Fixed TODOs/bugs in codegen_tools.dart for code generation of a directory.

pkg/analysis_server/tool/spec/codegen_tools.dart

Index: pkg/analysis_server/tool/spec/codegen_tools.dart
diff --git a/pkg/analysis_server/tool/spec/codegen_tools.dart b/pkg/analysis_server/tool/spec/codegen_tools.dart
index aff38861d9e0a19e2c6cb742e5585d233ea57f2f..15abf4c6ae4867902c1c21c51e6d0a2d2f6d3ab4 100644
--- a/pkg/analysis_server/tool/spec/codegen_tools.dart
+++ b/pkg/analysis_server/tool/spec/codegen_tools.dart
@@ -83,14 +83,16 @@ class CodeGenerator {
   /**
    * Execute [callback], using [additionalIndent] to indent any code it outputs.
    */
-  void indentBy(String additionalIndent, void callback()) => indentSpecial(additionalIndent, additionalIndent, callback);
+  void indentBy(String additionalIndent, void callback()) =>
+      indentSpecial(additionalIndent, additionalIndent, callback);
 
   /**
    * Execute [callback], using [additionalIndent] to indent any code it outputs.
    * The first line of output is indented by [firstAdditionalIndent] instead of
    * [additionalIndent].
    */
-  void indentSpecial(String firstAdditionalIndent, String additionalIndent, void callback()) {
+  void indentSpecial(String firstAdditionalIndent, String additionalIndent, void
+      callback()) {
     String oldNextIndent = _state.nextIndent;
     String oldIndent = _state.indent;
     try {
@@ -114,7 +116,8 @@ class CodeGenerator {
    * If [javadocStyle] is true, then the output is compatable with Javadoc,
    * which understands certain HTML constructs.
    */
-  void docComment(List<dom.Node> docs, {int width: 79, bool javadocStyle: false}) {
+  void docComment(List<dom.Node> docs, {int width: 79, bool javadocStyle:
+      false}) {
     writeln('/**');
     indentBy(' * ', () {
       write(nodesToText(docs, width - _state.indent.length, javadocStyle));
@@ -299,10 +302,13 @@ class _HtmlCodeGeneratorState {
 }
 
 /**
- * Type of functions used to compute the contents of generated files.
+ * Type of functions used to compute the contents of a generated file.
  */
 typedef String FileContentsComputer();
 
+/**
+ * Type of functions used to compute the contents of a set of generated files.
+ */
 typedef Map<String, FileContentsComputer> DirectoryContentsComputer();
 
 abstract class GeneratedContent {
@@ -362,21 +368,36 @@ class GeneratedFile extends GeneratedContent {
   }
 }
 
+/**
+ * Class representing a single output directory (either generated code or
+ * generated HTML). No other content should exisit in the directory.
+ */
 class GeneratedDirectory extends GeneratedContent {
 
+  /**
+   * The path to the directory that will have the generated content.
+   */
   final String outputDirPath;
+
+  /**
+   * Callback function which computes the directory contents.
+   */
   final DirectoryContentsComputer directoryContentsComputer;
+
   GeneratedDirectory(this.outputDirPath, this.directoryContentsComputer);
 
   /**
    * Get a Directory object representing the output directory.
    */
-  Directory get outputFile => new Directory(joinAll(posix.split(outputDirPath)));
+  Directory get outputFile =>
+      new Directory(joinAll(posix.split(outputDirPath)));
 
+  /**
+   * Check whether the directory has the correct contents, and return true if it
+   * does.
+   */
   @override
   bool check() {
-    // TODO (jwren) the lists of files in the directories need to be compared to
-    // ensure no unexpected files have been added
     Map<String, FileContentsComputer> map = directoryContentsComputer();
     map.forEach((String file, FileContentsComputer fileContentsComputer) {
       String expectedContents = fileContentsComputer();
@@ -392,12 +413,22 @@ class GeneratedDirectory extends GeneratedContent {
         return false;
       }
     });
-    return true;
+    return outputFile.listSync().length == map.length;
   }
 
+  /**
+   * Replace the directory with the correct contents.  [spec] is the "tool/spec"
+   * directory.  If [spec] is unspecified, it is assumed to be the directory
+   * containing Platform.executable.
+   */
   @override
   void generate() {
-    // TODO (jwren) Delete contents in the directory first.
+    // delete the contents of the directory (and the directory itself)
+    outputFile.deleteSync(recursive: true);

[Paul Berry, 2014/08/14 12:44:05]

Put a try/catch around this line as well, so that if the directory doesn't exist
at the time generate() is called, we just create it without complaining.

[jwren, 2014/08/14 18:12:29]

Done.

+    // re-create the empty directory
+    outputFile.createSync(recursive: true);
+
+    // generate all of the files in the directory
     Map<String, FileContentsComputer> map = directoryContentsComputer();
     map.forEach((String file, FileContentsComputer fileContentsComputer) {
       File outputFile = new File(joinAll(posix.split(outputDirPath + file)));