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REPL - after failed assignment identifier cannot be reused #3704
Description
A:\floppy>node -r lodash
> const _ = require('lodash');
const _ = require('lodash');
TypeError: Cannot assign to read only property '_' of #<Object>
at finish (repl.js:438:24)
at REPLServer.defaultEval (repl.js:185:5)
at bound (domain.js:280:14)
at REPLServer.runBound [as eval] (domain.js:293:12)
at REPLServer.<anonymous> (repl.js:393:12)
at emitOne (events.js:82:20)
at REPLServer.emit (events.js:169:7)
at REPLServer.Interface._onLine (readline.js:210:10)
at REPLServer.Interface._line (readline.js:549:8)
at REPLServer.Interface._ttyWrite (readline.js:826:14)
>
> ;
TypeError: Cannot assign to read only property '_' of #<Object>
at finish (repl.js:438:24)
at REPLServer.defaultEval (repl.js:185:5)
at bound (domain.js:280:14)
at REPLServer.runBound [as eval] (domain.js:293:12)
at REPLServer.<anonymous> (repl.js:393:12)
at emitOne (events.js:82:20)
at REPLServer.emit (events.js:169:7)
at REPLServer.Interface._onLine (readline.js:210:10)
at REPLServer.Interface._line (readline.js:549:8)
at REPLServer.Interface._ttyWrite (readline.js:826:14)
> let _ = require('lodash');
TypeError: Identifier '_' has already been declared
at repl:1:1
at REPLServer.defaultEval (repl.js:164:27)
at bound (domain.js:280:14)
at REPLServer.runBound [as eval] (domain.js:293:12)
at REPLServer.<anonymous> (repl.js:393:12)
at emitOne (events.js:82:20)
at REPLServer.emit (events.js:169:7)
at REPLServer.Interface._onLine (readline.js:210:10)
at REPLServer.Interface._line (readline.js:549:8)
at REPLServer.Interface._ttyWrite (readline.js:826:14)
> process.version
TypeError: Cannot assign to read only property '_' of #<Object>
at finish (repl.js:438:24)
at REPLServer.defaultEval (repl.js:185:5)
at bound (domain.js:280:14)
at REPLServer.runBound [as eval] (domain.js:293:12)
at REPLServer.<anonymous> (repl.js:393:12)
at emitOne (events.js:82:20)
at REPLServer.emit (events.js:169:7)
at REPLServer.Interface._onLine (readline.js:210:10)
at REPLServer.Interface._line (readline.js:549:8)
at REPLServer.Interface._ttyWrite (readline.js:826:14)
I am running Node 4.2.1 x64 on Windows 8.1 x64.
Activity
thefourtheye commentedon Nov 10, 2015
@SamuelMarks
_is used internally to track the result of the last evaluated expression. Please check this section of the REPL doc. Since you are making it aconst, internally, when REPL tries to store the result on_, it fails because it is read-only now. So, I don't think this is a bug per-se and closing the issue. Please feel free to comment if you have strong reasons to believe that this should be fixed and we can reopen this and find a solution.SamuelMarks commentedon Nov 10, 2015
Oh right, forgot about that. When I was coding Node years ago I now remember setting
l = require('lodash').thefourtheye commentedon Nov 10, 2015
@SamuelMarks No problem :-) I created a PR (#3729) with doc changes regarding the same. Please feel free to review it.