Validate that a single library has the same name as the package.

BUG=7045

Review URL: https://codereview.chromium.org//11519049

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@16139 260f80e4-7a28-3924-810f-c04153c831b5

lib/src/validator/name.dart

@@ -26,18 +26,35 @@ class NameValidator extends Validator {
   Future validate() {
     _checkName(entrypoint.root.name, 'Package name "${entrypoint.root.name}"');
 
+    return _libraries.transform((libraries) {
+      for (var library in libraries) {
+        var libName = path.basenameWithoutExtension(library);
+        _checkName(libName, 'The name of "$library", "$libName",');
+      }
+
+      if (libraries.length == 1) {
+        var libName = path.basenameWithoutExtension(libraries[0]);
+        if (libName == entrypoint.root.name) return;
+        warnings.add('The name of "$libraries[0]", "$libName", should match '
+            'the name of the package, "${entrypoint.root.name}".\n'
+            'This helps users know what library to import.');
+      }
+    });
+  }
+
+  /// Returns a list of all libraries in the current package as paths relative
+  /// to the package's root directory.
+  Future<List<String>> get _libraries {
     var libDir = join(entrypoint.root.dir, "lib");
     return dirExists(libDir).chain((libDirExists) {
       if (!libDirExists) return new Future.immediate([]);
       return listDir(libDir, recursive: true);
     }).transform((files) {
-      for (var file in files) {
-        file = relativeTo(file, libDir);
-        if (splitPath(file).contains("src")) continue;
-        if (path.extension(file) != '.dart') continue;
-        var libName = path.basenameWithoutExtension(file);
-        _checkName(libName, 'The name of "$file", "$libName",');
-      }
+      return files.map((file) => relativeTo(file, dirname(libDir)))
+          .filter((file) {
+        return !splitPath(file).contains("src") &&
+            path.extension(file) == '.dart';
+      });
     });
   }
 

test/validator_test.dart

@@ -210,7 +210,7 @@ main() {
       run();
     });
 
-    test('has a package name that is a Dart identifier', () {
+    test('has a package name that is a Dart reserved word', () {
       dir(appPath, [libPubspec("operator", "1.0.0")]).scheduleCreate();
       expectValidationError(name);
       run();
@@ -243,7 +243,7 @@ main() {
       run();
     });
 
-    test('has a library name that is a Dart identifier', () {
+    test('has a library name that is a Dart reserved word', () {
       dir(appPath, [
         libPubspec("test_pkg", "1.0.0"),
         dir("lib", [file("operator.dart", "int i = 0;")])
@@ -252,6 +252,15 @@ main() {
       run();
     });
 
+    test('has a single library named differently than the package', () {
+      file(join(appPath, "lib", "test_pkg.dart"), '').scheduleDelete();
+      dir(appPath, [
+        dir("lib", [file("best_pkg.dart", "int i = 0;")])
+      ]).scheduleCreate();
+      expectValidationWarning(name);
+      run();
+    });
+
     test('has no lib directory', () {
       dir(join(appPath, "lib")).scheduleDelete();
       expectValidationError(lib);