathFn().trim();
      if (bashPath) {
        candidates.push({ command: bashPath, args: ["--login", "-i"] });
      }
    } catch {
      // Git Bash not available; fall back to PowerShell / cmd.
    }

    candidates.push({ command: "pwsh", args: [] });
    candidates.push({ command: "powershell", args: [] });

    candidates.push({ command: getWindowsFallbackCommand(env, isPathAccessible), args: [] });
  } else if (platform === "darwin") {
    candidates.push({ command: "/bin/zsh", args: [] });
  } else {
    candidates.push({ command: "/bin/bash", args: [] });
  }

  for (const candidate of candidates) {
    if (isCandidateAvailable(candidate.command, { isCommandAvailable, isPathAccessible })) {
      return candidate;
    }
  }

  // Last-resort fallback if all candidates above are unavailable.
  // Keep platform-native: cmd.exe on Windows, /bin/zsh on macOS, /bin/bash elsewhere.
  if (platform === "win32") {