public void InstallSnapshot()

in src/DependencyManagement/DependencySnapshotInstaller.cs [40:106]
49 lines of code
5 McCabe index (conditional complexity)

        public void InstallSnapshot(
            IEnumerable<DependencyManifestEntry> dependencies,
            string targetPath,
            PowerShell pwsh,
            DependencySnapshotInstallationMode installationMode,
            ILogger logger)
        {
            var installingPath = CreateInstallingSnapshot(targetPath);

            logger.Log(
                isUserOnlyLog: false,
                LogLevel.Trace,
                string.Format(
                    PowerShellWorkerStrings.InstallingFunctionAppRequiredModules,
                    installingPath,
                    installationMode));

            try
            {
                foreach (DependencyInfo module in GetExactVersionsOfDependencies(dependencies))
                {
                    InstallModule(module, installingPath, pwsh, logger);
                }

                _snapshotContentLogger.LogDependencySnapshotContent(installingPath, logger);

                switch (installationMode)
                {
                    case DependencySnapshotInstallationMode.Optional:
                        // If the new snapshot turns out to be equivalent to the latest one,
                        // removing it helps us save storage space and avoid unnecessary worker restarts.
                        // It is ok to do that during background upgrade because the current
                        // worker already has a good enough snapshot, and nothing depends on
                        // the new snapshot yet.
                        PromoteToInstalledOrRemove(installingPath, targetPath, installationMode, logger);
                        break;

                    case DependencySnapshotInstallationMode.Required:
                        // Even if the new snapshot turns out to be equivalent to the latest one,
                        // removing it would not be safe because the current worker already depends
                        // on it, as it has the path to this snapshot already added to PSModulePath.
                        // As opposed to the background upgrade case, this snapshot is *required* for
                        // this worker to run, even though it occupies some space (until the workers
                        // restart and the redundant snapshots are purged).
                        PromoteToInstalled(installingPath, targetPath, installationMode, logger);
                        break;

                    default:
                        throw new ArgumentException($"Unexpected installation mode: {installationMode}", nameof(installationMode));
                }
            }
            catch (Exception e)
            {
                var message = string.Format(
                                PowerShellWorkerStrings.FailedToInstallDependenciesSnapshot,
                                targetPath,
                                installationMode);

                logger.Log(isUserOnlyLog: false, LogLevel.Warning, message, e);
                _storage.RemoveSnapshot(installingPath);
                throw;
            }
            finally
            {
                _moduleProvider.Cleanup(pwsh);
            }
        }