microsoft / microsoft/TypeScript

Line break in module declaration causes compile time error

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Bug Domain: Parser Help Wanted
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Description

TypeScript Version: 2.0.3

A line break in the declaration of a module causes a compile time error.
This could either be that the language specification isn't clear that this is illegal or a bug.

Code

// Example declaration with line break
declare module 
     my.very.long.name.foo.bar.baz.able.baker {}

Expected behavior:
I don't see anything in the language specification that would make this a compile time error, so I would expect the statement to work as if declaration was all on one line, ie:

// Example declaration with line break
declare module my.very.long.name.foo.bar.baz.able.baker {}

Actual behavior:

A compile time error, in particular: (1, 9): error TS1005: ';' expected.

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by compiling the provided TypeScript snippet with the line break after declare module and compare it with the one-line version. Trace the parser handling of module declarations; done means the multiline declaration compiles without TS1005 while existing behavior remains intact.

Written by the indexing model from the issue text.

Assessment

Tech stack
typescript
Domain
compilers
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
45/100

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