Return completions for JsDoc tagname even when there are no "@' sign prefix

Author: Kanchalai Tanglertsampan

src/services/completions.ts

@@ -16,11 +16,11 @@ namespace ts.Completions {
             return undefined;
         }
 
-        const { symbols, isGlobalCompletion, isMemberCompletion, isNewIdentifierLocation, location, isJsDocTagName } = completionData;
+        const { symbols, isGlobalCompletion, isMemberCompletion, isNewIdentifierLocation, location, isJsDocTagName, shouldAppendAtSignBeforeJsDocTagName } = completionData;
 
         if (isJsDocTagName) {
             // If the current position is a jsDoc tag name, only tag names should be provided for completion
-            return { isGlobalCompletion: false, isMemberCompletion: false, isNewIdentifierLocation: false, entries: JsDoc.getAllJsDocCompletionEntries() };
+            return { isGlobalCompletion: false, isMemberCompletion: false, isNewIdentifierLocation: false, entries: JsDoc.getAllJsDocCompletionEntries(shouldAppendAtSignBeforeJsDocTagName) };
         }
 
         const entries: CompletionEntry[] = [];
@@ -815,6 +815,12 @@ namespace ts.Completions {
         const isJavaScriptFile = isSourceFileJavaScript(sourceFile);
 
         let isJsDocTagName = false;
+        // This is for the case when users request completion in JsDoc without "@"
+        // i.e.
+        //      /**
+        //       * |completion here|
+        //       **/
+        let shouldAppendAtSignBeforeJsDocTagName = false;
 
         let start = timestamp();
         const currentToken = getTokenAtPosition(sourceFile, position);
@@ -826,10 +832,24 @@ namespace ts.Completions {
         log("getCompletionData: Is inside comment: " + (timestamp() - start));
 
         if (insideComment) {
-            // The current position is next to the '@' sign, when no tag name being provided yet.
-            // Provide a full list of tag names
-            if (hasDocComment(sourceFile, position) && sourceFile.text.charCodeAt(position - 1) === CharacterCodes.at) {
-                isJsDocTagName = true;
+            if (hasDocComment(sourceFile, position)) {
+                // The current position is next to the '@' sign, when no tag name being provided yet.
+                // Provide a full list of tag names
+                if (sourceFile.text.charCodeAt(position - 1) === CharacterCodes.at) {
+                    isJsDocTagName = true;
+                }
+                else {
+                    const lineStart = getLineStartPositionForPosition(position, sourceFile);
+                    shouldAppendAtSignBeforeJsDocTagName = sourceFile.text.substr(lineStart, position).indexOf("@") === -1;
+
+                    // This is for the case
+                    //      /**
+                    //       * |completion here|
+                    //       **/
+                    if (shouldAppendAtSignBeforeJsDocTagName) {
+                        isJsDocTagName = true;
+                    }
+                }
             }
 
             // Completion should work inside certain JsDoc tags. For example:
@@ -854,8 +874,8 @@ namespace ts.Completions {
                 }
             }
 
-            if (isJsDocTagName) {
-                return { symbols: undefined, isGlobalCompletion: false, isMemberCompletion: false, isNewIdentifierLocation: false, location: undefined, isRightOfDot: false, isJsDocTagName };
+            if (isJsDocTagName || shouldAppendAtSignBeforeJsDocTagName) {
+                return { symbols: undefined, isGlobalCompletion: false, isMemberCompletion: false, isNewIdentifierLocation: false, location: undefined, isRightOfDot: false, isJsDocTagName, shouldAppendAtSignBeforeJsDocTagName };
             }
 
             if (!insideJsDocTagExpression) {
@@ -983,7 +1003,7 @@ namespace ts.Completions {
 
         log("getCompletionData: Semantic work: " + (timestamp() - semanticStart));
 
-        return { symbols, isGlobalCompletion, isMemberCompletion, isNewIdentifierLocation, location, isRightOfDot: (isRightOfDot || isRightOfOpenTag), isJsDocTagName };
+        return { symbols, isGlobalCompletion, isMemberCompletion, isNewIdentifierLocation, location, isRightOfDot: (isRightOfDot || isRightOfOpenTag), isJsDocTagName, shouldAppendAtSignBeforeJsDocTagName };
 
         function getTypeScriptMemberSymbols(): void {
             // Right of dot member completion list

src/services/jsDoc.ts

@@ -42,7 +42,8 @@ namespace ts.JsDoc {
         "prop",
         "version"
     ];
-    let jsDocCompletionEntries: CompletionEntry[];
+    let jsDocTagNameCompletionEntries: CompletionEntry[];
+    let jsDocTagNameWithAtSignCompletionEntries: CompletionEntry[];
 
     export function getJsDocCommentsFromDeclarations(declarations: Declaration[]) {
         // Only collect doc comments from duplicate declarations once:
@@ -88,15 +89,27 @@ namespace ts.JsDoc {
         return undefined;
     }
 
-    export function getAllJsDocCompletionEntries(): CompletionEntry[] {
-        return jsDocCompletionEntries || (jsDocCompletionEntries = ts.map(jsDocTagNames, tagName => {
-            return {
-                name: tagName,
-                kind: ScriptElementKind.keyword,
-                kindModifiers: "",
-                sortText: "0",
-            };
-        }));
+    export function getAllJsDocCompletionEntries(shouldAppendAtSign: boolean): CompletionEntry[] {
+        if (!shouldAppendAtSign) {
+            return jsDocTagNameCompletionEntries || (jsDocTagNameCompletionEntries = ts.map(jsDocTagNames, tagName => {
+                return {
+                    name: tagName,
+                    kind: ScriptElementKind.keyword,
+                    kindModifiers: "",
+                    sortText: "0",
+                };
+            }));
+        }
+        else {
+            return jsDocTagNameWithAtSignCompletionEntries || (jsDocTagNameWithAtSignCompletionEntries = ts.map(jsDocTagNames, tagName => {
+                return {
+                    name: `@${tagName}`,
+                    kind: ScriptElementKind.keyword,
+                    kindModifiers: "",
+                    sortText: "0"
+                }
+            }));
+        }
     }
 
     /**