Future _runUpgradeNullSafety()

in lib/src/command/upgrade.dart [277:396]
89 lines of code
11 McCabe index (conditional complexity)

  Future<void> _runUpgradeNullSafety() async {
    final toUpgrade = _directDependenciesToUpgrade();

    final nullsafetyPubspec = await _upgradeToNullSafetyConstraints(
      entrypoint.root.pubspec,
      toUpgrade,
    );

    /// Solve [nullsafetyPubspec] in-memory and consolidate the resolved
    /// versions of the packages into a map for quick searching.
    final resolvedPackages = <String, PackageId>{};
    final solveResult = await log.spinner('Resolving dependencies', () async {
      return await resolveVersions(
        SolveType.upgrade,
        cache,
        Package.inMemory(nullsafetyPubspec),
      );
    }, condition: _shouldShowSpinner);
    for (final resolvedPackage in solveResult.packages) {
      resolvedPackages[resolvedPackage.name] = resolvedPackage;
    }

    /// Changes to be made to `pubspec.yaml`.
    /// Mapping from original to changed value.
    final changes = <PackageRange, PackageRange>{};
    final declaredHostedDependencies = [
      ...entrypoint.root.pubspec.dependencies.values,
      ...entrypoint.root.pubspec.devDependencies.values,
    ].where((dep) => dep.source is HostedSource);
    for (final dep in declaredHostedDependencies) {
      final resolvedPackage = resolvedPackages[dep.name]!;
      if (!toUpgrade.contains(dep.name)) {
        // If we're not to upgrade this package, or it wasn't in the
        // resolution somehow, then we ignore it.
        continue;
      }

      final constraint = VersionConstraint.compatibleWith(
        resolvedPackage.version,
      );
      if (dep.constraint.allowsAll(constraint) &&
          constraint.allowsAll(dep.constraint)) {
        // If constraint allows the same as the existing constraint then
        // there is no need to make changes.
        continue;
      }

      changes[dep] = dep.withConstraint(constraint);
    }

    final newPubspecText = _updatePubspec(changes);
    if (_dryRun) {
      // Even if it is a dry run, run `acquireDependencies` so that the user
      // gets a report on changes.
      // TODO(jonasfj): Stop abusing Entrypoint.global for dry-run output
      await Entrypoint.inMemory(
        Package.inMemory(Pubspec.parse(newPubspecText, cache.sources)),
        cache,
        lockFile: entrypoint.lockFile,
        solveResult: solveResult,
      ).acquireDependencies(
        SolveType.upgrade,
        dryRun: true,
        precompile: _precompile,
        analytics: null,
        generateDotPackages: false,
      );
    } else {
      if (changes.isNotEmpty) {
        writeTextFile(entrypoint.pubspecPath, newPubspecText);
      }
      // TODO: Allow Entrypoint to be created with in-memory pubspec, so that
      //       we can show the changes in --dry-run mode. For now we only show
      //       the changes made to pubspec.yaml in dry-run mode.
      await Entrypoint(directory, cache).acquireDependencies(
        SolveType.upgrade,
        precompile: _precompile,
        analytics: analytics,
        generateDotPackages: argResults['legacy-packages-file'],
      );
    }

    _outputChangeSummary(changes);

    // Warn if not all dependencies were migrated to a null-safety compatible
    // version. This can happen because:
    //  - `upgradeOnly` was given,
    //  - root has SDK dependencies,
    //  - root has git or path dependencies,
    //  - root has dependency_overrides
    final nonMigratedDirectDeps = <String>[];
    final directDeps = [
      ...entrypoint.root.pubspec.dependencies.keys,
      ...entrypoint.root.pubspec.devDependencies.keys
    ];
    await Future.wait(directDeps.map((name) async {
      final resolvedPackage = resolvedPackages[name]!;

      final boundSource = resolvedPackage.source!.bind(cache);
      final pubspec = await boundSource.describe(resolvedPackage);
      if (!pubspec.languageVersion.supportsNullSafety) {
        nonMigratedDirectDeps.add(name);
      }
    }));
    if (nonMigratedDirectDeps.isNotEmpty) {
      log.warning('''
\nFollowing direct 'dependencies' and 'dev_dependencies' are not migrated to
null-safety yet:
 - ${nonMigratedDirectDeps.join('\n - ')}

You may have to:
 * Upgrade git and path dependencies manually,
 * Upgrade to a newer SDK for newer SDK dependencies,
 * Remove dependency_overrides, and/or,
 * Find other packages to use.
''');
    }

    _showOfflineWarning();
  }