chore(doc-gen): put typescript stuff into its own package

This means that we can now run just the d.ts file generation by running:

```bash
gulp docs/typings
```

In addition the type definition generation was messing with the other docs tasks
so separating it also fixes problems there.

docs/typescript-package/services/modules.js

@@ -0,0 +1,3 @@
+module.exports = function modules() {
+  return {};
+};

docs/typescript-package/services/tsParser/createCompilerHost.js

@@ -0,0 +1,62 @@
+var ts = require('typescript');
+var fs = require('fs');
+var path = require('canonical-path');
+
+// We need to provide our own version of CompilerHost because we want to set the
+// base directory and specify what extensions to consider when trying to load a source
+// file
+module.exports = function createCompilerHost(log) {
+
+  return function createCompilerHost(options, baseDir, extensions) {
+
+    return {
+      getSourceFile: function(fileName, languageVersion, onError) {
+        var text, resolvedPath, resolvedPathWithExt;
+
+        // Strip off the extension and resolve relative to the baseDir
+        baseFilePath = fileName.replace(/\.[^.]+$/, '');
+        resolvedPath = path.resolve(baseDir, baseFilePath);
+
+        // Iterate through each possible extension and return the first source file that is actually found
+        for(var i=0; i<extensions.length; i++) {
+
+          // Try reading the content from files using each of the given extensions
+          try {
+            resolvedPathWithExt = resolvedPath + extensions[i];
+            log.silly('getSourceFile:', resolvedPathWithExt);
+            text = fs.readFileSync(resolvedPathWithExt, { encoding: options.charset });
+            log.debug('found source file:', fileName, resolvedPathWithExt);
+            return ts.createSourceFile(baseFilePath + extensions[i], text, languageVersion);
+          }
+          catch(e) {
+            // Try again if the file simply did not exist, otherwise report the error as a warning
+            if(e.code !== 'ENOENT') {
+              if (onError) onError(e.message);
+              log.warn('Error reading ' + resolvedPathWithExt + ' : ' + e.message);
+            }
+          }
+        }
+      },
+      getDefaultLibFileName: function(options) {
+        return path.resolve(path.dirname(ts.sys.getExecutingFilePath()), ts.getDefaultLibFileName(options));
+      },
+      writeFile: function(fileName, data, writeByteOrderMark, onError) {
+        // no-op
+      },
+      getCurrentDirectory: function() {
+        return baseDir;
+      },
+      useCaseSensitiveFileNames: function() {
+        return ts.sys.useCaseSensitiveFileNames;
+      },
+      getCanonicalFileName: function(fileName) {
+        // if underlying system can distinguish between two files whose names differs only in cases then file name already in canonical form.
+        // otherwise use toLowerCase as a canonical form.
+        return ts.sys.useCaseSensitiveFileNames ? fileName : fileName.toLowerCase();
+      },
+      getNewLine: function() {
+        return ts.sys.newLine;
+      }
+    };
+  };
+};

docs/typescript-package/services/tsParser/createCompilerHost.spec.js

@@ -0,0 +1,80 @@
+var mockPackage = require('../../mocks/mockPackage');
+var Dgeni = require('dgeni');
+var path = require('canonical-path');
+var ts = require('typescript');
+
+describe('createCompilerHost', function() {
+  var dgeni, injector, options, host, baseDir, extensions;
+
+  beforeEach(function() {
+    dgeni = new Dgeni([mockPackage()]);
+    injector = dgeni.configureInjector();
+    var createCompilerHost = injector.get('createCompilerHost');
+
+    options = { charset: 'utf8' };
+    baseDir = path.resolve(__dirname, '../../mocks/tsParser');
+    extensions = ['.ts', '.js'];
+
+    host = createCompilerHost(options, baseDir, extensions);
+  });
+
+  describe('getSourceFile', function() {
+    it('should return a SourceFile object for a given path, with fileName relative to baseDir', function() {
+      var sourceFile = host.getSourceFile('testSrc.ts');
+      expect(sourceFile.fileName).toEqual('testSrc.ts');
+      expect(sourceFile.pos).toEqual(0);
+      expect(sourceFile.text).toEqual(jasmine.any(String));
+    });
+
+    it('should try each of the configured extensions and update the filename to the correct extension', function() {
+      var sourceFile = host.getSourceFile('testSrc.js');
+      expect(sourceFile.fileName).toEqual('testSrc.ts');
+
+      sourceFile = host.getSourceFile('../mockPackage.ts');
+      expect(sourceFile.fileName).toEqual('../mockPackage.js');
+    });
+  });
+
+
+  describe('getDefaultLibFileName', function() {
+    it('should return a path to the default library', function() {
+      expect(host.getDefaultLibFileName(options)).toContain('typescript/bin/lib.d.ts');
+    });
+  });
+
+
+  describe('writeFile', function() {
+    it('should do nothing', function() {
+      host.writeFile();
+    });
+  });
+
+
+  describe('getCurrentDirectory', function() {
+    it('should return the baseDir', function() {
+      expect(host.getCurrentDirectory()).toEqual(baseDir);
+    });
+  });
+
+
+  describe('useCaseSensitiveFileNames', function() {
+    it('should return true if the OS is case sensitive', function() {
+      expect(host.useCaseSensitiveFileNames()).toBe(ts.sys.useCaseSensitiveFileNames);
+    });
+  });
+
+
+  describe('getCanonicalFileName', function() {
+    it('should lower case the filename', function() {
+      var expectedFilePath = host.useCaseSensitiveFileNames() ? 'SomeFile.ts' : 'somefile.ts';
+      expect(host.getCanonicalFileName('SomeFile.ts')).toEqual(expectedFilePath);
+    });
+  });
+
+
+  describe('getNewLine', function() {
+    it('should return the newline character for the OS', function() {
+      expect(host.getNewLine()).toEqual(require('os').EOL);
+    });
+  });
+});

