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Bug 439003

Summary:	[esprima] Esprima parser recovery fails before for loop
Product:	[ECD] Orion	Reporter:	Ashwin Baliga <ashbaliga>
Component:	JS Tools	Assignee:	Michael Rennie <Michael_Rennie>
Status:	RESOLVED WORKSFORME	QA Contact:
Severity:	normal
Priority:	P3	CC:	ken_walker
Version:	unspecified
Target Milestone:	---
Hardware:	PC
OS:	Windows 7
Whiteboard:

Description Ashwin Baliga

2014-07-07 05:16:56 EDT

In the following JavaScript file, code assist works and shows number properties correctly:

var abc=20;
abc.|  <-- code assist here
while(true)
{
}

But in the following case, number properties are not shown:

var abc=20;
abc.|  <-- code assist here
for(;;)
{
}

Comment 1 Michael Rennie

2014-07-07 11:05:57 EDT

The problem is that we are completely failing to recover in this case.
 
> var abc=20;
> abc.|  <-- code assist here
> while(true)
> {
> }

In this case we get an AST rooted as:

VariableDeclaration
ExpressionStatement
WhileStatement

OK - this is the expected AST

> But in the following case, number properties are not shown:
> 
> var abc=20;
> abc.|  <-- code assist here
> for(;;)
> {
> }

In this case we get an AST rooted as:

VariableDeclaration
ExpressionStatement
ExpressionStatement

WRONG - third root should be ForStatement, there are also a bunch of (what look like) cascading syntax errors:

 Syntax error on token ';', delete this token.
 Syntax error on token ')', delete this token.
 Syntax error on token '{', delete this token.

Comment 2 Michael Rennie

2014-07-07 11:35:21 EDT

(In reply to Michael Rennie from comment #1)
> The problem is that we are completely failing to recover in this case.
>  
> > var abc=20;
> > abc.|  <-- code assist here
> > while(true)
> > {
> > }
> 
> In this case we get an AST rooted as:
> 
> VariableDeclaration
> ExpressionStatement
> WhileStatement
> 
> OK - this is the expected AST

This is actually the 'no errors' AST, I grabbed the shot of it just prior to the re-parse.

The actual rooted AST for the while-case is:

VariableDeclaration
ExpressionStatement
  CallExpression
ExpressionStatement

Comment 3 Michael Rennie

2016-04-21 11:51:33 EDT

Now that we use Acorn as our base parser this is working as expected.

Closing worksforme.