cerxes/babel
3
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Fix perf issue in typescript parser plugin (#8792)

Browse Source
This commit is contained in:
Matthew Robertson 2018-10-01 10:59:16 -07:00 committed by Brian Ng
parent ca89212b45
commit 07862e7272
1 changed files with 9 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
packages/babel-parser/src/plugins/typescript.js
View File

@ -1368,10 +1368,11 @@ export default (superClass: Class<Parser>): Class<Parser> =>
return this.finishNode(nonNullExpression, "TSNonNullExpression"); return this.finishNode(nonNullExpression, "TSNonNullExpression");
} }
if (this.isRelational("<")) {
// tsTryParseAndCatch is expensive, so avoid if not necessary.
// There are number of things we are going to "maybe" parse, like type arguments on // There are number of things we are going to "maybe" parse, like type arguments on
// tagged template expressions. If any of them fail, walk it back and continue. // tagged template expressions. If any of them fail, walk it back and continue.
const result = this.tsTryParseAndCatch(() => { const result = this.tsTryParseAndCatch(() => {
if (this.isRelational("<")) {
if (!noCalls && this.atPossibleAsync(base)) { if (!noCalls && this.atPossibleAsync(base)) {
// Almost certainly this is a generic async function `async <T>() => ... // Almost certainly this is a generic async function `async <T>() => ...
// But it might be a call with a type argument `async<T>();` // But it might be a call with a type argument `async<T>();`
@ -1409,12 +1410,12 @@ export default (superClass: Class<Parser>): Class<Parser> =>
); );
} }
} }
}
this.unexpected(); this.unexpected();
}); });
if (result) return result; if (result) return result;
}
return super.parseSubscript(base, startPos, startLoc, noCalls, state); return super.parseSubscript(base, startPos, startLoc, noCalls, state);
} }