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fix(typescript-estree): improve comment parsing code (#1120)
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@bradzacher
bradzacher committed Nov 3, 2019
1 parent 366518f commit e54998d
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Showing 3 changed files with 30 additions and 198 deletions.
3 changes: 2 additions & 1 deletion packages/typescript-estree/package.json
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Expand Up @@ -43,7 +43,8 @@
"glob": "^7.1.4",
"is-glob": "^4.0.1",
"lodash.unescape": "4.0.1",
"semver": "^6.3.0"
"semver": "^6.3.0",
"tsutils": "^3.17.1"
},
"devDependencies": {
"@babel/code-frame": "7.5.5",
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190 changes: 28 additions & 162 deletions packages/typescript-estree/src/convert-comments.ts
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@@ -1,82 +1,8 @@
import * as ts from 'typescript'; // leave this as * as ts so people using util package don't need syntheticDefaultImports
import { getLocFor, getNodeContainer } from './node-utils';
import { forEachComment } from 'tsutils';
import { getLocFor } from './node-utils';
import { TSESTree } from './ts-estree';

/**
* Converts a TypeScript comment to an Esprima comment.
* @param block True if it's a block comment, false if not.
* @param text The text of the comment.
* @param start The index at which the comment starts.
* @param end The index at which the comment ends.
* @param startLoc The location at which the comment starts.
* @param endLoc The location at which the comment ends.
* @returns The comment object.
* @internal
*/
function convertTypeScriptCommentToEsprimaComment(
block: boolean,
text: string,
start: number,
end: number,
startLoc: TSESTree.LineAndColumnData,
endLoc: TSESTree.LineAndColumnData,
): TSESTree.Comment {
const comment: TSESTree.OptionalRangeAndLoc<TSESTree.Comment> = {
type: block ? 'Block' : 'Line',
value: text,
};

if (typeof start === 'number') {
comment.range = [start, end];
}

if (typeof startLoc === 'object') {
comment.loc = {
start: startLoc,
end: endLoc,
};
}

return comment as TSESTree.Comment;
}

/**
* Convert comment from TypeScript Triva Scanner.
* @param triviaScanner TS Scanner
* @param ast the AST object
* @param code TypeScript code
* @returns the converted Comment
* @private
*/
function getCommentFromTriviaScanner(
triviaScanner: ts.Scanner,
ast: ts.SourceFile,
code: string,
): TSESTree.Comment {
const kind = triviaScanner.getToken();
const isBlock = kind === ts.SyntaxKind.MultiLineCommentTrivia;
const range = {
pos: triviaScanner.getTokenPos(),
end: triviaScanner.getTextPos(),
kind: triviaScanner.getToken(),
};

const comment = code.substring(range.pos, range.end);
const text = isBlock
? comment.replace(/^\/\*/, '').replace(/\*\/$/, '')
: comment.replace(/^\/\//, '');
const loc = getLocFor(range.pos, range.end, ast);

return convertTypeScriptCommentToEsprimaComment(
isBlock,
text,
range.pos,
range.end,
loc.start,
loc.end,
);
}

/**
* Convert all comments for the given AST.
* @param ast the AST object
Expand All @@ -90,93 +16,33 @@ export function convertComments(
): TSESTree.Comment[] {
const comments: TSESTree.Comment[] = [];

/**
* Create a TypeScript Scanner, with skipTrivia set to false so that
* we can parse the comments
*/
const triviaScanner = ts.createScanner(
ast.languageVersion,
false,
ast.languageVariant,
code,
forEachComment(
ast,
(_, comment) => {
const type =
comment.kind == ts.SyntaxKind.SingleLineCommentTrivia
? 'Line'
: 'Block';
const range: TSESTree.Range = [comment.pos, comment.end];
const loc = getLocFor(range[0], range[1], ast);

