From ab340756bc5a54bf61a9179206403d358ecba207 Mon Sep 17 00:00:00 2001
From: Arthur Ozga <aozgaa@umich.edu>
Date: Fri, 17 Jul 2015 16:32:29 -0700
Subject: [PATCH] Get Scaffolding

---
 src/services/services.ts  | 47 +++++++++++++++++++--------------------
 src/services/utilities.ts | 14 +++++++++---
 2 files changed, 34 insertions(+), 27 deletions(-)

diff --git a/src/services/services.ts b/src/services/services.ts
index 876d5646a13..058029af9f4 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -6762,31 +6762,30 @@ namespace ts {
             let sourceFile = syntaxTreeCache.getCurrentSourceFile(fileName);
             log("getDocCommentScaffoldingAtPosition: getCurrentSourceFile: " + (new Date().getTime() - start));
 
-            // Check if in comment context
-           if(isInString(sourceFile, position) || isInComment(sourceFile,position)) { return nullResult; }
+            // Check if in a context where we don't want to perform any insertion
+            if (isInString(sourceFile, position) || isInComment(sourceFile, position)) {
+                return nullResult;
+            }
 
-            // Get the next non-comment token
-            var nodeAtPos = getTokenAtPosition(sourceFile, position);
-            var containingFunction = getAncestor(nodeAtPos, SyntaxKind.FunctionDeclaration);
-            
-            // check if token is a function keyword
-            if(!containingFunction) { return emptyCompletion; }
-            
-            // Get the parsed object corresponding to the token
-            
-            // get the function's param list
-            
-            // map the params to JSDoc declarations. ie:
-            // foo: T -> '* @param foo '
-            
-            // Get the indentation level
-            // * perhaps just use the carat's indentation?
-            
-            // Recall that the in-comment have one extra whitespace character
-            
-            // Create the JSDoc comment string from the parts
-            
-            return "/** getDocCommentScaffoldingAtPosition -- TS side! */";
+            let nodeAtPos = getTokenAtPosition(sourceFile, position);
+            let containingFunction = <FunctionDeclaration>getAncestor(nodeAtPos, SyntaxKind.FunctionDeclaration);
+
+            if (hasDocComment(sourceFile, position) || !containingFunction) {
+                return emptyCompletion;
+            }
+
+            let parameters = containingFunction.parameters;
+            let posLineAndChar = sourceFile.getLineAndCharacterOfPosition(position);
+            let lineStart = sourceFile.getLineStarts()[posLineAndChar.line];
+
+            let indentationStr = sourceFile.text.substr(lineStart, posLineAndChar.character).match(/\s*/).toString();
+
+            let docParams = parameters.map((p, index) =>
+                indentationStr + " * @param " + (p.name.kind === SyntaxKind.Identifier ? (<Identifier>p.name).text : "param" + index.toString()) + "\n");
+
+            let result = "/**\n" + docParams.reduce((prev, cur) => prev + cur, "") + indentationStr + " */";
+
+            return result;
         }
 
         function getTodoComments(fileName: string, descriptors: TodoCommentDescriptor[]): TodoComment[] {
diff --git a/src/services/utilities.ts b/src/services/utilities.ts
index 4c0ce77c522..999b3d30427 100644
--- a/src/services/utilities.ts
+++ b/src/services/utilities.ts
@@ -433,11 +433,8 @@ namespace ts {
         let token = getTokenAtPosition(sourceFile, position);
 
         if (token && position < token.getStart()) {
-            // First, we have to see if this position actually landed in a comment.
             let commentRanges = getLeadingCommentRanges(sourceFile.text, token.pos);
 
-            // Then we want to make sure that it wasn't in a "///<" directive comment
-            // We don't want to unintentionally update a file name.
             return forEach(commentRanges, c => c.pos < position &&
                 // The end marker of a single-line comment does not include the newline character.
                 // In the following case, we are inside a comment (^ denotes the cursor position):
@@ -455,6 +452,17 @@ namespace ts {
         return false;
     }
 
+    export function hasDocComment(sourceFile: SourceFile, position: number) {
+        let token = getTokenAtPosition(sourceFile, position);
+
+        let JSDocPrefixRegex = /^\/\*\*\s*/;
+
+        // First, we have to see if this position actually landed in a comment.
+        let commentRanges = getLeadingCommentRanges(sourceFile.text, token.pos);
+
+        return forEach(commentRanges, c => JSDocPrefixRegex.test(sourceFile.text.substring(c.pos, c.end)));
+    }
+
     function nodeHasTokens(n: Node): boolean {
         // If we have a token or node that has a non-zero width, it must have tokens.
         // Note, that getWidth() does not take trivia into account.