What are the rules for JavaScript's automatic semicolon insertion (ASI)? -

OK, first of all I should ask that this browser is dependent.

I have read that if an invalid token is found, but that segment of code is valid unless an invalid token is inserted before a semicolon token, if it occurs before a line break .
However, a common example is given for bugs caused by semicolon insertion:

  back _a + b;  

That does not follow this rule, because _a will be a valid token. On the other hand, breaking the call chain works as expected:

  $ ('# mybutton'). Do anybody have a more detailed description of the rules?   
 < First class you should know which statements are automatically affected by semicolon insertion (briefly known as ASI). ):  
 
 The empty statement  
  var  
   
 Expression statement  
 two-hour  statement 
 
  issued  statement  
  pauses  
  W C  
  throw  statement 
 
 
 
  
 Three cases were described 
 
  
 Ol> 
 
 When a token ( LineTerminator  or } ) is grammar Permission is not granted, then a semicolon is inserted before it: 
 
 
 The token is separated from the last token with at least one  LineTerminator . < For example: 
 
  {1 2} 3 // to {/>  
 token }  
 
 
 1; 2;} has been changed to 3;  

Numerical literals 1 meets the first condition, the following token is a line terminator. 2 meets the second condition, the following token } .

When the tokens input stream ends and the parser is unable to parse the input token stream as a complete program, at the end of the input stream A semicolon is automatically inserted.

Example:

  A = B ++ c // It is converted to: A = B; ++ C;  
 
 This occurs when tokens are allowed by some production of grammar, but production is a  restricted product , a semicolon Automatically insert before a restricted token. Restricted presentations: 
 
  Update expression: Left hand side expense [no line not guarantor] ++ LeftHandSideExpression [No line terminator here] - Continue: Continue; Continue [no linearminator here] LabelIdentifier; BreakStatainment: Break; Break [No linearminator here] LabelIdentifier; Return Status: Return; Return [No linear terminator here] expression; ThrowStatement: Throw [no linearminator] expression; ArrowFunction: ArrowParameters [no LineTerminator here] => ConciseBody YieldExpression: Production [No line terminator is not here] * AssignmentAxample yield [no linemaninator] AssignmentExpress  
 
  ReturnStatement : 
   return "something"; // changed for return; "something";