Simplify getRangeOfEnclosingComment

Author: Andy Hanson

src/services/formatting/formatting.ts

@@ -1146,48 +1146,35 @@ namespace ts.formatting {
     export function getRangeOfEnclosingComment(
         sourceFile: SourceFile,
         position: number,
-        onlyMultiLine: boolean,
         precedingToken?: Node | null, // tslint:disable-line:no-null-keyword
-        tokenAtPosition = getTokenAtPosition(sourceFile, position, /*includeJsDocComment*/ false),
-        predicate?: (c: CommentRange) => boolean): CommentRange | undefined {
+        tokenAtPosition = getTokenAtPosition(sourceFile, position, /*includeJsDocComment*/ false)): CommentRange | undefined {
         const tokenStart = tokenAtPosition.getStart(sourceFile);
         if (tokenStart <= position && position < tokenAtPosition.getEnd()) {
             return undefined;
         }
 
-        if (precedingToken === undefined) {
-            precedingToken = findPrecedingToken(position, sourceFile);
-        }
+        precedingToken = precedingToken === null ? undefined : precedingToken === undefined ? findPrecedingToken(position, sourceFile) : precedingToken; //neater
 
         // Between two consecutive tokens, all comments are either trailing on the former
         // or leading on the latter (and none are in both lists).
         const trailingRangesOfPreviousToken = precedingToken && getTrailingCommentRanges(sourceFile.text, precedingToken.end);
         const leadingCommentRangesOfNextToken = getLeadingCommentRangesOfNode(tokenAtPosition, sourceFile);
-        const commentRanges = trailingRangesOfPreviousToken && leadingCommentRangesOfNextToken ?
-            trailingRangesOfPreviousToken.concat(leadingCommentRangesOfNextToken) :
-            trailingRangesOfPreviousToken || leadingCommentRangesOfNextToken;
-        if (commentRanges) {
-            for (const range of commentRanges) {
-                // The end marker of a single-line comment does not include the newline character.
-                // With caret at `^`, in the following case, we are inside a comment (^ denotes the cursor position):
-                //
-                //    // asdf   ^\n
-                //
-                // But for closed multi-line comments, we don't want to be inside the comment in the following case:
-                //
-                //    /* asdf */^
-                //
-                // However, unterminated multi-line comments *do* contain their end.
-                //
-                // Internally, we represent the end of the comment at the newline and closing '/', respectively.
-                //
-                if ((range.pos < position && position < range.end ||
-                    position === range.end && (range.kind === SyntaxKind.SingleLineCommentTrivia || position === sourceFile.getFullWidth()))) {
-                    return (range.kind === SyntaxKind.MultiLineCommentTrivia || !onlyMultiLine) && (!predicate || predicate(range)) ? range : undefined;
-                }
-            }
-        }
-        return undefined;
+        const commentRanges = concatenate(trailingRangesOfPreviousToken, leadingCommentRangesOfNextToken);
+        return commentRanges && find(commentRanges, range => rangeContainsPositionExclusive(range, position) ||
+            // The end marker of a single-line comment does not include the newline character.
+            // With caret at `^`, in the following case, we are inside a comment (^ denotes the cursor position):
+            //
+            //    // asdf   ^\n
+            //
+            // But for closed multi-line comments, we don't want to be inside the comment in the following case:
+            //
+            //    /* asdf */^
+            //
+            // However, unterminated multi-line comments *do* contain their end.
+            //
+            // Internally, we represent the end of the comment at the newline and closing '/', respectively.
+            //
+            position === range.end && (range.kind === SyntaxKind.SingleLineCommentTrivia || position === sourceFile.getFullWidth()));
     }
 
     function getOpenTokenForList(node: Node, list: ReadonlyArray<Node>) {

src/services/formatting/smartIndenter.ts

@@ -34,8 +34,8 @@ namespace ts.formatting {
 
             const precedingToken = findPrecedingToken(position, sourceFile);
 
-            const enclosingCommentRange = getRangeOfEnclosingComment(sourceFile, position, /*onlyMultiLine*/ true, precedingToken || null); // tslint:disable-line:no-null-keyword
-            if (enclosingCommentRange) {
+            const enclosingCommentRange = getRangeOfEnclosingComment(sourceFile, position, precedingToken || null); // tslint:disable-line:no-null-keyword
+            if (enclosingCommentRange && enclosingCommentRange.kind === SyntaxKind.MultiLineCommentTrivia) {
                 return getCommentIndent(sourceFile, position, options, enclosingCommentRange);
             }
 

