Qualify library names in packages

lib/src/analyzer/multi_package_resolver.dart

Index: lib/src/analyzer/multi_package_resolver.dart
diff --git a/lib/src/analyzer/multi_package_resolver.dart b/lib/src/analyzer/multi_package_resolver.dart
index 66905eca920fb7b54801265e105d244a7fd2b67d..5d12f5e7393c4d3b79bda4b49dc13132defb790c 100644
--- a/lib/src/analyzer/multi_package_resolver.dart
+++ b/lib/src/analyzer/multi_package_resolver.dart
@@ -7,7 +7,7 @@ import 'dart:io';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
-import 'package:path/path.dart' show join;
+import 'package:path/path.dart' as path;
 
 /// A package resolver that supports a non-standard package layout, where
 /// packages with dotted names are expanded to a hierarchy of directories, and
@@ -31,11 +31,33 @@ class MultiPackageResolver extends UriResolver {
     return null;
   }
 
-  /// Resolve [path] by looking at each prefix in [searchPaths] and returning
-  /// the first location where `prefix + path` exists.
-  String _resolve(String path) {
+  @override
+  Uri restoreAbsolute(Source source) {

[Paul Berry, 2016/04/27 19:19:57]

FYI, technically this breaks the interface contract of
UriResolver.restoreAbsolute, which says "The computation should be based solely
on [source.fullName]".

The rationale is: some callers of restoreAbsolute start with a path in the file
system and nothing else, and then they create a Source object whose .fullName
points to that path and whose other properties (.uri, .etc.) are likely to be
bogus.  Then they pass this bogus Source object to restoreAbsolute(), get back a
Uri, and then pass it to resolveAbsolute() to get a non-bogus Source object.

I think this would be easy to fix; simply drop the uri.scheme checks at the top
of the function, and set filePath = path.absolute(source.fullName).

Having said that, restoreAbsolute() is used in such limited circumstances that
if you want to chance it, you probably won't run into any trouble.

+    var uri = source.uri;
+    if (uri.scheme == 'package' || uri.scheme == 'dart') {
+      return uri;
+    }
+    if (uri.scheme == '' || uri.scheme == 'file') {
+      var filePath = path.absolute(uri.path);

[Paul Berry, 2016/04/27 19:19:57]

This won't work on Windows, since uri.path uses '/', and path.absolute() assumes
the conventions of the host OS.

My suggestion above (set filePath = path.absolute(source.fullName) would address
this.

+      for (var searchPath in searchPaths) {
+        if (path.isWithin(searchPath, filePath)) {
+          var relativePath = path.relative(filePath, from: searchPath);
+          var segments = path.split(relativePath);
+          var libIndex = segments.lastIndexOf('lib');

[vsm, 2016/04/27 18:24:35]

This is not yet tested and seems brittle...

+          var packageName = segments.sublist(0, libIndex).join('.');
+          var packageRelativePath = segments.sublist(libIndex + 1).join('/');
+          return Uri.parse('package:$packageName/$packageRelativePath');
+        }
+      }
+    }
+    return null;
+  }
+
+  /// Resolve [packagePath] by looking at each prefix in [searchPaths] and returning

[Jennifer Messerly, 2016/04/27 18:30:05]

long line

+  /// the first location where `prefix + packagePath` exists.
+  String _resolve(String packagePath) {
     for (var prefix in searchPaths) {
-      var resolvedPath = join(prefix, path);
+      var resolvedPath = path.join(prefix, packagePath);
       if (new File(resolvedPath).existsSync()) return resolvedPath;
     }
     return null;