docs/typescript-package/services/tsParser/getContent.js

@@ -0,0 +1,49 @@
+var ts = require('typescript');
+var LEADING_STAR = /^[^\S\r\n]*\*[^\S\n\r]?/gm;
+
+module.exports = function getContent() {
+  return function(symbol) {
+
+    var content = "";
+
+    if (!symbol.declarations) return content;
+
+    symbol.declarations.forEach(function(declaration) {
+
+      // If this is left side of dotted module declaration, there is no doc comment associated with this declaration
+      if (declaration.kind === ts.SyntaxKind.ModuleDeclaration && declaration.body.kind === ts.SyntaxKind.ModuleDeclaration) {
+          return content;
+      }
+
+      // If this is dotted module name, get the doc comments from the parent
+      while (declaration.kind === ts.SyntaxKind.ModuleDeclaration && declaration.parent.kind === ts.SyntaxKind.ModuleDeclaration) {
+          declaration = declaration.parent;
+      }
+
+      // If this is a variable declaration then we get the doc comments from the grand parent
+      if (declaration.kind === ts.SyntaxKind.VariableDeclaration) {
+        declaration = declaration.parent.parent;
+      }
+
+      // Get the source file of this declaration
+      var sourceFile = ts.getSourceFileOfNode(declaration);
+      var commentRanges = ts.getJsDocComments(declaration, sourceFile);
+
+      if (commentRanges) {
+        commentRanges.forEach(function(commentRange) {
+          content += sourceFile.text
+              .substring(commentRange.pos+ '/**'.length, commentRange.end - '*/'.length)
+              .replace(LEADING_STAR, '')
+              .trim();
+          if (commentRange.hasTrailingNewLine) {
+            content += '\n';
+          }
+        });
+      }
+
+      content += '\n';
+    });
+
+    return content;
+  };
+};

docs/typescript-package/services/tsParser/getExportDocType.js

@@ -0,0 +1,56 @@
+var ts = require('typescript');
+
+module.exports = function getExportDocType(log) {
+
+  return function(symbol) {
+    if(symbol.flags & ts.SymbolFlags.FunctionScopedVariable) {
+      return 'var';
+    }
+    if(symbol.flags & ts.SymbolFlags.BlockScopedVariable) {
+      return getBlockScopedVariableDocType(symbol);
+    }
+    if(symbol.flags & ts.SymbolFlags.Function) {
+      return 'function';
+    }
+    if(symbol.flags & ts.SymbolFlags.Class) {
+      return 'class';
+    }
+    if(symbol.flags & ts.SymbolFlags.Interface) {
+      return 'interface';
+    }
+    if(symbol.flags & ts.SymbolFlags.ConstEnum) {
+      return 'enum';
+    }
+    if(symbol.flags & ts.SymbolFlags.RegularEnum) {
+      return 'enum';
+    }
+    if(symbol.flags & ts.SymbolFlags.Property) {
+      return 'module-property';
+    }
+    if(symbol.flags & ts.SymbolFlags.TypeAlias) {
+      return 'type-alias';
+    }
+
+    log.warn('getExportDocType(): Unknown symbol type', {
+      symbolName: symbol.name,
+      symbolType: symbol.flags,
+      symbolTarget: symbol.target,
+      file: ts.getSourceFileOfNode(symbol.declarations[0]).fileName
+    });
+    return 'unknown';
+  }
+
+  function getBlockScopedVariableDocType(symbol) {
+
+    var node = symbol.valueDeclaration;
+    while(node) {
+      if ( node.flags & 0x2000 /* const */) {
+        // DefinitelyTyped is still TS 1.4 so const is not allowed.
+        // https://github.com/borisyankov/DefinitelyTyped/issues/4564
+        return 'var'; // change to const when targetting TS 1.5
+      }
+      node = node.parent;
+    }
+    return 'let';
+  }
+};