src/services/services.ts

@@ -2033,8 +2033,8 @@ namespace ts {
 
         function getSpanOfEnclosingComment(fileName: string, position: number, onlyMultiLine: boolean): TextSpan | undefined {
             const sourceFile = syntaxTreeCache.getCurrentSourceFile(fileName);
-            const range = formatting.getRangeOfEnclosingComment(sourceFile, position, onlyMultiLine);
-            return range && createTextSpanFromRange(range);
+            const range = formatting.getRangeOfEnclosingComment(sourceFile, position);
+            return range && (!onlyMultiLine || range.kind === SyntaxKind.MultiLineCommentTrivia) ? createTextSpanFromRange(range) : undefined;
         }
 
         function getTodoComments(fileName: string, descriptors: TodoCommentDescriptor[]): TodoComment[] {

src/services/utilities.ts

@@ -1029,12 +1029,8 @@ namespace ts {
      * @param tokenAtPosition Must equal `getTokenAtPosition(sourceFile, position)
      * @param predicate Additional predicate to test on the comment range.
      */
-    export function isInComment(
-        sourceFile: SourceFile,
-        position: number,
-        tokenAtPosition?: Node,
-        predicate?: (c: CommentRange) => boolean): boolean {
-        return !!formatting.getRangeOfEnclosingComment(sourceFile, position, /*onlyMultiLine*/ false, /*precedingToken*/ undefined, tokenAtPosition, predicate);
+    export function isInComment(sourceFile: SourceFile, position: number, tokenAtPosition?: Node): CommentRange | undefined {
+        return formatting.getRangeOfEnclosingComment(sourceFile, position, /*precedingToken*/ undefined, tokenAtPosition);
     }
 
     export function hasDocComment(sourceFile: SourceFile, position: number) {
@@ -1154,17 +1150,16 @@ namespace ts {
     }
 
     export function isInReferenceComment(sourceFile: SourceFile, position: number): boolean {
-        return isInComment(sourceFile, position, /*tokenAtPosition*/ undefined, c => {
-            const commentText = sourceFile.text.substring(c.pos, c.end);
-            return tripleSlashDirectivePrefixRegex.test(commentText);
-        });
+        return isInReferenceCommentWorker(sourceFile, position, /*shouldBeReference*/ true);
     }
 
     export function isInNonReferenceComment(sourceFile: SourceFile, position: number): boolean {
-        return isInComment(sourceFile, position, /*tokenAtPosition*/ undefined, c => {
-            const commentText = sourceFile.text.substring(c.pos, c.end);
-            return !tripleSlashDirectivePrefixRegex.test(commentText);
-        });
+        return isInReferenceCommentWorker(sourceFile, position, /*shouldBeReference*/ false);
+    }
+
+    function isInReferenceCommentWorker(sourceFile: SourceFile, position: number, shouldBeReference: boolean): boolean {
+        const range = isInComment(sourceFile, position, /*tokenAtPosition*/ undefined);
+        return !!range && shouldBeReference === tripleSlashDirectivePrefixRegex.test(sourceFile.text.substring(range.pos, range.end));
     }
 
     export function createTextSpanFromNode(node: Node, sourceFile?: SourceFile): TextSpan {

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -10742,7 +10742,7 @@ declare namespace ts {
      * @param tokenAtPosition Must equal `getTokenAtPosition(sourceFile, position)
      * @param predicate Additional predicate to test on the comment range.
      */
-    function isInComment(sourceFile: SourceFile, position: number, tokenAtPosition?: Node, predicate?: (c: CommentRange) => boolean): boolean;
+    function isInComment(sourceFile: SourceFile, position: number, tokenAtPosition?: Node): CommentRange | undefined;
     function hasDocComment(sourceFile: SourceFile, position: number): boolean | undefined;
     function getNodeModifiers(node: Node): string;
     function getTypeArgumentOrTypeParameterList(node: Node): NodeArray<Node> | undefined;
@@ -11350,8 +11350,8 @@ declare namespace ts.formatting {
     /**
      * @param precedingToken pass `null` if preceding token was already computed and result was `undefined`.
      */
-    function getRangeOfEnclosingComment(sourceFile: SourceFile, position: number, onlyMultiLine: boolean, precedingToken?: Node | null, // tslint:disable-line:no-null-keyword
-    tokenAtPosition?: Node, predicate?: (c: CommentRange) => boolean): CommentRange | undefined;
+    function getRangeOfEnclosingComment(sourceFile: SourceFile, position: number, precedingToken?: Node | null, // tslint:disable-line:no-null-keyword
+    tokenAtPosition?: Node): CommentRange | undefined;
     function getIndentationString(indentation: number, options: EditorSettings): string;
 }
 declare namespace ts.formatting {