// both comments start with 2 characters - /* or //
const textStart = range[0] + 2;
const textEnd =
comment.kind === ts.SyntaxKind.SingleLineCommentTrivia
? // single line comments end at the end
range[1] - textStart
: // multiline comments end 2 characters early
range[1] - textStart - 2;
comments.push({
type,
value: code.substr(textStart, textEnd),
range,
loc,
});
},
ast,
);

let kind = triviaScanner.scan();
while (kind !== ts.SyntaxKind.EndOfFileToken) {
const start = triviaScanner.getTokenPos();
const end = triviaScanner.getTextPos();

let container: ts.Node | null = null;
switch (kind) {
case ts.SyntaxKind.SingleLineCommentTrivia:
case ts.SyntaxKind.MultiLineCommentTrivia: {
const comment = getCommentFromTriviaScanner(triviaScanner, ast, code);

comments.push(comment);
break;
}
case ts.SyntaxKind.GreaterThanToken:
container = getNodeContainer(ast, start, end);
if (
(container.parent &&
container.parent.parent &&
// Rescan after an opening element or fragment
(container.parent.kind === ts.SyntaxKind.JsxOpeningElement &&
// Make sure this is the end of a tag like `<Component<number>>`
container.parent.end === end)) ||
container.parent.kind === ts.SyntaxKind.JsxOpeningFragment ||
// Rescan after a self-closing element if it's inside another JSX element
(container.parent.kind === ts.SyntaxKind.JsxSelfClosingElement &&
(container.parent.parent.kind === ts.SyntaxKind.JsxElement ||
container.parent.parent.kind === ts.SyntaxKind.JsxFragment)) ||
// Rescan after a closing element if it's inside another JSX element
((container.parent.kind === ts.SyntaxKind.JsxClosingElement ||
container.parent.kind === ts.SyntaxKind.JsxClosingFragment) &&
container.parent.parent.parent &&
(container.parent.parent.parent.kind === ts.SyntaxKind.JsxElement ||
container.parent.parent.parent.kind ===
ts.SyntaxKind.JsxFragment))
) {
kind = triviaScanner.reScanJsxToken();
continue;
}
break;
case ts.SyntaxKind.CloseBraceToken:
container = getNodeContainer(ast, start, end);

// Rescan after a JSX expression
if (
container.parent &&
container.parent.kind === ts.SyntaxKind.JsxExpression &&
container.parent.parent &&
container.parent.parent.kind === ts.SyntaxKind.JsxElement
) {
kind = triviaScanner.reScanJsxToken();
continue;
}

if (
container.kind === ts.SyntaxKind.TemplateMiddle ||
container.kind === ts.SyntaxKind.TemplateTail
) {
kind = triviaScanner.reScanTemplateToken();
continue;
}
break;
case ts.SyntaxKind.SlashToken:
case ts.SyntaxKind.SlashEqualsToken:
container = getNodeContainer(ast, start, end);

if (container.kind === ts.SyntaxKind.RegularExpressionLiteral) {
kind = triviaScanner.reScanSlashToken();
continue;
}
break;
default:
break;
}
kind = triviaScanner.scan();
}

return comments;
}
35 changes: 0 additions & 35 deletions packages/typescript-estree/src/node-utils.ts
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Expand Up @@ -612,41 +612,6 @@ export function convertTokens(ast: ts.SourceFile): TSESTree.Token[] {
return result;
}

/**
* Get container token node between range
* @param ast the AST object
* @param start The index at which the comment starts.
* @param end The index at which the comment ends.
* @returns typescript container token
* @private
*/
export function getNodeContainer(
ast: ts.SourceFile,
start: number,
end: number,
): ts.Node {
let container: ts.Node | null = null;

/**
* @param node the ts.Node
*/
function walk(node: ts.Node): void {
const nodeStart = node.pos;
const nodeEnd = node.end;

if (start >= nodeStart && end <= nodeEnd) {
if (isToken(node)) {
container = node;
} else {
node.getChildren().forEach(walk);
}
}
}
walk(ast);

return container!;
}

export interface TSError {
index: number;
lineNumber: number;
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