function printPackageLegacy()

in internal/npm_install/generate_build_file.ts [1105:1246]
99 lines of code
17 McCabe index (conditional complexity)

function printPackageLegacy(pkg: Dep) {
  function starlarkFiles(attr: string, files: string[], comment: string = '') {
    return `
    ${comment ? comment + '\n    ' : ''}${attr} = [
        ${files.map((f: string) => `"//:node_modules/${pkg._dir}/${f}",`).join('\n        ')}
    ],`;
  }

  const includedRunfiles = filterFiles(pkg._runfiles, config.included_files);

  // Files that are part of the npm package not including its nested node_modules
  // (filtered by the 'included_files' attribute)
  const pkgFiles = includedRunfiles.filter((f: string) => !f.startsWith('node_modules/'));
  const pkgFilesStarlark = pkgFiles.length ? starlarkFiles('srcs', pkgFiles) : '';

  // Files that are in the npm package's nested node_modules
  // (filtered by the 'included_files' attribute)
  const nestedNodeModules = includedRunfiles.filter((f: string) => f.startsWith('node_modules/'));
  const nestedNodeModulesStarlark =
      nestedNodeModules.length ? starlarkFiles('srcs', nestedNodeModules) : '';

  // Files that have been excluded from the ${pkg._name}__files target above because
  // they are filtered out by 'included_files' or because they are not valid runfiles
  // See https://github.com/bazelbuild/bazel/issues/4327.
  const notPkgFiles = pkg._files.filter(
      (f: string) => !f.startsWith('node_modules/') && !includedRunfiles.includes(f));
  const notPkgFilesStarlark = notPkgFiles.length ? starlarkFiles('srcs', notPkgFiles) : '';

  // If the package is in the Angular package format returns list
  // of package files that end with `.umd.js`, `.ngfactory.js` and `.ngsummary.js`.
  // TODO(gmagolan): add UMD & AMD scripts to scripts even if not an APF package _but_ only if they
  // are named?
  const namedSources = isNgApfPackage(pkg) ?
      filterFiles(pkg._runfiles, ['.umd.js', '.ngfactory.js', '.ngsummary.js']) :
      [];
  const namedSourcesStarlark = namedSources.length ?
      starlarkFiles(
          'named_module_srcs', namedSources,
          '# subset of srcs that are javascript named-UMD or named-AMD scripts') :
      '';

  // Typings files that are part of the npm package not including nested node_modules
  const dtsSources =
      filterFiles(pkg._runfiles, ['.d.ts']).filter((f: string) => !f.startsWith('node_modules/'));
  const dtsStarlark = dtsSources.length ?
      starlarkFiles(
          'srcs', dtsSources,
          `# ${
              pkg._dir} package declaration files (and declaration files in nested node_modules)`) :
      '';

  // Flattened list of direct and transitive dependencies hoisted to root by the package manager
  const deps = [pkg].concat(pkg._dependencies.filter(dep => dep !== pkg && !dep._isNested));
  const depsStarlark =
      deps.map(dep => `"//${dep._dir}:${dep._name}__contents",`).join('\n        ');

  let result = `load("@build_bazel_rules_nodejs//:index.bzl", "js_library")

# Generated targets for npm package "${pkg._dir}"
${printJson(pkg)}

# Files that are part of the npm package not including its nested node_modules
# (filtered by the 'included_files' attribute)
filegroup(
    name = "${pkg._name}__files",${pkgFilesStarlark}
)

# Files that are in the npm package's nested node_modules
# (filtered by the 'included_files' attribute)
filegroup(
    name = "${pkg._name}__nested_node_modules",${nestedNodeModulesStarlark}
    visibility = ["//:__subpackages__"],
)

# Files that have been excluded from the ${pkg._name}__files target above because
# they are filtered out by 'included_files' or because they are not valid runfiles
# See https://github.com/bazelbuild/bazel/issues/4327.
filegroup(
    name = "${pkg._name}__not_files",${notPkgFilesStarlark}
    visibility = ["//visibility:private"],
)

# All of the files in the npm package including files that have been
# filtered out by 'included_files' or because they are not valid runfiles
# but not including nested node_modules.
filegroup(
    name = "${pkg._name}__all_files",
    srcs = [":${pkg._name}__files", ":${pkg._name}__not_files"],
)

# The primary target for this package for use in rule deps
js_library(
    name = "${pkg._name}",
    package_name = "${LEGACY_NODE_MODULES_PACKAGE_NAME}",
    package_path = "${config.package_path}",
    # direct sources listed for strict deps support
    srcs = [":${pkg._name}__files"],
    # nested node_modules for this package plus flattened list of direct and transitive dependencies
    # hoisted to root by the package manager
    deps = [
        ${depsStarlark}
    ],
)

# Target is used as dep for main targets to prevent circular dependencies errors
js_library(
    name = "${pkg._name}__contents",
    package_name = "${LEGACY_NODE_MODULES_PACKAGE_NAME}",
    package_path = "${config.package_path}",
    srcs = [":${pkg._name}__files", ":${pkg._name}__nested_node_modules"],${namedSourcesStarlark}
    visibility = ["//:__subpackages__"],
)

# Typings files that are part of the npm package not including nested node_modules
js_library(
    name = "${pkg._name}__typings",
    package_name = "${LEGACY_NODE_MODULES_PACKAGE_NAME}",
    package_path = "${config.package_path}",${dtsStarlark}
)

`;

  let mainEntryPoint = resolvePkgMainFile(pkg);

  // add an `npm_umd_bundle` target to generate an UMD bundle if one does
  // not exists
  if (mainEntryPoint && !findFile(pkg, `${pkg._name}.umd.js`)) {
    result +=
        `load("@build_bazel_rules_nodejs//internal/npm_install:npm_umd_bundle.bzl", "npm_umd_bundle")

npm_umd_bundle(
    name = "${pkg._name}__umd",
    package_name = "${pkg._moduleName}",
    entry_point = "@${config.workspace}//:node_modules/${pkg._dir}/${mainEntryPoint}",
    package = ":${pkg._name}",
)

`;
  }

  return result;
}