Function readPlanFile

src/node/utils/runtime/helpers.ts:119–165

(
  runtime: Runtime,
  workspaceName: string,
  projectName: string,
  workspaceId: string
)

 * ~/.mux/plans/{projectName}/{workspaceName}.md
 */
export async function readPlanFile(
  runtime: Runtime,
  workspaceName: string,
  projectName: string,
  workspaceId: string
): Promise<ReadPlanResult> {
  const muxHome = runtime.getMuxHome();
  const planPath = getPlanFilePath(workspaceName, projectName, muxHome);
  // Legacy paths only used for non-Docker runtimes
  const legacyPath = getLegacyPlanFilePath(workspaceId);

  // Resolve tilde to absolute path for client use (editor deep links, etc.)
  // For local runtimes this expands ~ to /home/user; for SSH it resolves remotely
  const resolvedPath = await runtime.resolvePath(planPath);

  // Try new path first
  try {
    const content = await readFileString(runtime, planPath);
    return { content, exists: true, path: resolvedPath };
  } catch {
    // Fall back to legacy path
    try {
      const content = await readFileString(runtime, legacyPath);
      // Migrate: move to new location.
      // Resolve paths first because shellQuote() intentionally prevents ~ expansion.
      try {
        const planDir = planPath.substring(0, planPath.lastIndexOf("/"));
        const resolvedPlanDir = await runtime.resolvePath(planDir);
        const resolvedLegacyPath = await runtime.resolvePath(legacyPath);
        await execBuffered(
          runtime,
          `mkdir -p ${shellQuote(resolvedPlanDir)} && mv ${shellQuote(resolvedLegacyPath)} ${shellQuote(resolvedPath)}`,
          {
            cwd: "/tmp",
            timeout: 5,
          }
        );
      } catch {
        // Migration failed, but we have the content
      }
      return { content, exists: true, path: resolvedPath };
    } catch {
      // File doesn't exist at either location
      return { content: "", exists: false, path: resolvedPath };
    }
  }
}

/**
 * Check if a non-empty plan file exists for this workspace.