docs/typescript-package/services/tsParser/getFileInfo.js

@@ -0,0 +1,20 @@
+var path = require('canonical-path');
+var ts = require('typescript');
+
+module.exports = function getFileInfo(log) {
+
+  return function (symbol, basePath) {
+    var fileName = ts.getSourceFileOfNode(symbol.declarations[0]).fileName;
+
+    var file = path.resolve(basePath, fileName);
+    var fileInfo = {
+      filePath: file,
+      baseName: path.basename(file, path.extname(file)),
+      extension: path.extname(file).replace(/^\./, ''),
+      basePath: basePath,
+      relativePath: fileName,
+      projectRelativePath: fileName
+    };
+    return fileInfo;
+  };
+};

docs/typescript-package/services/tsParser/index.js

@@ -0,0 +1,74 @@
+var ts = require('typescript');
+var path = require('canonical-path');
+
+module.exports = function tsParser(createCompilerHost, log) {
+
+  return {
+
+    // These are the extension that we should consider when trying to load a module
+    // During migration from Traceur, there is a mix of `.ts`, `.es6` and `.js` (atScript)
+    // files in the project and the TypeScript compiler only looks for `.ts` files when trying
+    // to load imports.
+    extensions: ['.ts', '.js'],
+
+    // The options for the TS compiler
+    options: {
+      allowNonTsExtensions: true,
+      charset: 'utf8'
+    },
+
+    parse: function(fileNames, baseDir) {
+
+      // "Compile" a program from the given module filenames, to get hold of a
+      // typeChecker that can be used to interrogate the modules, exports and so on.
+      var host = createCompilerHost(this.options, baseDir, this.extensions);
+      var program = ts.createProgram(fileNames, this.options, host);
+      var typeChecker = program.getTypeChecker();
+
+      // Create an array of module symbols for each file we were given
+      var moduleSymbols = [];
+      fileNames.forEach(function(fileName) {
+        var sourceFile = program.getSourceFile(fileName);
+
+        if (!sourceFile) {
+          throw new Error('Invalid source file: ' + fileName);
+        } else if (!sourceFile.symbol) {
+          // Some files contain only a comment and no actual module code
+          log.warn('No module code found in ' + fileName);
+        } else {
+          moduleSymbols.push(sourceFile.symbol);
+        }
+      });
+
+
+      moduleSymbols.forEach(function(tsModule) {
+
+        // The type checker has a nice helper function that returns an array of Symbols
+        // representing the exports for a given module
+        tsModule.exportArray = typeChecker.getExportsOfModule(tsModule);
+
+        // Although 'star' imports (e.g. `export * from 'some/module';) get resolved automatically
+        // by the compiler/binder, it seems that explicit imports (e.g. `export {SomeClass} from 'some/module'`)
+        // do not so we have to do a little work.
+        tsModule.exportArray.forEach(function(moduleExport) {
+          if (moduleExport.flags & ts.SymbolFlags.Alias) {
+            // To maintain the alias information (particularly the alias name)
+            // we just attach the original "resolved" symbol to the alias symbol
+            moduleExport.resolvedSymbol = typeChecker.getAliasedSymbol(moduleExport);
+          }
+        });
+      });
+
+      moduleSymbols.typeChecker = typeChecker;
+
+      return {
+        moduleSymbols: moduleSymbols,
+        typeChecker: typeChecker,
+        program: program,
+        host: host
+      };
+    }
+  };
+
+
+};

docs/typescript-package/services/tsParser/index.spec.js

@@ -0,0 +1,21 @@
+var mockPackage = require('../../mocks/mockPackage');
+var Dgeni = require('dgeni');
+var path = require('canonical-path');
+
+describe('tsParser', function() {
+  var dgeni, injector, parser;
+
+  beforeEach(function() {
+    dgeni = new Dgeni([mockPackage()]);
+    injector = dgeni.configureInjector();
+    parser = injector.get('tsParser');
+  });
+
+  it("should parse a TS file", function() {
+    var parseInfo = parser.parse(['testSrc.ts'], path.resolve(__dirname, '../../mocks/tsParser'));
+    var tsModules = parseInfo.moduleSymbols;
+    expect(tsModules.length).toEqual(1);
+    expect(tsModules[0].exportArray.length).toEqual(3);
+    expect(tsModules[0].exportArray.map(function(i) { return i.name; })).toEqual(['MyClass', 'myFn', 'x']);
+  });
+});