Crash in getJSDocTags on `const a = b = () => 0;`

TypeScript Version: 3.0.0-dev.20180609

Code

a.js

/** doc */
const a = b = () => 0;

Expected behavior:

No crash.

Actual behavior:

Error: Debug Failure. False expression.
    at getJSDocTags (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:10444:22)
    at getFirstJSDocTag (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:10451:24)
    at Object.getJSDocType (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:10428:19)
    at getContextualSignature (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:34131:32)
    at checkFunctionExpressionOrObjectLiteralMethod (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:36920:43)
    at checkExpressionWorker (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:37846:28)
    at checkExpression (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:37779:42)
    at checkBinaryLikeExpression (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:37393:29)
    at checkBinaryExpression (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:37385:20)
    at checkExpressionWorker (/home/andy/.nvm/versions/node/v10.1.0/lib/node_modules/typescript/lib/tsc.js:37867:28)

CC @sandersn

[mhegazy]

@sandersn can you take a look.

[sandersn]

The assert is the one that detects duplicated jsdoc tags. () => 0 is getting doc added twice.

[MLoughry]

Is there any plan to release a 2.9.3 with this fix?

[larssn]

Pretty please?

[RyanCavanaugh]

TypeScript 3.0 is out, which contains a fix for this issue and doesn't have any major breaking changes associated with it. I'd recommend upgrading to that version as we don't plan to backport a new 2.9 release at this time.