JSDocTag#comment has CRLF newlines as CR

[dsherret]

TypeScript Version: 3.8.0-dev.20191128

Search Terms: JSDocTag newlines comment

Code

import * as ts from "typescript";

console.log(ts.version); // 3.8.0-dev.20191128

const testFilePath = "/file.ts";
const testFileText = `
/**
 * @example
 * Some\n * text\r\n * with newlines.
 */
function test() {}`;

const testSourceFile = ts.createSourceFile(testFilePath, testFileText, ts.ScriptTarget.Latest, true);
const funcDec = testSourceFile.statements.find(ts.isFunctionDeclaration)!;
const tags = ts.getJSDocTags(funcDec);

console.log(JSON.stringify(tags[0].comment)); // "Some\ntext\rwith newlines."

Expected behavior:

Either:

• "Some\ntext\r\nwith newlines." <-- probably as-is?
• "Some\ntext\nwith newlines."

Actual behavior:

Outputs: "Some\ntext\rwith newlines."

[sandersn]

I don't think I'll have time to fix this for 3.9, so I'm moving to 4.0.

Reminder: It's still help wanted in case anybody else wants to look at it.

[sandersn]

The problem is in the interaction between the scanner and the jsdoc comment parser; the scanner treats \r and \n as two newlines in a row. The parser only includes the first newline in a sequence of multiple empty newlines.

Either of those rules could be incorrect. The scanner one feels wrong to me — \r\n should really be one newline — but there may be compatibility concerns with changing it.

Squashing completely empty newlines makes sense, although it's kind of a corner case. I suspect there are additional reasons for the rule though.

[sandersn]

Turns out it was the jsdoc scanner at fault, so I'm pretty confident in changing it; I think only API users will already depend on its current newline treatment.