generate suggestions during analysis

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/verifier/PubVerifier.java

Index: editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/verifier/PubVerifier.java
diff --git a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/verifier/PubVerifier.java b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/verifier/PubVerifier.java
new file mode 100644
index 0000000000000000000000000000000000000000..e9e5e12ae5dc6fb2382c5098c06bb00e1b3ea064
--- /dev/null
+++ b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/verifier/PubVerifier.java
@@ -0,0 +1,176 @@
+/*
+ * Copyright (c) 2013, the Dart project authors.
+ * 
+ * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.dart.engine.internal.verifier;
+
+import com.google.dart.engine.ast.ASTNode;
+import com.google.dart.engine.ast.CompilationUnit;
+import com.google.dart.engine.ast.ImportDirective;
+import com.google.dart.engine.ast.StringLiteral;
+import com.google.dart.engine.ast.visitor.RecursiveASTVisitor;
+import com.google.dart.engine.element.CompilationUnitElement;
+import com.google.dart.engine.error.PubSuggestionCode;
+import com.google.dart.engine.internal.error.ErrorReporter;
+import com.google.dart.engine.source.FileUriResolver;
+import com.google.dart.engine.source.PackageUriResolver;
+import com.google.dart.engine.source.Source;
+
+import java.io.File;
+
+/**
+ * Instances of the class {@code PubVerifier} traverse an AST structure looking for deviations from
+ * pub best practices.
+ */
+public class PubVerifier extends RecursiveASTVisitor<Void> {
+
+  /**
+   * The error reporter by which errors will be reported.
+   */
+  private final ErrorReporter errorReporter;
+
+  public PubVerifier(ErrorReporter errorReporter) {
+    this.errorReporter = errorReporter;
+  }
+
+  @Override
+  public Void visitImportDirective(ImportDirective directive) {
+
+    // Don't bother showing a suggestion if there is a more important issue to be solved.
+    StringLiteral uriLiteral = directive.getUri();
+    if (uriLiteral == null) {
+      return null;
+    }
+    String uriContent = uriLiteral.getStringValue();
+    if (uriContent == null) {
+      return null;
+    }
+    uriContent = uriContent.trim();
+
+    // Analyze the URI
+    int index = uriContent.indexOf(':');
+    String scheme;
+    String path;
+    if (index > -1) {
+      scheme = uriContent.substring(0, index);
+      path = uriContent.substring(index + 1);
+    } else {
+      scheme = FileUriResolver.FILE_SCHEME;
+      path = uriContent;
+    }
+
+    if (scheme.equals(FileUriResolver.FILE_SCHEME)) {
+      if (checkForFileImportOutsideLibReferencesFileInside(directive, path)) {
+        // Files outside the lib directory hierarchy should not reference files inside
+        // ... use package: url instead
+        errorReporter.reportError(
+            PubSuggestionCode.FILE_IMPORT_OUTSIDE_LIB_REFERENCES_FILE_INSIDE,
+            uriLiteral);
+      } else if (checkForFileImportInsideLibReferencesFileOutside(directive, path)) {
+        // Files inside the lib directory hierarchy should not reference files outside
+        errorReporter.reportError(
+            PubSuggestionCode.FILE_IMPORT_INSIDE_LIB_REFERENCES_FILE_OUTSIDE,
+            uriLiteral);
+      }
+    } else if (scheme.equals(PackageUriResolver.PACKAGE_SCHEME)) {
+      if (checkForPackageImportContainsDotDot(path)) {
+        // Package import should not to contain ".."
+        errorReporter.reportError(PubSuggestionCode.PACKAGE_IMPORT_CONTAINS_DOT_DOT, uriLiteral);
+      }
+    }
+    return null;
+  }
+
+  /**
+   * Determine if the file file path lies inside the "lib" directory hierarchy but references a file
+   * outside that directory hierarchy.
+   * 
+   * @param directive the import directive (not {@code null})
+   * @param path the file path being verified (not {@code null})
+   * @return {@code true} if the file is inside but references a file outside
+   */
+  private boolean checkForFileImportInsideLibReferencesFileOutside(ImportDirective directive,
+      String path) {
+    String fullName = getSourceFullName(directive);
+    if (fullName != null) {
+      int pathIndex = 0;
+      int fullNameIndex = fullName.length();
+      while (pathIndex < path.length() && path.startsWith("../", pathIndex)) {
+        fullNameIndex = fullName.lastIndexOf('/', fullNameIndex);
+        if (fullNameIndex < 4) {
+          return false;
+        }
+        // Check for "/lib" at a specified place in the fullName
+        if (fullName.startsWith("/lib", fullNameIndex - 4)) {
+          return true;
+        }
+        pathIndex += 3;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Determine if the given file path lies outside the "lib" directory hierarchy but references a
+   * file inside that directory hierarchy.
+   * 
+   * @param directive the import directive (not {@code null})
+   * @param path the file path being verified (not {@code null})
+   * @return {@code true} if the file is outside but references a file inside
+   */
+  private boolean checkForFileImportOutsideLibReferencesFileInside(ImportDirective directive,
+      String path) {
+    if (path.startsWith("lib/") || path.contains("/lib/")) {
+      String fullName = getSourceFullName(directive);
+      if (fullName != null) {
+        if (!fullName.contains("/lib/")) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Determine if the given package import path contains ".."
+   * 
+   * @param path the path to be validated (not {@code null})
+   * @return {@code true} if the import path contains ".."
+   */
+  private boolean checkForPackageImportContainsDotDot(String path) {
+    return path.contains("/../");
+  }
+
+  /**
+   * Answer the full name of the source associated with the compilation unit containing the given
+   * AST node. The returned value will have all {@link File#separatorChar} replace by '/'.
+   * 
+   * @param node the node (not {@code null})
+   * @return the full name or {@code null} if it could not be determined
+   */
+  private String getSourceFullName(ASTNode node) {
+    CompilationUnit unit = node.getAncestor(CompilationUnit.class);
+    if (unit != null) {
+      CompilationUnitElement element = unit.getElement();
+      if (element != null) {
+        Source librarySource = element.getSource();
+        if (librarySource != null) {
+          String fullName = librarySource.getFullName();
+          if (fullName != null) {
+            return fullName.replace(File.separatorChar, '/');
+          }
+        }
+      }
+    }
+    return null;
+  }
+}