How to extract the used libraries in a dart file using the `analyzer` package.

README.md

#analyzer:analyzer example

How to extract the used libraries in a dart file using the analyzer package.

Main library: analyzer:analyzer
Main elements: parseCompilationUnit CompilationUnit.directives ImportDirective.uri
Gist: https://gist.github.com/kasperpeulen/d086078ed00429d5a335
Tags: #server

main.dart

import 'package:analyzer/analyzer.dart';

const dartFile = '''
import 'dart:collection';
import 'dart:io' as io;
import 'package:path/path.dart' as path;
import 'package:analyzer/src/analyzer.dart';

void main() {}
''';

main() {
  List<String> libraries = findLibraries(dartFile);

  // prints [dart:collection, dart:io, path:path, analyzer:src.analyzer]
  print(libraries);
}

List<String> findLibraries(String dartFile) {
  // Parse the dart string
  CompilationUnit compilationUnit = parseCompilationUnit(dartFile);

  // directive ::= [ExportDirective] | [ImportDirective] | [LibraryDirective] |
  // [PartDirective] | [PartOfDirective]
  List<Directive> directives = compilationUnit.directives;

  // Only retain the imports.
  directives.retainWhere((directive) => directive is ImportDirective);

  // Convert the ImportDirective object to a good looking string.
  List<String> libraries = directives.map(_beautifyImportDirective).toList();

  return libraries;
}

String _beautifyImportDirective(ImportDirective import) {
  String uri = import.uri.stringValue;
  if (uri.startsWith('dart'))
    return uri;

  if (uri.startsWith('package:'))
    return uri
      .replaceAll('package:', '')
      .replaceFirst('/', ':')
      .replaceAll('/', '.')
      .replaceAll('.dart', '');

  if (uri.startsWith('packages/'))
    return uri
      .replaceAll('packages/', '')
      .replaceFirst('/', ':')
      .replaceAll('/', '.')
      .replaceAll('.dart', '');

  throw 'Oh noes! I could not extract the library from $uri... My bad!';
}

pubspec.yaml

name: analyzer.analyzer_parseCompilationUnit_CompilationUnit.directives_ImportDirective.uri_'server'
description: |
  How to extract the used libraries in a dart file using the `analyzer` package.
homepage: https://gist.github.com/kasperpeulen/d086078ed00429d5a335
homepage: https://gist.github.com/kasperpeulen/d086078ed00429d5a335
environment:
  sdk: '>=1.0.0 <2.0.0'
dependencies:
  analyzer: '>=0.25.2 <0.26.0'